A New Strategy For Papillary Muscle Ablation Using Multifunctional Intracardiac Echocardiography Catheter: A Feasibility Study In Canines

Objective: This study investigated the feasibility and safety of leftventricular papillary muscle ablation using multifunctional intracardiacechocardiography catheter in animals, which sought to explore a newmethod to treat the ventricular arrhythmias (VAs) originated from thepapillary muscle (PM) by transcatheter method.Methods: A multifunctional intracardiac echocardiography catheter,integrated with a32-element ultrasound imaging transducer and a nitinolneedle was delivered into the left ventricle in12canines transcarotid wayguiding by TTE. After identification of the APM (n=6) and PPM (n=6) bythe ICE probe, the injection needle was advanced to the base of PMguiding by ICE imaging.0.5ml-1.0ml ethanol was injected into themyocardium.4days after this ablation, the animals were sacrificed and theheart was harvested for gross and histological examination.Results: In all animals, the ICE probe could provide the detail anatomicstructure of the heart chamber and the APM and PPM could be identified. The advance of the needle and the injection process was with a ICEimaging guidance. After sliced the myocardium, the injection region in thebase of PM showed pale color coagulation necrosis with a border battenlesions and normal tissue. There was a dose-related correlation betweenmyocardial ablation and the volume of ethanol infusion. During thefollow-up period, there was no death, papillary muscle rupture ormyocardial perforation occurred.Conclusions: It was safety and effective for ablation of the leftventricle PM using this multifunctional ICE catheter. This catheter mayprovide a more safety, more effective, and more convenience method fortreatment of VAs origined from the PM, which merged ultrasoniclocalization and ablation function.