Plasma endothelin-1 levels after exercise in patients with congenital heart disease

We have previously reported that plasma endothelin-1 (ET-1) levels were significantly increased after exercise in healthy athletes. In the present study, venous plasma ET-1 levels were measured to investigate whether the role of ET-1 during exercise differs between healthy athletes and patients with congenital heart disease. Seven patients (mean age 13 years) performed symptom-limited treadmill exercise (Bruce protocol). All patients were in class I of the NYHA functional classification. The mean end-exercise O2 utilization was 32 ml/min/kg (166% of ventilatory threshold). Blood sampling was carried out in the seated position. The plasma ET-1 level was 1.21 pg/ml before exercise and did not alter immediately after or 30 min after exercise. The plasma level of norepinephrine was markedly elevated immediately after exercise and returned to the basal level 30 min after exercise. The present study demonstrated that exercise failed to alter plasma ET-1 levels in patients with congenital heart disease.