You may often hear the terms “heart attack” and “cardiac arrest” used interchangeably. In fact, they are distinct conditions.
A heart attack, clinically called a myocardial infarction, results when a narrowed or blocked artery obstructs blood flow to an area of the heart. This lack of blood flow causes injury or death to portions of the heart. Symptoms include chest or upper-body pain, fatigue, weakness, nausea, and shortness of breath. The person will have a pulse and typically not lose consciousness. However, a heart attack can cause cardiac arrest.
Cardiac arrest results from an electrical malfunction that causes the heart to suddenly stop pumping, rather than from a clot or blockage that prevents blood flow. Cardiac arrest very quickly results in loss of consciousness with no pulse, and most sufferers will die without immediate action to perform cardiopulmonary resuscitation and defibrillation to shock the heart back into rhythm.