Causes of Sudden Myocardial Infarction
Feb 22, 2022
Source: Cainiu Health
Dr. Song Qiang
Introduction
Acute myocardial infarction primarily occurs when, under conditions of unstable coronary artery blood supply, certain precipitating factors cause rupture of atherosclerotic plaques in the coronary arteries. Platelets then aggregate at the site of plaque rupture, forming a thrombus that obstructs the coronary artery, leading to myocardial ischemia, hypoxia, and necrosis. Common precipitating factors include excessive physical exertion, emotional stress, heavy meals, straining during defecation, smoking, and excessive alcohol consumption.
Myocardial infarction generally refers to acute myocardial infarction (AMI). AMI is caused by acute, sustained ischemia and hypoxia of the myocardium due to coronary artery obstruction. So, what triggers an acute myocardial infarction? Below, we address this question.
Causes of Acute Myocardial Infarction
Acute myocardial infarction primarily occurs when, under conditions of unstable coronary blood supply, certain precipitating factors trigger rupture of an atherosclerotic plaque in the coronary artery. Platelets then aggregate at the site of rupture, forming a thrombus that obstructs the coronary artery—leading to myocardial ischemia, hypoxia, and eventual necrosis. Common precipitants include excessive physical exertion, emotional stress, overeating, straining during defecation, smoking, and heavy alcohol consumption. In younger patients, myocardial infarction is often associated with chronic sleep deprivation, hypertension, prolonged sedentary behavior, physical inactivity, and high-fat diets. Therefore, avoiding these triggers in daily life is essential for reducing the risk of myocardial infarction.
Acute myocardial infarction results from the interplay of internal and external factors. Internal factors constitute the underlying cause: most patients have pre-existing coronary atherosclerosis with unstable plaques; in a minority, persistent coronary vasospasm is responsible. Under specific external triggers—i.e., precipitating events—unstable atherosclerotic plaques may rupture, bleed, and induce thrombosis, leading to narrowing or complete occlusion of one or more coronary arterial lumens. Since collateral circulation has not yet fully developed, myocardial blood supply declines significantly, resulting in ischemia, hypoxia, and ultimately myocardial necrosis—i.e., myocardial infarction.
The most common cause of myocardial infarction is acute myocardial infarction secondary to unstable coronary artery perfusion. Most patients with myocardial infarction also suffer from hypertension; a smaller proportion have concomitant diabetes mellitus. Thus, patients must pay close attention to dietary habits: limiting intake of oils and salt; substituting animal fats with plant-based oils; avoiding fatty meats, organ meats, and soy products. Instead, they should consume low-fat foods such as fresh fruits and vegetables, fish, and lean meats. They should also avoid hard-to-digest foods and overeating, engage in appropriate physical activity, and avoid intense emotional excitement or excessive stimulation.
The above outlines the primary causes of acute myocardial infarction. We hope this information proves helpful to you.
