Advertisement

Reply to the Editor—Mexiletine in myotonic dystrophy: Beware of ventricular arrhythmias!

Published:December 17, 2020DOI:https://doi.org/10.1016/j.hrthm.2020.12.013
      We thank Ballesteros et al for their interest on our article on treatment with mexiletine of patients with myotonic dystrophy type 1 (DM1).
      • Vio R.
      • Zorzi A.
      • Bello L.
      • et al.
      Evaluation of mexiletine effect on conduction delay and bradyarrhythmic complications in patients with myotonic dystrophy type 1 over long-term follow-up.
      Our study results demonstrated the safety of the use of mexiletine, which was not associated with significant electrocardiogram modification or bradyarrhythmic complications. The problem raised by Ballesteros et al that in patients with DM1 sudden death from tachyarrhythmias may occur despite pacemaker implantation goes beyond the objective of our study.
      • Bhakta D.
      • Shen C.
      • Kron J.
      • Epstein A.E.
      • Pascuzzi R.M.
      • Groh W.J.
      Pacemaker and implantable cardioverter-defibrillator use in a US myotonic dystrophy type 1 population.
      The authors hypothesize that a subclinical infra-Hisian conduction impairment related to mexiletine might increase the risk of bundle branch reentry ventricular tachycardia. Accordingly, they suggest performing an electrophysiology study with programmed ventricular stimulation under sodium channel blockers to test the arrhythmia susceptibility before beginning the mexiletine therapy. However, current guidelines recommend that patients with DM1 and a prolonged HV interval should be treated with a pacemaker, while an implantable defibrillator is indicated in the presence of spontaneous malignant ventricular tachyarrhythmias.
      • Priori S.G.
      • Blomstrom-Lundqvist C.
      • Mazzanti A.
      • et al.
      2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: the Task Force for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death of the European Society of Cardiology (ESC). Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC).
      The significance of ventricular tachycardia induced by programmed ventricular stimulation in patients with DM1 without documented spontaneous arrhythmias is still uncertain and the role of electrophysiology study in arrhythmic risk stratification requires further studies.
      • Lau J.K.
      • Sy R.W.
      • Corbett A.
      • Kritharides L.
      Myotonic dystrophy and the heart: a systematic review of evaluation and management.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic and Personal
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Heart Rhythm
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Vio R.
        • Zorzi A.
        • Bello L.
        • et al.
        Evaluation of mexiletine effect on conduction delay and bradyarrhythmic complications in patients with myotonic dystrophy type 1 over long-term follow-up.
        Heart Rhythm. 2020; 17: 1944-1950
        • Bhakta D.
        • Shen C.
        • Kron J.
        • Epstein A.E.
        • Pascuzzi R.M.
        • Groh W.J.
        Pacemaker and implantable cardioverter-defibrillator use in a US myotonic dystrophy type 1 population.
        J Cardiovasc Electrophysiol. 2011; 22: 1369-1375
        • Priori S.G.
        • Blomstrom-Lundqvist C.
        • Mazzanti A.
        • et al.
        2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: the Task Force for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death of the European Society of Cardiology (ESC). Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC).
        Eur Heart J. 2015; 36: 2793-2867
        • Lau J.K.
        • Sy R.W.
        • Corbett A.
        • Kritharides L.
        Myotonic dystrophy and the heart: a systematic review of evaluation and management.
        Int J Cardiol. 2015; 184: 600-608

      Linked Article

      • To the Editor—Mexiletine in myotonic dystrophy: Beware of ventricular arrhythmias!
        Heart RhythmVol. 18Issue 4
        • Preview
          Vio et al1 have reported data on the safety of mexiletine in patients with myotonic dystrophy type 1 (MD). They included cases without major conduction disturbances who did not develop serious bradyarrhythmic events after 9-year follow-up. These results are reassuring for daily practice, but mexiletine benefits in patients with MD and HV interval > 70 ms and an implanted pacemaker must be carefully counterbalanced with the potential risk of ventricular arrhythmias.
        • Full-Text
        • PDF