Ventricular venting during coronary revascularization: assessment of benefit by intraoperative ventricular function curves.

Although the physiological benefits of left ventricular venting during cardiopulmonary bypass have been documented experimentally, air embolus is still a concern clinically, and surgeons, therefore, continue to debate whether or not to vent routinely during coronary revascularization. In this study, 10 patients vented during revascularization and 10 not vented were studied immediately before and after cardiopulmonary bypass using Sarnoff ventricular function curves to assess changes in ventricular performance. Stroke work index by each patient before and after bypass was compared at common left atrial pressures and concomitant similar systemic resistances. In patients who were vented, there was overall no change in function (98 +/- 7% of control; range, 146--73%). In patients who were not vented, there was overall significant depression of function (67 +/- 5% of control; range, 91--45%, p less than 0.01). The overall absence of depression in patients who were vented, several of whom had very poor ventricles before bypass, strongly supports venting for coronary revascularization.