Cardiac complications are the leading cause of death in patients with Duchenne muscular dystrophy (DMD). Two-dimensional echocardiography is the current standard for monitoring of LV systolic function in these patients, but it might not detect early systolic dysfunction. The current study examined the use of speckle tracking echocardiography (STE) to detect early signs of cardiac dysfunction in DMD patients. A retrospective review of charts and offline strain analysis of transthoracic echocardiographic studies of DMD patients at our institution from April 2014 to January 2015 were performed and compared to age-matched healthy male subjects. Nineteen DMD patients (age range 12.6 ± 3.1 years) with normal ejection fraction and shortening fraction were compared with sixteen controls. The global circumferential strain was lower in DMD patients compared with controls (-14.7 ± 4.7 vs. -23.1 ± 2.9 %, respectively, p value: 0.001). Circumferential strain measured at basal, mid-ventricular and apical parasternal short-axis views was lower in DMD patients compared with controls. Segmental circumferential strain was lower in DMD patients in most segments compared with controls. The global longitudinal strain was lower in DMD patients compared with controls (-13.6 ± 5 vs. -18.8 ± 3 %, respectively, p value: 0.001). Segmental longitudinal strain measured in various segments was lower in DMD patients compared with controls. DMD patients can have occult cardiovascular dysfunction as shown by reduction in circumferential and longitudinal strain measurements with STE despite normal standard echocardiographic parameters. The clinical significance of early detection of cardiac dysfunction in these patients warrants further studies.
Keywords: Duchenne muscular dystrophy; Speckle tracking echocardiography; Strain.