HEART DISEASE

Cardiovascular disease is the leading cause of mortality worldwide. As cigarette smoking continues to be a status symbol in developing countries, this ranking is expected to continue well into twenty-first century. Heart disease rates increase with age, and older adults have worse outcomes and face special problems, including unusual disease presentation, increasing complications, and particular effects on daily activities and quality of life.

The heart is a muscle in the center of the chest. It is approximately the size of a fist and pumps blood throughout the body, working continuously and requiring a large blood supply. The heart can function through a large range of demands, from sleep to vigorous activity.

Ischemic heart disease

With increasing age, narrowings may develop in the coronary arteries that lead to the heart. This reduced blood supply causes ischemia (insufficient blood supply for the heart's work) and may produce chest pain or angina. Sudden blockages will result in a heart attack, also known as myocardial infarction (MI).

The incidence of heart disease begins to increase in men after the age of forty-five and in women after the age of fifty-five, but the rate for women tends to equal that of men after the age of seventy. It was once believed that hormone replacement therapy would protect women from heart disease, but more recent studies suggest this is not true. The Heart and Estrogen/Progestin Replacement Study (HERS) showed no benefit, as well as an increased risk of blood clots in the leg (deep vein thrombosis) and of gallbladder disease. Along with age, male gender, family history, and ethnicity are nonmodifiable risk factors for heart disease.

The most modifiable risk factor for heart disease is smoking, which leads to increased obstruction of the coronary arteries. Each cigarette also causes spasms in these arteries. Smokers have twice the risk of heart attacks as nonsmokers, and death rates for heavy smokers are two to three times that of nonsmokers. Quitting smoking at any age likely confers benefit. This implies that it reduces disease progression and reduces the risk of MI and stroke; it also leads to a 25 to 50 percent reduction in mortality and recurrent heart attacks (MI).

There are many aids available to help quit smoking. These include nicotine gum (although people with dentures find the gum difficult to use). A nicotine patch is also available. Success rates for quitting using nicotine replacement are 18 to 25 percent, compared to 5 to 10 percent without nicotine replacement. Patients with heart disease may be concerned that nicotine replacement is not safe (potential dangers are dream abnormalities, insomnia, and application site reaction, also known as patch-rash), but if the options are replacement therapy or continued smoking, replacement therapy is probably safer.

Other aids in quitting smoking include medication (e.g., Bupropion, cloridine, mortiptyline) that can help relieve the agitation associated with quitting. Success rates are in the range of 30 percent. Other aids include hypnosis, acupuncture, laser therapy, and relaxation therapy. It is not important which method is chosen; what is important is the need to stop smoking.

The next major modifiable risk factor is diabetes. Diabetes, like heart disease, also increases with age, and prevalence approaches 10 to 20 percent in people over the age of sixty-five. People with diabetes have a two- to four-fold increased risk of coronary artery disease. While good control of diabetes probably reduces risk for heart disease, it seems that control of blood pressure is even more important for diabetics in reducing the risk of developing heart disease.

High blood pressure has also been strongly associated with heart disease, and it also increases with aging. Treating hypertension with low-dose thiazide diuretics and long-acting dihydropyridine calcium channel blockers has been shown to reduce heart attack, stroke, and death for people over the age of sixty.

Cholesterol has also been shown to be a significant risk factor for increasing coronary artery disease (CAD). The HMG-CoA reductase inhibitors (statins) have consistently shown a 20 to 30 percent reduction in heart attacks and death. The cholesterol-lowering trials of statins excluded elderly patients over the age of seventy-five, but the medications are still considered safe. This is because there is wide experience with statins outside the elderly community, randomized trials have proven safe, and side effects have very rarely been reported. In addition, older patients have the greatest risk and suffer the greatest burden from heart attacks and strokes and therefore have the most to gain from the use of these drugs.

Obesity and physical inactivity are also associated with heart disease. Regular physical activity five to seven times per week for twenty to thirty minutes a day can reduce the risk of heart disease by 20 percent. This may pose problems for some older adults, as there is an increase in arthritis in the older population, which can limit their physical ability. The use of a stationary bicycle allows people to sit while exercising and takes the weight off the lower joints, as does swimming and water exercise.

The use of antioxidants such as vitamin E and beta carotene have proven to be of no benefit in reducing heart disease. Fish oil supplements, which contain polyunsaturated fatty acids, have been shown to have a small but significant benefit in those with established heart disease. A Mediterranean-style diet has also been shown to be protective for heart disease. Such a diet includes "more bread, more root vegetables and green vegetables, more fish, less meat (beef, lamb, and pork to be replaced with poultry), no day without fruit, and butter and cream to be replaced with. . . a rapeseed (canola) oil-based margarine" (de Lorgeril, 1994).

Angina is classified into four stages. Functional class I indicates symptoms only with vigorous exertion. Class II indicates symptoms with moderate exertion; such as climbing a flight of stairs, or walking more than two blocks. Functional class III occurs with less activity, and functional class IV occurs at rest or with very low levels of activity such as walking around the room. The classic symptoms of angina are central pressure or chest pain, although the full range of symptoms felt may also include burning; a feeling of heaviness, squeezing, tightness, or fullness; an ache or sharp pain; or even no chest symptoms at all. The chest pain often radiates up into the shoulder and neck and down the arm (the left more so than right). It may also present in the upper abdomen, back, and ears or jaw as well. Other typical features include shortness of breath, a cold sweat (diaphoresis), weakness, nausea and vomiting, or even a loss of consciousness. Typically, these symptoms occur with exertion and are resolved with rest. If there is a change in symptoms with less activity or if they are more severe or prolonged, then the condition is considered unstable angina. Worsening of symptoms is related to an increase in the amount of obstruction of the coronary arteries. At the extreme of this spectrum of acute ischemic syndromes or unstable angina is a myocardial infarction, or heart attack. This occurs when the circulation is insufficient to keep the heart muscle alive. Typically, it is associated with a blood clot forming on a partial obstruction in the coronary arteries.

Unfortunately, as people get older they are less likely to present with typical symptoms. They may not have pain or discomfort; problems with nausea, diaphoresis, and weakness may not be attributed to a heart problem; and, frequently, people do not seek attention. Also, diabetics and women are more prone not to have typical symptoms, resulting in misdiagnosis and undertreatment.

More alarmingly, the rates of death from heart attack increase sharply with increasing age. Mortality under the age of sixty-five is probably in the range of 4 percent. Mortality over the age of seventy-five climbs to 20 percent. Complications after an infarct are also increased in the elderly.

When presenting with a heart attack, patients are treated initially with aspirin. Provided there has been no recent surgery or problems with bleeding, they may also be treated with medication to dissolve the clot causing the heart attack. Best results occur if treated within an hour after the onset of symptoms, but benefits are still seen even six to twelve hours after the onset of pain. These thrombolytic medications (e.g., streptokinase, tissue plasminogen activator, reteplase, tenecteplase) have been shown to significantly reduce death, but they are also associated with an increased risk of bleeding. This can be controlled, however, unless there is bleeding in the head, which is almost always fatal. The benefits of the medication outweigh the risks, and, given that older patients have a much greater risk of dying, they also enjoy a much greater absolute benefit from this therapy. For two to three days following an infarct, patients are treated with intravenous medication or an injection of heparin, which keeps the blood thin.

Another possible treatment at the time of a myocardial infarction is angioplasty. Angioplasty has the greatest success for treating MIs, but requires rapid availability and experienced physicians.

Other medications given to patients to reduce mortality after a heart attack are beta blockers and ACE inhibitors. Calcium channel blockers and nitroglycerin under the tongue, in a pill or patch form, or even intravenously, help control pain with acute ischemic syndromes.

With an uncomplicated heart attack, people can expect to be in the hospital five to seven days. After one to two days of rest, patients start to mobilize. This is done while being monitored. Medications are adjusted as tolerated, and patients generally have an assessment of their heart function by an echocardiogram (ultrasound of the heart) or a wall motion study (a nuclear X-ray). Prior to going home, most patients have an exercise stress test in which they walk on a treadmill while heart rate, blood pressure, and any changes in the electrocardiogram, as well as any recurrence of symptoms, are monitored. If these occur at low levels of activity, there is increased risk and more aggressive investigations or treatment are warranted. If not, the patient is considered low risk and should be safe for discharge.

Following discharge, patients can gradually increase their physical activity, watching for any recurrence of symptoms. Walking for five to ten minutes twice a day, and gradually increasing this up to thirty minutes twice a day, and then to forty to sixty minutes of walking or exercise once a day is recommended.

Congestive heart failure

Congestive heart failure (CHF), or cardiomyopathy, occurs when the pumping action of the heart has been weakened, causing shortness of breath, fatigue, and swelling, particularly in the legs and feet. There is decreased circulation to the major organs, and the kidneys retain more fluid to compensate. There are also neurohormonal factors that tend to stimulate or overdrive the heart. This ultimately can lead to further damage and deterioration of the heart function. Patients with functional class III to IV heart failure, where they are short of breath with low levels of activity or at rest, have a three- to four-year mortality rate of 35 to 45 percent. Mortality may be higher in older patients.

The most common cause of congestive heart failure is ischemic heart disease or prior myocardial infarctions. Older patients with congestive heart failure and coronary artery disease may benefit from revascularization, and they are at higher risk for silent ischemia or missed infarcts. While this accounts for 70 percent of the patients with congestive heart failure, there are numerous other causes, including hypertension, valvular heart disease, viral infection, and arrhythmias. Another age-related problem is chemotherapy (e.g., adriamycin, anthracycline, herceptin, taxanes, and others) for cancer.

With acute congestive heart failure, patients become suddenly short of breath, cannot lie flat, and develop edema. Patients in an emergency room will be treated with oxygen therapy as well as intravenous diuretics and nitroglycerin to help remove the fluid.

CHF can also be more insidious, with a gradual or progressive course of increasing shortness of breath over hours and days. This may be related to a change in fluid or salt intake. CHF patients require polypharmacy (the use of multiple medications, as heart patients often take anywhere from four to twelve drugs a day) to control their symptoms and improve survival. Angiotensin-converting enzyme (ACE) inhibitors have been shown to significantly reduce symptoms, hospitalizations, and mortality. For patients who are intolerant of ACE inhibitors, a reasonable next choice would probably be angiotensin receptor blockers (ARBs).

Beta blockers lower blood pressure, slow the heart rate, and decrease the heart's workload. Previously felt to worsen CHF, studies have shown that beta blockers actually improve survival, reduce symptoms, and improve heart function. Side effects may include fatigue or depression, and it is important that such side effects not be simply blamed on "old age."

Patients with severe heart failure (functional class III to IV) and an ejection fraction less than 30 percent should be treated with spironolactone. This medication is a diuretic with unique neurohormonal-blocking properties that have been shown to significantly reduce mortality. Other diuretics are also useful to help control symptoms of fluid retention.

Digoxin also reduces symptoms and decreases hospitalizations in heart failure. There are other inotropic medications available that make the heart stronger and can temporarily improve symptoms. Unfortunately, these medications decrease survival. Some patients with very severe CHF, however, may feel the benefit of fewer symptoms is worth the risk of not living as long as they would otherwise.

Certain medications are generally contraindicated in heart failure. Most calcium channel blockers worsen heart failure, though amilodipine and felodipine have been shown to be safe. Nonsteroidal anti-inflammatory drugs (NSAIDS) used to treat arthritis may also aggravate heart failure, as can alcohol, which should generally be avoided. Exercise is useful but must be individualized to a patient's physical state. Most lifestyle modifications are probably best coordinated through a heart function clinic run by nurse specialists.

Heart transplantation is an option only if patients have failed all other medical treatments and still have severe heart failure. It is also restricted to patients under sixty-five, as older patients do not do as well with the burden of aggressive immunosuppressive therapy.

