Right Ventricular Mechanics in Adults after Surgical Repair of Tetralogy of Fallot: Insights from Three-Dimensional Speckle-Tracking Echocardiography

Background: The clinical relevance of evaluating right ventricular (RV) myocardial deformation in congenital heart disease is increasingly recognized. The aim of this study was to explore, using three-dimensional (3D) speckle-tracking echocardiography, RV mechanics in terms of 3D global area strain and mechanical dyssynchrony in adults with repaired tetralogy of Fallot. Methods: Twenty patients (12 men) aged 24.7 +/- 8.6 years and 22 age-matched controls (11 men) were studied. Global RV peak area strain and area strain-derived systolic dyssynchrony index (SDI) were determined using 3D speckle-tracking echocardiography. RV end-diastolic volume and end-systolic volume, ejection fraction (EF), and pulmonary regurgitation fraction were measured in patients using cardiac magnetic resonance. Results: Coefficients of variation for intraobserver and interobserver measurements of RV global area strain were 6.1% and 7.9%, respectively, and those for SDI were 7.6% and 10.1%, respectively. Compared with controls, patients had significantly lower global area strain (P = .005) and greater SDI (P = .008). The prevalence of RV mechanical dyssynchrony (SDI > control mean + 2 SDs) in patients was 30%. In patients, global area strain correlated inversely with SDI (r = - 0.42, P = .04), RV end-diastolic volume (r = - 0.48, P = .032), and RV end-systolic volume (r = - 0.48, P = .031) and positively with EF (r = - 0.51, P = .02), while RV SDI correlated positively with RV end-systolic volume (r = 0.55, P = .012), pulmonary regurgitation fraction (r = 0.54, P = .031), and QRS duration (r = 0.51, P = .022) and negatively with RV EF (r = - 0.62, P = .004). Multivariate analysis showed that RV EF (beta = 0.22, P = .048) was a significant correlate of global area strain in patients. Conclusions: In adults after tetralogy of Fallot repair, 3D RV deformation is impaired in association with RV dyssynchrony, volume overloading, and reduced EF.