MYOCARDIAL INFARCTION (HEART ATTACK)

PRERNA FOR IAS

MYOCARDIAL INFARCTION (HEART ATTACK)

1. Definition of Myocardial Infarction (Heart Attack)

Myocardial Infarction (MI), commonly known as a heart attack, is the irreversible death (necrosis) of heart muscle due to prolonged interruption of blood supply to the heart. It usually occurs when a coronary artery becomes blocked by a blood clot formed after the rupture of an atherosclerotic plaque. Without oxygen-rich blood, heart muscle cells begin to die within minutes. Myocardial infarction is a life-threatening medical emergency requiring immediate treatment to restore blood flow and minimize heart damage. Early recognition and rapid medical intervention significantly improve survival, reduce complications, and preserve the heart's pumping function.

2. Causes of Myocardial Infarction

The most common cause of myocardial infarction is atherosclerosis, in which fatty plaques accumulate inside the coronary arteries. When a plaque ruptures, a blood clot forms and blocks blood flow to the heart muscle. Other causes include coronary artery thrombosis, coronary artery spasm, and, rarely, coronary artery embolism, where a clot travels from another part of the body. Less common causes include severe anemia, cocaine abuse, and spontaneous coronary artery dissection. Identifying the underlying cause is essential for proper treatment and prevention of future heart attacks. Lifestyle changes and medications help reduce these risks.

3. Risk Factors of Myocardial Infarction

Several risk factors increase the likelihood of developing myocardial infarction. Smoking damages blood vessels and promotes plaque formation. Hypertension increases pressure on artery walls, while high cholesterol accelerates atherosclerosis. Diabetes mellitus damages blood vessels and increases clot formation. Other important risk factors include obesity, sedentary lifestyle, increasing age, and a family history of heart disease. Poor diet, excessive alcohol intake, and chronic stress also contribute. Many of these factors are preventable through healthy eating, regular exercise, maintaining a healthy weight, controlling blood pressure and blood sugar, and avoiding tobacco use.

4. Pathophysiology of Myocardial Infarction