Addition of inspiratory muscle training to aerobic training improves cardiorespiratory responses to exercise in patients with heart failure and inspiratory muscle weakness
Received 14 June 2009; accepted 3 September 2009. published online 05 October 2009.
Background
This small clinical trial tested the hypothesis that the addition of inspiratory muscle training (IMT) to aerobic exercise training (AE) results in further improvement in cardiorespiratory responses to exercise than those obtained with AE in patients with chronic heart failure (CHF) and inspiratory muscle weakness (IMW).
Methods
Twenty-four patients with CHF and IMW (maximal inspiratory pressure <70% of predicted) were randomly assigned to a 12-week program of AE plus IMT (AE + IMT, n = 12) or to AE alone (AE, n = 12). Before and after intervention, the following measures were obtained: maximal inspiratory muscle pressure (PImax), peak oxygen uptake (Vo2peak), peak circulatory power, oxygen uptake efficiency slope, ventilatory efficiency, ventilatory oscillation, oxygen uptake kinetics during recovery (T1/2V̇o2), 6-minute walk test distance, and quality of life scores.
Results
Compared to AE, AE + IMT resulted in additional significant improvement in PImax (110% vs 72%), V̇o2peak (40% vs 21%), circulatory power, oxygen uptake efficiency slope, ventilatory efficiency, ventilatory oscillation, and T1/2V̇o2. Six-minute walk distance and quality of life scores improved similarly in the 2 groups.
Conclusion
This randomized trial demonstrates that the addition of IMT to AE results in improvement in cardiorespiratory responses to exercise in selected patients with CHF and IMW. The clinical significance of these findings should be addressed by larger randomized trials.
aExercise Pathophysiology Research Laboratory and Cardiology Division, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil
bUniversidade Regional do Noroeste do Estado do Rio Grande do Sul-UNIJUI, Ijui, Brazil
cFaculty of Medicine, Department of Medicine, Federal University of Rio Grande Sul, Porto Alegre, Brazil
Reprint requests: Jorge P. Ribeiro, MD, ScD, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-007, Porto Alegre, RS, Brazil.
ABSTRACT