Heart Failure

Heart failure develops when the heart cannot pump as much blood as the body needs. Heart failure does not mean that the heart has stopped. Rather, it means that the heart cannot keep up with the work required of it—its workload.

Heart failure is one of the most common disorders among older people. Heart failure usually worsens over a period of years, eventually leading to death. However, treatment can relieve symptoms and prolong life.

The heart is a muscular organ with four chambers designed to pump blood efficiently, reliably, and continuously over a lifetime. The right and left sides of the heart each have an upper chamber (atrium) and a lower chamber (ventricle). The right atrium receives blood from the body and pumps it into the right ventricle, which pumps blood to the lungs. The left atrium receives blood from the lungs and pumps it into the left ventricle. The left ventricle, which is the workhorse of the heart, pumps blood to the rest of the body. The four chambers contract in rhythm to pump blood efficiently.

When the heart cannot pump enough blood, the tissues of the body may not get enough oxygen and nutrients. As a result, muscles may tire more quickly, and other organs may not function normally. Also, blood may back up in the veins, causing fluid to leak out and accumulate in tissues. When blood coming into the right side of the heart backs up (called right-sided heart failure), fluid may accumulate in the abdomen, legs, and feet. When blood coming into the left side of the heart backs up (called left-sided heart failure), fluid may accumulate in the lungs. The backup of blood, called congestion, is why heart failure is also known as congestive heart failure. Often, both sides of the heart are affected, although one side may be affected more.

See the figure Heart Failure: Filling and Pumping Problems.

As heart failure progresses, the heart works harder in an effort to pump more blood. The heart's walls may become thicker, just as arm or leg muscles do after months of weight training. The heart's chambers may also enlarge, because pressure inside the heart increases. At first, these changes may help the heart keep up with its workload. But eventually, the thickened heart walls become stiff, and the ventricles cannot fill with blood normally. Or the stretched-out chambers, like stretched-out rubber bands, become less able to contract and pump blood. Most people tend to have problems with both filling and pumping to some degree.

Blood clots may form in the heart's stretched-out chambers. Clots are more likely to form when heart failure is advanced or when a person also has another heart disorder, such as an abnormal heart rhythm (arrhythmia) called atrial fibrillation or a heart valve disorder. Part of a clot may break loose, travel through the bloodstream (becoming an embolus), and block an artery elsewhere in the body. If a clot blocks an artery to the brain, a stroke may result.

Causes

Aging alone does not cause heart failure. But changes due to aging, such as slight thickening and stiffening of the heart's walls, make older people more susceptible to heart failure.

In older people, the most common causes of heart failure are high blood pressure and heart attacks (due to coronary artery disease). Other heart disorders, such as heart valve disorders, abnormal heart rhythms, a problem with the heart muscle itself (cardiomyopathy), inflammation of the sac around the heart (pericarditis), and heart infections, can also result in heart failure. A sudden illness, such as pneumonia, can strain the heart, contributing to the development of heart failure.

Drinking large amounts of alcohol and taking certain drugs (such as doxorubicin, a chemotherapy drug) can damage the heart. Then, the heart may be unable to pump forcefully enough, resulting in heart failure. Sometimes the cause of heart failure is unknown.

For additional detail on this topic, see How Heart Failure Occurs.

Symptoms

Symptoms of heart failure may develop slowly, over weeks, months, or years. Or they may occur suddenly, especially if heart failure is due to a heart attack.

The main symptoms are shortness of breath (especially when exercising or lying in bed), fatigue, and swelling in the feet or ankles. A little swelling is not worrisome, but too much swelling in the legs and feet can make the skin fragile (resulting in sores) and make walking difficult. The legs, liver, and abdomen may also swell because of fluid accumulation.

Usually, heart failure does not cause pain. However, it may cause a sensation of fullness or tightness in the chest.

At first, people may feel short of breath only during exercise and other physical activities. Symptoms occur during physical activity because active muscles need more blood and the malfunctioning heart cannot pump enough. Inactive people may have vague symptoms, such as sleepiness, irritability, or confusion.

