Ventricular Function And Dyssynchrony In Children With A Functional Single Right Ventricle Using Real Time Three-Dimensional Echocardiography After Fontan Operation

Background This study aimed to evaluate the feasibility and clinical value of real time three-dimensional echocardiography (RT-3DE) for assessing ventricular systolic dysfunction and dyssynchrony in children with an functional single right ventricle (FSRV) having undergone the Fontan procedure. Methods Twenty-five children with an FSRV and 25 healthy children were enrolled in our study. RV volume analysis was performed compared with magnetic resonance imaging (MRI) as the reference standard in FSRV patients. The patients were divided into wide and narrow QRS interval groups. Global and regional functions of the RV in three compartments (inflow, body, and outflow) were compared between FSRV and control subjects, including RV systolic dyssynchrony indices of maximal difference of time to minimal volume (Tmsv-Dif), standard deviation of time to minimal volume (Tmsv-SD), maximal difference of time to minimal volume corrected by R-R interval (Tmsv-Dif%), and standard deviation of time to minimal volume corrected by R-R interval (Tmsv-SD%). Results RT-3DE measurements were significantly lower than MRI measurements for RV-EDV, RV-ESV, RV-SV, and RVEF (p < 0.01).Compared with controls, patients with an FRSV had significantly higher dyssynchrony indices and significantly lower global EF in both narrow QRS interval and wide QRS interval groups. Tmsv-SD% was shown to be most strongly correlated with MRI-RVEF (r = -.570, p = 0.003). Conclusions RT-3DE tended to underestimate RV ventricular volume in children with FSRV. Children with an FSRV and either a wide or narrow QRS interval had reduced ventricular function and higher dyssynchrony than normal subjects. Worsening RV dyssynchrony is associated with overall decline in function after the Fontan operation.