Cause

Many problems can cause heart failure, including damage to the heart's muscle, valves, or electrical system. These can all affect how well the heart pumps.

Problems that damage the heart muscle

• High blood pressure
• Heart attack
• Coronary artery disease
• Diabetes that is not controlled
• Alcohol, illegal drugs (such as cocaine), and some prescription medicines (such as those for chemotherapy)
• Heart problems you've had from birth (congenital heart disease)
• Infection or inflammation of the heart muscle (such as myocarditis)

Other things that damage the heart's valves

• Valve problems you've had since birth
• Infection of a heart valve (endocarditis)
• Aging
• Rheumatic fever

Problems with the heart's electrical system

• Fast, slow, or irregular heart rhythms, including atrial fibrillation
• Electrical signals that don't flow as they should from the upper to the lower part of the heart (heart block)

Other problems

• Disease of the sac around the heart (pericarditis)
• Postpartum heart failure. This rare problem can happen late in a woman's pregnancy or within the first 5 months after delivery.
• Severe anemia
• Hyperthyroidism

Certain triggers, such as too much sodium or not taking medicines the right way, may suddenly make heart failure worse. This can sometimes cause deadly problems such as pulmonary edema or cardiogenic shock.