Use of an Insertable Loop Recorder in a Myotonic Dystrophy Patient

Abstract

The case of a 66-year-old woman with myotonic dystrophy is presented. This patient underwent implantation of an insertable loop recorder as a participant in a clinical trial. At 1-month follow-up, interrogation of the insertable loop recorder revealed multiple episodes of wide complex tachycardia. She underwent electrophysiologic study, which revealed moderate His-Purkinje disease, focal atrial tachycardia, monomorphic ventricular tachycardia, and ventricular fibrillation. Successful radiofrequency ablation of the focal atrial tachycardia and implantation of a dual-chamber implantable cardioverter defibrillator was performed.

Myotonic dystrophy and the heart: A systematic review of evaluation and management

“…Implantable loop recorders (ILR) have the capacity to detect rare arrhythmias because of their duration of monitoring and have been used in small studies of patients with MD [61,62]. In predominantly asymptomatic patients, the ILR recorded arrhythmias (such as asystole and VT) that led to device implantation in 4 of 7 patients.…”

Increased temporal dispersion of myocardial repolarization in myotonic dystrophy Type 1

“…In fact, albeit probably overestimated [36], the risk of sudden cardiac death represents a concern in DM1 [5,10,37] and its underlying mechanisms remain partially unclear. Even though the progressive conduction system degeneration, leading to advanced atrioventricular blocks, represents one of the most prevalent mechanism [1,7], malignant (15) .0001 lnTP RR , ms 2 6.2 ± .6 7.5 ± .5 .0001 lnLF RR , ms 2 4.9 ± .9 5.9 ± .6 .0001 lnHF RR , ms 2 4.8 ± 1. ventricular arrhythmias may be implicated in sudden cardiac death cases even after pacemaker implantation [8][9][10][11]. Several studies report that in patients with moderate-to-high risk of arrhythmias, cardiac repolarization typically fluctuates temporally, as a function of structural and ultrastructural myocardial damage [12][13][14][15].…”

“…It has long been believed that bradyarrhythmias, resulting from a progressive sinus-node dysfunction leading to an advanced atrioventricular block, represent the main underlying cause of sudden cardiac death in DM1 patients [1,7]. However, growing evidence of a significant rate of sudden cardiac death in this population regardless of pacemaker implantation, has led to a re-appraisal of the significance of malignant ventricular arrhythmias [8][9][10][11]. Both the structural myocardial damage accompanied by myocardial repolarization changes [12] and the autonomic nervous system (ANS) abnormalities characterized by low heart rate variability [13], represent well known mechanisms involved in determining malignant ventricular arrhythmias in various diseases at high risk of sudden cardiac death [14][15][16] and, most likely, in DM1 too.…”

Asymptomatic, Nonsustained Ventricular Tachycardia in Myotonic Dystrophy Type 1 Detected with a Loop Recorder

“…VT can be most easily detected on 24-hour ambulatory ECG or loop recording. The latter has only rarely been carried out in patients with MD1 so far [18] . Though some authors recommend the implantation of ICDs for documented VTs in MD1 patients [6] , ICDs have only occasionally been implanted for the prevention of sudden cardiac death in patients with MD1 [19,20] .…”