Valvular heart disease

The heart consists of four chambers. The two upper chambers, or atria, pump blood into the lower chambers, or ventricles. The right ventricle pumps blood through the lungs, and the blood then returns with oxygen to the left ventricle. The left ventricle pumps blood to the rest of the body and the veins return blood to the right atria. The valves between the atria and ventricle are the tricuspid valve (right) and the mitral valve (left). The valves out of the heart are the pulmonary valve (right) and the aortic valve (left). These prevent blood from going backwards, optimizing pumping efficiency. There are two possible malfunctions with any valve. The valves can become stenotic, or tight, and cause a flow obstruction, or the valves can become loose or floppy and allow backward flow, or insufficiency. Most valve disease in adults involves the mitral valve or the aortic valve. Rheumatic fever is probably the most common cause of valvular heart disease worldwide. Caused by untreated streptococcal infections, rheumatic fever can cause either stenosis or insufficiency. This is much less common where antibiotics are widely available. The aortic and the mitral valve are also prone to calcification, or thickening, and stenosis with aging.

Mild-to-moderate mitral insufficiency does not require any surgical intervention, but if the insufficiency becomes severe, or if there are signs of worsening heart failure, then repair or replacement of the mitral valve may be necessary. If the mitral valve is too tight, it can cause CHF. This is diagnosed by an echocardiogram. Mitral stenosis can be repaired either by surgery or with a balloon (valvuloplasty). The balloon prevents the need for invasive surgery but may result in some mitral insufficiency. If a patient is not a good candidate for open heart surgery, a valvuloplasty is an attractive option.

Artificial valves are either tissue or metal. Tissue valves are frequently used on older patients because they do not require anticoagulation and cause less risk of stroke, but they tend to wear out within ten to fifteen years. Metal or mechanical valves require special blood thinners (e.g., warfarin) to prevent the valve from clotting up and blocking, and to prevent strokes. These blood thinners do increase the risk of bleeding and require regular monitoring.

The aortic valve occasionally shows significant leaking. If this is mild or moderate, it can be treated with medication. Nifedipine has been shown to reduce the progression and the need for surgery. If regurgitation is severe, valve replacement may be necessary. Aortic stenosis causes an increased strain on the pumping action of the heart. This can lead to angina, CHF, or loss of consciousness (syncope). Surgery is the only definitive treatment with severe aortic stenosis.

The risks of valvular surgery is increased in elderly patients, including an increased rate of perioperative mortality, increased postoperative infection, stroke and renal failure, prolonged hospital stay, and postoperative disability. Operative risks also depend on other comorbidities. Surgical consideration must be individualized for each patient and a balanced discussion of all reasonable risks and benefits is necessary for making the right decision.

Patients with valvular heart disease or artificial heart valves are at increased risk for developing endocarditis—an infection on the heart valve. Antibiotics are needed to prevent such infections when undergoing surgery and dental work.

Arrhythmias

The sinus node is the pacemaker of the heart. It sits high in the atria and sends out a regular signal for the heart to beat. This signal is controlled by neurological and hormonal triggers that make the heart speed up and slow down as needed. There is a delay switch between the atria and ventricle that is called the AV node. Arrhythmias occur when the heart is either beating too fast (tachycardia) or too slow (bradycardia). The most common arrhythmias consist of isolated and premature atrial contractions (PACs), and extra beats, called premature ventricular contractions (PVCs). These are normal. Some people are quite sensitive and can feel the heart skip or flip in their chest, followed by a brief pause before the heart returns to its normal rhythm. Most people notice this when sitting quietly or lying in bed. Triggers include smoking, alcohol, coffee, tea, chocolate, or other stimulants. These are not life threatening and do not require treatment.

PVCs are also associated with CHF. While frequent PVCs may be a sign of increased risk in patients with ischemic heart disease and congestive heart failure, treating these with antiarrhythmic medication has been proven to increase mortality. Treatment is therefore reserved only for symptomatic and sustained ventricular tachycardia (VT), which causes symptoms of weakness, lightheadedness, or syncope. Sustained VT can cause sudden death and requires defibrillation with electrical paddles. This is commonly depicted in television and movies, with survival rates on television of approximately 75 percent. In reality, survival rates are generally less than 20 percent.

Unfortunately, medications that have been used to treat ventricular tachycardia have had modest success at best. Newer automatic implantable cardiac defibrillators (AICD) are special pacemakers, and they can be programmed to give a shock to restore normal rhythm when VT is detected. These devices are very expensive, but very effective.

Other common arrhythmias in the upper chamber of the heart include supraventricular (SVT) or atrial tachycardias. If prolonged, these can cause palpitations, shortness of breath, fatigue, weak spells, and even syncope.

Atrial fibrillation is an irregular SVT that can occur intermittently or continuously. Increasing age is a major risk factor for atrial fibrillation, which occurs in 5 percent of people over sixty-five and as many as 10 percent of people over the age of eighty. Patients who have infrequent atrial fibrillation lasting only a few minutes may not require any antiarrhythmic medication. If atrial fibrillation causes weakness, shortness of breath, angina, or heart failure, treatment with medication is warranted.

If patients do not convert (from abnormal to normal rhythm) with medication or are unstable, they may require electrical cardioversion, in which patients are sedated ,or asleep, and then shocked with external paddles to restore normal rhythm.

Frequently, patients are not symptomatic with atrial fibrillation, and it may be picked up incidentally. This can happen when a patient undergoes an electrocardiogram (ECG) as part of a routine or presurgical check-up and atrial fibrillation is discovered as a result. In this situation, there is no clear benefit to trying to restore sinus rhythm, as many antiarrhythmic medications carry significant side effects. Beta blockers or calcium channel blockers may be used to control heart rates with atrial fibrillation. The other important risk is stroke. Patients who have atrial fibrillation and no valvular disease, as well as no other risk factors, have a risk of stroke of 1 percent per year. Risk factors include age greater than seventy-five, prior stroke or transient ischemic attack (TIA), diabetes, and hypertension. These risks increase the annual stroke rate to 4 to 5 percent per year. Anticoagulation using warfarin reduces the risk of stroke by 70 to 80 percent. The major risk associated with using this medication is an increased risk of bleeding. If warfarin is deemed unsafe, aspirin reduces the risk by 35 percent.

Bradycardia, or slow heart rate, is caused by sinus node disease, AV node disease, or heart block (which means the electrical impulse fails to reach the ventricle; heart block is caused by AV node disease). It also increases in frequency with increasing age. Symptoms include weakness or lightheadedness, fatigue, shortness of breath, or syncope. Bradyarrhythmias can be diagnosed by an ECG at the time of symptoms. Additionally, a holter monitor (a small device worn for twenty-four to forty-eight hours to record all heart beats) can detect and record arrhythmias.

Several cardiac medications, such as beta blockers, calcium channel blockers, and digoxin, can cause bradyarrhythmias and may need to be stopped. A pacemaker is used to treat bradycardia, and is generally inserted in the operating room or in a cardiac care unit. Pacemakers have a single wire in the ventricle and sometimes a second one in the atria. Modern pacemakers are no longer affected by interference caused by micro-waves, metal detectors, or store security systems, though there has been some interactions noted with cellular phones. As the world becomes more electronically busy, the potential for interference with pacemakers changes, and pacemaker manufacturers must continue to strive to keep ahead of new potential hazards.

Driving and heart disease

Regulations regarding driving and heart disease vary in different locations. Patients who are functional class IV should not drive, while those who are functional class III or better may drive, provided their doctor agrees. Following unstable angina or a heart attack, patients should be stabilized one month before driving. Patients should also wait one month after bypass surgery or insertion of a pacemaker before driving. Patients with AICD and documented episodes of VT should probably not drive if spells or shocks are frequent.

Sex and heart disease

Sexual activity is an important part of people's lives, including both older adults and patients with heart disease. Many of the problems that give rise to heart disease, such as diabetes, hypertension, and various medications, can also give rise to sexual dysfunction. More commonly, patients and their partners may be afraid to engage in sexual intercourse for fear it may trigger a heart attack, though the risk of precipitating a heart attack or heart disease during intercourse is quite low.

The first question to be asked is whether the heart can cope with the physical exertion involved. A middle-aged person uses approximately four to five METS (metabolic equivalent units) during intercourse. This is the equivalent of a brisk walk or of climbing two to three flights of stairs. An exercise stress test is measured in METS, and this is an easy way to determine if the work of intercourse will bring on angina. In general, it is safe to resume sexual activity two to three weeks after a heart attack. While elderly patients likely exert less energy than younger individuals during sexual intercourse, if symptoms such as angina or excessive shortness of breath develop, then the activity should be stopped and, if necessary, nitroglycerin may be used to relieve angina.

The question of patients with heart disease using Viagra raises some serious concerns. While Viagra is a highly effective and popular medication to treat erectile dysfunction, it is contraindicated in patients who are using nitroglycerin. This includes patients who are using nitroglycerin pills or patches, or people who need to use nitroglycerin by spray or pills under the tongue to relieve angina. Viagra and nitroglycerin taken together may cause significant and severe drops in blood pressure. This effect may occur up to twenty-four hours after using Viagra, and the potential exists for these effects occurring even later in elderly patients.

Glossary of cardiac medication

Angiotensin-converting enzyme (ACE) inhibitors improve survival with congestive heart failure and ischemic heart disease, reduce complications and incidence of diabetes, and lower blood pressure. They may decrease kidney function, increase potassium levels, and cause a dry cough. Also present the rare risk of angioedema. Angiotensin receptor blockers are useful to lower blood pressure and for congestive heart failure with no cough. However, they may cause renal failure or elevated potassium levels.

Aspirin is a blood thinner that reduces death from heart attacks and angina and reduces the chance of strokes. It does present a very small increased risk of bleeding and ulcer irritation may occur.

Beta blockers improve survival following heart attacks with congestive heart failure and with hypertension, lower blood pressure, have antiarrhythmic benefits, and also improve heart function. Side effects include possible fatigue, depression, erectile dysfunction, and bradycardia. Beta blockers are contraindicated in asthmatics. Calcium channel blockers are used to reduce blood pressure and help with angina. May be associated with constipation or reflux. Constipation may be a bigger problem with older patients, especially if immobility is present. Edema is another possible problem associated with these drugs.

Clopedigrol is a blood thinner used to reduce heart attack or stroke and may be used with or instead of aspirin.

Digoxin is used in the treatment of heart failure and reduces symptoms and hospitalizations. Adverse effects include nausea, GI upset, and bradycardia.

Diuretics are useful for lowering blood pressure and treating symptoms of congestive heart failure. May be associated with postural hypotension. Also can cause electrolyte abnormalities, including low potassium. May increase uric acid and precipitate gouty attacks.

Nitroglycerin is used to treat symptoms of angina. It may cause headaches, but tolerance develops.

Spironolactone is used to treat severe congestive heart failure, but may increase potassium and decrease renal function. It also may cause gynecomastia and increased hair growth.

Statins (HMG-CoA reductase inhibitors) are useful in reducing cholesterol and decreasing the risk of heart attacks and strokes. Very rare problems with liver abnormalities or muscle pain sometimes occur.

Warfarin is used to prevent strokes with valvular heart disease and with atrial fibrillation. Negative effects include the increased risk of bleeding.

Paul MacDonald

See also Aging; Cholesterol; Dementia; Dementia with Lewy Bodies; Diabetes Mellitus; Disease Presentation; Exercise; Fainting; High Blood Pressure; Revascularization: Bypass Surgery and Angioplasty; Stroke; Vascular Dementia; Vascular Disease; Vitamins.

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Yusus, S. Evidence Based Cardiology, 1st ed. London: British Medical Journal Publications, 1998.

Zijlstra, F.; Hoorntje, J. C. A.; De Boer, M.; et al. "Long-Term Benefit of Primary Angioplasty as Compared with Thrombolytic Therapy for Acute Myocardial Infarction." New England Journal of Medicine 341 (1999): 1413–1419.

Heart disease

Definition

Heart disease is a group of conditions affecting the structure and functions of the heart. The four primary conditions that make up heart disease are coronary artery disease, heart attack , congenital heart disease, and rheumatic heart disease. Other diseases include angina (chest pain ) and arrhythmia (irregular heartbeat).

