Abstract 19403: Abnormal Conduction is Predictive of a Higher Risk of Ventricular Arrhythmias in Myotonic Dystrophy Patients
Introduction: Permanent pacing is often indicated in myotonic dystrophy (MD) patients due to a high risk of conduction disease; however, the risk factors for ventricular arrhythmias (VA) and indications for defibrillator placement in MD patients are not well defined. We sought to define risk factors for VA in MD patients who underwent electrophysiology (EP) study.
Hypothesis: MD patients with prolonged AV conduction and inducible ventricular arrhythmias have a greater risk of VA during follow up.
Methods: We conducted a single center retrospective analysis of 24 MD patients [Age 49.7±12.8 yo, male 50%, LVEF 55±7.6%] who presented for EP study. Patients were followed for an average 1.9±1.5 years. Patients who had ventricular arrhythmias (VA+) were compared to patients who did not have a ventricular arrhythmia (VA-). Patients with sustained and non-sustained VA’s were included in the VA+ group.
Results: There were 2 patients who presented with ventricular fibrillation, did not have an EP study prior to ICD placement and were excluded. The VA+ patient cohort consisted of 4 patients who had VA during follow-up. VA+ patients had similar demographics and echocardiographic parameters compared to VA- patients. On electrocardiogram (ECG), VA+ patient had a longer PR interval compared to VA- patients (VA+ vs. VA-: 263±69 ms vs. 190±30 ms, p = 0.003). At EP study (Table), VA+ patients had a longer HV interval [VA+ vs. VA-: 81±9 ms vs. 67±17 ms, p = 0.05]. Programmed ventricular stimulation during EP study induced VA in [3/22] patients during EP study, who received an ICD; however, inducible VA was not predictive of VA during follow up [0 VA events / 3 inducible vs. 4 VA events / 19 non-inducible, p = 0.5].
Conclusions: AV nodal or infra-nodal conduction disease was associated with a higher incidence of ventricular arrhythmias during follow up among MD patients. Inducibility of ventricular arrhythmias during EP study was not predictive.
Author Disclosures: Q. Nguyen: None. M. Zipse: None. W.H. Sauer: None. W. Tzou: None. J. Schuller: None. R. Aleong: None.
- © 2016 by American Heart Association, Inc.