Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or other changes that may further weaken or stiffen the heart.
Heart failure develops when the contracting action or the relaxing action of the heart is inadequate, typically because the heart muscle is weak, stiff, or both.
Many disorders that affect the heart can cause heart failure.
Most people have no symptoms at first, and shortness of breath and fatigue develop gradually over days to months.
Fluid may accumulate in the lungs, abdomen, or legs.
Doctors usually suspect heart failure on the basis of symptoms, but tests, such as echocardiography (ultrasound of the heart), are usually done to evaluate heart function.
Treatment focuses on treating the disorder causing heart failure, making lifestyle changes, and treating heart failure with drugs or with surgery or other interventions.
About 6.5 million people in the United States have heart failure and about 960,000 new cases occur each year. Worldwide, about 26 million people are affected. The disorder
is likely to become more common because people are living longer and because, in some countries, certain risk factors for heart disease (such as obesity
Obesity Obesity is excess body weight. Obesity is influenced by a combination of factors, which usually results in consuming more calories than the body needs. These factors may include physical inactivity... read more
Heart failure does not mean that the heart has stopped. It means that the heart cannot keep up with the work required to pump adequate blood to all parts of the body (its workload). However, this definition is somewhat simplistic. Heart failure is complex, and no simple definition can encompass its many causes, aspects, forms, and consequences.
The right side of the heart pumps blood from the veins into the lungs
The left side of the heart pumps blood from the lungs out through the arteries to the rest of the body
Blood goes out of the heart when the heart muscle contracts (called systole) and comes into the heart when the heart muscle relaxes (called diastole). Heart failure develops when the contracting or the relaxing action of the heart is inadequate, typically because the heart muscle is weak, stiff, or both. As a result, blood may not flow out in adequate amounts. Blood may also build up in the tissues, causing congestion. That is why heart failure is sometimes known as congestive heart failure.
Accumulation of blood coming into the left side of the heart causes congestion in the lungs, making breathing difficult. Accumulation of blood coming into the right side of the heart causes congestion and fluid accumulation in other parts of the body, such as the legs and the liver. Heart failure usually affects both the right and left sides of the heart to some degree. However, one side may be affected by disease more than the other. In such cases, heart failure may be described as right-sided heart failure or left-sided heart failure.
In heart failure, the heart may not pump enough blood to meet the body’s need for oxygen and nutrients, which are supplied by the blood. As a result, arm and leg muscles may tire more quickly, and the kidneys may not function normally. The kidneys filter fluid and waste products from the blood into the urine, but when the heart cannot pump adequately, the kidneys malfunction and cannot remove excess fluid from the blood. As a result, the amount of fluid in the bloodstream increases, and the workload of the failing heart increases, creating a vicious circle. Thus, heart failure becomes even worse.
The types of heart failure are classified by the ejection fraction (EF), which is the percentage of blood pumped out by the heart with each beat and is a measure of how well the heart is pumping. A normal left ventricle ejects about 55 to 60% of the blood in it.
In heart failure with reduced ejection fraction (HFrEF—sometimes called systolic heart failure):
The heart contracts less forcefully and pumps out a lower percentage of the blood that is returned to it. As a result, more blood remains in the heart. Blood then accumulates in the lungs, veins, or both.
In heart failure with preserved ejection fraction (HFpEF—sometimes called diastolic heart failure):
The heart is stiff and does not relax normally after contracting, which impairs its ability to fill with blood. The heart contracts normally, so it is able to pump a normal proportion of blood out of the ventricles, but the total amount pumped with each contraction may be less. Sometimes the stiff heart compensates for its poor filling by pumping out an even higher proportion of the blood than it normally does. However, eventually, as in systolic heart failure, the blood returning to the heart accumulates in the lungs or veins.
Heart failure with ejection fraction (HFmrEF) is a newer concept that includes people whose ejection fraction is somewhere between preserved and reduced ejection fraction.
Heart Failure: Pumping and Filling Problems
Normally, the heart stretches as it fills with blood (during diastole), then contracts to pump out the blood (during systole). The main pumping chambers in the heart are the ventricles.
