Heart failure is a condition with many possible causes. Heart failure describes the inability of the heart muscle to pump enough blood to meet the body’s needs for oxygen and nutrients that are delivered by the bloodstream. The condition is commonly caused by heart defects in children (congenital heart disease) or by coronary artery disease (which causes heart attacks), diabetes or high blood pressure in adults.
What Causes Ischemic Heart Failure?
The terms ischemia and ischemic simply describe any situation when tissue in the body cannot receive adequate blood flow because of blockages in the arteries that supply that tissue with blood. Coronary artery disease—a disease process that causes narrowing or “hardening” of the arteries that supply blood to the heart muscle—is an ischemic process. Blood flow to the heart muscle through the arteries is reduced or cut off as the disease progresses.
Coronary artery disease can cause a heart attack, a dangerous condition when a sudden blockage in an artery causes heart muscle tissue to be damaged and begin to die. Heart muscle damage from long-term coronary artery disease or from a prior heart attack can weaken the heart muscle. As the heart muscle weakens, it is less able to pump blood efficiently to the body, leading to heart failure.
You can learn more about coronary artery disease here.
What Causes Nonischemic Heart Failure?
Nonischemic heart failure is any form of heart failure that is not caused by blockages in the heart arteries. Nonischemic contributors to heart failure include the following:
High Blood Pressure (Hypertension)
High blood pressure occurs when the force of blood against artery walls is too high as the blood circulates throughout the body. Uncontrolled high blood pressure can make the heart work harder to pump against this high pressure. Over time, the main pumping chamber of the heart (left ventricle) can begin to stiffen from overwork and lose its ability to pump blood effectively.
You can learn more about high blood pressure, including how to work with your care team to manage your blood pressure, here.
The relationship between diabetes and heart failure is a complex one. It has long been known that people with diabetes are at substantially increased risk of developing heart failure, and women with diabetes are at greatest risk. Additionally, new research suggests that people who have heart failure may be at greater risk of developing diabetes.
In uncontrolled diabetes, high levels of blood sugar (glucose) circulating in the bloodstream can cause damage to arteries that supply blood to the heart muscle. The high blood sugar can also damage the heart muscle itself. Damage to arteries can make them more prone to accumulate plaque—a fatty, waxy substance made up of cholesterol, calcium and other substances. Plaque builds up in the artery lining, narrowing and “hardening” the artery, restricting blood flow to the heart muscle and potentially leading to a heart attack. Reduced blood flow from heart disease or tissue damage from a heart attack causes the heart muscle to work harder and can lead to heart failure.
Click here to learn more about diabetes and cardiovascular disease.
Viral, Bacterial and Fungal Infections
Certain types of viruses, bacteria and fungi can cause inflammation of the heart muscle, called myocarditis. Myocarditis can be mild and resolve without treatment. However, in some cases, inflammation of the heart muscle leads to damage of the tissue and a weakening of the heart’s ability to pump, resulting in heart failure.
Long-term alcoholism can damage the heart muscle and lead to heart failure. Chronic alcohol abuse can cause the main pumping chamber of the heart (left ventricle) to expand, the muscle wall to thin and the chamber’s pumping action to weaken.
Structural problems with the heart that are present at birth can prevent the heart from pumping oxygen-rich blood properly throughout your body. These defects 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. There are many forms of congenital heart disease—ranging from some that do not require treatment to serious defects that must be treated immediately to save a baby’s life.
To learn more about heart defects that may be present at birth and care for pediatric heart patients, visit Congenital Heart Disease and Children and Heart Disease.
Valvular Heart Disease
The heart has valves that keep blood flowing through the heart in the right direction and prevent blood from flowing backward. Defects or disease in these valves can cause the heart to work harder and to develop heart failure over time. Valvular heart disease is often treatable with medications, in-hospital procedures and surgeries.
To learn more about valvular heart disease, visit Heart Valve Problems.
Unfortunately, some life-saving cancer treatments can also damage the heart muscle. Certain chemotherapy drugs are cardiotoxic, meaning they are toxic to the heart. Radiation treatment in the region of the heart can also cause damage to the heart muscle and the surrounding arteries. If you are undergoing chemotherapy, you may wish to talk with your doctor about receiving a test called an echocardiogram to assess any damage to the heart and arteries.
The thyroid gland is located in the neck and regulates metabolism through production of thyroid hormones. These hormones regulate many functions, including heart rate. If your thyroid overproduces the hormone thyroxin, hyperthyroidism can result. When the thyroid underproduces hormones, hypothyroidism is the result. Both hyperthyroidism and hypothyroidism can contribute to heart failure.
Idiopathic Heart Failure
The term idiopathic just means there is no identifiable cause. Idiopathic heart failure is very common. Patients who have idiopathic dilated cardiomyopathy have an enlarged and weakened main pumping chamber (left ventricle) in the heart with no known cause for why the left ventricle is failing. While heart failure may sometimes initially be labeled “idiopathic,” careful investigation will find other family members with similarly weakened hearts, suggesting a shared genetic cause for heart failure.
To better understand heart failure, it may be helpful to gain a general understanding of how a healthy heart and blood vessels function.
After heart failure causes have been identified (when possible), treatment will begin. Heart failure treatment most often takes a management approach. There is no cure for most cases of heart failure, but carefully managing or eliminating risk factors and causes can improve quality and extend length of life.