Causes of heart attack
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Coronary Artery Disease and Plaque Buildup as Primary Causes of Heart Attack
The most common cause of heart attack is coronary artery disease. This happens when the coronary arteries, which supply oxygen-rich blood to the heart muscle, become narrowed or blocked due to the buildup of plaque—a mixture of fat, cholesterol, and other substances. Over time, this plaque can rupture, leading to the formation of a blood clot that can block blood flow to the heart, resulting in damage to the heart muscle. This process is known as atherosclerosis and is the main reason for most heart attacks worldwide 149.
Blood Clots and Sudden Blockages
A heart attack often occurs when a blood clot forms on top of a ruptured plaque, suddenly blocking the flow of blood to part of the heart muscle. If the blockage is complete, it can cause significant and permanent damage to the heart. If the blockage is partial, it may cause angina, which is chest pain that signals an increased risk of a future heart attack 149.
Other Medical and Genetic Risk Factors
Several underlying medical conditions increase the risk of heart attack. These include high blood pressure (hypertension), high cholesterol, and diabetes. Genetic predispositions and family history also play a significant role in determining an individual's risk of developing heart disease and experiencing a heart attack 53710.
Lifestyle Factors: Diet, Smoking, and Physical Inactivity
Lifestyle choices are major contributors to heart attack risk. Smoking, poor diet (especially diets high in fat and sugar), and lack of physical activity all increase the likelihood of developing the conditions that lead to heart attacks. Obesity, which is often a result of these lifestyle factors, further raises the risk by contributing to high blood pressure, high cholesterol, and diabetes 459.
The Role of Stress and the Nervous System
Chronic stress is widely recognized as a contributing factor to heart attacks. Stress can increase blood pressure and may have direct effects on the heart through the nervous system, particularly by reducing the control function of the parasympathetic nervous system (PNS). The type of work a person does and the stress associated with it are seen as indirect causes, often operating through increased blood pressure 238.
Less Common Causes: MINOCA and Other Heart Conditions
Not all heart attacks are caused by blocked arteries. Some occur without significant coronary artery obstruction, a condition known as MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries). These cases can be triggered by other heart or blood vessel conditions .
Conclusion
Heart attacks are primarily caused by the buildup of plaque in the coronary arteries, leading to blockages that restrict blood flow to the heart muscle. High blood pressure, high cholesterol, diabetes, genetic factors, and unhealthy lifestyle choices such as smoking, poor diet, and lack of exercise all increase the risk. Chronic stress and certain heart conditions can also contribute. Understanding these causes is essential for prevention and early intervention.
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