Heart Disease Health Article

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.