Description

The heart is a muscle that gets energy from blood carrying oxygen and nutrients. Having a constant supply of blood keeps the heart working properly. Most people think of heart disease as one condition. But in fact, heart disease is a group of conditions affecting the structure and functions of the heart and has many root causes. Coronary artery disease (CAD) is the most common of these conditions and occurs when blood vessels in the heart become blocked or narrowed, preventing oxygen-rich blood from reaching the heart. It can cause chest pain (angina) or even a heart attack (myocardial infarction).

A normal heart is a strong muscular pump. It weighs between 200 to 425 grams (7–15 ounces) and is a little larger than the size of an adult fist. During an average lifetime, the human heart will beat more than 2.5 billion times. The average heart beats about 100,000 times each day and pumps about 7,200 liters (1,900 gallons) of blood. The heart sits between the lungs in the middle of the chest, behind and slightly to the left of the breastbone. A double-layered membrane called the pericardium surrounds the heart like a sac. Blood loaded with oxygen comes from the lungs and enters the heart. To function, the heart needs a continuous supply of oxygen and nutrients, which it gets from the blood that is pumped through the coronary arteries. The heart and circulatory system make up the cardiovascular system. The heart pumps blood to the organs, tissues, and cells of the body, delivering oxygen and nutrients to every cell and removing carbon dioxide and waste products made by those cells.

Oxygen-rich blood is carried from the heart to the rest of the body through a complex network of arteries, arterioles and capillaries. Oxygen-poor blood is carried back to the heart through veins.

Coronary artery disease

Coronary artery disease (CAD) is a condition in which plaque builds up inside the coronary arteries. These arteries supply the heart muscle with oxygen-rich blood. Plaque is made up of fat, cholesterol, calcium , and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis , commonly called hardening of the arteries. Plaque narrows the arteries and reduces blood flow to the heart. It also makes it more likely that blood clots will form in arteries. Blood clots can partially or completely block blood flow. When coronary arteries are narrowed or blocked, oxygen-rich blood can't reach the heart. This can cause angina or a heart attack. Angina is chest pain or discomfort that occurs when not enough oxygen-rich blood is flowing to an area of the heart. Angina may feel like pressure or squeezing in the chest. The pain also may occur in the shoulders, arms, neck, jaw, or back. A heart attack occurs when blood flow to an area of the heart is completely blocked. This prevents oxygen-rich blood from reaching that area of heart and causes it to die. Without quick treatment, a heart attack can lead to serious problems and even death . Over time, CAD can weaken the heart and lead to heart failure and arrhythmias . Heart failure is a condition in which the heart can't pump enough blood throughout the body. Arrhythmias are irregularities with the speed or rhythm of the heartbeat.

Heart attack (myocardial infarction)

A heart attack (myocardial infarction) occurs when the blood supply to the heart is slowed or stopped because of a blockage. Atherosclerosis, the narrowing of coronary arteries due to plaque buildup, causes more than 90% of heart attacks. A heart attack may also occur when a coronary artery temporarily contracts or goes into a severe spasm, effectively shutting off the flow of blood to the heart. The length of time the blood supply is cut off will determine the amount of damage to the heart.

Congenital heart disease

Congenital means existing at birth. A congenital heart defect happens when the heart or the blood vessels near the heart don't develop normally before birth. Congenital heart defects are present in about 1% of live births and are the most frequent congenital malformations in newborns. In most cases, researchers don't know why they happen. Some causes include viral infections, certain conditions such as Down Syndrome, and drug abuse during pregnancy, especially of alcohol, cocaine, and methamphetamines.

Rheumatic heart disease

Rheumatic heart disease describes a group of acute (short-term) and chronic (long-term) heart disorders that can occur as a result of rheumatic fever. One common result of rheumatic fever is heart valve damage. Due to the control of rheumatic fever in the United States and most developed countries, it is relatively rare in these regions but is still a significant heart disease in parts of Africa, Asia, and South America. Rheumatic fever is an inflammatory disease that may affect many connective tissues of the body, especially those of the heart, joints, brain or skin. It usually starts out as a strep throat (streptococcal) infection. Anyone can get acute rheumatic fever, but it usually occurs in children between the ages of 5 and 15 years. About 60% of people with rheumatic fever develop some degree of subsequent heart disease.

Demographics

Heart disease is the leading cause of death in the United States and Canada and is a major cause of disability. Almost 700,000 people die of heart disease in the U.S. each year, about 29% of all U.S. deaths. Worldwide, heart disease and stroke kill 17 million people a year, almost one-third of all deaths globally, according to the World Health Organization (WHO). By 2020, heart disease and stroke will become the leading cause of both death and disability worldwide, with the number of fatalities projected to increase to over 20 million a year and by 2030 to over 24 million a year. Men are slightly more likely to develop heart disease than women. An increasing number of women are experiencing heart disease but they are underdiagnosed. For both sexes, the risk of heart disease increases with age. In the United States, the number of heart disease deaths per 100,000 people by race is: Hispanics, 72; Asians and Pacific Islanders, 78; Native Americans, 80; African Americans, 206; and Caucasians, 259. However, when adjusted for differences in age distributions, the death rate from heart disease was 30% higher among African Americans than whites. In 2004, the number of deaths per 100,000 people in the U.S. by age groups was: 55–64, 218.8; 65–74, 541.6;75–84, 1,506; and 85 and older, 4,896.

Causes and symptoms

Coronary artery disease

Over many years, plaque builds up on artery walls. Plaque is a sticky, yellow substance made of fatty substances like cholesterol, as well as calcium and waste products from cells. It narrows and clogs the arteries, slowing the flow of blood. The process is called atherosclerosis. Atherosclerosis is a slow, progressive condition that may begin as early as childhood and occur anywhere in the body but it usually affects large and medium sized arteries. Sometimes plaque in an artery can rupture. The body's repair system in turn creates a blood clot to heal the wound. The clot, however, can block the artery, leading to a heart attack or stroke.

Early warning signs may include: fatigue, pain, and dizziness as well as the symptoms associated with angina: a squeezing, suffocating, or burning feeling in the chest that tends to start in the center of the chest but may move to the arm, neck, back, throat or jaw. Women are more likely to experience atypical symptoms such as vague chest discomfort.

Heart attack (myocardial infarction)

A heart attack occurs when the blood supply to the heart is partially or completely blocked. Symptoms include pain in the chest, neck, jaw, shoulder, arms or back, sudden discomfort or pain (especially in the chest) that does not go away, difficulty breathing, nausea, sweating, and anxiety .

Congenital heart disease

Congenital heart disease is caused by a defect in the heart at birth. The most common symptoms of congenital heart defects are a heart murmur, a bluish tint to the skin, lips, or fingernails, fast breathing, shortness of breath, and fatigue, especially during exercise or physical activity.

Rheumatic heart disease

It may take several years after an episode of rheumatic fever for valve damage to develop or symptoms to appear. Antibiotics can prevent streptococcal infection from developing into rheumatic fever. Any child with a persistent sore throat should have a throat culture to check for strep infection. Penicillin or another antibiotic will usually prevent strep throat from developing into rheumatic fever. Symptoms of heart valve problems, which is often the result of rheumatic heart disease, can include: chest pain, excessive fatigue, heart palpitations (when the heart flutters or misses beats), a thumping sensation in the chest, shortness of breath, and swollen ankles, wrists or stomach.

Diagnosis

The patient's doctor will start by taking a medical history, doing a physical exam, and probably some chest x rays. The doctor may also want to do other tests as well, including an angiogram, echocardiogram , and electrocardiogram.

Angiogram

An angiogram is a test that takes x-ray pictures of the coronary arteries and the vessels that supply blood to the heart. During an angiogram, a special dye is released into the coronary arteries from a catheter (special tube) inserted in a blood vessel. This dye makes the blood vessels visible when an x ray is taken of them. Angiography allows doctors to clearly see how blood flows into the heart. This helps them to pinpoint problems with the coronary arteries. Angiography may be recommended for patients with angina or those with suspected coronary artery disease. The test gives doctors valuable information on the condition of the coronary arteries, such as atherosclerosis, regurgitation (blood flowing backwards through the heart valves), or pooling of blood in a chamber because of a valve malfunction.

Echocardiogram

An echocardiogram uses sound waves (ultrasound) to create a picture of the heart. The recorded waves show the shape, texture, and movement of the heart valves, as well as the size of the heart chambers and how well they are working. An echocardiogram may be done to determine whether a stroke was caused by a heart condition and can also help determine if there is a risk of blood clots forming in the heart. It may also be recommended if the patient is experiencing abnormal heart sounds, shortness of breath, palpitations, angina, or has a history of stroke. It is very useful in diagnosing heart valve problems.

Electrocardiogram

An electrocardiogram (ECG or EKG) is a test that checks how the heart is functioning by measuring the electrical activity of the heart. With each heart beat, an electrical impulse (wave) travels through the heart. This wave causes the muscle to squeeze and pump blood from the heart. By measuring how long the electrical wave takes to pass through the heart, a cardiologist can determine if the electrical activity is normal, fast, or irregular. The cardiologist may also be able to determine if the heart is enlarged or overworked. It may be recommended if the patient is experiencing arrhythmia, palpitations, dizziness, excessive fatigue, or angina. An ECG is used to:

• Detect abnormal heart rhythms that may have caused blood clots to form.
• Detect heart problems, including a recent or ongoing heart attack, abnormal heart rhythms (arrhythmias), coronary artery blockage, areas of damaged heart muscle (from a prior heart attack), enlargement of the heart, and inflammation of the sac surrounding the heart (pericarditis).
• Detect non-heart conditions such as electrolyte imbalances and lung diseases.
• Monitor recovery from a heart attack, progression of heart disease, or the effectiveness of certain heart medications or a pacemaker.
• Rule out hidden heart disease in patients about to undergo surgery.

Treatment

There is no cure for heart disease, but there are many treatments, such as medications, surgery, and lifestyle changes, that can slow down its progression.

Coronary artery disease

Medications

ANTIPLATELETS Antiplatelets help prevent dangerous blood clots from forming. They may be used to reduce the risk of clot-induced heart attack or stroke, which is called preventive or prophylactic treatment. One of the most common antiplatelets is aspirin . Ticlopidine (Ticlid) may be prescribed to stroke survivors or those who are at high risk of stroke, particularly if they are not able to take aspirin. Clopidogrel (Plavix) is an antiplatelet drug that is effective in preventing strokes and heart attacks and is often prescribed in patients who receive a coronary stent. Dipyridmalole (Persantine) is usually given with other antiplatelet or anticoagulant medications. It can also be given by injection during tests on the heart.

ace inhibitors Angiotensin converting enzyme (ACE) inhibitors are usually given to people with high blood pressure, congestive heart failure , or people with a high likelihood of developing coronary artery disease. They may also be given after a heart attack to prevent more complications and to people living with congestive heart failure. They help control blood pressure to make it easier for the heart to pump. ACE inhibitors may also make people with CAD feel less tired and short of breath, reduce the time they spend in a hospital, and help them live longer. ACE inhibitors have been shown to reduce the risk of heart attack, stroke, and death in people with a history of coronary artery disease. Since ACE inhibitors are used to control and prevent conditions of the heart, they are usually prescribed for the long term.

beta blockers Beta blockers are used to treat high blood pressure, congestive heart failure, abnormal heart rhythms, and chest pain. They are sometimes used to prevent future heart attacks in someone who has had a heart attack, to treat tremors caused by an overactive thyroid, as well as anxiety or migraines. Beta blocker is short for beta-adrenergic blocking drugs. Beta blockers block the responses from the beta nerve receptors. This slows the heart rate and lowers blood pressure to reduce the workload on the heart.

calcium channel blockers Calcium channel blockers , sometimes called calcium channel antagonists, are used to control high blood pressure, chest pain caused by coronary artery disease, and irregular heartbeats. Calcium channel blockers are often taken in combination with beta blockers or diuretics to help reduce blood pressure. Calcium channel blockers are vasodilators, which means they widen (dilate) blood vessels, letting blood flow through more easily. By relaxing blood vessels, the blood pressure drops and the heart doesn't have to work as hard.

nitrates Nitrates are vasodilators and can be used to prevent chest pain, limit the number of angina attacks, relieve the pain of a current attack, or treat the symptoms of congestive heart failure. Nitroglycerin is a type of nitrate.

