Heart Failure

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Heart failure (sometimes known as congestive heart failure [CHF]) is a serious condition in which the heart is not pumping efficiently. It is a chronic condition that is the result of other cardiac conditions.

In the late stages of heart failure, the heart is unable to meet the body’s demand for oxygen. In addition, it may cause congestion in the lungs or other problems throughout the body. As a result of the lack of oxygen-rich blood flowing to the body, the heart tries to work harder, which only makes the problem worse.

Conditions that could lead to heart failure include:

About heart failure

Heart failure is a serious condition in which the heart’s pumping action is compromised. In the early stages, heart failure may not have any symptoms. In the later stages, the patient may have severe symptoms because their weakened heart is unable to pump enough oxygen-rich blood with each contraction to satisfy the body. These symptoms may include shortness of breath (dyspnea) that initially occurs only during exercise, and later even while at rest.

Heart failure is a chronic and complex condition. By itself, heart failure is not considered a disease. Rather, it is the result of other conditions that damaged the heart. These other conditions include diseases of the coronary arteries that lay on the surface of the heart, heart valve disorders, high blood pressure and damage to the heart muscle itself.

In spite of its name, heart failure does not mean the heart has completely stopped, which is the case when someone has gone into cardiac arrest. Heart failure means the heart is not operating efficiently and therefore must work harder to make up for the shortcoming. For example, the heart may pump more frequently to compensate for its weakened pumping ability, or the size of its chambers may increase, especially the left ventricle.

The longer the heart must overwork to compensate for its shortcomings, the more its pumping ability is damaged and the more likely that serious pumping failure will result. Before a pumping failure occurs, however, various physical changes may take place in the heart and throughout the body as a result of the heart failure. They include:

  • Remodeling . This significant physical change occurs with heart failure. Remodeling is most notably characterized by enlargement and thinning of the left ventricle. This results in an increased use of oxygen, a greater degree of mitral valve regurgitation and decreased ejection fraction. The process is a complex one. Contributing factors include the release of hormones in response to inflammation caused by heart failure and certain genetic factors that affect how the heart reacts to disease or injury. Whatever the causes, left ventricular remodeling sets in motion an unhealthy domino effect, as progressive damage to heart cells leads to reduced cardiac output and more severe heart disease. This weakening may be “global,” as in cardiomyopathy, or regional, affecting only part of the left ventricle.

Enlarged Heart

  • Hypertrophy of the heart walls. The heart walls may thicken in an attempt to strengthen their pumping ability.
  • Tachycardia . An abnormally fast heartbeat that could result from the heart’s attempt to function more efficiently.
  • Kidney malfunction. Initially, the kidneys respond to the heart’s low volume output by retaining water and salt. This is because the kidneys perceive a low volume state, as if the person is dehydrated, and respond in kind. Unfortunately, the kidneys’ response actually worsens the fluid buildup and can contribute to high blood pressure. This places added stress on the filters in the kidneys (nephrons) and is a major cause of kidney failure.

Although the term heart failure usually refers to the chronic condition described in this article, there is also a condition known as acute heart failure. It is sudden in onset and usually results from a sudden catastrophic change in the heart (e.g., massive heart attack, endocarditis, ruptured or torn heart valve leaflets, aortic dissection). In acute heart failure, the heart muscle does not have time to hypertrophy and enlarge. This condition is often fatal, even if emergency medical treatment is received immediately.

Types and differences of heart failure

There are a number of different ways that physicians and medical institutions classify and define heart failure. It may be classified by the portion of the heart that it affects or by its involvement with the heart rhythm. Alternatively, heart failure may be defined by the symptoms that are present or by the progressive stage of the condition.

Heart failure may be classified by which side of the heart it affects:

  • Left-sided heart failure occurs when the left ventricle cannot adequately pump oxygen-rich blood from the heart to the rest of the body. The main symptoms include shortness of breath, fatigue and coughing, especially at night or while lying down. There may also be lung congestion (with both blood and fluid).
  • Right-sided heart failure (cor pulmonale) takes place when the right ventricle is not pumping adequately, which tends to cause fluid build-up in the veins and swelling (oedema) in the legs and ankles. Right-sided heart failure usually occurs as a direct result of left-sided heart failure. It can also be caused by severe lung disease (e.g., chronic obstructive pulmonary disease, pulmonary hypertension) in which the right side of the heart cannot generate enough force to pump blood through a diseased pair of lungs.

Heart failure is also commonly defined by which portion of the cardiac cycle is affected:

  • Systolic heart failure means that the heart is unable to pump adequate amounts of blood during its contraction (systole). Lung congestion and swelling (oedema) of the lower extremities are typical symptoms of systolic heart failure. This is most commonly caused by coronary artery disease, high blood pressure and heart valve disease.
  • Diastolic heart failure refers to the heart’s inability to relax between contractions (diastole) and allow enough blood to enter the ventricles. Symptoms may be identical to systolic heart failure. Diastolic heart failure is often a precursor to systolic heart failure. Patients with diastolic heart failure may or may not have normal systolic function. Diastolic dysfunction causes about one-third of all heart failure in people over age 65 and occurs more often among women. This is most commonly caused by coronary artery disease, high blood pressure and cardiomyopathy.

