[Aptitude for sports in case of congenital heart block. Apropos of a case].

Cardiorespiratory adaptation of congenital atrioventricular block is not well known. The authors present the case of a 20 year old patient with excellent muscular force and maximal aerobic capacity despite severe chronotropic insufficiency on exercise, the heart rate not exceeding 80/mn. This condition may be explained by increased peripheral oxygen uptake and an increased oxygen transport due to high hemoglobin level.