What is a Heart Attack?

The words heart attack can bring vivid images to mind. One pictures someone sweaty or pale, who complains of severe chest pains, nausea or shortness of breath. You may know what a heart attack looks like, but do you know what it is or how it occurs? A heart attack, or myocardial infarction, is caused by a complete blockage of an artery that supplies blood to an area of the heart.

In a heart attack, the heart muscle does not get enough blood nutrients and oxygen to survive. When pain persists for more than 30 minutes, irreversible damage of the heart muscle begins to occur. The longer the artery is blocked, the greater the amount of heart damage, though studies show that re-establishment of blood flow from 30 minutes up to 6 to 12 hours may save heart muscle.

Most heart attacks are caused by coronary artery disease (CAD), which is a build up of fat and cholesterol, depositing plaque in the arteries that supply blood to the heart muscle. A heart attack occurs when a blood clot forms at the site of cholesterol plaque. The blood clot may then grow to block off the artery and prevent blood flow.

Since CAD is the principle cause of a heart attack, factors that contribute to CAD also increase the risk of a heart attack. These factors include age, smoking, inactive lifestyle, family history, and other diseases like diabetes. An aggressive program to stop smoking, control hypertension, diabetes and cholesterol. and implement changes in lifestyle to include healthy eating and regular exercise is crucial to continued good health.

Recent studies show that estrogen replacement therapy may help to reduce the possibility of heart attacks among women. In the March 1996 issue of the Harvard Heart Letter, it is reportée that estrogen replacement lowered the risk of CAD by 44% amon^ postmenopausal women. However, the benefits of estroger must be weighed against the risks of breast and uterine cancer although this risk may be substantially reduced by the use of progesterone.