Is there only one type of heart failure?

The term congestive heart failure is often used to describe all patients with heart failure. In reality, congestion (the build up of fluid) is just one feature of the condition and does not occur in all patients. There are two main categories of heart failure--systolic and diastolic. However, within each category, symptoms and effects may differ from patient to patient. The two categories are:

 Systolic heart failure--This occurs when the heart's ability to contract decreases. The heart cannot pump with enough force to push a sufficient amount of blood into the circulation. Blood coming into the heart from the lungs may back up and cause fluid to leak into the lungs, a condition known as pulmonary congestion.

 Diastolic heart failure--This occurs when the heart has a problem relaxing. The heart cannot properly fill with blood because the muscle has become stiff, losing its ability to relax. This form may lead to fluid accumulation, especially in the feet, ankles, and legs. Some patients may have lung congestion.

How common is heart failure?

Between 2 to 3 million Americans have heart failure, and 400,000 new cases are diagnosed each year. The condition is slightly more common among men than women and is twice as common among African Americans as whites.

Heart failure causes 38,000 deaths a year and is a contributing factor in another 225,000 deaths. The death rate attributed to heart failure has doubled since 1968, in contrast to a greater than 50 percent decrease in coronary disease mortality during the same period. Heart failure mortality is twice as high for African Americans as whites for all age groups.

In a sense, heart failure's growing presence as a health problem reflects the Nation's changing population: More people are living longer. People aged 65 and older represent the fastest growing segment of the population, and the risk of heart failure increases with age. The condition affects 1 percent of people aged 50-59, but 10 percent of people aged 80-89.

What causes heart failure?

As stated, the heart loses some of its blood-pumping ability as a natural consequence of aging. However, a number of other factors can lead to a potentially life-threatening loss of pumping activity.

As a symptom of underlying heart disease, heart failure is closely associated with the major risk factors for coronary heart disease: smoking, high cholesterol levels, hypertension (persistent high blood pressure), diabetes and abnormal blood sugar levels, and obesity. A person can change or eliminate those risk factors and thus lower their risk of developing or aggravating their heart disease and heart failure.

Among prominent risk factors, hypertension (high blood pressure) and diabetes are particularly important. Uncontrolled high blood pressure increases the risk of heart failure by 200 percent, compared with those who do not have hypertension. Moreover, the degree of risk appears directly related to the severity of the high blood pressure.

Persons with diabetes have a three- to eight-fold greater risk of heart failure than those without diabetes. Women with diabetes having a greater risk of heart failure than men with diabetes. Part of the risk comes from diabetes' association with other heart failure risk factors, such as high blood pressure, obesity, and high cholesterol levels. However, the disease process in diabetes also damages the heart muscle.

The presence of coronary disease is among the greatest risks for heart failure. Muscle damage and scarring caused by a heart attack greatly increase the risk of heart failure. Cardiac arrhythmias, or irregular heartbeats, also raise heart failure risk. Any disorder that causes abnormal swelling or thickening of the heart sets the stage for heart failure.

In some people, heart failure arises from problems with heart valves, the flap-like structures that help regulate blood flow through the heart. Infections in the heart are another source of increased risk for heart failure.

A single risk factor may be sufficient to cause heart failure, but a combination of factors dramatically increases the risk. Advanced age adds to the potential impact of any heart failure risk.

Finally, genetics contributes to the risk for certain types of heart disease, which in turn may lead to heart failure. However, in most instances, a specific genetic link to heart failure has not been identified.

What are the symptoms?

A number of symptoms are associated with heart failure, but none is specific for the condition. Perhaps the best known symptom is shortness of breath ("dyspnea"). In heart failure, this may result from excess fluid in the lungs. The breathing difficulties may occur at rest or during exercise. In some cases, congestion may be severe enough to prevent or interrupt sleep.

Fatigue or easy tiring is another common symptom. As the heart's pumping capacity decreases, muscles and other tissues receive less oxygen and nutrition, which are carried in the blood. Without proper "fuel," the body cannot perform as much work, which translates into fatigue.

Fluid accumulation, or edema, may cause swelling of the feet, ankles, legs, and occasionally, the abdomen. Excess fluid retained by the body may result in weight gain, which sometimes occurs fairly quickly.

Persistent coughing is another common sign, especially coughing that regularly produces mucus or pink, blood-tinged sputum. Some people develop raspy breathing or wheezing.

Because heart failure usually develops slowly, the symptoms may not appear until the condition has progressed over years. The heart hides the underlying problem by making adjustments that delay--but do not prevent--the eventual loss in pumping capacity. The heart adjusts, or compensates, in three ways to cope with and hide the effects of heart failure:

Enlargement ("dilatation"), which allows more blood into the heart;

Thickening of muscle fibers ("hypertrophy") to strengthen the heart muscle, which allows the heart to contract more forcefully and pump more blood; and

More frequent contraction, which increases circulation.

By making these adjustments, or compensating, the heart can temporarily make up for losses in pumping ability, sometimes for years. However, compensation has its limits. Eventually, the heart cannot offset the lost ability to pump blood, and the signs of heart failure appear.

How do doctors diagnose heart failure?

In many cases, physicians diagnose heart failure during a physical examination. Readily identifiable signs are shortness of breath, fatigue, and swollen ankles and feet. The physician also will check for the presence of risk factors, such as hypertension, obesity, and a history of heart problems. Using a stethoscope, the physician can listen to a patient breathe and identify the sounds of lung congestion. The stethoscope also picks up the abnormal heart sounds indicative of heart failure.

If neither the symptoms nor the patient's history point to a clear-cut diagnosis, the physician may recommend any of a variety of laboratory tests, including, initially, an electrocardiogram, which uses recording devices placed on the chest to evaluate the electrical activity of a patient's heartbeat.

Echocardiography is another means of evaluating heart function from outside the body. Sound waves bounced off the heart are recorded and translated into images. The pictures can reveal abnormal heart size, shape, and movement. Echocardiography also can be used to calculate a patient's ejection fraction, a measure of the amount of blood pumped out when the heart contracts.

Another possible test is the chest x-ray, which also determines the heart's size and shape, as well as the presence of congestion in the lungs.

The chest x-ray also helps rule out other possible causes of a patient's symptoms. For instance, the symptoms of heart failure can result when the heart is made to work too hard, instead of from damaged muscle. Conditions that overload the heart occur rarely and include severe anemia and thyrotoxicosis (a disease resulting from an overactive thyroid gland).

What treatments are available?

Heart failure caused by an excessive workload are curable by treating the primary disease, such as anemia or thyrotoxicosis. Also curable are forms caused by anatomical problems, such as a heart valve defect. These defects can be surgically corrected.

However, for the common forms of heart failure--those due to damaged heart muscle--no known cure exists. But treatment for these forms may be quite successful. The treatment seeks to improve patients' quality of life and length of survival through lifestyle change and drug therapy.

Patients can minimize the effects of heart failure by controlling the risk factors for heart disease. Obvious steps include quitting smoking, losing weight if necessary, abstaining from alcohol, and making dietary changes to reduce the amount of salt and fat consumed. Regular, modest exercise is also helpful for many patients, though the amount and intensity should be carefully monitored by a physician.

But, even with lifestyle changes, most heart failure patients must take medication. Many patients receive two or more drugs.

Several types of drugs have proven useful in the treatment of heart failure:

Diuretics help reduce the amount of fluid in the body and are useful for patients with fluid retention and hypertension.

Digitalis increases the force of the heart's contractions, helping to improve circulation.

Results of recent studies have placed more emphasis on the use of drugs known as angiotensin converting enzyme (ACE) inhibitors. Several large studies have indicated that ACE inhibitors improve survival among heart failure patients and may slow, or perhaps even prevent, the loss of heart pumping activity.

Originally developed as a treatment for hypertension, ACE inhibitors help heart failure patients by, among other things, decreasing the pressure inside blood vessels. As a result, the heart does not have to work as hard to pump blood through the vessels.

Patients who cannot take ACE inhibitors may get a nitrate and/or a drug called hydralazine, each of which helps relax tension in blood vessels to improve blood flow.