Heart failure due to systolic dysfunction usually develops because the heart cannot contract normally. It may fill with blood, but the heart cannot pump out as much of the blood it contains because the muscle is weaker or because a heart valve malfunctions. As a result, the amount of blood pumped to the body and to the lungs is reduced, and the ventricle usually enlarges.
Heart failure due to diastolic dysfunction develops because the heart muscle stiffens (particularly the left ventricle) and may thicken so that the heart cannot fill normally with blood. Consequently, blood backs up in the left atrium and lung (pulmonary) blood vessels and causes congestion. Nonetheless, the heart may be able to pump out a normal percentage of the blood it receives (but the total amount pumped out may be less).
The heart chambers always contain some blood, but different amounts of blood may enter or leave the chambers with each heartbeat as indicated by the thickness of the arrows.
Doctors often divide causes of heart failure into
Disorders that directly affect the heart (cardiac causes)
Disorders of other body systems that indirectly affect the heart (non-cardiac causes)
Cardiac disorders that cause heart failure may impair the entire heart or one area of the heart. In many cases, a combination of factors results in heart failure.
A common cardiac cause of heart failure is
Other cardiac causes of heart failure include
Myocarditis (inflammation of heart muscle)
Some drugs (for example, some chemotherapy drugs)
Some toxins (for example, alcohol)
Heart valve disorders
Disorders that affect the heart's electrical conduction system and cause an abnormal heart rhythm
Some genetic disorders
Disorders that stiffen the heart
Some drugs used to treat cancer and some toxins (such as alcohol) may also damage heart muscle.
Heart failure may result from disorders that cause the heart’s walls to stiffen, such as infiltrations and infections. For example, in amyloidosis
Amyloidosis Amyloidosis is a rare disease in which abnormally folded proteins form amyloid fibrils that accumulate in various tissues and organs, sometimes leading to organ dysfunction, organ failure, and... read more
The most common non-cardiac cause of heart failure is
Less common non-cardiac causes of heart failure include
High blood pressure in arteries to the lungs (pulmonary hypertension, sometimes caused by pulmonary embolism)
Anemia
Thyroid gland disorders
Kidney failure
Some drugs
Some drugs, such as nonsteroidal anti-inflammatory drugs, may cause the body to retain fluid, which increases the workload of the heart and may precipitate heart failure.
The body has several mechanisms to compensate for heart failure.
The body’s first response to stress, including that due to heart failure, is to release the fight-or-flight hormones, epinephrine (adrenaline) and norepinephrine (noradrenaline). For example, these hormones may be released immediately after a heart attack damages the heart. Epinephrine and norepinephrine cause the heart to pump faster and more forcefully. They help the heart increase the amount of blood pumped out (cardiac output), sometimes to a normal amount, and thus initially help compensate for the heart’s impaired pumping ability.
People who do not have heart disease usually benefit from release of these hormones when more work is temporarily required of the heart. However, for people who have chronic heart failure, this sustained response increases demands on an already damaged heart. Over time, the heart stops responding as well to the hormones, and the increased demands lead to further deterioration of heart function.
Another of the body’s main compensatory mechanisms for the reduced blood flow in heart failure is to increase the amount of salt and water retained by the kidneys. Retaining salt and water instead of excreting it into urine increases the volume of blood in the bloodstream and helps maintain blood pressure. However, the larger volume of blood also stretches the heart muscle, enlarging the heart chambers, particularly the ventricles. At first, the more the heart muscle is stretched, the more forcefully it contracts, which improves heart function. However, after a certain amount of stretching, stretching no longer helps but instead weakens the heart’s contractions (as when a rubber band is overstretched). Consequently, heart failure worsens. In addition, salt and water retention increase fluid congestion in organs such as the lungs, leading to worsening symptoms of heart failure.
Another important compensatory mechanism is enlargement of the muscular walls of the ventricles (ventricular hypertrophy). When the heart must work harder, the heart’s walls enlarge and thicken, as biceps muscles enlarge after months of weight training. At first, the enlargement allows the heart to maintain the amount of blood it pumps out (cardiac output). However, the enlarged and/or thickened heart eventually becomes stiff, causing or worsening heart failure. Also, the enlargement can stretch the heart valve openings, causing them to malfunction, which causes more pumping problems.
