Effects of exercise training on the hemodynamics in patients with chronic heart failure

Background and purpose: It is still unclear physiological mechanisms of preserved exercise-tolerance in patients with stable chronic heart failure, irrespective decreased left ventricular ejection fraction. We tried to investigate underlying mechanisms. Methods: Consecutive 62 patients with stable chronic heart failure under oral medications were enrolled (NYHA II-III). Exercise test was performed on a symptomlimited bicycle ergometer. We analyzed changes in cardiac parameters by means of non-invasive whole body electrical bio-impedance using NICaS apparatus during exercise. Age (yrs, 25%-75% range): 63 (49-72). Ejection Fraction (%): 61 (38- 69). Basic diseases of heart failure: Idiopathic dilated cardiomyopathy 22; Valvular heart disease 22; Old myocardial infarction 15; Congenital heart disease 2; Hypertensive heart disease 1. Results: Comparing before and after exercise, heart rate was significantly increased after exercise, but there were no significant changes in mean blood pressure. While total peripheral vascular resistance index tended to be decreased, cardiac index tended to be increased. Conclusions: There might exist beneficial physiological mechanisms to decrease total peripheral vascular resistance accompanied with increasing cardiac output during exercise in patients with stable chronic heart failure associated with preserved exercise-tolerance. Exercise-induced peripheral vasodilation may underlie