Optimal ablation strategies for different types of ventricular tachycardias

Abstract

Ablation strategies for almost all types of ventricular tachycardias have now been established. The optimal ablation strategy for ventricular tachycardia is determined by the site of origin and the electrophysiological mechanisms. Electrocardiograms, an understanding of the common sites of basic disease, and identification of the scar site using imaging modalities might be helpful for predicting the originating location. Electrophysiological activation mapping is the gold standard for identification of the ventricular tachycardia substrate. However, when activation mapping of scar-related ventricular tachycardias is not possible, substrate mapping might be performed to identify isolated diastolic potentials. Substrates are commonly located in the endocardium, but transvenous or subxiphoidal intrapericardial approaches can be used to map epicardial substrates. Unusual types of ventricular tachycardia might require special strategies, such as transcoronary ethanol or intramural needle ablation. For idiopathic ventricular tachycardias, ablation might be a first-line therapy because of its high efficacy and very low risk of complications. However, the recurrence rate of scar-related ventricular tachycardias remains considerable, and ablation remains an adjunctive therapy to medical therapy and implantable cardioverter-defibrillators. When incessant ventricular tachycardia or fibrillation requiring defibrillator therapy (electrical storm) is refractory to antiarrhythmic drugs, neuraxial modulation, including sedation, might be the next option before catheter ablation is attempted.