Final answer:
A heart attack, also known as a myocardial infarction (MI), occurs when blood flow to a part of the heart is blocked, resulting in damage to the heart muscle and the death of myocardial cells.
Step-by-step explanation:
A heart attack, also known as a myocardial infarction (MI), occurs when blood flow to a part of the heart is blocked, resulting in damage to the heart muscle and the death of myocardial cells. This blockage usually happens due to the complete blockage of a coronary artery, often caused by a blood clot or the rupture of a plaque. Symptoms of a heart attack can include chest pain, pressure, and other possible symptoms. At least one-quarter of heart attacks may not cause any symptoms.