A myocardial infarction, also called a heart attack, occurs when the flow of blood to the heart is blocked.
The blockage is most often a buildup of fat, cholesterol and other substances, which form a plaque in the arteries that feed the heart (coronary arteries).
The plaque eventually breaks away and forms a clot. The interrupted blood flow can damage or destroy part of the heart muscle.
There are two main causes of myocardial infarction, and they are:
- Coronary artery disease, causing most heart attacks.
- A spasm of a coronary artery - using tobacco and illicit drugs, such as cocaine, can cause a life-threatening spasm.