What is the primary cause of myocardial infarction?

The primary cause of myocardial infarction is atherosclerosis. This condition involves the buildup of plaque within the coronary arteries, which can lead to a decrease in blood flow to the heart muscle. When a plaque ruptures, it may trigger the formation of a blood clot that can further obstruct the artery, severely limiting blood supply and causing tissue ischemia or infarction.

While coronary artery spasms, severe hypertension, and cardiac arrhythmias can contribute to heart problems, they are generally not considered the primary cause of myocardial infarction. Coronary artery spasms can temporarily reduce blood flow but usually occur in the context of underlying atherosclerotic disease. Severe hypertension can increase the workload on the heart and contribute to heart failure or other complications but is less directly linked to the occlusion of coronary arteries. Cardiac arrhythmias can be a consequence of ischemia rather than a primary cause of the infarction itself. Thus, atherosclerosis stands out as the fundamental underlying issue leading to myocardial infarction.