What causes heart attacks? High electricity bills. No. A heart attack or myocardial infarction is the complete blockage of blood flow to a part of the heart. Causing its muscle cells to die. So sad. A network of blood vessels called coronary arteries. Continuously supply oxygenated blood to muscle cells of heart to keep them working properly. However, due to bad lifestyle choices and stress. Cholesterol and fats start building in these arteries reducing blood flow to the muscle cells. This buildup is called plaque. Plaque is the main culprit behind most heart attacks. So, shall we put plaque in jail? Just listen. When plaque ruptures, a blood clot forms around it causing the artery to get completely blocked. The blood then cannot pass further to that part of the heart. Thus, due to lack of oxygen, the muscle cells in that part die. This condition is called a heart attack.