Fascicular Ventricular Tachycardia

Abstract

Fascicular ventricular tachycardia (fascicular VT) is the most common idiopathic VT of the left ventricle. It presents with a right bundle branch block morphology and predominantly left axis deviation.Most of the available evidence supports the origin of fascicular VT as localized reentry circuits located close to the fascicle of the left bundle branch. During VT, the antegrade limb of the reentry circuit is the abnormal tissue in the left ventricular septum that is associated with slow and decremental conduction with verapamil sensitivity while the retrograde limb is usually the posterior fascicle forming the fast conduction zone. Catheter ablation is a highly effective therapy with long-term success rates of 90% and a low incidence of complications. Most of the fascicular VTs can be ablated during tachycardia by targeting the pre-Purkinje potential or Purkinje potential sites.