RESUMO
Objectives: The study was aimed at using speckle tracking echocardiography as a novel technique to diagnose right ventricular failure (RVF) in children with total correction of tetralogy of Fallot (TOF) through surgery. Methods: A quasi-experimental study was performed at the Children's Heart Hospital of Sulaimani for 9 months. A total of 150 children with completely repaired TOF were enrolled to investigate RVF. Conventional echocardiographic data were recorded, including right ventricular (RV) ejection fraction (EF), tricuspid annular plane systolic excursion (TAPSE), myocardial performance index (MPI), and RV end-systolic and diastolic volume (RVESV and RVEDV). Additionally, speckle tracking was performed for the regional and longitudinal strain and strain rate in four-chamber apical view. RVF diagnosis was determined on the basis of electrocardiography measurement of P-wave dispersion, T-wave dispersion, and QRS duration. Results: Children with repaired TOF who were diagnosed with RVF through conventional echocardiography exhibited abnormalities with respect to children with normal RV function, including a TAPSE of 1.3 ± 0.11 cm, RVEF of 35.5 ± 6.72, RVESV of 69.8 ± 15.13 ml, RVEDV of 110.1 ± 14.13 ml, MPI of 0.60 ± 0.12, and Pmax of 52.4 ± 14.08. The use of speckle tracking in RVF diagnosis revealed a relatively lower longitudinal strain and strain rate (-12.1 ± 2.3 and -0.9 ± 0.3, respectively) in the children with RVF. Moreover, longitudinal right ventricular strain was positively correlated with TAPSE (r = 0.656) and EF (r = 0.675), and negatively correlated with RVEDV (r = -0.684), RVESV (r = -0.718), MPI (r = -0.735), and Pmax (r = -0.767). Conclusions: The application of speckle tracking with the longitudinal RV strain and strain rate to estimate RV function in children with repaired TOF is a new advanced method that, compared with conventional echo, significantly improves the diagnosis of regional myocardial deformations and cardiac muscle motion velocity.
