What causes heart failure?

Heart failure is caused primarily by either having a heart attack or developing a cardiomyopathy. The heart, which is the main pump in the body, will fail when it cannot generate blood flow. This may occur because the heart becomes weak, because of a cardiomyopathy, viral or other infectious etiologies, because of a heart attack where the blood supply was interrupted, or because the electrical circuits are not working properly and the heart cannot keep up. At times the heart fails because the valves become blocked or leak. Such terms as aortic stenosis, mitral stenosis, aortic insufficiency, or mitral regurgitation are some of the examples where the heart fails because the valves fail. Some patients develop heart failure because of having a hole in the heart that they were born with. Others may fail because of other congenital heart diseases  they were born with. The main goal is to diagnose the cause of the heart failure and to employ the therapies that will best allow the heart to perform to the best of its ability, which may include medicines, catheterization and/or surgery.

Heart failure can be from a variety of causes, but in general, in the US, is divided into to main categories—ischemic, and non-ischemic. Ischemic, which is the overwhelming majority, is due to coronary artery disease, a leading cause of death in developed countries. Non-ischemic, can be due to a variety of causes, such as valvular disease, certain infections, congenital problems, etc.

Dr. Sean P. Pinney, MD
Cardiologist (Heart Specialist)

Congestive heart failure may be caused by one or more conditions that weaken or damage the heart muscle or its vessels. They include:

  • High blood pressure, or hypertension
  • Heart attack and coronary artery disease
  • Heart infections or inflammations
  • Heart valve disease
  • Abnormal heart rhythms, or arrhythmia
  • Congenital heart defects, which are conditions present at birth

A heart attack or the long-term effects of high blood pressure causes heart failure. The condition occurs when the weakened heart muscle cannot maintain adequate blood flow to the body's tissues and organs. It is a serious health problem, and a major cause of death.

Heart failure can be treated, but cannot be cured. Once a patient receives a diagnosis of heart failure, the condition will require lifelong treatment.

Linda Martinez
Cardiac Rehabilitation Specialist

There are several causes of heart failure. The most common cause is blockages in the heart arteries also called coronary artery disease or atherosclerosis (can be referred to as hardening of the arteries). This is the same disease that causes heart attacks. Other causes include, excessive alcohol intake, drug abuse with cocaine or methamphetamines, viruses, many years of high blood pressure, heart defects since birth or damaged heart valves (can also be caused by birth defects or caused by disease or aging). Sometimes the cause is never known.

Heart blockages are the most common cause of heart failure. There's a variety of other causes, such as other diseases like diabetes.

Dr. William D. Knopf, MD
Cardiologist (Heart Specialist)

Conditions that damage the heart muscle or make it work too hard can cause heart failure. Over time, the heart weakens. It isn't able to fill with and/or pump blood as well as it should. As the heart weakens, certain proteins and other substances may be released into the blood. They have a toxic effect on the heart and blood flow, and they cause heart failure to worsen.

Major causes
The most common causes of heart failure are coronary artery disease (CAD), high blood pressure, and diabetes. Treating these problems can prevent or improve heart failure.

Coronary artery disease
CAD occurs when a fatty material called plaque builds up in your coronary arteries. These arteries supply oxygen-rich blood to your heart. Plaque narrows the arteries, causing less blood to flow to your heart muscle. This can lead to chest pain, heart attack, and heart damage.

High blood pressure
Blood pressure is the force of blood pushing against the walls of the arteries. Blood pressure is "high" if it stays at or above 140/90 mmHg over a period of time. High blood pressure stiffens blood vessels and makes the heart work harder. Without treatment, the heart may be damaged.

This disease occurs when the level of sugar in the blood is high. The body doesn't make enough insulin or doesn't use its insulin properly. Insulin is a hormone that helps convert food to energy. High sugar levels can damage blood vessels around the heart.

Other causes
Other diseases and conditions that can lead to heart failure are:

  • Heart muscle diseases: These diseases may be present at birth or due to injury or infection.
  • Heart valve disorders: These problems may be present at birth or due to infections, heart attacks, or damage from heart disease.
  • Arrhythmias, or irregular heartbeats: These heart problems may be present at birth or due to heart disease or heart defects.
  • Congenital heart defects: These heart problems are present at birth.

Other factors also can injure the heart muscle and lead to heart failure. These include:

  • Treatments for cancer, such as radiation and chemotherapy
  • Thyroid disorders (having either too much or too little thyroid hormone in the body)
  • Alcohol abuse
  • Cocaine and other illegal drug use
  • Too much vitamin E

This answer from the National Heart, Lung and Blood Institute.

Dr. Francis X. Downey, MD
Cardiothoracic Surgeon

Heart failure can be caused by different things. Coronary artery disease, or blockages of the coronary arteries, can limit blood flow to certain areas of the heart muscle and then that muscle can die off as in a myocardial infarction, or heart attack.

There are certain viral illnesses that can cause a sudden decrease in heart function. Those are called cardiomyopathies or viral or dilated cardiomyopathies. A person can experience shortness of breath and fatigue; sometimes older people they get lower extremity swelling. These can be signs of heart failure.

