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Heart Diseases

Future Challenges

Though knowledge about the treatment and prevention of heart disease has expanded dramatically, heart disease remains an immense threat. A total of 925,000 Americans die each year of cardiovascular disease, a general category which includes heart disease, stroke, and high blood pressure, all of which are linked. The biggest killer is coronary heart disease, which claimed 480,170 U.S. deaths in 1992. Stroke and hypertension together killed about 180,000 and artery diseases killed 40,730.

Many more people suffer than die from heart disease. For example, a total of 5.6 million Americans had angina pectoris in 1992, and 1,290 people died from it, according to the AHA. As many as 11.2 million Americans have a history of heart attack, chest pain, or both. While 39,206 Americans died of heart failure in 1991, more than 800,000 Americans were discharged from the hospital after treatment for the problem in 1992.

Approximately 250,000 Americans die sudden and unexpected deaths due to heart disease each year, the AHA reports. Such findings support the need for educational efforts about heart disease and for the expansion of emergency care for heart attack victims.

Genetic therapy for heart disease is considered a fertile area for progress. In 1994, surgeons performed a procedure on a woman who had a genetic defect that prevented her liver from removing adequate amounts of LDL cholesterol. She had suffered a heart attack at age 16. The procedure, which took place in Michigan, involved the insertion of genetically modified cells in her liver, to enable the organ to remove LDL cholesterol properly. With the new cells, her heart should no longer be threatened by high levels of cholesterol.

Though much is known about risk factors for heart disease, new theories will continue to be tested in the future. For example, various studies have shown that individuals who eat large amounts of fish (especially containing particular oils called omega-3 fatty acids) or who consume vitamin E have a lower than average rate of coronary heart disease. But more ambitious studies are needed to confirm this information.

Researchers are also looking carefully at women and heart disease, a topic which has been overshadowed by research concerning men and heart disease in the past. Certain estrogen/progestin supplements that were thought to reduce the risk of heart disease in postmenopausal women were found to actually increase the number of heart attacks in a long-term study published in 2002 by the NIH (National Institutes of Health).

Additionally, scientists are studying the correlation between levels of a protein in the blood known as known as C-reactive protein (CRP) and heart disease. Blood levels of C-reactive protein increase in the presence of systemic (throughout the body) inflammation, and increased CRP levels have been linked to heart attack and stroke. With elevated levels of CRP indicating blood vessel inflammation, the white blood cells are stimulated and may cause fatty cholesterol deposits to break from the vessel walls and clog arteries. Inflamed artery walls may also release greater portions of the weakened plaques, causing stroke. Elevated CRP is considered a predictor of heart disease even in the absence of other risk factors such as obesity, high blood pressure, or smoking, and may indicate heart disease even before symptoms are present. A blood test is becoming widely available to detect CRP levels.

In 1998, the American Heart Association published its third list of what it considers to be the most promising research areas in heart disease. These included: gene therapy which could potentially encourage the growth of new blood vessels to and from the heart, thus bypassing diseases vessels; the discovery of new "super aspirins" which seem to have even greater protective effects for both heart attack and stroke; more data to support the association between inflammation and heart attacks; better techniques for early detection of obstructed vessels in the heart (using magnetic resonance imaging, or MRI); hope that damaged left ventricular muscle can regain better functioning, if a mechanical device called a left ventricular assist device (LVAD) takes over the work of the left ventricle for a time; further evidence that tobacco is a crucial risk factor in the development of heart disease, as evidenced by research which showed that as few as 10 cigarettes a day shortens life; more research supporting the importance of diet and exercise on levels of cholesterol in the blood; efforts to encourage people to seek treatment more quickly when a heart attack is suspected; the association between non-responsiveness to nitric oxide, and the development of high blood pressure.

Over the past century, researchers have made huge advances in the understanding, treatment, and prevention of heart disease. For the first time in history, medicine has acquired the tools to provide many individuals who suffer from heart disease with active, full lives. Being born with a faulty heart is no longer a reason to live a sedentary, shortened life. Yet even as the medical profession has gained skill in healing, preserving, and even replacing the failing heart, this crucial organ remains vulnerable.

Resources

Books

Bulpitt, C.J. Epidemiology of Hypertension. Series: Handbook of Hypertension. Vol. 20. Amsterdam: Elsevier, 2000.

Crawford, M.H., and J.P. DiMarco, ed. Cardiology. London: Mosby Limited Ltd., 2000.

Grubb, N., and D. Newby. Churchill's Pocketbook of Cardiology. London: Churchill Livingstone, 2000

Grundy, S.M., ed. Cholesterol-Lowering Therapy—Evaluation of Clinical Trial Evidence. New York: Dekker, 2000

Katz, A.M. Physiology of the Heart. 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 2000

Periodicals

Avezum Jr., Alvaro, Marcus Flather, and Salim Yusuf. "Recent Advances and Future Directions in Myocardial Infarction." Cardiology 84 (1994): 391-407.

Detjen, Jim. "U.S. Scientists Successfully Treat Patient with Gene Therapy." Knight-Ridder-Tribune News Service (March 31, 1994).

"A Heart Disease Checkup." Tufts University Diet and Nutrition Letter (September 1993): 2.


Patricia Braus

KEY TERMS

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Angina pectoris

—Chest pain that occurs when blood flow to the heart is reduced, causing a shortage of oxygen. The pain is marked by a suffocating feeling.

Auricular fibrillation

—Now known as atrial fibrillation; a condition marked by the irregular contraction of the atrial heart muscle.

Coronary artery disease, or ischemic heart disease

—Common cause of death due to heart attack, which results from narrowing or blockage of the coronary arteries. The disease can also cause angina.

Coronary thrombosis

—A potentially fatal event in which the coronary artery is blocked by a thrombus, a clot of platelets and other blood factors which can prevent the passage of blood.

Electrocardiogram (ECG)

—A picture of the operation of the heart, obtained by measuring the electric potential of the heart muscle.

Heart block

—Impairment of the electrical signal which controls the heart's activity.

Heart failure

—A clinical syndrome which takes place when the heart's activity no longer meets the body's needs. Congestive heart failure is marked by water retention and breathlessness.

Stenosis

—The narrowing of a canal or duct.

Additional topics

Science EncyclopediaScience & Philosophy: Habit memory: to HeterodontHeart Diseases - Early Knowledge, The Middle Ages, The Artful Heart, Explosion Of Knowledge, The Critical Arteries