Aerobic Interval Exercise Training Improves Ventilatory Efficiency in Patients with Chronic Heart Failure

Abstract

Ventilation-perfusion mismatching is responsible for dyspnea-related exercise intolerance in HF. However, which exercise prescription yields optimal ventilatory efficiency against exercise dyspnea in HF patients remains unclear. This study investigates how interval and continuous exercise regimens affect ventilatory efficiency with exercise in patients with HF. Thirty patients with HF were randomly divided into moderate continuous exercise training group (MCT; 60% VO2peak, n=10), aerobic interval exercise training group (AIT; 3-minute intervals at 80% and 40% of VO2peak, n=10), and general healthcare group (GHC, n=10) for 12 weeks. Hemodynamic and ventilatory responses to exercise were determined by an integrated system of bio-reactance-based measurement and automatic gas analysis. The results demonstrated that AIT increased value of VO2peak, steeped oxygen uptake efficiency slopes (OUES), and depressed VE-VO2 slope, whereas these levels of VO2peak, OUES, and VE-VO2 slope unchanged following MCT. Moreover, AIT furthered the extent of cardiac output (CO) elevated by exercise compared to MCT did. However, GHC decreased hemodynamic and ventilatory responses to exercise below to pre-interventional levels. The COpeak were directly related the OUES and VO2peak, and inversely related to the VE-VCO2 slope. Therefore, we conclude that AIT improves more efficiency in ventilation-perfusion matching during exercise than MCT does in patients with HF.