In adults with atrial switch operation for transposition of the great arteries low physical activity relates to reduced exercise capacity and decreased perceived physical functioning

OBJECTIVE: Patients with Mustard/Senning repair for transposition of the great arteries (d-TGA) have an impaired exercise capacity, but information about physical activity levels is scarce. The aim of the study was to come to a better understanding of the interrelationships between determinants of exercise capacity, physical activity and self-perceived health status. METHODS AND RESULTS: We studied 39 d-TGA patients who underwent echocardiography and exercise testing, and who completed questionnaires about physical activity and perceived health status. All results were compared with normal values. Stepwise multiple regression analysis was used to assess the determinants of peak V02% and exercise duration. Peak VO2 averaged 64 +/- 14.1% of the predicted normal values, which is significantly lower than expected (P < 0.0001). Physical activity measures as well as perceived general health were significantly lower compared to a reference population (P < 0.05). Peak heart rate and peak oxygen pulse explained together 90% of the variability in exercise duration (model F = 162.72; P < 0.0001). Type of surgery, total energy expenditure and right ventricular contractility were independent predictors of peak VO2% explaining 43% of the variability (model F = 8.75; P = 0.0002). CONCLUSIONS: Impaired peak exercise performance in d-TGA patients results mainly from the inability to increase stroke volume and heart rate at higher exercise intensities. Senning repair and a well-preserved right ventricular function are related to a better peak V02%. Furthermore, an active lifestyle has a positive effect on exercise capacity and perceived physical functioning. Therefore it might be indicated to encourage d-TGA patients to adopt a more physically active lifestyle.