Article

Noninvasive ventilation may improve cardiovascular function and exercise
performance. We evaluated the physiologic impact of noninvasive ventilation
during isokinetic knee extension resistance exercise in patients with heart failure. This clinical trial included 10 male compensated patients with
ischemic heart failure (age, 57 +/- 9.1 years; ejection fraction, 28.5 +/- 5.8%).
Subjects underwent 2 bouts of exercise on an isokinetic dynamometer, separated by
72 hours of rest. The resistance exercise was concentric knee extension, at a
speed of 60 degrees /s. Five sets of 10 repetitions were performed during the 2
exercise bouts, and each set was separated by 2 minutes of rest. Subjects were
administered either bilevel positive airway pressure ventilation (BV) or sham
ventilation 20 minutes before and during the 2 exercise sessions in a randomized
fashion. Heart rate, systolic blood pressure, and diastolic blood pressure were
measured at rest, during exercise, and into recovery. Changes in peak torque
(DeltaPT), total work (DeltaTW), and power (DeltaPw) between the fifth and first
sets were also measured. RESULTS: Compared with the sham intervention, BV
significantly decreased heart rate, systolic blood pressure, and diastolic blood
pressure at rest and during exercise (P < .01). There were no significant
differences in these variables during recovery. Bi-level positive airway pressure
ventilation also significantly reduced DeltaPT, DeltaTW, and DeltaPw compared
with the sham intervention (P < .01). CONCLUSIONS: Bi-level positive airway
pressure ventilation significantly improved the cardiovascular response and
fatigability during resistance exercise in patients with heart failure. These
results suggest that use of BV during exercise training may be beneficial in this
population with chronic disease.

Langue : ANGLAIS