Reverse Septal Movement: A Step Forward in the Comprehension of the Underlying Causes

(1) Background: Reverse septal movement (RSM) often occurs after cardiac surgery, consisting of a paradoxical systolic movement of the interventricular septum. In this retrospective study, we aimed to investigate possible determinants of RSM after coronary artery bypass surgery (CABG). (2) Methods: Patients who underwent CABG with on- or off-pump techniques at our center from March 2019 to October 2021 were retrospectively included. Exclusion criteria were: exposure to combined procedures (e.g., valve implantation), prior cardiac surgery, intraventricular conduction delays, and previous pacemaker implantation. Laboratory tests and echocardiographic and cardiopulmonary bypass (CPB) duration data were collected. (3) Results: We enrolled 138 patients, of whom 32 (23.2%) underwent off-pump CABG. Approximately 89.1% of the population was male; the mean age was 70 ± 11 years. There was no difference in RSM incidence in patients undergoing the off-pump and on-pump techniques (71.9% vs. 62.3%; p = 0.319). In patients undergoing on-pump surgery, the incidence of RSM was slightly higher in longer CPB procedures (OR 1.02 (1.00–1.03) p = 0.012), and clamping aortic time was also greater (OR 1.02 (1.00–1.03) p = 0.042). (4) Conclusions: CPB length seems to be correlated with a higher RSM appearance. This better knowledge of RSM reinforces the safety of CABG and its neutral effect on global biventricular function.