Abstract des Autors

Objective: Heart rate provides a poor guide to exercise prescription after cardiac transplantation. This study explores whether the rating of perceived exertion (RPE) provides useful alternative information. Methods: Borg's original categoric scale was applied to 36 male patients (T, age 47(SD 9) years) as they performed a progressive cycle ergometer test an average of seven months (range two to 23 months) after cardiac transplantation. The test was repeated after 16(7) months of progressive exercise-centred rehabilitation. Sedentary but healthy controls (C, n=45, age 45(7) years) performed a similar progressive cycle test. Results: Initially, 13 RPE units corresponded to 66(12)% of peak VO2 in T and 50(11)% in C. Rehabilitation augmented peak VO2 (by 19%) and estimated lean body mass (by 3.5%) in the cardiac transplant patients. The increase of heart rate (HR) at 13 RPE units (delta HR=10(17) beats/min) showed moderate correlations with gains of lean mass (r=0.72) and gains of peak VO2 (r=0.58). The relative oxygen intake at 13 RPE units remained unchanged at 68(12)% of peak VO2. Conclusions: Large inter-individual variations of RPE at a given VO2 limit the value of perceived exertion in exercise presecription. Ratings seem best restricted to fine tuning fixed distance/fixed speed exercise prescriptions in patients undergoing rehabilitation after cardiac transplantation. Verf.-Referat