Medical procedures

angioplasty with stent Percutaneous Coronary Intervention (PCI), commonly called angioplasty with a stent, is a non-surgical procedure that uses a catheter (a thin flexible tube) to place a small structure called a stent (a small tubular structure made of stainless steel or plastic) to open up blood vessels in the heart that have been narrowed by plaque buildup. PCI improves blood flow, thus decreasing heart-related chest pain, making the patient feel better and increasing their ability to be physically active. During the procedure, a catheter is inserted into the blood vessels either in the groin or in the arm. Using a special type of X-ray called fluoroscopy, the catheter is threaded through the blood vessels into the heart where the coronary artery is narrowed. When the tip is in place, a balloon tip covered with a stent is inflated. The balloon tip compresses the plaque and expands the stent. Once the plaque is compressed and the stent is in place, the balloon is deflated and withdrawn. The stent stays in the artery, holding it open. The doctor may use a coated stent or a bare metal stent. A coated stent has medicine on its outside that slows the regrowth of the artery wall into and blocking the stent. If a coated stent is used, the patient will need to take Plavix for at least two years, perhaps for life.

coronary artery bypass surgery Coronary artery bypass surgery improves the blood flow to the heart muscle. It is commonly referred to as bypass surgery or Coronary Artery Bypass Graft (CABG, pronounced like cabbage) surgery. Bypass surgery is performed to improve blood flow problems to the heart muscle caused by the buildup of plaque in the coronary arteries. The surgery involves using a piece of blood vessel (artery, vein) taken from elsewhere in the body to create a detour or bypass around the blocked portion of the coronary artery. By improving blood flow, bypass surgery may decrease heart-related chest pain, making patients feel better and increasing their ability for physical activity.

In coronary artery bypass surgery, a piece of a healthy blood vessel from the patient's leg, arm, or chest will be removed to be used as the bypass. Unless a patient is undergoing one of the newer procedures (minimally invasive bypass or off-pump or beating-heart surgery), the heart is stopped so the surgeons can work on it. A machine called the heart-lung machine will take over the work of the heart and lungs while the surgeon is operating on the heart. The section of healthy blood vessel is attached above and below the blocked artery. When the heart is restarted, blood flow is diverted through the bypass around the narrowed portion of the diseased artery. Depending upon the number of blockages, one to five bypasses may be created.

counter pulsation Another medical procedure that can help with CAD is counter pulsation. In this procedure, inflatable cuffs are placed on the legs and lower abdomen. When the heart relaxes, the cuffs inflate and push blood into the blood vessels of the heart. This procedure is repeated over a few days and it stimulates improved blood flow to the heart. Counter pulsation can't be done in people with dilated aortas or who have severe peripheral vascular disease .

Heart attack (myocardial infarction)

When someone is experiencing a heart attack or believe they are, they should seek immediate emergency help. In the United States, call or have someone else call 911 and request paramedics or emergency medical technicians (EMTs). Most fire departments in the United States and Canada have paramedics and/or EMTs. Doctors also recommend that at the first sign of a heart attack, the patient chew and swallow an adult (325 mg) aspirin, which can help improve blood flow to the heart. Only aspirin can improve blood flow, no other pain medications, such as acetaminophen (Tylenol) or ibuprofen (Advil), will work. Until medical help arrives, the patient should sit or lie down. If the patient is on the drug nitroglycerine, they should take a normal dose. Following a heart attack, patients may be put on nitrates, ACE inhibitors, beta-blockers, and antiplatelets (all described above under coronary artery disease medications). Other drugs used include thrombolytic drugs, used to dissolve blood clots that are blocking the coronary arteries, and anticoagulants, used to thin the blood and prevent clots from forming in the arteries. Surgical treatments include angioplasty and coronary bypass (both described above under coronary artery disease medical procedures).

Congenital heart disease

The heart defects of congenital heart disease are treated with several medications, including ACE inhibitors, beta blockers, diuretics, and digoxin. Diuretics act on the kidneys to produce more urine and remove excess salt and water from the body. By decreasing water and salt, diuretics lower blood pressure and help reduce the workload on the heart. This may make it easier for the heart to pump, improve shortness of breath, reduce swelling and bloating, reduce the time spent in a hospital, and help patients live longer. Digoxin helps the heart pump stronger and slows down the heart rate to improve its pumping action.

In many cases, the strain to the heart requires procedures that either fix holes between the chambers, replace valves, or repair or reconnect major blood vessels. In severe cases, heart transplant surgery may be needed. Several other surgical procedures can be used to repair and correct congenital heart defects They include:

• Cardiac catheterization is often used to repair simple holes in the heart. A catheter (thin tube) is inserted into a blood vessel in the groin or arm and guided to the heart so that a surgeon can insert a plug inside the hole to repair it.
• Angioplasty is used to repair defective cardiac valves that can be either too narrow or leaky. A tiny balloon is guided to the heart inside a catheter (a thin tube). When the balloon is inflated, it can stretch the opening of a narrowed heart valve and restore normal blood flow. It is removed once blood flow returns.

Rheumatic heart disease

If heart damage from rheumatic fever is identified in childhood or young adulthood, daily antibiotics may be required until the age of 25 or 30, to help prevent recurrence of rheumatic fever and avoid the development of infective bacterial endocarditis, an infection of the heart valves or lining of the heart. Additional treatment will depend on the type of heart damage. Surgery may be required to repair or replace damaged heart valves. In rare cases, heart transplant surgery may be recommended.

Nutrition/Dietetic concerns

A healthy diet is essential in both the prevention and treatment of heart disease. This includes eating a variety of foods that are low in fat (especially saturated fat and trans-saturated fat), low in cholesterol, and high in fiber; plenty of fruits and vegetables; and limited sodium . Some foods are low in fat but high in cholesterol, and some are low in cholesterol but high in fat. Saturated and trans-saturated fats raise cholesterol, and, in excessive amounts, it increases the amount of the proteins in blood that form blood clots. Polyunsaturated and monounsaturated fats are relatively good for the heart. Fat, such as olive oil, should comprise no more than 30% of total daily calories. Drinking alcoholic beverages should be done in moderation. Modest consumption of alcohol, particularly red wine, can actually protect against heart disease. This is believed to be because alcohol raises HDL cholesterol levels. The American Heart Association defines moderate consumption as one ounce of alcohol per day-roughly one cocktail, one 8-ounce glass of wine, or two 12-ounce glasses of beer. However, people age 65 and older should be advised to limit their alcohol intake to one drink per day.

QUESTIONS TO ASK YOUR DOCTOR

• What type of treatment do you recommend for me?
• What other treatment options are available?
• How will having heart disease affect my daily life?
• What lifestyle changes will improve my condition?
• What is the likely progression of my heart disease?
• What role does cholesterol, blood pressure, and/or diabetes play in relation to my heart condition?

Therapy

Regular aerobic exercise can lower blood pressure, help control weight, and increase HDL (“good”) cholesterol. All of these can reduce the risk of heart disease. Exercise may also keep the blood vessels more flexible. Moderate intensity aerobic exercise lasting about 30 minutes four or more times per week is recommended for maximum heart health, according to the CDC. Three 10-minute exercise periods also are beneficial. Aerobic exercise-activities such as walking, jogging, and cycling-uses the large muscle groups and forces the body to use oxygen more efficiently. It also can include everyday activities such as active gardening, climbing stairs, or brisk housework. Persons with heart disease should consult with their doctor before starting any exercise routine.

Prognosis

Lifestyle changes, medicines, and medical procedures can effectively prevent or treat heart disease in most people.

Prevention

The only way to prevent rheumatic heart disease is to prevent rheumatic fever or successfully treat rheumatic fever before it can damage heart valves.

There is no way to prevent congenital heart disease, since it is an inherited (genetic) disorder that develops in the womb.

KEY TERMS

Angina —Chest pain.

Angiogram —An x-ray photograph of one or more blood vessels.

Angioplasty —A surgical operation to clear a narrowed or blocked artery.

Arrhythmia —An irregular heartbeat.

Atherosclerosis —A buildup of plaque in the arteries, also called hardening of the arteries.

Echocardiogram —An image of the heart created by ultrasound waves.

Electrocardiogram —A test that measures the electrical activity of the heart.

Plaque —A compound made up of fat, cholesterol, calcium, and other substances found in the blood. It can stick to the walls of arteries, partially or totally blocking blood flow.

Ultrasound —A technique that uses high-frequency sound waves for medical diagnosis and treatment by creating images of internal organs.

Vasodilator —A class of drugs that widen the blood vessels, that in turn decreases resistance to blood flow and lowers blood pressure.

People can lower their risk of coronary artery disease and heart attack by knowing and controlling their blood pressure, diabetes, and cholesterol. It is also important to lead a healthy lifestyle by not smoking and being physically active (exercising regularly), eating a healthy diet that is lower in fat, especially saturated and trans fat, achieving and maintaining a healthy weight, limiting alcohol use, and reducing stress . Seniors can reduce stress by regularly socializing with friends and family and by such activities as yoga and meditation. Many doctors also recommend taking a low-dose (81–125 mg) of aspirin daily.

Caregiver concerns

Patients with heart disease may have as many as five (or more) medications that need to be taken daily. Caregivers should have a system to make sure that the patient takes the medications when and how they are prescribed. Alarms or timers can be used to remind the patient when to take each pill. Also, weekly pill dispensers can help to insure patients only take the dose that is prescribed. Caregivers may want to keep a medicine calendar and note every time the patient takes a dose, or have the patient do it themselves. It is vital that the caregiver makes sure that prescriptions are refilled before they run out. Make sure that the patient is not taking anything that is contraindicated by their condition or that may interact with their medication. Examples include such things as herbal supplements, antihistamines , and analgesics. Check with the patient's doctor or pharmacist for possible drug interactions . Also, people who take nitrates (such as nitroglycerine) should not take medications for erectile dysfunction (ED), including sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis).

Helping a patient stick to their diet and exercise routine is critical to their overall health. One way to ensure adherence to a restricted diet is to prepare meals for the patient. If this is not feasible, the caregiver can try to limit the amount of forbidden foods that are present in the patient's home. The level of exercise required of a patient will depend on their overall health, but for most patients, frequent walks are beneficial. If the caregiver can accompany them on their walks it will make the experience more enjoyable and increase adherence. Perhaps the most important role of a caregiver is providing emotional support. Simply being there to listen to the patient's concerns and to provide encouragement can keep them on the path toward better health. In some cases, the patient may require at-home oxygen therapy . The care giver should learn how the oxygen equipment is used and to make sure more oxygen is ordered well before the patient's current supply runs out.

Resources

BOOKS

Esselstyn, Caldwell B.

Prevent and Reverse Heart Disease: The Revolutionary, Scientifically Proven, Nutrition Based Cure New York: Avery, 2008.

Katzenstein, Larry. An AARP Guide: Living With Heart Disease: Everything You Need to Know to Safeguard Your Health and Take Control of Your Life New York: Sterling, 2007.

Lipsky, Martin S, et al. American Medical Association Guide to Preventing and Treating Heart Disease: Essential Information You and Your Family Need to Know About Having a Healthy Heart Hoboken, NJ: Wiley, 2008.

Sinatra, Stephen T., et al. Reverse Heart Disease Now: Stop Deadly Cardiovascular Plaque Before It's Too Late Hoboken, NJ: Wiley, 2008.

PERIODICALS

Grant, Ruth Ann. “Study: Elderly Lacking Heart Attack Care.” McKnight's Long-Term Care News(September 2007): 6.

