Comprehensive evaluation of right ventricular function in children with different anatomical subtypes of hypoplastic left heart syndrome after Fontan surgery

Background: There is some evidence that hypoplastic left heart syndrome (HLHS) survivors with a larger left ventricular (LV) cavity may have poorer long-term outcome than those with mitral and aortic valve atresia (MA/AA) and negligible LV. A negative impact of the LV remnant on right ventricular (RV) function may contribute to this.

Methods: We retrospectively evaluated RV function echocardiographically using 2D, Doppler and colour tissue Doppler techniques in 42 children with HLHS after Fontan surgery. Patients diagnosed with MA/AA at birth (group 1, n = 20) were compared to all the remaining anatomical subgroups of HLHS (group 2, n = 22).

Results: The MA/AA group had a smaller diameter of the ascending aorta at birth (p<0.0001), smaller LV area (p<0.0001) and larger RV area at end-diastole (p = 0.004) and end-systole (p = 0.01) after Fontan. All parameters of RV function including the myocardial performance index, tricuspid annular plane systolic excursion, RV fractional area change and all regional colour Doppler derived myocardial velocities were not different between groups.

Conclusion: In our cohort, RV function in HLHS after Fontan surgery was not different for the subgroup with MA/AA when compared to the remaining subgroups.