Early Marker of Myocardial Deformation in Children with Duchenne Muscular Dystrophy Assessed Using Echocardiographic Myocardial Strain Analysis

PURPOSE: As cardiomyopathy is more prevalent and currently the leading cause of death in Duchenne muscular dystrophy (DMD), early detection of myocardial involvement is important. The purpose of this study was to analyze myocardial strain in DMD children, for the possibility of early detection of myocardial dysfunction. MATERIALS AND METHODS: We reviewed medical records of DMD patients who were >10 years of age (15.6±1.6 years, 12.5-18 years), from March 2013 to June 2014. Data of 24 DMD children who underwent echocardiography with three-layer specific myocardial strain were compared with 24 controls (age: 9.3±4.0 years, 5.5-17 years). RESULTS: Epicardial longitudinal strain was lower in DMD (DMD: -9.3±3.8%; control: -12.3±4.3%; p=0.012). Radial strain (DMD: 24.1±11.1%; control: 37.3±25.9%; p=0.027) and strain rate (SR) (DMD: 1.68±0.91; control: 2.42±0.84; p=0.006) on parasternal short axis view were lower in DMD. Circumferential strains in the endocardium (DMD: -17.5±4.7%; control: -24.2±5.3%; p<0.001), myocardium (DMD: -12.7±3.8%; control: -18.0±4.0%; p<0.001), and epicardium (DMD: -8.4±4.0%; control: -12.2±5.0%; p=0.006) were significantly decreased in DMD. Circumferential SRs were lower in the endocardial (DMD: -1.46±0.38; control: -1.78±0.27; p=0.002) and myocardial layers (DMD: 1.02±0.27; control: -1.28±0.22; p=0.001). CONCLUSION: In DMD patients, deteriorations in myocardial circumferential strain might be an indicator for predicting cardiomyopathy.

XYY syndrome: a 13-year-old boy with tall stature

When evaluating the underlying causes of tall stature, it is important to differentiate pathologic tall stature from familial tall stature. Various pathologic conditions leading to adult tall stature include excess growth hormone secretion, Marfan syndrome, androgen or estrogen deficiency, testicular feminization, and sex chromosome anomaly, such as Klinefelter syndrome and XYY syndrome. Men with 47,XYY syndrome can exhibit multiple phenotypes. A 13-year-old boy visited the hospital for evaluation of tall stature. The boy had no other physical abnormalities except tall stature. All biochemical and imaging studies were within the normal ranges. He was diagnosed with XYY syndrome in this chromosome study. When evaluating men with tall stature, XYY syndrome should be ruled out.