Heart failure is a condition with many possible causes. These causes differ depending on the type of heart failure—ischemic or nonischemic. Heart failure is the leading cause of hospitalization in people 65 or older.1 Beyond this, certain conditions can significantly increase your risk of developing heart failure, while other risk factors can be stopped, controlled, or slowed with treatment and careful management.
Ischemic heart failure
The term “ischemic” describes any situation when tissue in the body cannot receive adequate blood flow because of blockages in the arteries that supply that tissue with blood. An example of an ischemic process is coronary artery disease (CAD), which is a disease process that causes the narrowing of the arteries that supply blood to the heart muscle, resulting in reduced or cut-off blood flow.
CAD can contribute to a heart attack, a sudden blockage in an artery that causes heart muscle tissue to be damaged and begin to die. Heart muscle damage from long-term CAD or a prior heart attack can weaken the heart muscle, leading to heart failure.
Nonischemic heart failure
Nonischemic heart failure is any form of heart failure that is not caused by blockages in the heart’s arteries. Nonischemic contributors to heart failure include the following:
- Hypertension (high blood pressure) – Uncontrolled hypertension can make the heart work harder to pump. Over time, it can cause the main heart chamber (left ventricle) to stiffen and lose its ability to pump blood effectively, thus leading to heart failure.
- Diabetes – In uncontrolled diabetes, high blood sugar (glucose) circulating in the bloodstream can cause damage to arteries that supply blood to the heart muscle and damage the heart muscle. Reduced blood flow from heart disease or tissue damage from a heart attack causes the heart muscle to work harder, which can result in heart failure.
- Viral, bacterial, and fungal infections – Certain viruses, bacteria, and fungi can cause inflammation of the heart muscle, called myocarditis. Myocarditis can be mild and resolved without treatment; however, it sometimes can lead to tissue damage and reduced pumping ability of the heart, resulting in heart failure.
- Alcoholism – Chronic alcohol abuse can cause the heart's left ventricle (main) pumping chamber to expand, the muscle wall to thin, and the chamber’s pumping action to weaken, leading to heart failure.
- Congenital heart disease – Structural defects in the heart that are present at birth can prevent the heart from pumping oxygen-rich blood properly throughout your body. These defects, which may be present in the heart muscle, the valves that regulate blood flow through the heart’s chambers, and the vessels attached to the heart, can eventually lead to heart failure.
- Valvular heart disease – The heart has valves that keep blood flowing in the right direction. Defects or diseases in these valves can cause the heart to work harder and develop heart failure over time.
- Cancer treatment – Unfortunately, some lifesaving cancer treatments, such as chemotherapy drugs and radiation, can also damage the heart muscle and potentially lead to heart failure.
- Thyroid disease – Your thyroid gland is located in the neck and regulates metabolism by producing thyroid hormones, which regulate many functions, including heart rate. When your thyroid overproduces these hormones, it’s called hyperthyroidism; when it underproduces these hormones, it’s called hypothyroidism. Both hyperthyroidism and hypothyroidism can contribute to heart failure.
- Idiopathic – This term means there is no identifiable cause. Idiopathic heart failure is widespread, and patients diagnosed with idiopathic dilated cardiomyopathy have an enlarged and weakened left (main) ventricle pumping chamber in the heart with no known cause for failure. While heart failure may sometimes initially be labeled “idiopathic,” careful investigation may find other family members with similarly weakened hearts, suggesting a shared genetic cause for heart failure.