Guthrie, Catherine. “Damage Control: The 6 Best Natural Supplements to Protect Against Heart Disease, Cholesterol, and High Blood Pressure.” Natural Health (February 2008): 62(6).

Hanna, Ibrahim R., and Nanette K. Wenger. “Secondary Prevention of Coronary Heart Disease in Elderly Patients.” American Family Physician(June 15, 2005): 2289.

Lowry, Fran. “Gastric Bypass Also Cuts Cancer, Diabetes, Heart Disease Mortality.” Family Practice News(February 1, 2008): 38.

Mast, Carlotta. “Go With the Flow: Support Your Circulatory System and Lower Your Risk of Stroke and Heart Disease With These Drug-Free Recommendations.” Delicious Living(February 2008): 41(4).

Sherman, Carl. “Reducing the Risk of Heart Disease in Women: Incorporating New Research Findings, the American Heart Association's Updated Guidelines Make Several Changes in the Previous Recommendations.” Clinical Advisor(January 2008): 49(3).

ORGANIZATIONS

Adult Congenital Heart Association, 6757 Greene St., Suite 335, Philadelphia, PA, 19119-3508, (215) 849-1260, (888) 921-2242, (215) 849-1261, info@achaheart.org, http://www.achaheart.org.

American Heart Association, 7272 Greenville Ave., Dallas, TX, 75231, (301) 223-2307, (800) 242-8721, http://www.americanheart.org.

Association of Black Cardiologists, 5355 Hunter Road, Atlanta, GA, 30349, (404) 201-6600, (800) 753-9222, (404) 201-6601, abcardio@abcardio.org, http://www.abcardio.org.

European Society of Cardiology, The European Heart House, 2035 Route des Colles, B.P. 179-Les Templiers, Sophia-Antipolis,, France, 06903, 33 4 9294 7600, 33 4 9294 7601, http://www.escardio.org.

Heart Foundation, 80 William St., Level 3, Sydney, NSW, Australia, 2011, 02 9219 2444, 300 36 27 87, http://www.heartfoundation.org.au.

National Heart, Lung, and Blood Institute, P.O. Box 30105, Bethesda, MD, 20824-0105, (301) 592-8573, (204) 629 3246, nhlbiinfo@nhlbi.nih.gov, http://www.nhlbi.nih.gov.

Ken R. Wells

Heart Disease

Max’s Story

What Is Heart Disease?

What Are the Different Types of Heart Disease?

What Causes Heart Disease?

How Do People Know They Have Heart Disease?

Diagnosis

How Is Heart Disease Treated?

Living with Heart Disease

Resources

Heart disease is a broad term covering many conditions that prevent the heart from working properly to pump blood throughout the body.

KEYWORDS

for searching the Internet and other reference sources

Arteriosclerosis

Atherosclerosis

Cardiovascular system

Coronary artery disease

Heart failure

Myocardial infarction

Rheumatic fever

Max’s Story

Max, who had just turned 14, and his grandfather Harry often shared a Saturday morning ritual: breakfast at their favorite diner, followed by a brisk game of tennis. On this occasion, they both ordered the special: two fried eggs, four strips of bacon, hotcakes, and a side of hash browns. Plates cleared, they hit the tennis courts, but only ten minutes into their game, Harry, breathing hard and sweating heavily, stopped and complained of a squeezing pain in his chest. Although his grandfather protested that it was most likely indigestion, Max went for help. At the emergency room, his grandfather was given aspirin and put on a heart monitor that showed

that he had experienced a mild heart attack. A nurse told Max that his quick action might have saved his grandfather’s life.

What Is Heart Disease?

Heart disease is a group of diseases that prevent the heart from working as well as it should.

Only a little larger than a fist, a normal, healthy heart is at the center of the body’s cardiovascular system*. Each day the average heart beats, or expands and contracts, about 100,000 times. In a 70-year lifetime, an average human heart beats more than 2.5 billion times.

* cardiovascular system

(kar-dee-o-VAS-ku-lur) is comprised of the heart and blood vessels.

The circulatory system* is responsible for providing nourishment to the body’s cells and removing wastes from them. The arteries take oxygenated blood from the heart to the cells; the veins take blood from the cells to the lungs for reoxygenation and recirculation by the heart.

* circulatory system

(SIR-ku-la-tor-ee) is made up of the heart, arteries, veins, capillaries, and circulating blood.

The coronary arteries encircle the heart from above and below like strands of ivy. With their strong, flexible walls and smooth linings, healthy coronary arteries supply blood to the heart itself, in much the same way as a hose transports water to a garden.

At birth, these coronary arteries are completely open and clear, permitting a maximum flow of blood to the heart, but as people age, these vessels can become clogged with a thick combination of lipids (fats), cholesterol, calcium, and other substances. As these layers accumulate inside the arteries, they can lead to arteriosclerosis (ar-teer-e-o-skle-RO-sis), a condition also known as “hardening of the arteries,” since this buildup eventually stiffens the inner artery walls. Atherosclerosis (ath-er-o-skle-RO-sis), a buildup of plaque* on the innermost portion of the vessel, is the most common form of arteriosclerosis. Over time, plaque continues to accumulate in the blood vessels, much like grease that clogs a kitchen drainpipe. The result is a narrowing of the inside diameter of the vessel.

* plaque

(PLAK) is a raised patch or swelling on a body surface. Arterial plaque occurs on the inner surface of an artery and is produced by fatty deposits.

What Are the Different Types of Heart Disease?

Coronary arteries affected by atherosclerosis will eventually develop coronary artery disease, a condition in which the vessels are so narrow that they can no longer provide adequate nutrients or oxygen to nourish the heart. Blood flow is blocked either partially or totally.

Heart attacks are injuries to the heart muscle that occur when blood flow through a coronary artery is interrupted, cutting off the vital supply of oxygen to the heart. Blood can be kept from the heart by narrowing

of the arteries by atherosclerotic plaque, by a blood clot blocking the narrowed vessel, or by a contraction (spasm) of the artery in response to a lack of oxygen or blood. The part of the heart muscle affected by the blockage is usually slowly starved of oxygen. The longer the heart muscle goes without nourishment, the more muscle tissue deteriorates or dies. Quick action, like that taken by Max, is essential.

Blocked arteries are not the only cause of heart attacks. Hypertension, or high blood pressure, can be a contributing factor. Pumping blood against high pressures in the blood vessels (as occur in people with uncontrolled hypertension) can put too much strain on the heart. Abuse of alcohol, viral infections, tuberculosis, parasites, or other vascular (blood vessel) diseases can also lead to heart disease.

Diseased valves can also put abnormal strain on the heart. The four valves, located between the atria (upper chambers) and ventricles (lower chambers) of the heart, open and close like tiny camera shutters to make sure that blood flows in the right amount and in the right direction. If a valve is scarred and cannot open completely, the heart has to work harder to pump enough blood through the obstruction. A valve that does not close completely can allow blood to go backward through the heart chambers, making the heart work harder by having to pump the same blood twice.

Bacterial endocarditis, or inflammation of the endocardium (the inner surface of the heart), is an infection that can cause the heart valves to malfunction. Such an infection may rarely follow oral surgery or dental work, when normally harmless bacteria are released into the bloodstream. This generally affects valves that were previously damaged from rheumatic heart disease or other conditions.

Body Mass Index

The body mass index (BMI) has been used since the early 1980s as a medical standard for obesity measurement. To calculate BMI:

1. Multiply weight in pounds by 700

2. Divide that number by height in inches

3. Divide that number by height in inches again

The recommended BMI is 20 to 26. The overweight range is 26 to 27.3 for women and 26 to 27.8 for men. Most “experts” say that obesity begins with a BMI greater than 27.3 for women and 27.87 for men. All agree that anyone with a BMI over 30 is obese.

Various forms of heart disease can also cause dysrhythmias (dis-RITH-me-as), or disturbances in the normal heartbeat pattern. Although many of these are harmless, some are quite serious. For example, ventricular fibrillation (ven-TRIK-yoo-lar fib-rill-AY-shun), a type of heart rhythm in which pumping is uncoordinated and ineffective, can cause sudden death.

What Causes Heart Disease?

Risk factors

Heart disease is not contagious and, to a large extent, can be prevented, controlled, and, in some cases, even reversed. When looking at what causes heart disease, researchers divide the risk factors* into those that people can control and those that they cannot. Among the factors that cannot be changed are:

* risk factors

are things about people, such as their age, weight or diet that increase their chances of getting a certain disease.

• Age. As people age, their cholesterol levels usually increase and hardening of the arteries appears and progresses in most people.
• Gender. Men have higher cholesterol levels than women until around age 45. Women catch up after menopause*.

* menopause

(MEN-o-pawz) is the time of life when women stop menstruating (having their monthly period) and can no longer become pregnant.

• Family histories. People with a family history of heart disease are at increased risk.

The good news is that some risk factors can be controlled. These include:

• Smoking. Smokers’ risk of heart attack is almost twice that of nonsmokers, and their risk of sudden cardiac death is two to four times that of nonsmokers. Quitting (or never starting!) is a definite heart-healthy move.
• High blood pressure. Hypertension puts extra stress on the heart. Taking medication to lower high blood pressure, maintaining healthy body weight, avoiding salt, and increasing exercise can help people reduce blood pressure.

• Blood lipids. Lowering fats in the blood, such as cholesterol, can reduce the risk of heart disease. Individuals who come from a family with heart disease; who have other risk factors such as smoking, diabetes, hypertension, obesity, or physical inactivity; or who have a parent with a high cholesterol level should have their lipid levels monitored by a doctor.
• Diabetes. Many people with diabetes have high blood pressure or are obese. Diabetes can also increase lipid levels and accelerate the development of atherosclerosis, heart attack, and stroke.
• Obesity. Obesity is generally defined as having an adult body mass index greater than 27 (see sidebar). About one third of American adults are obese, even though maintaining a healthy weight throughout life seems to be one of the best ways of living longer and healthier. In a famous 30-year study of 5,127 adults in Framingham, Massachusetts, between 1948 and 1978, those who maintained their weight from age 25 on had a lower risk of heart disease. Those who lowered their weight over this time reduced their risk even further.
• Physical activity. Exercisers have a lower rate of cardiovascular disease; those who are inactive have a higher rate. Aerobic exercise* lowers the heart rate, lipid levels, and blood pressure and decreases body fat. Such activities include brisk walking, running, swimming, rowing, and jumping rope for at least ten to fifteen minutes. It is estimated that 60 percent of American adults get no aerobic exercise.

* aerobic exercise

(air-O-bik) is exercise designed to increase oxygen consumption by the body; it helps keep the heart and lungs in shape.

The U.S. and the World

The American Heart Association says cardiovascular disease has been the leading cause of death in the United States every year since 1900, except the year 1918. According to the AHA’s 1999 Heart and Stroke Statistical Update:

• Almost 60 million Americans have some form of cardiovascular disease. The most common condition is high blood pressure, which affects 50 million Americans.
• Heart disease killed 944,148 people in the United States in 1997, making it the leading cause of death. It accounts for about 40 percent of all deaths each year in America.
• About 84 percent of heart disease deaths occur in people who are 65 and older.

Heart disease also is a leading cause of death worldwide. The World Health Organization reports that in 1998, for example, 32 percent of all deaths (16.7 million) resulted from heart disease. It was the number 1 cause of death in all regions of the world, except Africa (where it was ninth) and the western Pacific (where it was third).

WHO predicts that worldwide heart disease death rates will climb during the next two decades if developing nations continue their trend toward increased smoking and more westernized diets.

Other risk factors that can be controlled include drinking too much alcohol and having too much stress.

The fat connection

Cholesterol (ko-LES-ter-ol) is a soft, waxy substance that circulates in the blood and is found in every cell of the body. It is an important building material for cells and nerves and is used for the production of certain hormones. Cholesterol is used by the liver to make bile acids, which help digest food. Triglycerides (try-GLIS-er-ides) are fats in the blood that, like cholesterol, can come from either the diet or can be produced by the liver. Triglycerides are different from cholesterol, but like cholesterol, they are normally present in the blood. Elevated triglycerides may be associated with certain illnesses.

