Inhospital changes of left ventricular diastolic function in patients undergoing coronary bypass surgery

Aim. To evaluate changes of left ventricular (LV) diastolic function in patients with multivessel coronary artery disease before coronary artery bypass grafting (CABG) and in the early postoperative period (7-10 days), as well as to assess the relation- ship between diastolic LV dysfunction and postoperative atrial fibrillation (POAF). Material and methods. This original prospective study of included 50 patients undergoing CABG at the Cardiac Surgery Unit № 1 of the N. V. Sklifosovsky Research Institute for Emergency Medicine from December 2020 to December 2021. All patients underwent standard echocardiography before and after surgery. Diastolic function was assessed using the following parameters: septal mitral annulus velocity (e’septal), lateral mitral annulus velocity (e’lateral), the ratio of the peak early transmitral velocity to peak early diastolic velocity of the mitral annulus movement (E/e’), left atrial volume index (ml/m2), peak tricuspid regurgitation velocity (m/s), the ratio of the peak early to late filling velocity (E/A). Results. After CABG, 35 patients maintained sinus rhythm in the early postoperative period (group 1), while 15 patients had POAF (group 2). According to echocardiography, type 1 diastolic dysfunction prevailed in both groups; types 2 and 3 LV diastolic dysfunction were not identified. Among the parameters characterizing myocardial relaxation, in group 1 after CABG, a significant increase in the peak E (p=0,001) was noted, and due to this, the normalization of the E/A ratio was recorded (p<0,0001). An increase in e’lateral (p=0,05) was also revealed, in connection with which an increase in the E/e’ (p=0,02) was noted. In the group of patients with POAF, such changes were not detected. Left atrial volume index (ml/ m2) was significantly higher in the POAF group (p=0,02). Conclusion. Surgical myocardial revascularization has a positive effect on LV diastolic function. Improvement in LV diastolic function after CABG may be a sign of the restoration of hibernating myocardium function, while the absence of LV diastolic function improvement, together with left atrial dilatation, may be predictors of early POAF.