12 weeks of exercise training in patients with NYHA Class III heart failure significantly increased VO2peak (P=0.01) and maximal sustainable ventilatory capacity (P<0.001).
Cohort (n=24)
Does 12 weeks of exercise training improve respiratory muscle endurance, exercise tolerance, breathlessness, and quality of life in patients with NYHA Class III heart failure?
A 12-week exercise training program in patients with NYHA Class III heart failure improves respiratory muscle endurance, exercise capacity, and quality of life without changing cardiac output or stroke volume.
p-value: P=.01 for VO2peak, P<.001 for MSVC
PURPOSE: Increased respiratory muscle endurance and peak oxygen consumption (VO(2peak)) induced by respiratory muscle training support the relationship between respiratory muscle function and exercise capacity in patients with heart failure. This raises the question whether exercise-training results in increased respiratory muscle function contributing to an increased exercise tolerance, a decreased perception of breathlessness, and an improved quality of life. METHODS: Prospective cohort analysis was completed on 24 patients with New York Heart Association (NYHA) Class III heart failure 18 men, 6 women; aged = 64 (SD 7.9) years; percent ejection fraction (%EF) = 24.0 (SD 7.8). Maximal sustainable ventilatory capacity (MSVC), submaximal and peak exercise responses, perception of breathlessness, and quality of life were measured before (baseline) and after (end of study) 12 weeks of exercise training. RESULTS: As a result of exercise training, VO(2peak) (P=.01) and MSVC (P<.001) increased, with MSVC contributing to a larger proportion of the variability for VO(2peak) at study completion (r=0.57 vs 0.42). Although stroke volume did not increase beyond exercise at 25 W and did not change with exercise training, ventilation decreased during exercise (P<.05), perception of breathing difficulty (P<.05) was reduced, and quality of life was enhanced (P=.008). CONCLUSIONS: Despite no increase in cardiac output and stroke volume, respiratory muscle endurance improved with exercise training, contributing to increased exercise capacity, decreased breathlessness, and decreased perception of breathlessness. Practical implications can include less frequent rest periods and fatigue, greater confidence, maintenance of independence, and enhanced quality of life.
McConnell et al. (2003) conducted a cohort in New York Heart Association (NYHA) Class III heart failure (n=24). Exercise training vs. Baseline (before training) was evaluated on Peak oxygen consumption (VO2peak) and maximal sustainable ventilatory capacity (MSVC) (p=P=.01 for VO2peak, P<.001 for MSVC). 12 weeks of exercise training in patients with NYHA Class III heart failure significantly increased VO2peak (P=0.01) and maximal sustainable ventilatory capacity (P<0.001).