Mortality in myotonic dystrophy patients in the area of prophylactic pacing devices

Objectives: Our study purports to determine whether implantation of a prophylactic pacemaker in MD patients with HV interval ≥ 70 ms lowers the risk of sudden death, which may be essentially due to complete atrioventricular block.

Background: Sudden death occurs more frequently in patients with myotonic dystrophy (MD) than in the control population.

Methods: From 1994 to 2008, 100 consecutive patients were enrolled, 49 of whom were implanted.

Results: During an average follow-up of 74 ± 39 months, 10 deaths occurred. Nine were due to respiratory failure. Only one sudden death occurred, whereas 46% of patients were considered at risk of sudden death according to the criteria of Groh et al. [5]. The incidence rate of sudden death was only 0.2 per 100 patient-years. One patient developed a paroxysmal syncopal sustained ventricular tachycardia.

Conclusions: The prophylactic implantation of PM in MD patients who are identified as being at risk of sudden death according to Groh's criteria reduced the incidence rate of sudden death. The one sudden death in an implanted MD patient suggests the likelihood that pacemaker implantation did not totally forestall this event. Ventricular arrhythmias may be involved in the sudden deaths in MD patients, in which case the implantation of an implantable cardiac defibrillator could be indicated.