Myocardial Infarction

Synonyms

Acute coronary syndrome; Heart attack; MI

Definition

A myocardial infarction (MI) (or acute myocardial infarction (AMI), or “heart attack”) occurs when there is a sudden disruption of blood supply to the heart, causing death of the heart muscle.

Current Knowledge

This condition most commonly results from occlusion by an atherosclerotic plaque of one or more coronary arteries that supply the heart, causing inadequate supply of oxygen and nutrients and giving rise to infarction or death of the heart muscle tissue (myocardium). While the usual symptoms of MI include crushing or pressure-like chest pain, at times radiating to the neck and left arm, associated with nausea, diaphoresis (sweating), palpitation, dyspnea (shortness of breath), and anxiety, symptoms may be atypical, or even absent (occurs in about one-quarter of patients with MI, known as a “silent MI” and occurs in patients with diabetes). It usually occurs in patients with known “risk factors,” that is, hypertension,...