Abnormal interventricular septal motion following cardiac surgery: Clinical, surgical, echocardiographic and radionuclide correlates

Abstract

Interventricular septal motion was studied prospectively by echocardiography in 45 patients examined before and after cardiac surgery. In addition, nine of the patients underwent pre- and postoperative gated cardiac blood pool scintigraphy. All had normal septal motion preoperatively. Of the 40 patients whose surgery included cardiopulmonary bypass, 31 had abnormal and 9 had normal postoperative septal motion. All five patients without cardiopulmonary bypass had normal postoperative septal motion (p < 0.001). Among those patients undergoing cardiopulmonary bypass, there was no difference between those with normal and those with abnormal postoperative septal motion in clinical diagnosis, operative procedure, or surgical techniques (bypass time, aortic cross-clamp time, pericardium closed, prosthesis used), except that potassium arrest had been used more frequently in those with abnormal motion (18 of 31 vs 1 of 9, p < .02). Preoperatively, there was no difference in echocardiographic right ventricular dimension (8 ± 1 vs 8 ± 1 mm., mean ± SEM). However, postoperatively, those with abnormal motion had a larger right ventricle than those with normal motion (12 ± 1 vs 8 ± 1 mm., p < .005). The postoperative percent systolic septal thickening decreased in those with abnormal motion (42 ± 4 per cent to 23 ± 4 per cent) (p < 0.001) and did not change in those with normal postoperative motion (47 ± 7 per cent to 48 ± 4 per cent). These findings were corroberated on gated cardiac blood pool scanning, and in addition demonstrated that when present, the motion abnormality was more marked at the upper than the lower septum. These findings confirm that postoperative abnormal systolic septal motion and thickening are common but not invariable following cardiopulmonary bypass and that they appear unrelated to preoperative clinical diagnosis, hemodynamics, or surgical technique.