Symptoms may be triggered by eating salty foods or drinking an excessive amount of fluid in a day, especially if the kidneys are not functioning normally. Salt causes the body to retain fluid, so more fluid accumulates.

As heart failure progresses, shortness of breath occurs with less and less strenuous activity. It may occur when people lie down and be relieved when they sit up. This condition is called orthopnea. Some people wake up suddenly because they have trouble breathing when they lie down. Some people have a chronic cough that becomes worse when they lie down. Lying down causes problems because when a person lies down, fluid tends to accumulate in the lungs.

If heart failure becomes severe, any physical activity, such as going up steps or even walking short distances, may become difficult. Breathing becomes more and more difficult. To sleep, some people with severe heart failure need to sit up or use several pillows.

People may gasp for breath or make gurgling sounds when they breathe. They may feel restless, anxious, and as if they are suffocating. These symptoms occur when a large amount of fluid accumulates in the lungs (a condition called pulmonary edema). The skin may turn pale or bluish (cyanotic), and people may break out in a cold sweat. Blood pressure may become very high or very low. If the brain does not receive enough blood, people may become confused, lose consciousness, or faint.

When heart failure is very severe, people may go into shock. Shock occurs when blood pressure is too low to keep blood flowing to the body's organs. Unless treated quickly, people in shock due to heart failure usually die within a few hours or days.

Diagnosis

Doctors can sometimes diagnose heart failure on the basis of symptoms alone. Older people should tell their doctor if they feel short of breath or unusually tired or if they are no longer able to do their normal activities. Older people may think that these symptoms are unimportant or result from aging. But the symptoms may indicate heart failure.

When doctors suspect heart failure, they perform a physical examination. Using a stethoscope, they listen for abnormal heart and breathing sounds. Listening to the heart may provide clues about the cause of heart failure. Abnormal breathing sounds may mean that fluid has accumulated in the lungs. Doctors check for other signs of fluid accumulation: swollen neck veins, an enlarged liver, and swelling in the abdomen or legs.

Other tests are usually needed to confirm the diagnosis. The chest is x-rayed to see whether the heart is enlarged and whether fluid has accumulated in the lungs. Echocardiography (ultrasonography of the heart) is done to see how well the heart is filling and pumping. Echocardiography also helps doctors determine the cause of heart failure. It can show how well the heart is beating and whether heart valves are functioning normally.

With echocardiography, doctors can measure the ejection fraction and thus evaluate the heart's pumping ability. The ejection fraction is the percentage of blood that the left ventricle pumps out with each heartbeat (some blood remains in the left ventricle). Normally, the ejection fraction is between 50% and 75%.

Other tests that may be done include cardiac catheterization and nuclear scanning. A blood test may be done to measure the level of a protein (called B-type natriuretic peptide) that is released by the heart into the blood when pressure inside the heart increases.

Prevention and Treatment

Prevention and treatment of disorders that can cause heart failure (such as high blood pressure and coronary artery disease) can help prevent heart failure, regardless of a person's age. Being treated promptly and appropriately during a heart attack is particularly important.

Although heart failure is a chronic disorder for most people, much can be done to make physical activity more comfortable, improve the quality of life, and prolong life.

Sometimes treating the disorder causing heart failure can prevent heart failure from worsening and relieve symptoms. For example, high blood pressure may be controlled with antihypertensive drugs. After a heart attack, treatment may consist of drugs, angioplasty, or coronary artery bypass graft surgery. A damaged heart valve can be repaired or replaced. An abnormal heart rhythm can be corrected with drugs, surgery, or use of an artificial pacemaker. Excess fluid in the sac around the heart can be drained.

General measures: Some lifestyle changes can help prevent heart failure from worsening and relieve symptoms. Trying to stay physically fit, even for people who cannot exercise vigorously, is important. People with heart failure should follow an exercise program as prescribed by a doctor. A cardiac rehabilitation program may also be helpful.

