Infusion Needle Radiofrequency Ablation for Treatment of Refractory Ventricular Arrhythmias

Abstract Background Catheter ablation is effective for eliminating most drug-refractory ventricular arrhythmias (VA). However, a major reason for procedural failure is arrhythmia originating deep within the myocardium where it is inaccessible to conventional endocardial or epicardial approaches. Affected patients have limited therapeutic options. Objectives The objective of this study was to assess the safety and outcome of a novel radiofrequency ablation catheter that used an extendable/retractable 27-g needle capable of targeting deep arrhythmia (intramural) substrate. Methods Patients who failed at least one prior catheter ablation procedure for sustained ventricular tachycardia (VT) or nonsustained VA with associated left ventricular dysfunction were enrolled at 3 centers. The target was sustained monomorphic VT in 26 patients, including 8 with recent VT storm or VT requiring intravenous medication, and 5 with incessant VA associated with ventricular dysfunction. Results Needle ablation was performed in 31 patients (median of 2 failed prior ablation procedures; 71% nonischemic heart disease). After a median of 15 needle lesions/patient, ablation abolished at least 1 inducible VT in 19 of 26 VT patients (73%), and suppressed ambient arrhythmia in 4 of 5 nonsustained arrhythmia patients. At the 6-month follow-up, 48% of patients were free of recurrent arrhythmia and another 19% were improved. Procedure-related complications included a single pericardial effusion treated with percutaneous drainage and a left ventricular pacing lead dislodgement with no deaths. Conclusions In patients with recurrent ventricular arrhythmias refractory to medications and conventional catheter ablation, intramural needle radiofrequency ablation offers significant arrhythmia control with an acceptable procedural risk.