Is there any difference between a heart attack and cardiac arrest?
Cardiac arrest is stoppage of effective pumping of the heart. It could be due to ventricular asystole (no electrical activity) or fibrillation (fast irregular ineffective activity). Rarely a pulseless electrical activity also manifests as cardiac arrest. Heart attack means a region of the heart is suddenly deprived of blood supply due to blockage of the artery supplying blood to the region. It is known as myocardial infarction and can sometimes lead to cardiac arrest due to electrical instability of the myocardium deprived of oxygen. But most cases of heart attack are not associated with cardiac arrest as the heart continues to pump blood by the work of the remaining heart muscle. Cardiac arrest is immediately fatal unless immediate cardiopulmonary resuscitation is started.