Congestive heart failure is caused by many conditions that damage the heart muscle, including:
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.
Heart attack: A heart attack occurs when a coronary artery becomes suddenly blocked, stopping the flow of blood to the heart muscle. A heart attack damages the heart muscle, resulting in a scarred area that does not function properly.
Cardiomyopathy: Damage to the heart muscle from causes other than artery or blood flow problems, such as from infections or alcohol or drug abuse
Conditions that overwork the heart. Conditions including high blood pressure, valvular heart disease such as aortic stenosis, thyroid disease, kidney disease, diabetes, or heart defects present at birth can all cause heart failure.