A heart attack is when the heart's blood supply becomes obstructed or blocked. This occurs due to plaque or blood clot forming and stopping the blood from flowing any further into the affected coronary artery. The muscle cells that make up the heart require a constant supply of oxygen to operate and survive. A blood flow obstruction in a coronary artery causes the part of the heart it supplies to experience ischemia, where the cells that make up the heart muscles are deprived of nutrients and oxygen. With ischemia, cells begin to die in large numbers and cause entire tissues to die. When a part of an affected individual's heart muscle dies or becomes damaged due to ischemia, it is considered a heart attack.
Coronary Artery Narrowing And Blockage
One of the most common causes of a heart attack is coronary artery narrowing and blockage by the accumulation of plaque. Coronary artery disease is plaque accumulation and narrowing in the coronary arteries. The coronary arteries are two large arteries that branch off the area where the left ventricle and aorta come together. These arteries and their subsequent divisions are responsible for supplying the muscle tissues of the heart with oxygenated blood and nutrients. The left coronary artery separates into the left anterior descending artery, which provides blood to the left ventricle, and the circumflex artery, which provides blood to the left atrium. The right coronary artery divides into the posterior descending artery and right marginal artery, which provide blood supply to the right atrium, ventricle, and the bottom portion of the left ventricle. The right side of the heart pumps blood into the lungs, while the left side pumps oxygenated blood to the rest of the body. When plaque sticks to the coronary artery walls, it can narrow them to the point of restricting or obstructing blood flow in the areas of the heart it supplies. The tissues stop working due to oxygen deprivation, and the affected individual experiences a heart attack.