Symptoms of heart failure may begin suddenly, especially if the cause is a heart attack. However, most people have no symptoms when the heart first begins to develop problems. Symptoms then develop gradually over days to months or years. Heart failure may stabilize for periods of time but often progresses slowly and insidiously. However, people may become aware of symptoms suddenly, as when symptoms restrict an activity for the first time or when symptoms occur while at rest.
Some common symptoms are
Fatigue
Inability to exercise or do other activities that require exertion
In older people, heart failure sometimes causes vague symptoms such as sleepiness, confusion, and disorientation.
The severity of heart failure is usually classified based on how well the person is able to carry out activities of daily life. The New York Heart Association (NYHA) classification remains an important tool for people and their caregivers to understand the severity of the illness and its impact on their life.
Classification of Heart Failure*
I No limitation | Ordinary physical activity does not cause undue tiredness, shortness of breath, or awareness of heartbeats (palpitations). |
II Mild | Ordinary physical activity causes tiredness, shortness of breath, palpitations, or chest discomfort (angina). |
III Moderate | The person is comfortable at rest, but ordinary physical activity causes tiredness, shortness of breath, and palpitations or chest discomfort (angina). |
IV Severe | Symptoms occur at rest, and any physical activity increases symptoms. |
* New York Heart Association classification. |
Right-sided heart failure and left-sided heart failure cause different symptoms. Although both types of heart failure may be present, the symptoms of failure of one side often predominate. Eventually, left-sided heart failure causes right-sided failure.
The main symptom of right-sided heart failure is fluid accumulation, leading to swelling
(edema
Swelling Swelling is due to excess fluid in the tissues. The fluid is predominantly water. Swelling may be widespread or confined to a single limb or part of a limb. Swelling is often in the feet and... read more
Left-sided heart failure leads to fluid accumulation in the lungs, which causes shortness of
breath Shortness of Breath Shortness of breath—what doctors call dyspnea—is the unpleasant sensation of having difficulty breathing. People experience and describe shortness of breath differently depending on the cause... read more
Acute pulmonary edema is a sudden accumulation of a large amount of fluid in the lungs. It causes extreme difficulty breathing, rapid breathing, bluish skin, and feelings of restlessness, anxiety, and suffocation. Some people have severe spasms of the airways (bronchospasms) and wheezing. Acute pulmonary edema is a life-threatening emergency that can occur when people with heart failure develop very high blood pressure, have a heart attack, or sometimes just stop taking their heart failure drugs or eat salty food.
Chest x-ray
Electrocardiography (ECG)
Echocardiography and sometimes other imaging tests
Blood tests
Doctors usually suspect heart failure on the basis of symptoms alone. The diagnosis is supported by the results of a physical examination, including a weak, often rapid pulse, reduced blood pressure, abnormal heart sounds and murmurs and fluid accumulation in the lungs both heard through a stethoscope, an enlarged heart, swollen neck veins, an enlarged liver, and swelling in the abdomen or legs.
Procedures to evaluate heart function are usually done. Testing is also needed to identify the cause of heart failure.
A chest x-ray can show an enlarged heart, and congested blood vessels and fluid accumulation in the lungs.
Whether the heart walls are thickened and relax normally
Whether the valves are functioning normally
Whether contractions are normal
Whether any area of the heart is contracting abnormally
Echocardiography may help determine whether heart failure is due to systolic or diastolic dysfunction by enabling doctors to estimate the thickness and stiffness of the heart walls and the ejection fraction. The ejection fraction, an important measure of heart function, is the percentage of blood pumped out by the heart with each beat. A normal left ventricle ejects about 55 to 60% of the blood in it. If the ejection fraction is low (less than 40%), systolic heart failure is confirmed. If the ejection fraction is normal or high in a person who has symptoms of heart failure, diastolic heart failure is likely.
Blood tests are almost always done. Doctors frequently measure natriuretic peptides (NPs). NPs are substances that accumulate in the blood when heart failure is present but less often when other disorders that cause shortness of breath are present. Other blood tests may be done to look for disorders that may be causing heart failure.
