Routine echocardiography reveals distinct patterns of cardiac structural and functional abnormalities in patients with myotonic and Duchenne's muscular dystrophies.
Routine echocardiographic examinations were performed on 53 individuals with muscular dystrophy (29 with myotonic muscular dystrophy MMD and 24 with Duchenne's dystrophy DD). Five of 29 (17%) with MMD and six of 24 (25%) with DD had typical mitral valve prolapse evidenced by echocardiography. All patients with DD and mitral valve prolapse had severe thoracic skeletal deformities, while none with MMD and mitral valve prolapse had such abnormalities. Other echocardiographic parameters analyzed included the fractional shortening of the left ventricle (% delta S), excursions of the left ventricular posterior wall (LVPW) and the ventricular septum, pre-ejection period/left ventricular ejection time ratios (PEP/LVET), and thickness of the LVPW and ventricular septum. Abnormal prolongation of the PEP/LVET ratio and increased thicknesses of the LVPW and ventricular septum were noted in some individuals in the MMD group. Decreased % delta S with diminished excursion and diastolic velocity of the LVPW were noted in some with DD.
Reeves et al. (Thu,) studied this question.