Transient left ventricular dysfunction is commonly described in association with cardiopulmonary bypass (CPB). We evaluated changes in right ventricular (RV) function after elective cardiac surgery in 24 patients with normal preoperative cardiac function. In all, irrespective of distribution of coronary artery disease or use of pharmacologic support, a transient depression of RV systolic function with respect to both preinduction and initial postoperative (Postop) values occurred 262 +/- 116 min post-CPB as represented by a decrease in RV stroke volume index (25.0 +/- 1.7 vs. 33.4 +/- 1.9 ml/m2 Postop) and RV ejection fraction (31.0 +/- 2.2 vs. 45.6 +/- 2.5% Postop), and an increase in RV end-systolic and end-diastolic volume indices. This depression responded readily to pharmacologic therapy within 2 h, resolved within 24 h, and had no adverse consequences in these otherwise healthy patients. Further studies are needed to identify the cause of this phenomenon and its importance in patients with preexisting cardiac dysfunction.