Other procedures, such as
radionuclide imaging
Radionuclide Imaging of the Heart In radionuclide imaging, a tiny amount of a radioactive substance (radionuclide), called a tracer, is injected into a vein. The amount of radiation the person receives from the radionuclide... read more ,
magnetic resonance imaging
Magnetic Resonance Imaging (MRI) of the Heart With magnetic resonance imaging (MRI), a powerful magnetic field and radio waves are used to produce detailed images of the heart and chest. This expensive and sophisticated procedure is used... read more
(MRI), computed tomography
Computed Tomography (CT) of the Heart Computed tomography (CT) may be used to detect structural abnormalities of the heart, the sac that envelops the heart (pericardium), major blood vessels, lungs, and supporting structures in... read more ,
cardiac catheterization with angiography
Cardiac Catheterization and Coronary Angiography Cardiac catheterization and coronary angiography are minimally invasive methods of studying the heart and the blood vessels that supply the heart (coronary arteries) without doing surgery. These... read more
Preventing heart failure involves treating disorders that can cause heart failure before they lead to heart failure. Disorders that can be treated include the following:
High blood pressure
Obesity
Obstructive sleep apnea
Blockage of a coronary artery
Heart valve disorders
Some abnormal heart rhythms
Alcoholism
Anemia
Thyroid disorders
Diet and lifestyle changes
Treatment of the cause of heart failure
Drugs
Sometimes an implantable cardioverter-defibrillator, cardiac resynchronization therapy, or mechanical circulatory support
Sometimes heart transplantation
Treatment of heart failure requires several general measures, along with treatment of the disorder causing heart failure, lifestyle changes, and drugs for heart failure.
Although for most people heart failure is a chronic disorder, much can be done to make physical activity more comfortable, improve the quality of life, minimize the risk of sudden worsening (acute heart failure), and prolong life. Affected people and their family members should learn all they can about heart failure because much care occurs at home. In particular, they should know how to recognize the early warning symptoms of worsening heart failure and should be aware of the actions they need to take (for example, reduce salt intake, take an extra dose of a diuretic, or contact their doctor).
Regular communication with health care practitioners and examinations by doctors are critical because heart failure can worsen suddenly. For example, nurses may regularly call people who have heart failure to ask about changes in weight and in symptoms. Thus, they can gauge whether people need to see a doctor.
People may also go to specialized heart failure clinics. These clinics have doctors with expertise in heart failure who work closely with specially trained nurses and other health care practitioners, such as pharmacists, dietitians, and social workers, to care for people with heart failure by teaching self-care skills to people and their caregivers. These clinics can also help decrease symptoms, reduce hospitalizations, and improve life expectancy by making sure that people receive the most effective treatments and by teaching people how to fully participate in their care. This care complements rather than replaces care provided by primary care doctors.
People with heart failure should always check with their doctor before taking a new drug, even a nonprescription drug. Some drugs (including many used to treat arthritis) can cause salt and fluid retention. Other drugs may make the heart function less efficiently. Forgetting to take necessary drugs is a common cause of worsening symptoms, and people should be given ways to remind themselves to take their drugs.
Did You Know...
Heart failure is usually a chronic condition, and changes in lifestyle can help people feel and function better.
Changes in lifestyle can help people with heart failure feel and function better.
People who have heart failure should stay as physically fit as possible, even if they cannot exercise vigorously. People who have mild heart failure should follow an exercise program as prescribed by a doctor. People with more severe heart failure may need to exercise in a cardiovascular rehabilitation facility under the supervision of a trained attendant.
If people with heart failure are overweight, the heart has to work harder during activity, worsening heart failure. Such people should follow a healthy weight loss diet to attain and maintain ideal weight.
Excess salt (sodium) in the diet can cause fluid retention, which counteracts drugs given to increase the excretion of water (such as diuretics) and relieve fluid accumulation. Thus, consuming excess salt worsens symptoms. Almost all people with heart failure should limit their intake of table salt and salty foods and their use of salt in cooking. The sodium content of packaged foods can be determined by reading the label. People with severe heart failure are usually given detailed information about how to limit salt intake. Instruction by a dietitian can be helpful. People who limit their salt intake can usually consume a normal amount of water unless fluid retention is severe. Drinking extra amounts of water is not recommended.
