Effect of pulmonary resection on right ventricular function.

The effect of pulmonary resection on right ventricular (RV) performance and its possible contribution to morbidity or mortality remain unclear. Using thermodilution methods and a fast-response thermistor positioned in the pulmonary artery, it is now possible to measure RV end-diastolic volume and RV ejection fraction. Using this technique, RV performance during and after major pulmonary resection was studied in 15 patients. Significant RV dysfunction was demonstrated in the postoperative period. Right ventricular end-diastolic volume increased significantly on postoperative day 1 (177 +/- 9 mL) and postoperative day 2 (172 +/- 4 mL) versus early postoperatively (153 +/- 10 mL) (p less than 0.05). By postoperative day 2, RV ejection fraction was significantly decreased (0.36 +/- 0.03) from preoperative (0.45 +/- 0.02) and early postoperative (0.40 +/- 0.01) values (p less than 0.05). Although pulmonary artery pressures rose modestly in the postoperative period, and pulmonary vascular resistance increased by postoperative day 2, pulmonary vascular resistance remained significantly lower or unchanged from baseline values. We speculate that the etiology of the RV dysfunction after pulmonary resection may be multifactorial. Changes in RV afterload or alteration in RV contractility may be factors.