[Exercise tolerance after correction of tetralogy of Fallot]

Twenty-six postoperative patients with tetralogy of Fallot (TF) were evaluated by exercise stress test with an upright cycle ergometer. Oxygen uptake was assessed at the anaerobic threshold and the peak achieved work load. Oxygen uptake at the anaerobic threshold (VO2AT) was in the normal range regardless of the existence of residual stenosis (PS) or pulmonary regurgitation (PR). However, oxygen uptake at the peak achieved workload (VO2max) was subnormal in patients with PS or PR. Maximal heart rate in TF patients was lower than normal. Patients with PR showed significantly reduced VO2max as compared with those without PR (p less than 0.05). This is found to be resulted from limitation of the oxygen pulses increase.