A simple, reliable way to check whether the body is retaining fluid is to check body weight daily. Doctors often ask people with heart failure to weigh themselves as accurately as possible every day, typically once in the morning, after they arise and urinate and before they eat breakfast. Trends are easier to spot when people weigh themselves at the same time every day, use the same scale, wear a similar amount of clothing, and keep a written record of their daily weight. Increases of more than 2 pounds (about 1 kilogram) per day are early warning signs of fluid retention. A consistent, rapid weight gain (such as 2 pounds per day) is a clue that heart failure is worsening.
Many people who limit their salt intake still have swelling. Swollen legs should be kept elevated on a stool when sitting. This position helps the body reabsorb and eliminate the excess fluid. Some people also need to wear full-length supportive stockings that help prevent accumulation of fluid. If fluid accumulates in the lungs, sleeping with several pillows or elevating the head of the bed makes sleeping easier.
Drug treatment of heart failure involves
Drugs to help relieve symptoms: Diuretics Diuretics Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more , nitrates Vasodilators Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more , or digoxin Digoxin Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more
Drugs to help improve survival: Angiotensin-converting enzyme (ACE) inhibitors Angiotensin-converting enzyme (ACE) inhibitors Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more , beta-blockers Beta-blockers Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more , aldosterone antagonists Aldosterone antagonists Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more , angiotensin II receptor blockers Angiotensin II receptor blockers (ARBs) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more (ARBs), angiotensin receptor/neprilysin inhibitors Angiotensin receptor/neprilysin inhibitors Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more (ARNIs), sodium-glucose cotransporter-2 inhibitors Sodium-glucose cotransporter-2 inhibitors (SGLT2s) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more (SGLT2s), sinus node inhibitors Sinus node inhibitors Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more
The type of drug used depends on the type of heart failure. In systolic heart failure (HFrEF), all drug classes are helpful. In diastolic heart failure (HFpEF), only ACE inhibitors, ARBs, aldosterone antagonists and beta-blockers are typically used. In HFmrEF, ARNIs may be helpful.
It is important for people to take their drugs regularly and be sure not to let the prescription run out.
Mechanical devices that help pump blood are used for certain people with very severe heart failure that is not responding to drug therapy. Types of devices include
Intra-aortic counterpulsation balloon pump (IABP, also sometimes just called a balloon pump): A sausage-shaped balloon on the end of a catheter is placed in the aorta. A machine monitors the heart beat and inflates the balloon when the heart relaxes and deflates it when the heart contracts, which makes it easier for the heart to pump blood.
Ventricular assist devices: Different mechanical pumps can be implanted in or near the left or right ventricle to help the heart pump blood.
Intravascular assist devices: Small pumps can be implanted within large vessels such as the aorta to help pump blood.
Extracorporeal membrane oxygenation (ECMO): A device similar to a heart-lung bypass machine takes blood from a large artery and pumps it past a membrane that allows oxygen into the blood and then pumps it back into a large vein.
If heart failure is caused by a problem with a heart valve, doctors may repair or replace the valve.
Heart failure that develops or worsens quickly requires emergency treatment in a hospital.
If acute pulmonary edema (rapid accumulation of fluid in the lungs) develops, oxygen is given through a face mask. Diuretics given intravenously and other drugs such as nitroglycerin given intravenously or under the tongue can give rapid, dramatic improvement. Morphine relieves the anxiety that usually accompanies acute pulmonary edema but it also decreases the rate of breathing and is no longer used as often. If these measures do not adequately improve breathing, a specialized mask to deliver oxygen at controlled pressures may be used or a tube may be inserted into the person’s airway so that a mechanical ventilator can assist breathing.
For people who have severe symptoms and have not responded well to treatments, drugs that are similar to epinephrine and norepinephrine (such as dopamine or dobutamine) or other drugs that make cardiac muscle contract more forcefully (such as milrinone) are sometimes used for a short time to enhance the pumping function of the heart. These drugs are not useful for long-term treatment.
Life expectancy depends on many factors, including how severe the heart failure is, whether its cause can be corrected, and which treatment is used. However, once people have needed to be hospitalized for heart failure, only about 1 in 3 live another 5 years. About half of those who have severe heart failure live at least 2 years. Life expectancy does improve with treatment.
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
American Heart Association: Provides resources and information for people living with heart failure and their families