HEART FAILURE

inability of either or both sides of the heart to pump sufficient blood to meet the needs of the body. The term is to be distinguished from heart attack, which generally refers to myocardial infarction, or death of a section of heart muscle. The condition also differs from heart block, a lack of coordination of the contractions of the upper and lower chambers of the heart, and from heart arrest, the sudden cessation of cardiac function. Heart failure is characterized by distension of the veins serving the lungs or of those serving the rest of the body, or of both; this engorgement is expressed in the term congestive heart failure. Failure of the right side of the heart may result from pulmonary heart disease. Other prominent causes of heart failure are abnormally high blood pressure (hypertension), coronary atherosclerosis (the presence of fatty deposits in the lining of the coronary arteries), and rheumatic heart disease. A person with left-sided heart failure experiences shortness of breath after exertion, difficulty in breathing while lying down, spasms of breathlessness at night, and abnormally high pressure in the pulmonary veins. A person with right-sided failure experiences abnormally high pressure in the systemic veins, enlargement of the liver, and accumulation of fluid in the legs. A person with failure of both ventricles has an enlarged heart that beats in gallop rhythm-that is, in groups of three sounds rather than two. Treatment is directed toward increasing the strength of the heart muscle's contraction (rest in bed and digitalis are prescribed); toward reduction of fluid accumulation by restriction of sodium intake and increase of sodium excretion; and toward elimination of the underlying cause of the failure. See also heart block; myocardial infarction.