Elderly patients undergoing cardiac surgery are reported to be at a higher risk for circulatory failure than younger patients, most likely because of ventricular decompensation. To assess the role of the right heart in these patients, right ventricular (RV) hemodynamics in 40 consecutive elderly patients (greater than 70 years; mean = 77.1 +/- 3.4 years) were compared with 40 consecutive younger patients (50 to 60 years; mean = 55.2 +/- 3.0 years) undergoing elective coronary artery bypass surgery. In addition to standard hemodynamic variables, RV ejection fraction (RVEF) and RV end-systolic and end-diastolic volumes (RVESV, RVEDV) were studied perioperatively using a thermodilution technique. None of the elderly patients died in the perioperative period. The course of RV function was comparable in both groups during the entire investigation period, but the absolute values of RVEF before the onset of cardiopulmonary bypass (CPB) were significantly higher in the younger patients (48.0 +/- 4.4%) than in the older patients (38.9 +/- 4.6%). RVEDV and RVESV were always higher in the older patients in the pre-bypass period than in the control group. None of the other hemodynamic parameters showed significant differences between the groups. Analysis of covariance showed no correlation between RV volume and pressure parameters. Inotropic support during and after termination of CPB was necessary more often in the older (epinephrine, 6.7 +/- 2.0 micrograms/min) than in the younger patients (epinephrine, 4.4 +/- 2.2 micrograms/min). It is concluded that older patients undergoing myocardial revascularization can have excellent results. However, they may be predisposed to right heart complications because of their reduced RV function.