Losing excess weight and stopping smoking can help prevent heart failure from worsening. Alcohol consumption should be limited to one or two drinks a day. In people with heart failure, larger amounts of alcohol can cause the heart to function less well and beat abnormally. People with heart failure due to drinking large amounts of alcohol should not drink any alcohol.

Almost everyone with heart failure should avoid using table salt and eating salty foods (such as chips, pretzels, canned soups, and canned vegetables). The salt (sodium) content of packaged foods is listed on the label. The use of salt in cooking should also be limited. Health care practitioners usually give people with severe heart failure specific guidelines for salt consumption, such as no more than 2 grams of sodium a day. Usually, people who limit their salt consumption do not need to limit the amount of fluid they drink. But most people with heart failure should not drink more than six to eight glasses of fluid a day.

Limiting salt consumption may help prevent swelling but does not relieve it. Elevating the legs when sitting can reduce swelling. Some people also need to wear full-length support stockings. When lying down, using several pillows or elevating the head of the bed can help make breathing easier.

Recording body weight every day can help people determine whether they are retaining fluid. Usually, the best time to weigh is in the morning after urinating but before eating breakfast. If weight increases by more than 2 pounds (about 1 kilogram) a day or 5 pounds (about 2¼ kilograms) a week, fluid is probably being retained. A decrease of more than 2 pounds a day or 5 pounds a week may mean that too much fluid is being lost. People should report such changes to their doctor, because they may need a change in the dose of a drug.

A yearly influenza (often called flu) vaccination is particularly important for people with heart failure. Influenza can stress the heart and cause heart failure to worsen suddenly. A vaccination to help prevent pneumonia is also important.

People with heart failure should ask their doctor or another health care practitioner to review the drugs they are taking. Some drugs, such as all nonsteroidal anti-inflammatory drugs (NSAIDs) except aspirin, should be used only if recommended by a doctor. NSAIDs tend to make fluid retention worse.

Drugs: The choice of drugs depends on other disorders a person has and on the severity of heart failure.

Angiotensin-converting enzyme (ACE) inhibitors help prevent heart failure from worsening, relieve symptoms for most people, and prolong life. These drugs cause blood vessels to expand (dilate). Then, the heart can pump blood more easily. Angiotensin II receptor blockers have effects similar to those of ACE inhibitors, and they may have fewer side effects. Angiotensin II receptor blockers are often used instead of or in addition to an ACE inhibitor. Other drugs that dilate blood vessels (vasodilators) may be used when people cannot take ACE inhibitors or angiotensin II receptor blockers.

Beta-blockers are often given with ACE inhibitors. Beta-blockers help the heart function better and prolong life. They are especially helpful for people who have had a heart attack. Doctors adjust the dose carefully and monitor the person's response to the drug because these drugs may temporarily worsen symptoms.

Diuretics are used to remove extra fluid from the body and to help prevent fluid from accumulating. If heart failure is very mild, a diuretic may be taken only on days when fluid accumulation is noticeable. If heart failure is more severe, a diuretic is usually taken every day. Bumetanide, furosemide, and torsemide are most commonly used. People with severe heart failure may be given metolazone or a stronger diuretic. Most diuretics cause the body to lose potassium in the urine. For this reason, doctors may recommend increasing the amount of potassium in the diet. Good sources of potassium are bananas, oranges, and other fruits. Alternatively, doctors may recommend a potassium supplement. People who take a diuretic may need to urinate more often and more urgently. If they have urinary incontinence, taking a diuretic may cause problems. However, people can usually time when they take a diuretic so that a bathroom is available when they are likely to need to urinate.

Aldosterone antagonists, such as spironolactone and eplerenone, prevent potassium loss. These drugs are weak diuretics. Spironolactone prolongs life and reduces the need for hospitalization in people with severe heart failure. Eplerenone may prolong life in people with heart failure, particularly if it is due to moderate or severe heart damage after a heart attack.

Sometimes the dose of a diuretic needs to be adjusted. For example, the dose may need to be decreased in hot weather because people sweat more. Or the dose may need to be increased if the body is retaining fluid. Weighing every day helps people notice these changes. The dose of a diuretic must be adjusted by a doctor. However, with experience, many people can learn to adjust the dose of the diuretic with their doctor's supervision.

