Intraoperative Change of Right Ventricular Free Wall Strain in Coronary Artery Bypass Grafting and in Aortic Valve Replacement Surgery

Abstract

Background: Right ventricular (RV) function changes after on-pump cardiac surgery but the impact of the surgical procedure is largely unexplored. For this purpose, we aimed to describe the changes of RV function through the intraoperative period by transesophageal echocardiography (TEE) in patients scheduled for isolated on-pump coronary artery bypass grafting (CABG) or for isolated surgical aortic valve replacement (AVR). Methods: Thirty patients each scheduled for on-pump CABG and for isolated surgical AVR were included into this prospective observational study. TEE was performed intraoperatively after induction of anesthesia [T1], after termination of cardiopulmonary bypass [T2], and after sternal closure [T3]. Echocardiographic evaluation included the assessment of RV fractional area change (FAC), RV ejection fraction (RVEF), tricuspid annular plane systolic excursion (TAPSE), and RV free wall strain (FWS). Results: Although there was no significant difference in RVEF and FAC before and immediately after bypass, TAPSE decreased significantly. In contrast, FWS remained unchanged in the same period (−22.7% (IQR −18.9 to −29.6) v −22.1% (IQR −17.1 to −26.1), P = 1). After sternal closure [T2 v T3], there was a significant deterioration of FWS (−22.1% (IQR −17.1 to −26.1) v −17.1% (IQR −13.3 to −21.7), P < 0.001). In the same interval, the values of RVEF, FAC, and TAPSE remained unchanged. These alterations in RV contractile pattern were observed in both groups of patients. Conclusion: There was no difference in the change of RV contractile pattern after on-pump CABG and AVR surgery, suggesting similar impact of both procedures on RV function.