Cryoablation of parahisian premature ventricular contractions with an HD Grid multipolar mapping catheter: a case report.

Abstract

Catheter ablation of premature ventricular contractions (PVCs) arising from the parahisian region poses considerable technical challenges due to the proximity of the His bundle, increasing the risk of atrioventricular (AV) block. We report the case of a 69-year-old woman with symptomatic, high-burden parahisian PVCs refractory to beta-blocker therapy. After structural heart disease was excluded through standard clinical evaluations, a combined approach using high-density mapping and cryoablation was adopted. Using an HD Grid multipolar mapping catheter, the earliest ventricular activation site was precisely identified near the His bundle, with a local activation time of -26 ms. After confirming safety with a test freeze, cryoablation was performed at -75°C for 480 seconds. The PVCs were successfully eliminated without any AV conduction disturbances. At the 12-month follow-up, the patient remained asymptomatic, and the PVC burden had decreased by more than 95%. This case demonstrates the safety and efficacy of combining HD Grid mapping with cryoablation for treating parahisian PVCs.