Left ventricular mechanical synchrony and global systolic function in pediatric patients late after ventricular septal defect patch closure: A three-dimensional echocardiographic study

Background: Patients with large ventricular septal defects (VSDs) undergo surgical patch closure during infancy. The long-term effects of the presence of akinetic patch in the ventricular septum and postoperative right bundle branch block (RBBB) on the left ventricular (LV) mechanical synchrony and global systolic function have not been studied. Objective.: The objective of this study was to evaluate the long-term effects of an akinetic VSD patch and RBBB on the LV mechanical synchrony and global systolic function in pediatric patients more than 5 years after surgery. Methods: Eighteen asymptomatic VSD repair and 18 normal control patients were evaluated by an electrocardiogram and three-dimensional echocardiography. Left ventricular end-diastolic volumes (LVEDVs) and volumetric ejection fraction (EF) were calculated. Left ventricular intraventricular synchrony was assessed by the 16-segment volumetric dyssynchrony index. Results: Eight of 18 (44%) patients in the VSD repair group had RBBB. The LVEDV and volumetric EF were similar in the VSD repair and control groups. The LV dyssynchrony index was not significantly different between the VSD repair and control groups (2.46 ± 1.77% vs. 1.75 ± 1.08%, . P = .16). The VSD repair group was then divided into two subgroups: patients with RBBB (8/18) and those without RBBB (10/18). The two subgroups were similar in demographics, LVEDV, and volumetric EF. However, the RBBB subgroup demonstrated significant LV mechanical dyssynchrony compared with the non-RBBB VSD subgroup (2.70 ± 1.08% vs. 1.15 ± 0.35%, . P = .006). Conclusions: Pediatric patients 5-10 years after VSD patch closure have a normal LV function. The presence of the RBBB causes some mechanical dyssynchrony and tendency toward LV dilatation in this group of patients. Therefore, long-term follow-up of these patients is warranted.