What Is A Heart Attack?

A heart attack results when there is a sudden drop in the supply of oxygen and blood to a particular section of heart muscle. According to the National Institutes of Health of the Department of Health & Human Services, heart attacks are the leading cause of death in the United States.

Most heart attacks are due to a condition called coronary artery disease or CAD. The coronary arteries supply oxygen and blood to the heart. Plaque builds up over the years on the inside walls of the coronary arteries – as a result of bad eating habits, lack of exercise, smoking and other conditions. A blood clot forms when a portion of plaque ruptures. This clot increases in size and partially or wholly blocks off the artery, and consequently the supply of oxygen and blood to a particular portion of the heart. This blockage results in a heart attack.

Problems linked with heart attacks include irregular heartbeats (arrhythmias) and heart failure. Arrhythmia is the condition when the heart beats slower (bradycardia) or faster (tachycardia) than its normal heart rate. Heart attacks can bring on life threatening arrhythmias and can disrupt the flow of oxygen and blood to essential organs, including the heart and the brain. Heart attacks cause heart failure, which is the inability of the heart to supply enough oxygen and blood to the body.

Symptoms of heart attacks include chest pain or discomfort; upper body discomfort in the jaw, neck, back or stomach; shortness of breath; vomiting, nausea, fainting and lightheadedness; and uncomfortable contractions in the central portion of the chest. Heart attacks are most effectively treated if help is sought immediately, preferable within the first five minutes of the beginning of symptoms.
 

Reference:

U.S. Department of Health & Human Services, National Institutes of Health