Trial: Relationship between cardiac arrhythmias and sleep apnea in permanently paced patients with type I myotonic dystrophy

Authors: Lazarus, A; Varin, J; Jauvert, G; Alonso, C; Duboc, D.

Reference: Neuromuscul Disord. 2007 May;17(5):392-9.

Purpose: To detect the occurrence of rhythm disturbances and sleep apnea in permanently paced patients with Type I myotonic dystrophy (DM1), in order to examine the possible link between spontaneous, paroxysmal arrhythmias and ventilatory abnormalities detected and recorded by the device.

Number of Patients: 20

Number of Centers: 1

Design: Prospective, observational

Authors Conclusion: Arrhythmias were recorded by the pacemaker in 17 patients (85%), and 14 patients developed arrhythmic episodes that occurred either in the presence or absence of concomitant sleep apnea.  Conversely, among these 14 patients, the majority of sleep apnea episodes were not associated with concomitant arrhythmias.  In the other 3 patients who developed arrhythmias, simultaneous sleep apnea was never observed.  The authors concluded that a high incidence of arrhythmias and sleep apnea was observed in patients with DM1.  Arrhythmias may be attributed to organic substrate or are sometimes precipitated by functional triggers, such as sleep apnea.

Key words: Sleep apnea, arrhythmias, pacemaker

Comment: Episodes of sleep apnea developing in patients with DM1 should be meticulously treated, since this may help alleviate the arrhythmic burden.  However, the distinction between organic heart disease and functional mechanisms as underlying causes of bradyarrhythmias detected during ambulatory monitoring may be difficult, and this distinction may be clearer by invasive electrophysiogical testing or close monitoring following pacemaker implantation utilizing a device which is capable of diagnosing sleep apnea. 

Ongoing Related Studies:

1. Atrial Fibrillation Recurrence in Obstructive Sleep Apnea
2. Impact of Resynchronization Therapy on Sleep Disordered Breathing in Advanced Congestive Heart Failure

Summary written by Andrea Russo, MD