To better understand the differences between systolic and diastolic heart failure, picture the heart as a balloon. Systolic heart failure is when the heart muscle is weak and flabby, like an old, worn-out balloon. Diastolic heart failure is when the heart muscle is stiff and hard, like a brand-new, never-inflated balloon. Neither extreme allows the heart to function properly, leading to a build up of blood in the lungs and shortness of breath (dyspnea).

In addition to these classifications, heart failure may be defined by how it affects patients. The New York Heart Association has developed a system that defines heart failure by the functional limitation it imposes on the patient. These levels are as follows (with approximate percentage of patients):

  • Class I: No obvious symptoms, no limitations on patient physical activity (35 percent of heart failure patients).
  • Class II: Some symptoms during or after normal activity, mild physical activity limitations (35 percent of heart failure patients).
  • Class III: Symptoms with mild exertion, moderate to significant physical activity limitations (25 percent of heart failure patients).
  • Class IV: Significant symptoms at rest, severe to total physical activity limitations (5 percent of heart failure patients).

The American Heart Association (AHA) and American College of Cardiology have developed a way to define heart failure that groups patients by their risk of developing heart failure. This system is useful because it helps physicians design a therapeutic approach to heart failure. The AHA/ACC stages are:

  • Stage A: The patient at high risk for heart failure, but has no heart abnormalities.
  • Stage B: The patient has structural abnormalities of the heart, particularly the left ventricle, but no symptoms.
  • Stage C: The patient has past or present symptoms associated with heart failure.
  • Stage D: The patient has end-stage heart disease, requiring specialized treatment (e.g., continuous intravenous (I.V.) drug therapy, left ventricular assist device, heart transplant) or severely symptomatic heart failure.

Signs and symptoms of heart failure

There are two major underlying causes of the symptoms in heart failure: excess fluid accumulation that may occur in the lungs or elsewhere, and symptoms associated with reduced cardiac output that worsens with exertion. These symptoms may develop over a lengthy span of time, even over a period of years. Because they may not seem important on their own, people may not seek treatment until heart failure has caused significant damage. Specific symptoms include:

  • Shortness of breath (dyspnea). This is one of the earliest symptoms of heart failure. The patient gets winded and fatigued more quickly than before, just by doing regular daily activities or even lying in bed. There is also decreased tolerance to exercise, and the muscles may feel weaker than before.
  • Swelling (oedema) of the legs is another common symptom in heart failure, though it could also be caused by unrelated conditions.
  • Swollen neck veins.
  • Abdominal discomfort such as swelling, pain or nausea.
  • Mental confusion.
  • Racing or pounding heartbeat (palpitations).
  • Kidney malfunction or failure (in the later stages of heart failure).

In addition to the symptoms listed above, which the patient may notice, the physician may also be able to detect signs of congestive heart failure, which may include:

  • An abnormal heart murmur (a telltale sign of a valve-related disorder).
  • A crackling sound of fluid in the lungs (rales), which is a sign of pulmonary congestion.
  • A rapid heartbeat (tachycardia) or abnormal heart rhythm (arrhythmias).
  • Swelling and fluid retention (oedema) in the liver or gastrointestinal tract (in advanced stages of heart failure).
  • Hypertrophy or enlargement of the heart.
  • Liver malfunction.

Diagnosis methods for heart failure

There is no single test that can diagnose heart failure. Rather, the diagnosis is usually based upon a medical history and complete physical examination, which includes a blood pressure check, listening to the patient’s heart through a stethoscope and taking the patient’s pulse. Additional tests that a physician may use to determine the cause and severity of heart failure include:

  • Blood tests . Traditional tests evaluate potential causes of heart failure, such as anaemia and thyroid function, and electrolytes and kidney function. However, a new test may be effective in diagnosing heart failure. The blood test measures levels of B–type natriuretic peptide (BNP), a protein that is produced by the heart as it fails.
  • Echocardiogram of the heart and major arteries. This test uses ultrasound technology to closely examine the overall muscle function of the heart, allowing the physician to evaluate the size, thickness and pumping action of the heart, as well as evaluate how well the heart valves are functioning. A stress echocardiogram may also be useful in assessing how well the heart is functioning at rest and during exercise. An echocardiogram is the single most important test for the diagnosis of heart failure.
  • Electrocardiogram (ECG). A test that measures the heart’s electrical activity. It is designed to detect any abnormal heart rhythms, heart enlargement, cardiac ischemia or heart attack.
  • Exercise stress test . A test in which an ECG is performed at rest and then under the physical stress of exercise, to evaluate the heart’s performance at rest and during times of physical exertion.
  • Radionuclide imaging tests, such as a radionuclide stress test or ventriculogram. These provide contrast images of the heart, which can pinpoint areas of damage and/or dysfunction and determine how well the heart is pumping.
  • Chest x-ray to evaluate the size and shape of the heart, as well as to view the lungs and any fluid that may have built up.

