What is a Heart Attack? A heart attack (clinically known as a myocardial infarction) occurs when the crucial flow of oxygen-rich blood to a part of the heart muscle is suddenly blocked, usually by a blood clot. "Time is Muscle": Every single minute that the artery remains blocked, more of the heart tissue permanently dies. Immediate emergency medical treatment is absolutely critical to survival and recovery. ⚠️ MEDICAL EMERGENCY If you or someone else suspects a heart attack, call 911 (or your local emergency services) immediately. Do not attempt to drive yourself to the hospital unless there are absolutely no other options. Paramedics can begin life-saving treatments and heart monitoring the moment they arrive in the ambulance. Symptoms Not everyone clutches their chest and collapses to the floor like in the movies. Symptoms can vary wildly, and they often present very differently between men ...