Heart failure, also called congestive heart failure, is a disorder in which the heart loses its ability to pump blood efficiently. The term "heart failure" should not be confused with cardiac arrest, a situation in which the heart actually stops beating.

Heart failure is almost always a chronic, long-term condition, although it can sometimes develop suddenly. This condition may affect the right side, the left side, or both sides of the heart.

As the heart's pumping action is lost, blood may back up into other areas of the body:

• The liver
• The gastrointestinal tract and extremities (right-sided heart failure)
• The lungs (left-sided heart failure)

With heart failure, many organs don't receive enough oxygen and nutrients, which damages them and reduces their ability to function properly. Most areas of the body can be affected when both sides of the heart fail.

The most common causes of heart failure are the chronic cardiovascular diseases hypertension (high blood pressure) and coronary artery disease. Other structural or functional causes of heart failure include the following:

• Valvular heart disease
• Congenital heart disease
• Dilated cardiomyopathy
• Lung disease
• Heart tumor

Approximately 2 out of every 100 people between the ages of 27 and 74 have heart failure. Heart failure becomes more common with advancing age.

• Weight gain
• Swelling of feet and ankles
• Swelling of the abdomen
• Pronounced neck veins
• Loss of appetite, indigestion
• Nausea and vomiting
• Shortness of breath with activity, or after lying down for a while
• Difficulty sleeping
• Fatigue, weakness, faintness
• Sensation of feeling the heart beat (palpitations)
• Irregular or rapid pulse
• Decreased alertness or concentration
• Cough
• Decreased urine production
• Need to urinate at night

Infants may sweat during feeding (or other exertion).

Some patients with heart failure have no symptoms. In these people, the symptoms may develop only with these conditions:

• Infections with high fever
• Medications such as beta-blockers and calcium channel blockers
• Anemia
• Abnormal heart rhythm (arrhythmias)
• Hyperthyroidism
• Kidney disease

Other risk factors include obesity, excessive alcohol consumption, and a high-salt diet.

Listening to the chest with a stethoscope may reveal lung crackles or abnormal heart sounds. Blood pressure may be normal, elevated or low.

An enlargement of the heart or decreased heart functioning may be seen on several tests, including the following:

• Echocardiogram
• Heart catheterization
• Chest x-ray
• Chest CT scan
• Cardiac MRI
• Nuclear heart scans (MUGA, RNV)
• ECG, which may also show arrhythmias

This disease may also alter the following test results:

• CBC
• Blood chemistry
• Serum sodium
• BUN
• Creatinine
• Liver function tests
• Serum uric acid
• Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP)
• Urinalysis
• Urinary sodium
• Creatinine clearance
• Swan-Ganz measurements (right heart catheterization)

If excessive fluid has accumulated around the sac surrounding the heart (pericardium), you may need to have the fluid removed through a pericardiocentesis.

Heart failure must be monitored by your health care provider. The first step is usually to identify and treat any underlying disorders and precipitating factors. This may require a thorough diagnostic work-up, medications, catheter procedures, or surgery.

The goals include reducing the heart's workload, controlling excess salt and water retention (swelling, reduced urinary output) and improving heart function. In advanced cases or when the heart failure occurs suddenly (acute heart failure), bed rest or reduced physical activity are recommended to minimize the heart's workload.

If salt and fluid intake have been reduced and swelling persists or there are signs of severe systemic (body) or pulmonary (lung) congestion, it may be necessary to use diuretics (water pills). Diuretics include:

• Loop diuretics (e.g., furosemide, bumetanide) for moderate symptoms
• Thiazide diuretics (e.g., hydrochlorothiazide, chlorthalidone, chlorothiazide) for mild symptoms
• Potassium-sparing diuretics (spironolactone, triamterene) to prevent excessive potassium losses

Digoxin may also be given, especially if the heart rhythm is irregular due to atrial fibrillation.

Medications to reduce the heart's workload include ACE inhibitors such as captopril and enalapril, and angiotensin receptor blockers such as losartan and candesartan. Vasodilators such as hydralazine and long-acting nitrates are also commonly used.

The majority of patients, particularly those with a history of coronary artery disease, may benefit from low doses of beta-blockers.

Weight loss may be recommended for overweight patients. Patients should also reduce smoking and excessive alcohol consumption, because these decrease the pumping efficiency of the heart.

If symptoms are very limiting and minimal activity causes difficulty breathing, or if there is no response to the initial treatment, hospitalization may be required. Hospitalized patients may receive oxygen and intravenous medications such as vasodilators and diuretics.

The heart's ability to pump blood can be directly increased by medications called inotropic agents. These include dobutamine and milrinone, which are given intravenously.

Unstable patients receiving several medications usually need also hemodynamic monitoring with Swan-Ganz catheterization.

Severe cases require more drastic measures. For example, excess fluid can be removed through dialysis, and circulatory assistance can be provided by implanted devices such as the intra-aortic balloon pump (IABP) and the left ventricular assist device (LVAD). These devices can be life-saving, but they are not permanent solutions. Patients who become dependent on circulatory support will need a heart transplant.

• Pulmonary edema
• Total failure of the heart to function (circulatory collapse)
• Arrhythmias including lethal arrhythmias

Possible side effects of medications include:

• Low blood pressure (hypotension)
• Light-headedness and fainting
• Lupus reaction
• Headache
• Gastrointestinal upset (such as nausea, heartburn, diarrhea)
• Cough
• Muscle cramps
• Digitalis toxicity

Call your health care provider if weakness, increased cough or sputum production, sudden weight gain or swelling, or other new or unexplained symptoms develop.

Go to the emergency room or call the local emergency number (such as 911) if you experience severe crushing chest pain, fainting, or rapid and irregular heartbeat (particularly if other symptoms accompany a rapid and irregular heartbeat).