Heart failure is caused by many conditions that damage the heart muscle, including:
Coronary artery disease. Coronary artery disease (CAD), a disease of the arteries that supply blood and oxygen to the heart, causes decreased blood flow to the heart muscle. If the arteries become blocked or severely narrowed, the heart becomes starved for oxygen and nutrients.
Damage to the heart muscle from causes other than artery or blood flow problems, such as from infections or alcohol or drug abuse.