The body makes all the cholesterol it needs, but people also get cholesterol from their diets, particularly when they eat foods made from animal and dairy products. High blood cholesterol levels can have many causes, including genes (heredity) and lifestyle choices (diet). Too much cholesterol can lead to coronary heart disease. Hyperlipid disorders, in which there is too much cholesterol or too much triglyceride in the blood, are some of the most common inherited conditions in humans, affecting one in every 500 people. In persons with such disorders, risk factors such as obesity, cigarette smoking, and high blood pressure can increase the chance of coronary heart disease even further.

How Do People Know They Have Heart Disease?

Heart disease is the number one killer in developed countries, and heart attacks are recognized as the most obvious sign of heart disease. Each year, 1.5 million Americans have heart attacks. But one problem with heart disease is that in 20 to 40 percent of people (like Max’s grandfather), a heart attack is the first symptom of the disease. By then, plaque may have narrowed one or more arteries, limiting their ability to supply an area of the heart muscle with the oxygen and nutrients it needs.

Because a heart attack can cause severe damage by robbing the heart of oxygen, a quick reaction to the earliest signs of a heart attack is essential. Angina pectoris (an-JY-na PEK-to-ris), a squeezing, tightness, or heaviness in the chest that can extend to the left arm, neck, jaw, or shoulder blade, is often the first sign that someone with atherosclerosis is at risk for a heart attack. Physical exercise, a heavy meal, strong emotions, or extreme temperatures can bring it on. If angina occurs when a person is at rest, this means that the heart is starving for oxygen even when it is not working hard. Besides chest pain, weakness, fainting, profuse sweating, nausea, and vomiting can accompany a heart attack, although a heart attack that arrives without angina—a “silent” heart attack—may not be revealed until a patient shows up in the physician’s office for an unrelated condition.

Valve disease can cause related symptoms of dizziness, fatigue, weakness, shortness of breath, and chest pain when exercising. These same signs, along with edema (e-DEE-ma), an accumulation of fluid that occurs when the heart cannot keep the circulation moving properly, can indicate heart failure*. Gravity often pulls the fluid downward, causing swelling in the feet, ankles, and legs.

* heart failure

is a medical term used to describe a condition in which a damaged heart cannot pump enough blood to meet the oxygen and nutrient demands of the body. People with heart failure may find it hard to exercise due to the insufficient blood flow, but many people live a long time with heart failure.

Diagnosis

Depending on the type of heart disease, a physician can use a number of different tests to help pinpoint heart problems. They are divided into invasive tests done internally and noninvasive tests that can be performed externally. Noninvasive procedures include:

• Electrocardiogram (ECG or EKG). A recording of the heart’s electrical activity to help a doctor diagnose and monitor irregular heart rhythms, heart attacks, or other abnormalities. A portable ECG machine worn by a patient called a Holter monitor can also test the effectiveness of drug therapy for dysrhythmias and monitor pacemaker* functions for 12, 24, or 48 hours.
• Stress test . An ECG performed during exercise to determine the cause of chest pain and other symptoms related to physical activity.
• Echocardiogram . Ultrasonic waves, or high-frequency inaudible sound waves, are bounced off the surfaces of the heart and converted into an image that can be displayed on a monitor to diagnose congenital* heart disease, valve disease, congestive* heart failure, and other conditions.
• Ultra-fast computed tomography. Scanning that employs electron beams to detect calcium deposits in the coronary arteries.

* pacemaker,

a device whose function is to send electrical signals that control the heartbeat. The heart’s natural pacemaker is the sinoatrial node, a special group of cells. Sometimes it is necessary to implant a battery-powered pacemaker that sends small electrical charges through an electrode placed next to the wall of the heart.

* congenital

(kon-JEN-i-tul) means existing at birth.

* congestive

(kon-JES-tiv) means characterized by accumulation of too much fluid.

Invasive procedures include cardiac catheterization, which is used to evaluate coronary artery disease, causes of angina, complications following a heart attack, heart defects, and other internal disorders. A catheter, or long, thin tube, is inserted into the cardiovascular system, usually through

an arm or leg artery. A contrast solution (a dye that will show up on film) is then injected to visualize the blood vessels on film (angiography). Depending on where the catheter is positioned, it can diagnose the extent of coronary artery plaque buildup or abnormalities of the aorta* and valves.

* aorta

(ay-OR-ta) is the major large artery that carries blood from the heart to the rest of the the body.

How Is Heart Disease Treated?

Although many heart conditions cannot be cured, they can be controlled with lifestyle changes, medication, or surgery, or a combination of these strategies.

Medications

Irregular heartbeats, heart failure, and angina are often treated with a combination of healthy lifestyle changes and medications. One of the most common medications used is nitroglycerine (ny-tro-GLIS-er-in), in the form of a tiny pill dissolved under the tongue, which acts to open the heart’s blood vessels and permit more oxygen to flow to the heart muscle. Beta-blockers decrease the heart s demand for oxygen by slowing down the heart rate. Aspirin, which helps keep the blood from clotting easily, is given to people who have heart disease or a high risk of heart disease to decrease the likelihood of blood clots and thereby lowers the risk of heart attack and premature death. At the time of a heart attack, patients may be given special clot-dissolving medications intravenously (injected into a vein) to help unclog the diseased coronary arteries. Medications are also used to control high blood pressure.

Surgical procedures

Angioplasty (AN-je-o-plas-tee), also called balloon angioplasty, opens up vessels blocked by plaque buildup. A specially designed balloon is threaded through an artery. Once positioned, the balloon is set at the narrowest portion of the blocked artery and inflated, pumping up and widening the channel. After the artery is opened, the balloon is withdrawn.

One problem is that coronary arteries opened by angioplasty often close within three to six months. To prevent this, surgeons often place a stent, a 1-inch tube of wirelike stainless steel shaped like a tiny coiled spring, into the vessel, where it is expanded. The stent props the vessel open like scaffolding supports a tunnel. Stents can also be lifesaving for

Frog’s Legs and Galvanometers

Today’s sophisticated electrocardiograph (ECG or EKG) began with the study of frogs’ legs.

During the 1700s, scientists Luigi Galvani (1737-1798) and Alessandro Volta (1745-1827) used frogs to study muscle action. Their work led to development of the galvanometer (gal-va-NOM-e-ter), which measures current by electromagnetic action.

In 1903, William Einthoven (1860-1927) introduced the string galvanometer. Einthoven’s galvanometer evolved into today’s EKG machine, one of the fundamental tools that cardiologists use to monitor the heart’s rhythms.

Did You Know?

• Coronary heart disease is the largest killer of American men and women. Every 29 seconds someone suffers a coronary problem; every minute someone dies from one.
• Managing heart failure costs Americans between $10 and $15 billion annually.
• Almost 15,000 heart transplants have been done since the 1980s, according to the United Network of Organ Sharing. About 2,500 are performed each year, with many other patients waiting in line.

patients whose arteries suddenly collapse or spasm (contract) and close during angioplasty, setting off a heart attack.

Microwave Ovens

Convenience stores, cafeterias, and snack bars used to post warnings near their microwave ovens for people with pacemakers. Electromagnetic radiation emitted from the microwave ovens sometimes caused current variations in the pacemakers. Pacemakers today are shielded from stray electromagnetic forces and have a backup mode in case of disruption of the main circuit’s programming.

Atherectomy (ath-er-EK-to-mee) is the excision (cutting out) and physical removal of plaque from arteries. It is used in place of or along with balloon angioplasty. Once the balloon is inflated, a miniature cutter whirs forward to scrape deposits from the wall of the vessel like a tiny rotor clearing a clogged drain. Debris is pushed to a special collection chamber, and when the device is withdrawn, the debris comes with it.

Pacemakers can be inserted to restore a regular heartbeat. Advanced devices can sense and respond to changes in body movement, temperature, and breathing rate.

Bypass surgery is a procedure in which a segment of vein taken from the leg or an artery from the chest is grafted to an opening in the side of the normal coronary artery above the obstructed (blocked) segment and then to the normal portion of the artery below the obstruction. Blood then “bypasses” the obstructed segment, much like taking a road detour around a construction site.

Damaged valves can be replaced with mechanical valves made of plastic or Dacron or a biological valve taken from a pig, cow, or human donor.

Cardiac transplantation is the most dramatic means of treating patients with severe heart failure. Although still filled with challenges, the procedure is well accepted around the world and is being performed more often. However, not enough human hearts are available from organ donors.

Living with Heart Disease

Heart disease often represents a turning point in a person’s life. People who formerly led unhealthy, mainly inactive lives may be inspired to change the way they live by eating more healthily, exercising regularly, and quitting smoking.

Chewing the Fat

Experts suggest that it is a good idea for all healthy Americans above the age of two to modify their diets. Among specific suggestions are:

• Reduce total dietary fat to no more than 30 percent of total daily calories.
• Reduce dietary saturated fat and cholesterol: switch from whole to skim milk, reduce the number of egg yolks eaten, avoid solid cooking fats like lard, give up foods containing certain vegetable oils such as palm or coconut oils, and substitute frozen yogurt, sherbet, or ice milk for ice cream.

In the case of a heart attack, full recovery generally takes about four to six weeks, depending on the extent of the injury, the patient’s overall health, and the condition of the rest of the heart. Most people are able to resume regular activities within a few weeks or months. Like all patients with heart disease or damage, those who have had heart attacks need to adopt a healthier lifestyle, including eating a low-fat diet. Most go on to recover and enjoy many more productive years of life.

See also

Diabetes

Dysrhythmia

Endocarditis

Heart Murmur

Hypertension

Obesity

Stroke

Resources

Book

Arnold, Caroline. Heart Disease. Danbury, CT: Franklin Watts, 1992. Describes the heart and circulatory system and both genetic and acquired diseases that can affect the functioning of the heart.

Organizations

American Heart Association, 7272 Greenville Ave, Dallas, TX 75231. http://www.amhrt.org

The National Institutes of Health posts information about heart disease on its website at: http://www.nhlbi.nih.gov/health/public/heart/other/chdfacts.htm

Heart disease

Definition

Heart disease is the narrowing or blockage of the arteries and vessels that provide oxygen and nutrient-rich

blood to the heart. It is caused by atherosclerosis , an accumulation of fatty materials on the inner linings of arteries that restricts blood flow. When the blood flow to the heart is completely cut off, the result is a heart attack because the heart is starved of oxygen.

Description

Heart disease, also called coronary heart disease or coronary artery disease, is the leading cause of death for both men and women in the United States. According to the American Heart Association, deaths from coronary artery disease have declined somewhat since about 1990, but more than 40,000 people still died from the disease in 2000. About 13 million Americans have active symptoms of coronary artery disease.

Heart disease occurs when the coronary arteries become partially blocked or clogged. This blockage limits the flow of blood through the coronary arteries, the major arteries supplying oxygen-rich blood to the heart. The coronary arteries expand when the heart is working harder and needs more oxygen. If the arteries are unable to expand, the heart is deprived of oxygen (myocardial ischemia ). When the blockage is limited, chest pain or pressure called angina may occur. When the blockage cuts off the blood flow, the result is heart attack (myocardial infarction or heart muscle death).

Healthy coronary arteries are open, elastic, smooth, and slick. The artery walls are flexible and expand to let more blood through when the heart needs to work harder. The disease process is thought to begin with an injury to the linings and walls of the arteries. This injury makes them susceptible to atherosclerosis and production of blood clots (thrombosis).

Causes & symptoms

Heart disease is usually caused by atherosclerosis. Cholesterol and other fatty substances accumulate on the inner wall of the arteries. They attract fibrous tissue, blood components, and calcium . They then harden into artery-clogging plaques. Atherosclerotic plaques often form blood clots that can also block the coronary arteries (coronary thrombosis). Congenital defects and muscle spasms of arteries or heart muscles also block blood flow. Recent research indicates that infection from organisms such as chlamydia bacteria may be responsible for some cases of heart disease.

