POSTER SESSION 3: Friday, 2 May 2008, 8:00–13:00 Location: Poster Area

Abstract

M Zurek; RK Binder; H Saner; J-P Schmid Swiss Cardiovascular Centre Bern, Bern, Switzerland Purpose: Exercise oscillatory ventilation (EOV) is a respiratory pattern associated with severe chronic heart failure (CHF) and a predictor of poor prognosis. Cardiac rehabilitation (CR) is known to improve maximal exercise capacity and ventilatory efficiency in CHF patients (pts). However, the effect of CR on EOV is unknown. Methods: 20 CHF pts with EOV (mean age 59±9.3 years, LVEF 28.2 ±8.4%, peak VO2 16.3±3.4ml/min/kg) and 40 CHF pts without EOV (mean age 59±8.6 years, LVEF 27.2±8.8 %, peak VO2 18.6±4.6ml/min/ kg) underwent symptom limited cardiopulmonary exercise testing (CPET) on an upright bicycle ergometer before and after a 3 months outpatient CR programme. For the definition of EOV all of the following criteria had to be fulfilled: (1) 2 or more regular oscillatory fluctuations in VE; (2) minimal average amplitude of ventilatory oscillation of 5L; (3) a regular oscillation as defined by a standard deviation of 3 consecutive cycle lengths within 20% of the average. Magnitude of EOV was measured by the variation coefficient of minute ventilation (MV) during unloaded cycling and during incremental exercise by the correlation coefficient of MV. Results: Variation and correlation coefficient of MV significantly differed between pts with and without EOV before and after training (p<0.001). In pts with EOV both coefficients improved after CR (p<0.001 and p=0.004, respectively) whereas in the control group it remained unchanged (p=0.592 and p=0.617, respectively). In EOV pts VE/VCO2-slope significantly decreased from 36.6±6.9 to 30.7±5.9 (p=0.002) while PETCO2 significantly improved from 31.8±3.1 to 37.9 ±5.5 (p=0.001). The change in VE/VCO2-slope was significantly higher (p<0.019) than in the control group (change of PETCO2: p=0.063). The changes in the amplitude of EOV correlated significantly with changes in PETCO2 (r=0.667, p=0.007) and changes in VE/VCO2slope (r=0.591, p=0.02). Conclusion: EOV is sensitive to regular physical exercise training and improves after a 3 months CR programme. The amelioration of EOV correlates significantly with VE/VCO2 and PETCO2 . The impact of this amelioration on prognosis however remains to be shown.