We’ve seen enough of it in movies, a person clutching his chest and people around him running frantically trying to get help and the final pronouncement being made by a doctor – heart attack. What is a heart attack? What happens during an attack? Are all heart attacks fatal? Here’s a bird’s eye view of what takes place.

Broadly speaking, a heart attack occurs when the blood flow to a part of the heart is blocked, often by a blood clot. What actually happens is that a part of the heart muscle dies owing to a sudden loss of blood supply, caused by a spasm or blockage of a coronary artery (an artery that supplies blood to the heart muscle) by a blood clot. In medical terms, a heart attack is called myocardial infarct (death of a muscle in the heart). The death of the heart muscle is what causes the chest pain. It also causes electrical instability of the heart muscle tissue. That is, the electric signals that are transmitted in an orderly manner for the heart to pump regularly are rendered chaotic. This may lead to ventricular fibrillation, which causes the heart to quiver and makes it incapable of pumping oxygenated blood to the brain. This is the reason help needs to be summoned instantly. For, in extreme cases, it can cause death, or the irregular supply of oxygen to the brain can cause permanent damage to it. It is vital that oxygenated blood flow is restored within five minutes.

Where does the clot form?
Cholesterol is the fatty chemical portion of the outer lining of body cells. Usually, the blood clot forms on a cholesterol plaque anywhere in the body. Over a period of time, the accumulation of cholesterol plaque causes the artery walls to become thick and the arteries subsequently become narrow. This is known as atherosclerosis. Smoking, high blood pressure, increased cholesterol level and diabetes increase the possibility of artherosclerosis.

Sometimes, the surface of the cholesterol plaque in the artery may rupture, leading to the formation of blood clot on the surface of the plaque, which then completely blocks blood flow in the vessel and results in a heart attack.

What are the signs and symptoms?
A very common symptom of heart attack is chest pain. It may be an intense pain or a vague dull pain. The patient may experience heaviness or simply discomfort. He also suffers sweating, pain in the arm, nausea, shortness of breath and, sometimes, even pain in the jaw.