Assessing right ventricular systolic function using ultrasonic speckle-tracking imaging in repaired Tetralogy of Fallot with different pulmonary artery branch angles.

Zhang, Shuai; He, Xinjian; Liu, Lei; Fan, Yanhui; Chen, Jiaoyang; Yang, Lu; Cui, Yun; Fan, Di

OBJECTIVE This study assessed whether ultrasonic speckle-tracking imaging (STI) could help evaluate right ventricular systolic function in repaired Tetralogy of Fallot (TOF) with different pulmonary artery branch angles. METHODS We retrospectively evaluated 64 patients who underwent surgery for TOF and 60 normal children. The angle between the left pulmonary artery and main pulmonary artery was measured using echocardiography and computed tomography angiography (CTA). Furthermore, STI was used to record the global longitudinal strain of the four-chamber view (GLS4), the global longitudinal strain of the two-chamber view (GLS2), and the global longitudinal strain of the right ventricle (RVGLS). RESULTS The GLS4, GLS2, and RVGLS values in the TOF groups with different pulmonary artery branch angles were significantly lower than those in the control group. Furthermore, the GLS2 and RVGLS values were significantly lower for angles of 90-100° and <90° (vs >100°). Multivariate linear regression analyses revealed that pulmonary regurgitation and the angle between the left and main pulmonary arteries were two important factors affecting RVGLS. The Bland-Altman consistency test revealed good agreement regarding the pulmonary artery branch angles measured using echocardiography and CTA. CONCLUSION In patients with TOF, the RVGLS was lower for acute left pulmonary artery angulation than for round and blunt left pulmonary artery angulation. The angle of the pulmonary artery branches was an important factor affecting RVGLS. Echocardiography can be used to measure the angle of the pulmonary artery branches, which provides valuable information for surgical correction of pulmonary artery morphology.