Clinical results of combined amiodarone and mexiletine therapy in refractory ventricular tachycardias

Background: Refractory recurrent ventricular tachycardia is a difficult therapeutic problem. There are implantable cardioverter-defibrillator (ICD) patients with amiodarone-refractory of ventricular arrhythmia (VA) who are not eligible for catheter ablation. The aim of this cohort study was to assess the efficacy of mexiletine in combination with amiodarone in the reduction of VA in this group of patients. Methods: This was a retrospective study of all consecutive ICD patients who were treated by adding mexiletine to amiodarone in refractory electrical storm or frequent VA episodes. The enrolled patients were ineligible for catheter ablation. Results: Thirty-seven patients (32 males; mean age, 57 ± 14 years; range, 26–81 years) were studied. Adding mexiletine to amiodarone had no significant effect on QRS width, QTc interval, and PR interval (all P > 0.05). We observed a significant decrease in the number of total ICD shock and significant increase in appropriate antitachycardia pacing during follow-up after initiating mexiletine. Mexiletine therapy also significantly reduced the amiodarone dose during the follow-up. No mortality was observed in the present cohort during the study period. Conclusions: Mexiletine, when added in case of amiodarone failure, reduces VA episodes and appropriate therapies in patients with an implantable cardioverter defibrillator