EXERCISE CAPACITY OF CHILDREN AFTER REPAI R OF TETRALOGY OF FALLOT

Background. Long-term follow-up of patients after total surgical corre ction of tetralogy of Fallot indicates that they have a smaller workin g capacity than controls, with an increased incidence of late onset co mplete heart block and sudden death. These abnormalities may be less f requent when surgery is undertaken at an early age. Population and met hods. A cardio-pulmonary stress test was performed on 18 patients aged 8 to 20 years who had undergone correction of tetralogy of Fallot whe n they were 3 months to 7 years (mean age : 3 years). The basic ventil atory tests, exercise ventilatory tests and gas exchange were also per formed. Results. The cardiopulmonary stress test was maximal in 16 of the 18 cases. No stress-induced PVCs, or chronotropic insufficiency wa s found despite a basic long PR interval in 4 cases. A restrictive ven tilatory syndrome was seen in 4 cases with low respiratory reserve at exercice (defined as the ratio between maximal observed ventilation an d maximal theoretical ventilation, VEMS x 40). The respiratory functio n was normal in 14 cases with an aerobic capacity of over 40 ml/kg/min . Conclusion. Patients with a normal chronotropic function and preserv ed aerobic capacity show no post-operative restriction or cardiac of p ulmonary exercise capacity.