Myocardial Infarction

A myocardial infarction — commonly known as a heart attack — occurs when blood flow to a section of heart muscle is blocked for long enough that the muscle tissue begins to die. The blockage is almost always caused by a blood clot that forms when an atherosclerotic plaque in a coronary artery ruptures, suddenly obstructing the vessel.

The heart muscle requires a constant supply of oxygen-rich blood to function. When a coronary artery is blocked, the portion of heart muscle it supplies is starved of oxygen (a state called ischemia). If blood flow is not restored quickly — typically within minutes to hours — the affected heart tissue sustains permanent damage or dies. The extent of damage depends on which artery is blocked, how much muscle it supplies, and how quickly treatment is received.

Heart attacks are medical emergencies. The classic symptoms include chest pain or pressure (often described as a squeezing, heaviness, or tightness), pain radiating to the left arm, jaw, back, or stomach, shortness of breath, cold sweats, nausea, and lightheadedness. However, symptoms can vary significantly — particularly in women, who are more likely to experience atypical symptoms like unusual fatigue, nausea, and back or jaw pain without the classic chest pressure.

Knowing the warning signs of a heart attack could save your life or the life of someone you love. If you or anyone experiences symptoms suggestive of a heart attack, call emergency services immediately — do not drive yourself to the hospital. Modern treatments can restore blood flow and minimize heart damage, but they are most effective when administered within the first 1-2 hours of symptom onset.

After a heart attack, cardiac rehabilitation — a supervised program of exercise, education, and counseling — is one of the most effective interventions for reducing the risk of a second event and improving quality of life. Unfortunately, fewer than a third of eligible patients participate in cardiac rehab.