Left ventricular diastolic function in congenital myotonic dystrophy

ObjectiveExamination of left ventricular function and conduction abnormalities in myotonic dystrophy.DesignTwelve patients (median age, 13.7 years) with myotonic dystrophy had detailed electrocardiography and echocardiography performed. Echocardiographic parameters were compared with body surface area (BSA) matched median normal values.ResultsFractional shortening was slightly reduced (by 28-29%) in three patients and three patients had mild mitral valve prolapse. Diastolic function was abnormal; isovolumic relaxation time (IVRT) and duration of early filling were prolonged compared with control values (median IVRT, 74v61 ms). Peak E velocity was increased (median, 0.82v 0.78 m/s) but atrial phase filling was normal. Heart rate was reduced (median, 68v 81 beats/min). Conduction abnormalities were common but showed no clear relations with diastolic abnormalities.ConclusionsYoung patients with myotonic dystrophy have myocardial diastolic dysfunction as well as abnormal electrophysiology. The prognostic implications of such abnormalities require further study.