More invasive tests may be ordered in conjunction with, or instead of the above. These tests include a coronary angiogram, in which a contrast dye is delivered by catheter to the coronary arteries to visualize the blood vessels and identify heart damage or dysfunction.

Treatment options for heart failure

Heart failure is usually a chronic condition that has taken years to develop and worsen. Treatment for heart failure is generally designed for three purposes: to improve any symptoms, to slow progression of the heart failure, and to prolong survival. In addition, physicians may choose to treat the underlying conditions that contributed to the heart failure.

Finally, most patients are advised to make lifestyle changes, regardless of the severity of their condition. These may include modifying their diet, limiting salt intake, achieving and maintaining a healthy weight (see Weight Loss), learning and practicing stress management skills, quitting smoking, and getting regular exercise, depending on the severity of the illness.

Lifestyle choices that are more specific to heart failure may include:

  • Limiting physical activity until approved by one’s physician, and then staying as active as possible. Heart failure patients who exercise regularly typically show significant improvement, whereas heart failure patients who are inactive show a clear decline. In studies, Tai Chi (an ancient Chinese workout involving slow, relaxing movements) has been shown to benefit patients living with heart failure. However, exercise in any form is beneficial. Patients should consult their physician before beginning an exercise program.
  • Scheduling relaxation and rest periods throughout the day.
  • Avoiding excessive fluid intake.
  • Keeping a diary of one’s daily weight, and notifying one’s physician if there is a weight gain of three or more pounds in a single week (which may indicate fluid retention and the need for an immediate change in treatment). Patients experiencing weight loss in spite of what appears to be adequate calorie intake should also discuss their situation with their physician. A study has found that some patients with heart failure may need to adjust their diet to meet increased energy needs.
  • Avoiding excessive salt intake, which may contribute to fluid retention.
  • Limit alcohol intake.

Patients with heart failure should always consult their physician before taking any over-the-counter medicines, vitamins or herbal supplements.

Depending upon the nature of the underlying damage or malfunction that led to heart failure, medications may be prescribed to reduce the heart’s workload, affect remodeling, counter abnormal hormonal levels, increase blood flow, widen vessels or eliminate excess water from the body. Because the medications have different effects, they may be used in combination. Medications used to treat heart failure and related conditions include:

  • ACE inhibitors . A type of vasodilator that expands blood vessels to allow blood to flow easier and more freely, allowing the heart to pump more efficiently. ACE inhibitors act by preventing the production of a chemical that causes blood vessels to expand so the heart does not have to work as hard to pump blood. Reports from the National Institutes of Health indicate that the use of ACE inhibitors has been the most significant factor in heart failure survival rate improvement over recent years. They also have a favorable impact on the heart itself (e.g., affecting remodeling).
  • Angiotensin II receptor blockers may also be used in conjunction with ACE inhibitors. They can also be used in patients who cannot take ACE inhibitors or beta blockers.
  • Beta blockers . May prevent progression of the disease and improve symptoms by slowing the heart’s contraction rate and reducing its pumping action, thus lessening the heart’s workload. For many years beta blockers were considered inappropriate for people with heart failure because they can potentially weaken the heart muscle and cannot be used when the patient’s health is unstable. Recent studies have shown that selected beta blockers may be very helpful in treating heart failure. They have been shown to decrease mortality and improve left ventricular function in these patients. Beta blockers also reduce the likelihood that these patients will suffer from significant heart rhythm problems.
  • Diuretics . Often referred to as water pills, these reduce the symptoms of congestion by helping to flush excess salt and fluids from the body. They are very useful in treating people with heart failure and fluid retention. Spironolactone, a “potassium-sparing” diuretic, has been found to be effective therapy in patients with severe heart failure.
  • Inotropes . Intravenous (I.V.) drugs that increase the force of the heart’s contractions, allowing the heart to beat less frequently and more effectively. Individuals with severe heart failure often benefit from being hospitalized and being given these powerful medicines intravenously for 24 to 48 hours.
  • Digoxin . A weak inotrope, digoxin appears to have an effect on hormones that make heart failure worse. It helps the heart contract more vigorously and effectively, and helps to reduce the symptoms of heart failure. It is most often used to control the fast heart rate of atrial fibrillation.
  • Nitrates . These medications dilate the blood vessels, reduce the amount of blood returning to the heart, reduce the pressure in the arteries and make it easier for the heart to pump blood

In some cases, the physician will also seek to treat the underlying condition that caused the heart failure in the first place. Although not common, heart failure can be reversed once the underlying condition has been treated. For most people, however, heart failure is a chronic and progressive condition that can be managed but rarely cured.

If the heart failure was caused by coronary artery disease, the patient may be recommended for:

Other surgical and invasive therapies used to treat underlying conditions that contribute to heart failure include: