Reduced long-term exercise capacity in young adults operated for ventricular septal defect

Ventricular septal defects are normally closed in early childhood, and post-surgically the patients are considered as healthy and fit as their peers. However, data are inconsistent. We exercise-tested a cohort of ventricular septal defect-operated patients and a group of matched controls to evaluate long-term physical fitness.

Cardiopulmonary exercise capacity was tested on an ergometer cycle in 30 patients and 30 healthy age and gender-matched controls. Pulmonary ventilation and gas exchange were simultaneously measured breath-by-breath with Jaeger MasterScreen CPX® (CareFusion, San Diego, United States of America). During the test session, respiratory gas exchange was measured along with heart rate, blood pressure, and electrocardiogram. The endpoints were peak oxygen uptake, maximal workload, and ventilatory anaerobic threshold. The International Physical Activity Questionnaire and the SF-36 were applied for Health-Related Quality-of-Life assessment.

Ventricular septal defect-operated adults had a markedly lower peak oxygen uptake: mean 38.0(±8.2 ml O2/kg/minute) versus 47.9(±6.5 ml O2/kg/minute) in controls, p<0.01. Furthermore, ventilatory anaerobic threshold was impaired in ventricular septal defect patients: mean 25.3(±7.8 ml O2/kg/minute) versus 35.2(±7.7 ml O2/kg/minute) in controls, p<0.01. Maximal workload was reduced: mean 3.3(±0.7 W/kg) versus 4.0(±0.5 W/kg) in the control group, p<0.01. Lastly, ventricular septal defect patients had a significantly lower peak heart rate: mean 182(±8.8 beats/minute) versus 188(±9.0 beats/minute) in controls, p=0.03. Regarding Health-Related Quality of Life, the ventricular septal defect group had significantly lower scores in physical functioning, role physical, and social functioning.

Young adults with a surgically closed ventricular septal defect had a markedly reduced cardiopulmonary exercise capacity and a lower peak heart rate compared with controls.