A number of major contributing risk factors increase the chance of developing heart disease. Some of these can be changed and some cannot. The greater the number of risk factors, the greater the chance of developing heart disease.

Major risk factors

Major risk factors significantly increase the chance of developing heart disease. These include:

• Heredity. People whose parents have heart disease are more likely to develop it. African-Americans are also at increased risk because they experience a high rate of severe hypertension .
• Gender. Men are more likely to have heart attacks than women and to have them at a younger age. Over the age of 60, however, women have heart disease at a rate equal to that of men.
• Age. Men who are 45 years of age and older and women who are 55 years of age and older are more likely to have heart disease. Occasionally, heart disease may strike men or women in their 30s. People over 65 are more likely to die from a heart attack. Older women are twice as likely as older men to die within a few weeks of a heart attack.
• Smoking . Smoking increases both the chance of developing heart disease and the chance of dying from it. Smokers are more than twice as likely as nonsmokers to have a heart attack and are two to four times more likely die from it.
• High cholesterol levels. Dietary sources of cholesterol are meat, dairy food, eggs, and other animal fat products. It is also produced by the body. Age, body fat, diet, exercise , heredity, and sex affect one's blood cholesterol. Total blood cholesterol is considered high at levels above 240 mg/dL and borderline at 200-239 mg/dL. High-risk levels of low-density lipoprotein (LDL cholesterol) begin at 130-159 mg/dL, depending on other risk factors. Risk of developing heart disease increases steadily as blood cholesterol levels increase above 160 mg/dL.
• High blood pressure. High blood pressure makes the heart work harder and weakens it over time. It increases the risk of heart attack, stroke , kidney failure, and congestive heart failure. A blood pressure of 140 over 90 or above is considered high. The risk of heart attack or stroke is raised several times for people with high blood pressure combined with obesity , smoking, high cholesterol levels, or diabetes.
• Lack of physical activity. Lack of exercise increases the risk of heart disease. Even modest physical activity, like walking, is beneficial if done regularly.
• Diabetes mellitus. The risk of developing heart disease is seriously increased for diabetics. More than 80% of diabetics die of some type of heart or blood vessel disease.

Contributing risk factors

Contributing risk factors have been linked to heart disease, but their significance is not known yet. Contributing risk factors are:

• Obesity. Excess weight increases the strain on the heart and increases the risk of developing heart disease even if no other risk factors are present. Obesity increases blood pressure and blood cholesterol and can lead to diabetes.
• Hormone replacement therapy (HRT). Even though physicians once believed that HRT could help prevent heart disease in women, the Women's Health Initiative (WHI) released information in 2002 and 2003 showing that use of combined hormones (estrogen and progestin) is harmful in women who already have coronary artery disease.
• Stress and anger. Some scientists believe that poorly managed stress and anger can contribute to the development of heart disease and increase the blood's tendency to form clots (thrombosis). Stress increases the heart rate and blood pressure and can injure the lining of the arteries.
• Chest pain (angina). Angina is the main symptom of coronary heart disease but it is not always present. Other symptoms include shortness of breath, chest heaviness, tightness, pain, a burning sensation, squeezing, or pressure either behind the breastbone or in the left arm, neck, or jaws. According to the American Heart Association, 63% of women and 48% of men who died suddenly of heart disease had no previous symptoms of the disease.

Diagnosis

Diagnosis begins with a visit to the physician, who will take a medical history, discuss symptoms, listen to the heart, and perform basic screening tests. These tests will measure blood lipid levels, blood pressure, fasting blood glucose levels, weight, and other indicators. Other diagnostic tests include resting and exercise electrocardiograms, echocardiography, radionuclide scans, and coronary angiography. The treadmill exercise (stress) test is an appropriate screening test for those with high risk factors even though they feel well.

An electrocardiogram (ECG) shows the heart's activity and may reveal a lack of oxygen (ischemia). Electrodes covered with conducting jelly are placed on the patient's chest, arms, and legs. They send impulses of the heart's activity through an oscilloscope (a monitor) to a recorder that traces them on paper. Another type of electrocardiogram, known as the exercise stress test, measures how the heart and blood vessels respond to exertion when the patient is exercising on a treadmill or a stationary bike. Both tests can be performed in a physician's office or outpatient facility.

Echocardiography, or cardiac ultrasound, uses sound waves to create an image of the heart's chambers and valves. A technician applies gel to a hand-held transducer, then presses it against the patient's chest. The heart's sound waves are converted into an image that can be displayed on a monitor. The test does not reveal the coronary arteries themselves but can detect abnormalities in the heart wall caused by heart disease. Typically performed in a doctor's office or outpatient facility, the test takes 30-60 minutes.

Radionuclide angiography enables physicians to see the blood flow of the coronary arteries. Nuclear scans are performed by injecting a small amount of a radiopharmaceutical, such as thallium, into the bloodstream. As the patient lies on a table, a camera that uses gamma rays to produce an image of the radioactive material passes over the patient and records pictures of the heart. Radionuclide angiography is usually performed in a hospital's nuclear medicine department. The radiation exposure is about the same as that in a chest x ray.

Coronary angiography is considered the most accurate method for making a diagnosis of heart disease but it is also the most invasive. During coronary angiography the patient is awake but sedated. The cardiologist inserts a catheter into a blood vessel and guides it into the heart. A contrast dye (a radiopaque substance that is visible on x ray) is injected into the catheter and x rays are taken. Coronary angiography is performed in a cardiac catheterization laboratory in either an outpatient or inpatient surgery unit.

Treatment

Herbal medicine has a variety of remedies that may have a beneficial effect on heart disease. Garlic (Allium sativum ), myrrh (Commiphora molmol ), oats (Avena sativa ) may help reduce cholesterol and hawthorn (Crataegus spp.), linden (Tilia europaea ), and yarrow (Achillea millefolium ) are sometimes recommended to control high blood pressure, a risk factor for heart disease. Tea, especially green tea (Camellia sinensis ), is high in antioxidants ; studies have shown that it may have a preventative effect against atherosclerosis. Coenzyme Q10 has been shown to be beneficial for 70% of patients with congenitive heart failure. According to Dr. Elson Haas, taurine, an amino acid found in meat and fish proteins, is used to treat heart arrhythmia. Two grams three times a day for people with congestive heart failure showed improved cardiovascular functions.

Yoga and other bodywork, massage, relaxation , aromatherapy, and music therapies may also help prevent heart disease and stop, or even reverse, the progression of atherosclerosis. Vitamin and mineral supplements that reduce, reverse, or protect against heart disease include B-complex vitamins, calcium, chromium, magnesium , L-carnitine, zinc , and the antioxidant vitamins C and E. The effectiveness of vitamins C and E is still under debate, and physicians caution that they be used in moderation.

Traditional Chinese medicine (TCM) may recommend herbal remedies, massage, acupuncture , and dietary modification. A healthy diet (including cold water fish as a source of essential fatty acids ) and exercise are important components of both alternative and conventional prevention and treatment strategies.

New reports on diet and heart disease have answered some questions, but others remain unclear. While one study concludes that four servings per day of fruit and vegetables are associated with a slight drop in risk of heart disease, eight or more servings per day can produce a significant drop in risk. Another study showed that consuming legumes at least four times per week lowered risk of heart disease from 11% to 22% compared with consuming legumes less than once a week. Research on antioxidants continues to send mixed messages, with some reports showing that vitamins E, C, and other antioxidants can help prevent heart disease, and other studies showing they have no effect. Many physicians and researchers therefore recommend that those wanting to follow healthy heart habits continue to eat a diet rich in antioxidants but recognize that there is probably no value in adding antioxidant supplements to a good diet.

Allopathic treatment

Heart disease can be treated in many ways. The choice of treatment depends on the patient and the severity of the disease. Treatments include lifestyle changes and drug therapy, coronary artery bypass surgery, and percutaneous transluminal coronary angioplasty, although these are not cures. Heart disease is a chronic disease requiring lifelong care.

Percutaneous transluminal coronary angioplasty, usually called coronary angioplasty, is a nonsurgical procedure. A catheter tipped with a balloon is threaded from a blood vessel in the thigh into the blocked artery. The balloon is inflated, compressing the plaque to enlarge the blood vessel and open the blocked artery. The balloon is then deflated and the catheter removed.

People with moderate heart disease may gain adequate control through lifestyle changes and drug therapy. Drugs such as nitrates, beta-blockers, and calcium-channel blockers relieve chest pain and complications of heart disease, but they cannot clear blocked arteries. Nitrates improve blood flow to the heart, and beta-blockers reduce the amount of oxygen required by the heart during stress. Calcium-channel blockers help keep the arteries open and reduce blood pressure.

Aspirin helps prevent blood clots from forming on plaque deposits, reducing the likelihood of a heart attack and stroke. Cholesterol-lowering medications are also indicated in most cases.

Coronary angioplasty is successful about 90% of the time, but for one-third of patients the artery narrows again within six months. The procedure can be repeated. It is less invasive and less expensive than coronary artery bypass surgery.

In coronary artery bypass surgery, a healthy vein from an arm, leg, or chest wall is used to build a detour around the coronary artery blockage. The healthy vessel then supplies oxygen-rich blood to the heart. Bypass surgery is major surgery. It is appropriate for those patients with blockages in two or three major coronary arteries, those with severely narrowed left main coronary arteries, and those who have not responded to other treatments. About 70% of patients who have bypass surgery experience full relief from angina; about 20% experience partial relief. Only about 3-4% of patients per year experience a return of symptoms.

Three other surgical procedures for unblocking coronary arteries are being studied and used on a limited basis. Atherectomy is a procedure in which the cardiologist shaves off and removes strips of plaque from the blocked artery. In laser angioplasty, a catheter with a laser tip is inserted into the affected artery to burn or break down the plaque. A metal coil called a stent can be implanted permanently to keep a blocked artery open. Stenting is becoming more common.

Expected results

Advances in medicine and the adoption of healthier lifestyles have caused a substantial decline in death rates from heart disease since the mid-1980s. New diagnostic techniques enable doctors to identify and treat heart disease in its earliest stages. New technologies and surgical procedures have extended the lives of many patients who would have otherwise died. Research on heart disease continues.

Prevention

A healthy lifestyle can help prevent heart disease and slow its progress. A heart-healthy lifestyle includes maintaining a healthy diet, regular exercise, weight maintenance, no smoking, moderate drinking, controlling hypertension, and managing stress. Cardiac rehabilitation programs are excellent to help prevent recurring coronary problems for people who are at risk and who have had coronary events and procedures.

Eating right

A healthy diet includes a variety of foods that are low in fat, especially saturated fat, low in cholesterol, and high in fiber. It includes plenty of fruits and vegetables and limited salt. Saturated fats should equal seven to 10% of calories, polyunsaturated fats should equal about 10%, monounsaturated fat should be 15%, and carbohydrates should total 55-60% of daily calories. Fat should comprise no more than 30% of total daily calories and should be taken preferably as fish oil , olive oil, seeds, and vegetable oil. New evidence shows that replacing saturated fat with unsaturated fat is more effective in lowering coronary heart disease risk than reducing total fat intake. Eating cold-water fish or taking comparable omega-3 polyunsaturated fatty acid supplements can help prevent cardiac death. In 2003, the American Heart Association began advocating daily servings of fatty fish or three fish oil capsules daily.

Cholesterol, a waxy substance containing fats, is found in foods such as meat, dairy, eggs, and other animal products. It is also produced in the liver. Soluble fiber can help lower cholesterol. Dietary cholesterol should be limited to about 300 milligrams per day. Many popular lipid-lowering drugs can reduce LDL cholesterol by an average of 25-30% when used with a low-fat, lowcholesterol diet.