There are some more esoteric types of heart failure. Valvular heart disease can cause heart failure over time. People who undergo treatment for congenital heart disease as children can develop heart failure later in life.

There are two kinds of heart failure. In the first kind, the heart muscle has weakened and cannot pump enough blood out with each beat. This is called "systolic heart failure." In the second kind, the heart pumps normally but the heart muscle has become stiff. Your heart has lost its ability to relax and does not completely fill with blood. This is called "diastolic heart failure." Any disease that weakens the heart muscle can lead to heart failure. The most common causes of heart failure are:

  • Blockages in the blood vessels that may lead to a heart attack
  • High blood pressure that may cause diastolic heart failure
  • Disease of the heart valves
  • Diabetes
  • Infections of the heart muscle
  • Cancer drugs
  • Genetic abnormalities that run in families

In many cases, the cause is never known, in which case it is called "Idiopathic Cardiomyopathy."

Heart failure occurs most often in older people—but it can happen to anyone, at any age. Heart failure can be caused by anything that damages and weakens the heart muscle, but up to 40 percent of all cases of heart muscle damage have no known cause. The most common known causes of heart muscle damage include:

  • Atherosclerosis (coronary artery disease). If the arteries that supply your heart with blood become narrowed by fatty plaque buildup, you have atherosclerosis. Atherosclerosis limits the amount of oxygen your heart receives and weakens the muscle. It can also cause a heart attack, which can further damage your heart.
  • High blood pressure (hypertension). Poorly controlled blood pressure makes your heart work harder to pump blood throughout your body. Over time, this extra work can wear out your heart and lead to heart failure.
  • Heart valve problems. Heart valves control the one-way flow of blood through your heart. If valves are damaged or abnormal, you can have back-flow or limited forward flow. Both make your heart work harder and can lead to heart failure.
  • Alcohol abuse. Long-term alcohol abuse can severely weaken your heart muscle.
Dr. Sameer A. Sayeed, MD
Cardiologist (Heart Specialist)

Heart failure occurs when the heart muscle becomes very weak and its pump function fails, leading to inadequate amounts of blood being pumped out of the heart. The heart cannot eject as much blood out as it should and as a result some blood is left in the heart. Ultimately this unejected blood backs up into other chambers of the heart and then back into the lungs and the rest of the body. The end result is an enlarged heart that ultimately fails further from being enlarged and even less efficient at pumping, as well as fluid in the lungs, leading to difficulty breathing and swelling of the rest of the body, especially the abdomen and legs. Because the rest of the body is getting insufficient blood, the kidneys may start to fail, mental status may be affected from decreased blood to the brain, the legs may become blue from insufficient blood, blood pressure may be low and the liver may fail from blood backing up into the liver. Heart failure due to poor pump function can occur from a heart attack, from blocked and diseased coronary arteries, from a viral illness and from many other systemic diseases that can affect the heart. Heart failure can also occur in the presence of normal pump function of the heart. In this case it is due to the heart muscle being too stiff and blood is unable to come into the heart properly to be pumped out and again results in heart failure sequelae as above.

Heart failure is commonly caused by underlying conditions like coronary heart disease, diabetes, and high blood pressure. The underlying illnesses weaken or damage the heart muscle.

Coronary heart disease is a narrowing of the arteries by fatty deposits, called plaque, restricting blood flow to the heart. Without enough blood, the heart muscle weakens or dies.

High blood pressure forces the heart to pump harder to circulate blood to the body. Over time, the heart may enlarge and stiffen limiting its ability to pump blood effectively.

Diabetes is a condition where the body cannot break down blood sugars properly. Over time, high blood sugar can weaken and damage the heart muscle and surrounding blood vessels. Other causes of heart failure include heart valve disease, inflamed heart muscle (myocarditis), irregular heartbeat (arrhythmia), and heart defects at birth.

Dr. Ali Nsair, MD
Cardiologist (Heart Specialist)

Heart failure is a general description for many causes that lead to pump failure. The most common cause is coronary artery disease that leads to heart attacks and weakened heart muscle. The damage that happens during a significant heart attack causes muscle cell death and with less muscle to pump, heart failure ensues. Other common causes are poorly controlled diabetes, and high blood pressure. Chronic high blood pressure over time places an increased work burden on our heart and if left untreated can eventually cause muscle weakness and failure. Diabetes can increase our risk for heart failure by increasing our risks for vascular disease including heart attacks; as well, poorly controlled diabetes can directly weaken the heart muscle or cause the diastolic heart (stiff heart) heart failure as can poorly controlled high blood pressure.

Our hearts may be susceptible to viral infections that directly affect our heart muscle cells causing cell damage and failure. This condition is called viral myocarditis (inflammation of the heart) and can be precipitated by a common cold or flu illness. Less common causes are congenital defects (structural heart problems we are born with) and also damage to valves in the heart can lead to the muscle weakness. The end result regardless of the cause is similar with heart muscle weakening and leading to pump failure.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.