Digoxin, one of the oldest treatments for heart failure, slightly increases the force of each heartbeat and slows a heart rate that is too rapid. Digoxin helps relieve symptoms, especially if atrial fibrillation is present.

For people who have severe symptoms and have not responded well to the usual treatments, other drugs that help the heart pump more efficiently may be used. These drugs include dopamine, dobutamine, and milrinone. Nesiritide, which causes blood vessels to dilate, may also be given. These drugs are given intravenously and are used for a short time.

Anticoagulants (sometimes called blood thinners), such as warfarin, make blood less likely to clot. They can help prevent clots from forming in the heart's chambers. People who take warfarin must have blood tests periodically to check the blood's ability to clot. If blood is taking too long to clot, bleeding can occur. People who have coronary artery disease or diabetes are often given aspirin, which makes blood clots less likely to form. People who have an abnormal heart rhythm may be given antiarrhythmic drugs.

Oxygen therapy: Some people with severe heart failure need oxygen therapy. It helps relieve shortness of breath. Several devices can be used at home.

Surgery: If heart failure is severe, a pacemaker that stimulates the two ventricles to pump at the same time (biventricular pacemaker) may be implanted. It may help relieve symptoms and enable people to be more physically active. An implanted cardioverter-defibrillator (ICD) may be used to treat people who are likely to have a severe abnormal heart rhythm (such as ventricular tachycardia or ventricular fibrillation).

Emergency treatment: Severe symptoms of heart failure may occur suddenly and require prompt emergency treatment in a hospital. Such treatment can be life saving. The accumulation of fluid in the lungs (pulmonary edema) is often the most serious problem, so oxygen is usually given through a face mask or through short tubes inserted in each nostril (nasal prongs). A diuretic is given intravenously. Nitroglycerin (which dilates blood vessels) may be given intravenously or applied to the skin. Sometimes morphine is given to dilate blood vessels and relieve anxiety. These drugs can produce rapid, dramatic improvement. If needed, a breathing tube may be inserted into the person's airway for a short time. The tube is connected to a mechanical ventilator, which assists breathing.

Outlook

Heart failure usually worsens over time. Although many people with heart failure live for several years, more than three fourths of people die within 10 years. How fast heart failure worsens varies greatly from person to person. People with heart failure may die suddenly and unexpectedly, without symptoms becoming worse. Sudden death is usually caused by a severe abnormal heart rhythm (such as ventricular fibrillation). A person's outlook depends on the person's age, the cause of heart failure, and other disorders the person has. For example, the outlook is worse for people who have diabetes or a kidney disorder.

Eventually, severe heart failure may make doing daily activities difficult. If the usual treatments have not worked, health care practitioners should be asked to realistically describe what can be expected. Then together, the person with severe heart failure, family members, and practitioners can make decisions about care.

As heart failure progresses, care may focus more on treatments that relieve symptoms (palliative care) and less on treatments that may prolong life, although both types of treatment may be appropriate. Often, treatments to prolong life in people with severe heart failure are uncomfortable and expensive. They often do not improve quality of life. At some point, a decision to stop these treatments and to rely on palliative care may be appropriate.

Palliative care may involve using opioids (such as morphine) to relieve shortness of breath and tightness or fullness felt in the chest. Antianxiety drugs, such as clonazepam or lorazepam, can be used to relieve anxiety caused by feeling short of breath. Diuretics may be given in high doses to help the body get rid of excess fluid. Palliative care helps reduce suffering, enables a person to have a better quality of life, and helps the person prepare for death. Palliative care can also help family members cope with their grief.

Because people with heart failure often have little or no warning that death is near, they should prepare advance directives. For example, they should decide whether or under what circumstances they want cardiopulmonary resuscitation (CPR) if the heart suddenly stops beating. People should periodically review their advance directives because their wishes may change as heart failure worsens. Making or updating a will is also important.

See the sidebar What is Cardiomyopathy?

See the table Some Drugs Used for Heart Failure.