Regional and Transmural Dispersion of Repolarisation in Patients with Emery-Dreifuss Muscular Dystrophy

Background: The development of malignant ventricular arrhythmias is a possible feature in Emery-Dreifuss muscular dystrophy (EDMD) patients with normal left ventricular systolic function. This event may be the cause of sudden cardiac death in EDMD patients. QTc dispersion (QTc-D), JTc dispersion (JTc-D) and Tpeak-end dispersion (TDR) could reflect the physiological variability of regional and transmural ventricular repolarisation and could provide a substrate for life-threatening ventricular arrhythmias.

Aim: The current study was designed to evaluate the heterogeneity of ventricular repolarisation in EDMD patients.

Methods: Echocardiograms and electrocardiograms from 40 EDMD patients (age 20 ± 13) were evaluated and compared to those of 40 healthy age-matched controls.

Results: The EDMD group, compared to the healthy control group, presented increased values of QTc-D (82.8 ± 44.1 vs. 53.3 ± 13.9, p = 0.003), JTc-D (73.6 ± 32.3 vs. 60.4 ± 11.1 ms, p = 0.001) and TDR (100.54 ± 19.06 vs. 92.15 ± 15.5 ms, p = 0.004). No correlation between QTc dispersion and ejection fraction (R = 0.2, p = 0.3) was found.

Conclusions: EDMD is associated with significantly increased regional and transmural heterogeneity of ventricular repolarisation, in the absence of impaired systolic and diastolic cardiac function.