Epidemiologic patterns, clinical evaluation, and long-term prognosis in chronic congestive heart failure.

Congestive heart failure affects more than 2,000,000 Americans and is likely to increase in prevalence as our population ages. Clinical congestive heart failure should not be equated with cardiac dysfunction, as indexes of cardiac performance do not correlate with clinical manifestations. The clinical signs and symptoms of heart failure often lack sufficient sensitivity and specificity to permit accurate diagnosis. Objective tests, such as echocardiography and radionuclide angiography, are usually needed to establish the presence of left ventricular dysfunction, and exercise testing may be needed to quantitate symptomatic severity. Indexes of cardiac function do not correlate well with symptomatic status, and clinical assessment of severity of symptoms is often inaccurate. Therefore, exercise testing may be very useful in assessing symptomatic severity and in following patient progress. Prognosis in heart failure is very poor, with fewer than 50 percent of patients surviving five years from the time of initial diagnosis. Survival appears to relate more to the degree of cardiac dysfunction and less to the degree of symptomatic severity. Early recognition of heart failure in a latent stage and development of strategies aimed at preventing or delaying the onset of overt heart failure appear to offer the best chance of reducing mortality from heart failure.