Challenges and Strategies in Cryoablation of Para-Hisian Ventricular Arrhythmia: Insights from Two Intractable Cases.

The use of the Freezor Xtra catheter (Medtronic, Minneapolis, USA) is preferred for atrioventricular nodal reentrant tachycardia owing to its low atrioventricular block risk. Therefore, use of this catheter is occasionally applied to para-Hisian ventricular arrhythmia (VA). However, the tips for catheter use in intractable cases remain challenging. This report consists of two cases of drug-resistant VAs originating from para-His. Case 1 involved a 76-year-old man who was treated VA using the reverse bending catheter technique. Case 2 involved 59-year-old man with VA who was treated at the earliest left ventricular activation site using a transseptal approach. These cases highlight the practical strategies for challenging para-His VA cases.