Heart failure, also called congestive heart failure, is a life-threatening condition in which the heart can no longer pump enough blood to the rest of the body.

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, including:

• 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 hypertension (high blood pressure) and coronary artery disease (for example, you have had a heart attack). Other structural or functional causes of heart failure include the following:

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

Heart failure becomes more common with advancing age. You are also at increased risk for developing heart failure if you are overweight, have diabetes, smoke cigarettes, abuse alcohol, or use cocaine.

• 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
• Anemia
• Abnormal heart rhythm (arrhythmias)
• Hyperthyroidism
• Kidney disease

A physical examination may reveal either an irregular or a rapid heartbeat. There may be distended neck veins, enlarged liver, swelling of the limbs (peripheral edema), and signs of fluid around the lungs (pleural effusion).

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