Improved exercise performance and skeletal muscle strength after simulated altitude exposure: a novel approach for patients with chronic heart failure
Journal of Cardiac Failure, 05/04/2012
Saeed O et al. – Simulated altitude exposure up to 2,700 m is safe and well tolerated in patients with chronic stable heart failure (HF) and may have beneficial effects on exercise performance, muscular strength, and quality of life.Methods
- Subjects with chronic stable HF, left ventricular ejection fraction (LVEF) ≤35%, on optimal medical therapy were enrolled and underwent simulated altitude exposure for 10 sessions, each 3–4 hours, over a period of 22 days.
- Starting altitude was 1,500 m and was increased by 300 m with each subsequent session to a maximum altitude of 2,700 m.
- Peak oxygen consumption, 6–minute walk distance (6MW), skeletal muscle strength, quality of life scores, LVEF, and hematologic parameters were measured at baseline and 48 hours and 4 weeks after the final session.
- Twelve subjects (median age 52.5 y, ejection fraction 31.7%) successfully completed the protocol without any adverse effects.
- Peak oxygen consumption significantly improved after altitude sessions from 13.5 ± 1.8 to 14.2 ± 1.9 mL kg–1 min–1 (P = .036) and remained elevated after 4 weeks.
- There were significant improvements in exercise time, 6MW, skeletal muscle strength, and quality of life scores and a trend toward improvement in LVEF after completion of altitude sessions, which were sustained after 1 month.