What is a myocardial infarction?

What is a myocardial infarction?

• A. Atrial fibrillation
• B. A heart attack caused by sudden and complete occlusion of a coronary artery, depriving the myocardium of oxygen
• C. Chronic heart failure due to valve disease
• D. Pericarditis

Answer: (B)

A myocardial infarction is a heart attack caused by a sudden, complete blockage of a coronary artery, which stops blood flow and deprives the heart muscle of oxygen. When the artery is obstructed, the affected area becomes ischemic; without prompt restoration of blood supply, heart muscle cells begin to die (necrosis). This blockage is most often due to a ruptured atherosclerotic plaque that triggers rapid thrombosis. The resulting infarction can be transmural if the full thickness of the wall is involved, and its recognition is supported by symptoms, ECG changes, and cardiac enzyme release. In contrast, atrial fibrillation is an abnormal heart rhythm, chronic heart failure from valve disease is a long-term pump failure, and pericarditis is inflammation of the heart’s surrounding sac. The defining feature here is irreversible myocardial cell death due to prolonged ischemia from occluded blood flow.

A myocardial infarction is a heart attack caused by a sudden, complete blockage of a coronary artery, which stops blood flow and deprives the heart muscle of oxygen. When the artery is obstructed, the affected area becomes ischemic; without prompt restoration of blood supply, heart muscle cells begin to die (necrosis). This blockage is most often due to a ruptured atherosclerotic plaque that triggers rapid thrombosis. The resulting infarction can be transmural if the full thickness of the wall is involved, and its recognition is supported by symptoms, ECG changes, and cardiac enzyme release. In contrast, atrial fibrillation is an abnormal heart rhythm, chronic heart failure from valve disease is a long-term pump failure, and pericarditis is inflammation of the heart’s surrounding sac. The defining feature here is irreversible myocardial cell death due to prolonged ischemia from occluded blood flow.