Regulation of circulation in congestive heart failure.

Regulation of extremity (limb) circulation was studied in 21 patients suffering from congestive heart failure. In 11 cases the peripheral circulation was intact, while 10 patients also suffered from peripheral obliterative arterial disease. Data of 75 patients with normal cardiac condition served as control: 35 subjects with intact peripheral circulation and 40 patients suffering from peripheral obliterative arterial disease. Limb blood flow was measured by using venous isotope dilution technique. Cardiac output was determined by the dye dilution method. In chronic heart failure the limb circulation characteristically deviated from the normal; the limb blood flow and the limb oxygen consumption slightly decreased, while the limb vascular resistance markedly increased. The diminution of the limb blood flow and the increase in the limb vascular resistance due to obliterative arterial disease were more pronounced in patients suffering from congestive heart failure. The pathological increase in the peripheral vascular resistance due to chronic heart failure proved mostly reversible; on the administration of vasodilator drugs the elevated limb vascular resistance markedly decreased and the limb blood flow significantly increased.