Early detection of left ventricular involvement in patients with Duchenne's and Becker's muscular dystrophy

Background Patients with Duchenne muscular dystrophy (DMD) and Becker's muscular dystrophy (BMD) may have asymptomatic cardiac involvement for years before the development of dilated cardiomyopathy and even showed normal conventional echocardiographic parameters. We evaluated those patients with more recent echo modalities for early detection of subtle cardiac changes. Patients and methods Thirty patients [13 with BMD as group 1 (G1) and 17 with DMD as group 2 (G2)] compared with 30 age-matched and sex-matched healthy participants as group 3 (G3). All cases were subjected to history taking, clinical examination, ECG, conventional two-dimensional (2D) echocardiography, tissue Doppler imaging, 2D-speckle tracking echocardiography, and 4D echocardiography for measurement of left ventricular (LV) dimensions, systolic and diastolic function with focus on strain imaging modality. Results Nine patients of G2 and three patients in G1 had LV systolic dysfunction despite normal 2D-LV ejection fraction. Ten patients in G2 and five patients in G1 had LV diastolic dysfunction measured by LV early diastolic wave velocity over mitral valve measured by conventional Doppler/early diastolic mitral annular velocity by tissue Doppler imaging (E/Ea). Tissue Doppler myocardial performance index was significantly higher in both G1 and G2. 2D-LV septal strain, lateral strain, anteroseptal, 2D-global longitudinal strain (GLS), and 4D-GLS strains were significantly lower in G1 and G2. Apical, mid, and basal posterior LV strain were significantly lower in G2 compared with G1. 2D-GLS was lower in G2 compared with G1. Both LV global radial strain and global circumferential strain were significantly lower in G1 and G2. Mid and basal septal strain and basal posterior strain were significantly lower in G2 compared with G1. The mid and basal posterior strains were significantly lower in G2 compared with G1. Conclusion 2D-speckle tracking and 4D echocardiographic study of global and regional strain besides creatinine phosphokinase serum levels may add benefit in early detection of subtle LV dysfunction in patients with DMD and BMD.