[Abnormalities of the peripheral circulation and tolerance to exertion of patients with heart failure]

Abstract

Chronic heart failure is attended by a number of abnormalities of peripheral circulation. To a great extent, these abnormalities determine the patients' functional symptoms, their tolerance to exercise and their response to treatment, at least in the short term. The response to exercise of heart failure patients depends on their maximal oxygen consumption which is determined by their maximal cardiac output and by various peripheral adjustments, such as distribution of regional blood flow and peripheral oxygen extraction. Abnormalities of peripheral arteriolar and capillary dilatation are determined by hyperstimulation of neurohormonal systems. An increase in maximal muscular blood flow, which determines the patients' capacity of exercise, can be obtained with drugs which increase the muscular perfusion pressure (inotropic drugs) or which decrease muscular resistances without lowering the perfusion pressure (venous or balanced vasodilators, diuretics). Physical rehabilitation may improve maximal oxygen consumption by improving the peripheral use of oxygen. Thus, a better understanding of the physiopathology of heart failure will in the future improve the functional symptoms of these patients and prolong their survival, which has not always been the case with conventional therapies.