Heart Attacks Caused by Infections?

(December 26, 1997) - The way a heart attack (myocardial infarction) comes about is clear. It involves the death of part of the heart muscle (myocardium) due to blockage of a coronary artery delivering nutrients and oxygen to the myocardium. Blockage of the coronary artery is commonly caused by a clot that forms on the inner wall of the artery at the site of damage by atherosclerosis, the accumulation of cholesterol deposits on the walls of the artery. These cholesterol deposits cause hardening and thickening of artery walls and narrowing of their interior diameter.

Some of the risk factors for atherosclerosis and heart attacks are also quite well known. They include a high blood cholesterol (especially, an elevated level of the "bad" LDL cholesterol), high blood pressure (hypertension), diabetes mellitus, cigarette smoking, and a family history of coronary artery disease. There is considerable evidence that an elevated blood level of the amino acid homocysteine may be a risk factor, too.