Ventricular dynamics after surgical closure of VSD.

Twenty patients varying in age between 5 and 20 years at the time of surgical closure of VSD were studied 2 to 9 years postoperatively. Ventricular function was studied by echocardiography and measurement of systolic time intervals for the left and right ventricles and the findings were related to clinical and haemodynamic results of operation. The VSD was closed in all instances and the haemodynamic situation was normalized in all but 2 patients who had persisting pulmonary vascular disease. Right bundle branch block (RBBB) was recorded in 11 instances and in 5 there was an associated left axis deviation (LAD), suggesting left anterior hemiblock. LAD occurred as an isolated anomaly in another 2 patients. The heart size was within normal limits in all the patients. Abnormal septal motion (ASM) was recorded in 13 of the 20 patients, but other echocardiographic analyses, such as LV end-diastolic dimension, left atrial/aortic root ratio, posterior wall velocity index and maximal endocardial velocity, were all within predicted normal limits. There was an almost uniform prolongation of both left and right pre-ejection periods. left and right ejection period as a rule remained normal and gave an increased PEP/ET ratio, indicating the presence of postoperative ventricular dysfunction also in instances with complete normalization of the haemodynamic situation. Suggested background mechanisms for these findings are the frequent occurrence of conduction defects postoperatively, the likelihood of altered ventricular compliance and possibly also as a cause of ASM postoperative presence of an opened pericardial sac.