To elucidate the correlation between endothelin(ET) and pulmonary hypertension, plasma ET was measured perioperatively by radioimmunoassay in 22 patients with pulmonary hypertension who underwent open heart surgery(PH group) in comparison with 16 patients without pulmonary hypertension(non-PH group) also underwent cardiopulmonary bypass(CPB) surgery.
Results: Plasma ET was significantly increased during CPB in both group, Plasma ET decreased rapisly and returned to preoperative level within 6 hours after operation in the non-PH group. In the PH group, however, plasma ET decreased slowly and did not return to preoperative level within 48 hours postoperation.