Assessment of Left Ventricular Dyssynchrony by Speckle Tracking Echocardiography in Children with Duchenne Muscular Dystrophy

Abstract

Purpose-Prognosis of Duchenne muscular dystrophy (DMD) is related to cardiac dysfunction. Two dimensional-speckle tracking echocardiography (2D-STE) has recently emerged as a non-invasive functional biomarker for early detection of DMD-related cardiomyopathy. This study aimed to determine, in DMD children, the existence of a left ventricle (LV) dyssynchrony using 2D-STE analysis.Methods-This prospective controlled study enrolled 25 boys with DMD (mean age 11.0±3.5 years) with normal LV ejection fraction and 50 age-matched controls. Three measures were performed to assess LV mechanical dyssynchrony: the opposing-wall delays (longitudinal and radial analyses), the modified Yu index, and the time-to-peak delays of each segment. Feasibility and reproducibility of 2D-STE dyssynchrony were evaluated. Results-All three mechanical dyssynchrony criteria were significantly higher in the DMD group than in healthy subjects: (1) opposing-wall delays in basal inferoseptal to basal anterolateral segments (61.4±45.3 msec vs. 18.3±50.4 msec, P<0.001, respectively) and in mid inferoseptal to mid anterolateral segments (58.6±35.3 msec vs. 42.4±36.4 msec, P<0.05, respectively), (2) modified Yu index (33.3±10.1 msec vs. 28.5±8.1 msec, P<0.05, respectively), and (3) most of time-to-peak values, especially in basal and mid anterolateral segments. Feasibility was excellent and reliability was moderate to excellent, with ICC values ranging from 0.49 to 0.97.Conclusion-Detection of LV mechanical dyssynchrony using 2D-STE analysis is an easily and reproducible method in pediatrics. The existence of an early LV mechanical dyssynchrony visualized using 2D-STE analysis in children with DMD before the onset of cardiomyopathy represents a perspective for future pediatric drug trials in the DMD-related cardiomyopathy prevention. Clinical Trial Registration-Clinicaltrials.gov NCT02418338. Post-hoc study, registered on April 16, 2015.