Risk of arrhythmias in myotonic dystrophy: trial design of the RAMYD study.
OBJECTIVE
Myotonic dystrophy type 1 (DM1) is the most frequent muscular dystrophy in adults. DM1 is a multisystem disorder also affecting the heart with an increased incidence of sudden death, which has been explained with the common impairment of the conduction system often requiring pacemaker implantation; however, the occurrence of sudden death despite pacemaker implantation and the observation of major ventricular arrhythmias generated the hypothesis that ventricular arrhythmias may play a causal role as well. The aim of the study was to assess the 2-year cumulative incidence and the value of noninvasive and invasive findings as predictive factors for sudden death, resuscitated cardiac arrest, ventricular fibrillation, sustained ventricular tachycardia and severe sinus dysfunction or high-degree atrioventricular block.


METHODS
More than 500 DM1 patients will be evaluated at baseline with a clinical interview, 12-lead ECG, 24-h ECG and echocardiogram. Conventional and nonconventional indications to electrophysiological study, pacemaker, implantable cardioverter defibrillator or loop recorder implantation have been developed. In the case of an indication to electrophysiological study, pacemaker, implantable cardioverter defibrillator or loop recorder implant at baseline or at follow-up, the patient will be referred for the procedure. At the end of 2-year follow-up, all candidate prognostic factors will be tested for their association with the endpoints.


BACKGROUND
ClinicalTrials.gov ID NCT00127582.


CONCLUSIONS
The available evidence supports the hypothesis that both bradyarrhythmias and tachyarrhythmias may cause sudden death in DM1, but the course of cardiac disease in DM1 is still unclear. We expect that this large, prospective, multicenter study will provide evidence to improve diagnostic and therapeutic strategies in DM1.
Dello Russo
Antonio
A
Institute of Cardiology, Department of Cardiovascular Medicine, Catholic University, L.go A. Gemelli 8, 00168 Rome, Italy. adellorusso@tin.it
Mangiola
Fortunato
F
Della Bella
Paolo
P
Nigro
Giovanni
G
Melacini
Paola
P
Bongiorni
Maria Grazia
MG
Tondo
Claudio
C
Calò
Leonardo
L
Messano
Loredana
L
Pace
Manuela
M
Pelargonio
Gemma
G
Casella
Michela
M
Sanna
Tommaso
T
Silvestri
Gabriella
G
Modoni
Anna
A
Zachara
Elisabetta
E
Moltrasio
Massimo
M
Morandi
Lucia
L
Nigro
Gerardo
G
Politano
Luisa
L
Palladino
Alberto
A
Bellocci
Fulvio
F
D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D054537:Atrioventricular Block / Q000209:etiology; D002304:Cardiac Pacing, Artificial; D016887:Cardiopulmonary Resuscitation; D016757:Death, Sudden, Cardiac / Q000209:etiology; D017147:Defibrillators, Implantable; D018450:Disease Progression; D018572:Disease-Free Survival; D004452:Echocardiography; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006323:Heart Arrest / Q000209:etiology / Q000628:therapy; D006801:Humans; D007558:Italy; D053208:Kaplan-Meier Estimate; D008297:Male; D009223:Myotonic Dystrophy / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D017180:Tachycardia, Ventricular / Q000209:etiology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology