Congestive Heart Failure

Congestive Heart Failure Overview

The heart is fundamentally a blood pump. It pumps blood from the right side of the heart to the lungs to pick up oxygen. The oxygenated blood returns to the left side of the heart. The left side of the heart then pumps blood into the circulatory system of blood vessels that carry blood throughout the body.

The heart consists of four chambers.

• The two upper chambers are called atria and the two lower chambers are called ventricles.
• The right atrium and right ventricle receive blood from the body through the veins and then pump the blood to the lungs.
• The left atrium and left ventricle receive blood from the lungs and pump it out through the aorta into the arteries, which feed all organs and tissues of the body with oxygenated blood.
• Because the left ventricle has to pump blood to the entire body, it is a stronger pump than the right ventricle.

Heart failure sounds frightening because it sounds like the heart just stops working. Do not be discouraged by the term heart failure. Heart failure means the tissues of the body are temporarily not receiving as much blood and oxygen as needed. With advancements in diagnosis and therapy for heart failure, patients are feeling better and living longer.

Picture of congestive heart failure. The heart is a pump that works together with the lungs. The heart pumps blood from the veins through the lungs where oxygen is added and then moves it on to the arteries. This pumping action creates a relatively high pressure in the arteries and a low pressure in the veins. Image courtesy of Bryan Moss at Scott and White Hospital, and David A. Smith, MD.

Heart failure is an illness in which the pumping action of the heart becomes less and less powerful. When this happens, blood does not move efficiently through the circulatory system and starts to back up, increasing the pressure in the blood vessels and forcing fluid from the blood vessels into body tissues. Symptoms depend on which area of the body is most involved in the reduced pumping action.

• When the left side of the heart (left ventricle) starts to fail, fluid collects in the lungs (pulmonary edema). This extra fluid in the lungs (pulmonary congestion) makes it more difficult for the airways to expand as a person inhales. Breathing becomes more difficult and the person may feel short of breath, particularly with activity or when lying down.
• When the right side of the heart (right ventricle) starts to fail, fluid begins to collect in the feet and lower legs. Puffy leg swelling (edema) is a sign of right heart failure, especially if the edema is pitting edema. With pitting edema, a finger pressed on the swollen leg leaves an imprint. Non-pitting edema is not caused by heart failure.
• As the right heart failure worsens, the upper legs swell and eventually the abdomen collects fluid (ascites). Weight gain accompanies the fluid retention and is a reliable measure of how much fluid is being retained.

Although heart failure is a serious medical condition, there are many causes and the outcome can vary from person to person. Heart failure may develop gradually over several years, or more quickly after a heart attack or a disease of the heart muscle. Congestive heart failure (CHF) is generally classified as systolic or diastolic heart failure and becomes progressively more common with increasing age. In addition, patients with risk factors for heart disease are more likely to develop congestive heart failure.

Systolic heart failure: This condition occurs when the pumping action of the heart is reduced or weakened. A common clinical measurement is ejection fraction (EF). The ejection fraction is a calculation of how much blood is ejected out of the left ventricle (stroke volume) divided by the maximum volume remaining in the left ventricle at the end of diastole, or when the heart is relaxed after filling with blood. A normal ejection fraction is greater than 55%. Systolic heart failure is diagnosed when the ejection fraction has significantly decreased below the threshold of 55%.

Diastolic heart failure: This condition occurs when the heart can contract normally but is stiff, or less compliant, when it is relaxing and filling with blood. The heart is unable to fill with blood properly, which produces backup into the lungs and heart failure symptoms. Diastolic heart failure is more common in patients older than 75 years of age, especially in patients with high blood pressure, and it is also more common in women. In diastolic heart failure, the ejection fraction is normal or increased.

Heart failure affects 2% of the adult population. In the United States, nearly four million people have heart failure. Each year about 550,000 new cases are diagnosed. The condition is more common among African Americans than Caucasians.

• Heart failure affects 1% of people age 50 years or older, about 5% of those age 75 years or older, and 25% of those age 85 years or older.
• Heart failure is the most common reason for Medicare patients to be admitted to the hospital.
• As the number of elderly people continues to rise, often from the successful treatment of other types of heart disease, the number of people diagnosed with this condition will likely increase. The rate of death from heart failure is about 10% after one year. About half of those with congestive heart failure die within five years after their diagnosis. These statistics vary widely; a patient's exact diagnosis and response to therapy play a large role in patient survival. Any questions about diagnoses and therapy should be discussed with the treating physician. Advances in research are providing more options and improving outcomes for people with congestive heart failure.