Usefulness of real-time three-dimensional echocardiography to identify right ventricular dysfunction in patients with congenital heart disease
Because right ventricular (RV) dysfunction predicts a poor outcome in patients with congenital heart disease (CHD), regular monitoring of RV function is indicated. To date, cardiac magnetic resonance (CMR) imaging has been the reference method. A more practical, more accessible, and accurate tool would be preferred. We defined normality regarding RV systolic function using healthy controls and tested the ability of real-time 3-dimensional echocardiographic (RT3DE) findings to identify patients with CHD with RV dysfunction. The cutoff values for the RV volumes and ejection fraction (EF) were derived from the CMR imaging findings from 41 healthy controls (mean age 27 ± 8 years, 56% men). In 100 patients with varying CHDs (mean age 27 ± 11 years, 65% men), both RT3DE data sets (iE33) and short-axis CMR imaging (1.5 T) were obtained within 2 hours. The RT3DE and CMR RV volumes and EF were calculated using commercially available software. Receiver operating characteristic curves were created to obtain the sensitivity and specificity of the RT3DE data to identify RV dysfunction. Applying the cutoff values derived from the healthy controls using the CMR data of patients with CHD, we identified 23 patients with an enlarged indexed end-diastolic volume, 29 patients with an enlarged indexed end-systolic volume, and 21 patients with an impaired RVEF. The best cutoff values predicting RV dysfunction using the RT3DE findings were identified (indexed end-diastolic volume >105 ml/m2, indexed end-systolic volume >54 ml/m2, and EF <43%). The RT3DE findings revealed 23 patients with impaired RVEF, with 95% sensitivity, 89% specificity, and a negative predictive value of 99%. In conclusion, real-time 3-dimensional echocardiography is a very sensitive tool to identify RV dysfunction in patients with CHD and could be applied clinically to rule out RV dysfunction or to indicate additional quantitative analysis of RV function.