Real-time three-dimensional echocardiography: segmental analysis of the right ventricle in patients with repaired tetralogy of fallot.

BACKGROUND

The accurate assessment of right ventricular (RV) function and dimensions has important prognostic implications in patients with repaired tetralogy of Fallot (ToF). Three-dimensional imaging is the preferred methodology to evaluate RV function. Novel postprocessing software applications to evaluate three-dimensional data have provided insight into RV function and dimensions by analyzing the various RV components (inlet, apical trabecular, outlet). The aim of this study was to characterize regional RV function and dimensions with real-time three-dimensional echocardiography (RT3DE) in patients with repaired ToF.

METHODS

Forty-one patients with repaired ToF (age range, 8-18 years) and 20 control subjects were enrolled. Global and segmental RV volumes and ejection fraction (EF) were assessed with RT3DE and compared between patients with repaired ToF and controls.

RESULTS

Segmental analysis on RT3DE demonstrated that the apical trabecular region was the most remodeled RV component in patients with repaired ToF, with significantly increased end-diastolic volume and end-systolic volume compared with controls (59 ± 19 vs 41 ± 16 mL and 36 ± 13 vs 24 ± 8 mL, respectively; P = .001 for both). However, EF was preserved at that region. In contrast, EF was reduced at the RV inlet (53 ± 6% vs 58 ± 7%, P = .003) and outlet (44 ± 16% vs 52 ± 10% (P = .032).

CONCLUSIONS

Patients with repaired ToF show characteristic RV remodeling as assessed with RT3DE. At the apical trabecular region, the largest volumes were observed compared with control patients, whereas EF at the inlet and outlet components was significantly impaired. RT3DE may facilitate future studies of segmental RV volumes and function in patients with repaired ToF.