Approach to the Diagnosis and Management of Complex Fascicular Ventricular Tachycardias | Circulation: Arrhythmia and Electrophysiology
Complex ventricular tachycardias involving the fascicular system (fascicular ventricular tachycardias [FVTs]) can be challenging. In this review, we describe our approach to the diagnosis and ablation of these arrhythmias with 10 illustrative cases that involve (1) differentiation from supraventricular tachycardia; (2) assessment for atypical bundle branch reentry and other interfascicular FVTs; (3) examination of P1/P2 activation sequences in sinus rhythm, pacing, and tachycardia; and (4) entrainment techniques to establish the tachycardia mechanism and aid circuit localization. To summarize, 5 cases had prior ablation with 2 previously misdiagnosed as supraventricular tachycardia. A short His-ventricular interval supported ventricular tachycardia. Atrial stimulation could initiate and entrain 4 FVTs. P1 potentials were recorded in all cases of left posterior FVT. Entrainment at P1 and P1 to P2 connection sites at the mid-septal region, and the postablation emergence of a late P1 with