Catheter ablation of ventricular tachycardia

Sudden cardiac death from ventricular tachycardia and ventricular fibrillation is a leading cause of mortality worldwide. Patients with structural heart disease are at highest risk of ventricular arrhythmias. Although implantable cardioverter-defibrillators provide abortive therapy for ventricular arrhythmias, they can also lead to inappropriate shocks which adversely affect quality of life, morbidity and mortality. Medical therapy for the prevention of ventricular arrhythmias consists of beta-blockers and anti-arrhythmic drugs, where efficacy is limited and side effects are not infrequent. Catheter ablation of ventricular tachycardia is now a well-established therapeutic option for patients with ventricular arrhythmias. Greater understanding of the underlying mechanisms of ventricular tachycardia, potential strategies for ablation, and improvement in 3D mapping has improved our ability to eliminate a targeted ventricular tachycardia. Symptomatic ventricular tachycardia can also occur in patients with structurally normal hearts. Most common sites include outflow tract origin or ventricular tachycardia involving the fascicular system. Success rates for catheter based cure in this subset of patients are greater than 90%. The objective of this chapter is to provide an overview of the current state of catheter ablation for ventricular tachycardia. A review of ventricular tachycardia mechanisms, mapping techniques, and ablation in patients with and without structural heart disease will be discussed.