Ventricular Tachycardia with ICD Shocks: When to Medicate and When to Ablate

Ventricular tachycardia occurrence in implantable cardioverter defibrillator (ICD) patients may result in shock delivery and is associated with increased morbidity and mortality. In addition, shocks may have deleterious mechanical and psychological effects. Prevention of ventricular tachycardia (VT) recurrence with the use of antiarrhythmic drugs or catheter ablation may be warranted. Antiarrhythmic drugs are limited by incomplete efficacy and an unfavorable adverse effect profile. Catheter ablation can be effective but acute complications and long-term VT recurrence risk necessitating repeat ablation should be recognized. A shared clinical decision process accounting for patients’ cardiac status, comorbidities, and goals of care is often required.

There is evidence for the effectiveness of both catheter ablation and antiarrhythmic drug therapy for patients with myocardial infarction, an implantable defibrillator, and VT. If sotalol is ineffective in suppressing VT, either catheter ablation or initiation of amiodarone is a reasonable option. If VT occurs despite amiodarone therapy, there is evidence that catheter ablation is superior to administration of more aggressive antiarrhythmic drug therapy. Early catheter ablation may be appropriate in some clinical situations such as patients presenting with relatively slow VT below ICD detection, electrical storms, hemodynamically stable VT, or in very selected patients with left ventricular assist devices. The optimal first-line suppressive therapy for VT, after ICD implantation and appropriate programming, remains to be determined. Thus far, there has not been a randomized controlled trial to compare catheter ablation to antiarrhythmic drug therapy as a first-line treatment; the VANISH-2 study has been initiated as a pilot to examine this question.