The effect of pericardial incision on right ventricular systolic function: a prospective observational study

Abstract

Background: Echocardiographic longitudinal markers of right ventricular (RV) systolic function are commonly depressed after coronary artery bypass graft surgery (CABG) despite an uncomplicated course and good clinical recovery. The exact timing and cause of these changes is unknown. The aim of this observational study was to monitor echocardiographic markers of RV systolic function intraoperatively during CABG. We used angle-independent speckle tracking to measure the primary endpoints of tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (S′) before and after pericardiotomy. Methods: Twenty-four patients undergoing elective on-pump CABG were enrolled in the study. Speckle tracking-derived TAPSE, S’, free wall systolic strain, RV outflow tract strain, colour tissue Doppler-derived isovolumic acceleration (IVA) and two-dimensional RV dimensions and fractional area change (FAC) were measured at three intraoperative time points: 1) after sternotomy immediately prior to pericardiotomy; 2) after pericardiotomy and placement of pericardial retraction sutures; and 3) following cardiopulmonary bypass after chest closure. Results: Adequate image quality to perform speckle tracking measurements was obtained in twenty-one patients. We found that there were no significant changes to echocardiographic parameters of RV systolic function between pre- and post-pericardiotomy. The mean (SD) of the primary endpoints were: TAPSE [28.1 (5.1) mm vs 27.7 (7.4) mm, respectively; mean difference, −0.4 mm; 97.5% confidence interval (CI), −4.0 to 3.1; P = 0.76] and S′ [10.4 (2.1) cm·sec−1vs 10.8 (1.9) cm·sec−1, respectively; mean difference, 0.4 cm·sec−1; 97.5% CI, −0.9 to 1.7; P = 0.48]. Significant reductions in the parameters of RV systolic function were found only after cardiopulmonary bypass and chest closure. Conclusion: Pericardial opening and suspension had no significant effect on the indices of RV systolic function derived from speckle tracking or colour tissue Doppler.