Causes of a heart attack.
Atherosclerosis
Occurs when the coronary arteries that transport blood to heart muscle become narrowed due to the buildup of plaque (fat, cholesterol, and other substances). If a fragment of plaque breaks off, it can block blood flow through the arteries.
Ischemia
Occurs when blood flow to the heart is reduced. The heart muscle is starved of oxygen and nutrients. Prolonged ischemia can result in heart muscle damage/death (a heart attack).
Types of heart attacks.
- Type 1
- The most common type of heart attack.
- Occurs from a blockage in blood flow through an artery in the heart—resulting in reduced blood flow and an oxygen supply problem.
- Type 2
- A heart attack that occurs when oxygen supply to the heart is lacking due to a need for increased blood flow.
- Type 3
- A fatal heart attack with an unconfirmed diagnosis due to patient death.
- Type 4a
- A heart attack that occurs during angioplasty, a procedure that aims to clear a blocked blood vessel by inflating a balloon on the end of a flexible tube inserted into the artery.
- Type 4b
- A heart attack that occurs when blood flow through a stent (a metal mesh tube surgically inserted into the artery) is blocked by a blood clot.
- Type 5
- A heart attack that occurs during coronary artery bypass surgery.