Ventricular tachycardia ablation in ischaemic cardiomyopathy: who, when and how?

Ventricular tachycardia (VT) is an abnormal rapid heart rhythm that most commonly occurs in the setting of ventricular scar. In patients with ischaemic cardiomyopathy and VT, the most common mechanism is re-entry of electrical activation through narrow channels of diseased myocardium manifesting on the ECG as a regular sustained wide-complex tachycardia that can present clinically with sudden cardiac death (SCD). Implantable cardioverter-defibrillators (ICDs) are proven to reduce the risk of SCD, but do not prevent VT; they treat it when it occurs. Although antiarrhythmic drug therapy has a long history of use to suppress VT, recurrence rates remain high and adverse effects are not negligible. Significant advances have been made over the past decades in catheter-based techniques for VT suppression. Improvements in both mapping accuracy and ablation efficacy have resulted in recent studies demonstrating improved outcomes of catheter ablation of VT. Patient selection for a procedural approach will be important for achieving optimal clinical outcomes. This review provides a comprehensive overview of randomised trials of catheter ablation for VT as well as contemporary VT ablation techniques, and aims to understand which patients should undergo VT ablation, when is the ideal timing for intervention, and how best to achieve freedom from recurrent VT.