Antioxidants are chemical compounds in plant foods. When people eat antioxidant-rich foods, they may improve the function of the arteries, prevent arterial plaque formation, and reduce their risk of cancer . Colorful vegetables and fruits are sources of antioxidants, and are rich in fiber, vitamins, and minerals. They are lowcalorie and nearly fat-free. Vitamin C and beta-carotene, found in many fruits and vegetables, keep LDL-cholesterol from turning into a form that damages coronary arteries. Whole grains, especially whole oats and oat bran, reduce cholesterol.

Excess sodium can increase the risk of high blood pressure. Many processed foods contain large amounts of sodium. Daily intake should be limited to about 2,400 milligrams, about the amount in a teaspoon of salt.

The Food Guide Pyramid developed by the U.S. Departments of Agriculture and Health and Human Services provides easy-to-follow guidelines for daily heart-healthy eating.

Exercising regularly

Aerobic exercise can lower blood pressure, help control weight, and increase HDL (good) cholesterol. It also may keep the blood vessels more flexible. The Centers for Disease Control and Prevention and the American College of Sports Medicine recommend moderate to intense aerobic exercise lasting about 30 minutes four or more times per week for maximum heart health. People with heart disease or risk factors should consult a doctor before beginning an exercise program.

Maintaining a desirable body weight

People who are 20% or more over their ideal body weight have an increased risk of developing heart disease. Losing weight can help reduce total and LDL cholesterol, reduce triglycerides, and boost HDL cholesterol. It may also reduce blood pressure. Eating right and exercising are two key components of losing weight.

Quitting smoking

Smoking has many adverse effects on the heart. It increases the heart rate, constricts major arteries, and can create irregular heartbeats. It also raises blood pressure, contributes to the development of plaque, increases the formation of blood clots, and causes blood platelets to cluster and impede blood flow. When smokers quit the habit, heart damage can be repaired. Several studies have shown that ex-smokers face the same risk of heart disease as nonsmokers within five to 10 years after they quit.

Drinking in moderation

Modest consumption of alcohol may actually protect against heart disease because alcohol appears to raise levels of HDL cholesterol. The American Heart Association defines moderate consumption as one ounce of alcohol per day, roughly one cocktail, one 8-ounce glass of wine, or two 12-ounce glasses of beer. Excessive drinking is always bad for the heart. It usually raises blood pressure and can poison the heart and cause abnormal heart rhythms or even heart failure.

Seeking diagnosis and treatment for hypertension

High blood pressure, one of the most common and serious risk factors for heart disease, can be completely controlled through lifestyle changes and medication. Seeking out the diagnosis and treatment is critical because hypertension often exhibits no symptoms; many people do not know they have it. Moderate hypertension can be controlled by reducing dietary intake of sodium and fat, exercising regularly, managing stress, abstaining from smoking, and drinking alcohol in moderation.

KEY TERMS

Plaque

—A deposit of fatty substances and calcium that accumulates in the lining of the artery wall.

Managing stress

Everyone experiences stress. Stress can sometimes be avoided and, when it is inevitable, it can be managed through relaxation techniques, exercise, and other methods.

Resources

BOOKS

American Heart Association. 2000 Heart and Stroke Statistical Update. Dallas, TX.: American Heart Association, 1999.

DeBakey, Michael E., and Antonio M. Gotto, Jr. Heart disease, and Surgical Treatment of Heart disease. In The New Living Heart. Holbrook, MA: Adams Media Corporation, 1997.

Haas, Elson, M.D. Staying Healthy with Nutrition: The Complete Guide to Diet and Natural Medicine. Berkeley, CA: Celestial Arts, 1992.

Ody, Penelope. The Complete Medicinal Herbal. New York: DK Publishing. 1993.

PERIODICALS

Cerrato, Paul L. "Antioxidants, CAD, and Diabetes." Contemporary OB/GYN (January 2002): 111.

Dioreto, Stacy. "Legume Intake Lowers CHD Risk." Patient Care (January 30, 2002): 41.

"For Fighting Heart Disease, Vitamins C and E Fall Short." Tufts University Health and Nutrition Newsletter (January 2003): 2.

Mirzaei, H.A. "Role of Soy Protein in Lowering LDL Levels." The Journal of Nutrition (March 2002): 604S.

Sadovsky, Richard. "Omega-3 Fatty Acids and CHC Prevention." American Family Prevention (March 1, 2002): 952.

Wellbery, Caroline. "No HRT or Antioxidants in Women with Coronary Disease." American Family Physician (March 15, 2003): 1371.

Zoler, Michael L. "Heart Association Advocates Fish Oil Supplements." Family Practice News (January 15, 2003): 6.

ORGANIZATIONS

American Heart Association. National Center. 7272 Greenville Avenue, Dallas, Texas 75231. 1-800-AHA-USA1. <http://www.americanheart.org>.

OTHER

Lycos Health with Web MD. "Antioxidants." http://webmd.lycos.com/content/dmk/dmk_article_6463016.

Masley, Dr. Steven, M.D. The Vitality Center. http://www.drmasley.com/index.htm.

Paula Ford-Martin

Teresa G. Odle

Heart Disease

The heart, which is about the size of a human fist, is the body's largest, strongest, and most important muscle. The heart continuously pumps blood through the body, helps regulate and prolong health, and controls the flow (circulation) of blood to the lungs, organs, muscles, and tissues in the body.

Heart disease is a leading cause of debilitation and death worldwide in men and women over age sixty-five. In many countries heart disease is viewed as a "second epidemic," replacing infectious diseases as the leading cause of death. It is especially devastating in countries that do not have adequate health care. There are many types of diseases and disorders that affect the heart.

Congenital Heart Disease

Congenital cardiac anomaly (CAA), also known as congenital heart disease (CHD), refers to any structural defect of the heart or major vessels that exists from birth. It is the most common cause of infant death, other than problems of prematurity, and death is likely to occur in the first year of life. CAA may result either from genetic causes or from external causes such as maternal infection or exposure to other factors that affect embryonic development . The general problems associated with CAA include increased cardiac workload, hypertension , poor oxygenation of blood, and respiratory infections. There are many types of CAA, including aortic stenosis, atrial septal defect, valvular stenosis, and pulmonary stenosis.

Rheumatic Heart Disease

Rheumatic heart disease (RHD) involves damage to the heart and heart vessels caused by rheumatic fever. A susceptible person acquires a streptococcal infection, which may trigger an autoimmune reaction in the heart tissue. Rheumatic fever can cause swelling (inflammation) in the heart, joints, brain, and spinal cord. Rheumatic fever produces fatigue (tiredness) and the infection can damage or weaken heart valves. Problems with the heart may be evident early, or it may occur long after the infection. RHD is characterized by heart murmurs, abnormal pulse rate and rhythm, and congestive heart failure. Acute RHD requires aggressive treatment to prevent heart failure. Chronic RHD requires continuous observation. If poor cardiac function develops, it may be treated with a low-sodium diet and diuretics . Patients with deformed heart valves should be given prophylactic antibiotics before dental and surgical procedures.

Myocardial Infarction (MI)

Myocardial infarction (MI) is the clinical term for a heart attack . It is caused by occlusion (blockage) of the coronary artery (atherosclerosis ) or a blood clot (coronary thrombosis), resulting in the partial or total blockage of one of the coronary arteries. When this occurs, the heart muscle (myocardium) does not receive enough oxygen . If the MI is mild, the heart muscle may partially repair itself. Permanent damage may occur when a portion of the heart muscle dies (called an infarction).

MI is characterized by crushing chest pains that may radiate to the left arm, neck, or upper abdomen (which may feel like acute indigestion or a gallbladder attack). The affected person usually has shortness of breath, ashen color, clammy hands, and faints. Treatment within one hour of the heart attack is important and usually includes chewing aspirin and administering CPR. Many individuals die each year of their first MI.

Coronary Artery Disease (CAD)

Coronary artery disease (CAD) refers to any one of the conditions that affect the coronary arteries and reduces blood flow and nutrients to the heart. It is the leading cause of death worldwide for both men and women. The most common kind of CAD is atherosclerosis, which results in narrowing and hardening of the arteries. Coronary atherosclerosis is at epidemic proportions worldwide.

Traditionally, CAD was seen as a disease of aging and was observed primarily in the elderly. However, atherosclerosis is now occurring more often in younger populations. One out of every three individuals worldwide, and one in five in the United States, dies from heart disease each year. In the United States, CAD has declined more rapidly in whites than in blacks. CAD affects women ten years later than men, mostly due to the protective production of estrogen . After menopause , a woman is two times more susceptible to heart disease than women who have not reached menopause.

Risk factors. Controlled risk factors associated with CAD include hypertension; cigarette smoking; elevated blood lipids (e.g. cholesterol , triglyceride ); a high-fat diet (especially saturated fats and trans-fatty acids ); physical inactivity; obesity ; diabetes ; and stress . Lifestyle changes can assist in prevention of CAD. Uncontrolled risk factors include a family history of CAD, gender (higher in males), and increasing age.

Tobacco use is one of the leading contributors to heart disease. Smoking increases the risk of heart attacks (and increases the risk of lung diseases) by decreasing oxygen flow to the heart and lungs. Hypertension, which makes the heart work harder than normal, can be caused by poor diet, excessive dietary salt, lack of exercise, smoking, and chronic stress. Adult-onset diabetes mellitus may result from poor dietary habits and lack of exercise over a lifetime. Uncontrolled diabetes can lead to heart failure. Exercise can reduce the risk for CAD by increasing coronary blood flow, and it has shown positive effects on blood flow to the heart (myocardial perfusion). Long-term benefits of exercise include lower incidences of coronary heart failure and increased cardiac function in normal subjects.

Prevention. Health professionals recommend that dietary fat be reduced to 30 percent or less of total calories . The diet also should have no more than 10 percent of its calories from saturated fats, no more than 300 milligrams (mg) of cholesterol daily, no more than 2,400 mg of sodium, and at least 3,500 mg of potassium. A plant-based diet consisting primarily of whole grains, fruits, and vegetables is recommended. Eating at least 25 grams of fiber and five servings of fruits and vegetables daily may reduce the risk for heart disease.

Individuals who consume alcohol should do so in moderation. Moderation is defined as two drinks for men and one drink for women daily. Alcohol is a very addictive substance, however, and should not be used as a primary means of prevention. Caffeine in moderation has no adverse effect; however, excessive intake may make the heart pump faster. Increased heart rate stresses the heart and may cause long-term damage to blood vessels.

Establishing good exercise and dietary habits early in childhood is important to prevent heart disease. Regular activity and proper nutrition decreases reactivity to stress and makes the heart stronger and more efficient. At least thirty minutes of moderate exercise daily is recommended to prevent heart disease. Stress management helps to prevent high blood pressure , which is a major contributor to heart disease. Techniques such as yoga, deep breathing, and meditation may prevent coronary disease by improving resistance to stress.

see also Arteriosclerosis; Atherosclerosis; Cardiovascular Diseases; Exercise.

Teresa Lyles

Bibliography

Goldberg, I. J.; Mosca, L.; Piano, M. R.; and Fisher, E. A. (2001). "Wine and Your Heart: A Science Advisory for Healthcare Professionals from the Nutrition Committee, Council on Epidemiology and Prevention, and Council on Cardiovascular Nursing of the American Heart Association." Circulation 103:472–475.

Insel, P. M., and Roth, W. T. (2004). "Cardiovascular Disease and Cancer." In Core Concepts in Health, 9th (brief) edition. New York: McGraw-Hill.

Mosby's Medical, Nursing, and Allied Health Dictionary, 6th edition (2003). St. Louis, MO: American Dietetic Association.

Internet Resources

American Heart Association. "Congenital Heart Defects in Children Fact Sheet." Available from <http://www.americanheart.org>

American Heart Association/American Stroke Association. "Heart Disease and Stroke Statistics—2003 Update." Available from <http://www.americanheart.org>

"Description of Congenital Heart Defects." Available from <http://www.congenitalheartdefects.com/typesofcad.html>

"Heart Attack." Available from <http://www.heartcenteronline.com/myheartdr>