Relationship of characteristic duration and magnitude of the oscillatory breathing related with exercise functional capacity in patients with chronic heart failure

Abstract

Objective: To find out the relationship between the duration and amplitude of oscillatory breathing (OB) and their exercise capacity in patients with chronic heart failure (CHF) we did this study. Methods: Two hundred and thirty-seven CHF patients performed a maximum incremental upright cycle ergometry cardiopulmonary exercise testing (CPET). Respiratory gas exchange was measured on a breath-by-breath basis throughout the test. OB was defined as 3 or more continuous cycle fluctuations of ventilation during CPET, and the amplitude of VE oscillations exceed 25% of concurrent mean value. The CHF patients with OB (OB+) were divided into 3 sub-groups according to their Peak VO2. Group1 (mild OB+) Peak VO2 of ≥16 ml/min/kg, group 2 (moderate OB+) Peak VO2 is between 12~16 ml/min/kg, group 3 (severe OB+) Peak VO2 ≤ 12 ml/(min·kg). Results: There were 78(32.6%) patients detected as OB+ in 237 CHF patients. Among OB+ patients, OB duration in s related negatively to Peak VO2 in mL/min/kg (r=-0.82), Peak VO2 in %pred (r=-0.65), VO2 at AT (r=-0.78), and related positively to VE/VCO2 at AT (r=0.61). Conclusion: OB duration is related negatively to exercise capacity of CHF patients.