Effects of interval exercise training on respiratory drive in patients with chronic heart failure

SummaryBackgroundPatients with chronic heart failure (CHF) suffer from ventilatory abnormalities. This study examined the effects of interval exercise training on the respiratory drive in CHF patients.MethodsForty-six clinically stable CHF patients (38 males/8 women, mean age = 53 ± 11 years) participated in an exercise rehabilitation program (ERP) 3 times/week, for 12 weeks by interval training modality with or without the addition of resistance training. All patients underwent symptom-limited cardiopulmonary exercise testing (CPET), and measurements of mouth occlusion pressure at 100 ms (P0.1) and maximum inspiratory muscle strength (PImax) before and after ERP. Respiratory drive was estimated by mouth occlusion pressure P0.1 and P0.1/PImax ratio at rest, and the ventilatory pattern by resting mean inspiratory flow (VT/TI) and by VT/TI at identical CPET workloads, before and after ERP. We also studied a control non exercising group of 11 patients (8 men and 3 women).ResultsP0.1 at rest decreased from 3.04 ± 1.52 to 2.62 ± 0.9 cmH2O (p = 0.015), P0.1/PImax % at rest from 4.56 ± 3.73 to 3.69 ± 2.03 (p = 0.006), resting VT/TI from 0.44 ± 0.10 to 0.41 ± 0.10 l/s (p = 0.014), and VT/TI at identical work rate from 2.13 ± 0.59 to 1.93 ± 0.58 l/s (p = 0.001) after ERP. VO2 at peak exercise increased from 16.3 ± 4.8 to 18.5 ± 5.3 ml/kg/min (p < 0.001) in the exercise group. No improvement was noted in the control group.ConclusionsERP by interval training improves the respiratory drive and ventilatory pattern at rest and during exercise in CHF patients