RIGHT-VENTRICULAR FUNCTION AFTER CORONARY-ARTERY BYPASS-GRAFTING IN PATIENTS WITH AND WITHOUT REVASCULARIZATION OF THE RIGHT CORONARY-ARTERY

Objectives: To evaluate the influence of revascularization of a stenos is of the right coronary artery on right ventricular function. Design: Prospective study. Setting: Single institutional study in a universit y hospital. Participants: 20 patients with different degrees of stenos is of the right coronary artery undergoing elective coronary artery by pass grafting. Interventions: In 10 patients, bypass surgery included revascularization of a significant stenosis of the right coronary arte ry (group 1) In 10 other patients, the pathology of the right coronary artery was judged to be not significant, without indication for revas cularization (group 2). Measurements and Main Results: Using the fast- response thermodilution pulmonary artery catheter, right ventricular f unction was estimated perioperatively. After termination of extracorpo real circulation, there was an increase in right ventricular volumes i n group 2 (p < 0.05) and an initial decrease in group 1 (p < 0.05), wi th higher volumes in group 2 compared with group 1 (p < 0.05). The eje ction fraction increased in group 1 (P < 0.05) and decreased in group 2 after operation (p < 0.05), with higher values in group 1 compared w ith group 2 (p < 0.05). In addition to these findings, the pressure-vo lume relationship showed a leftward and upward shift in group 1 and a rightward shift in group 2 postoperatively. Conclusions: These results indicate that right ventricular depression can occur after bypass gra fting in patients with a moderate stenosis of the right coronary arter y that is not revascularized. Revascularization of more severe stenosi s of the right coronary artery appears to preserve postoperative right ventricular function. (C) 1995 by W.B. Saunders Company