Many people confuse heart attacks with cardiac arrests, but they are very different.
A heart attack is a circulatory problem that results when blood flow to the heart is suddenly stopped due to a blocked artery, usually causing symptoms like chest discomfort, sweating, and shortness of breath. A cardiac arrest arises when an electrical malfunction in the heart leads to an arrhythmia that causes the heart to suddenly stop beating.
While a heart attack victim may experience immediate discomfort, generally their symptoms will worsen over hours and the vast majority of these people do not die. A victim of cardiac arrest will become unresponsive within seconds and die within minutes if they do not receive treatment. A very small percentage of heart attack victims—10-20%–may secondarily go into cardiac arrest. For either situation, call 911 right away.