Abstract: Objective · To assess the clinical outcome of catheter ablation guided by remote magnetic navigation(RMN)  for ventricular arrhythmias (VAs) including ventricular tachycardia (VT) and ventricular premature complex (PVC) originating from ouflow tract (OT).  Methods · A total of 42 patients with idiopathic VT/PVC originated from outflow tract were enrolled. All the patients underwent catheter ablation guided by RMN and 3D Carto mapping system. OT-VAs were divided into two groups:right ventricular outflow tract(RVOT) group and left ventricular outflow tract(LVOT) group. VAs arising from LVOT were mapped and ablated by transaortic retrograde and/or transseptal puncture approaches. The primary study endpoint was acute success rate. The secondary study endpoints were procedure-related parameters, including operator X ray time, ablation time, procedure time and complications. VAs recurrence was detected by Holter electrocardiograph (ECG) which was followed-up at 3 months, 6 months and 1 year after ablation.  Results · 74% (31/42) VAs arised from RVOT. 93% (39/42) OT-VAs were achieved acute success. The acute success rate was not different between VAs from RVOT and LVOT (30/31 vs 9/11, P=0.160). Compared to LVOT group, the ablation time and fluoroscopic time of RVOT group were significantly reduced s by 31% (P=0.020) and by 33% (P=0.004). There was no major complication in two groups. Within the 11 cases of LVOT-VAs, 4 LVOT-VAs cases which were ablated by tansaortic retrograde with failure were transferred to transseptal approach and ablated successfully.  At one-year follow-up, frequent PVCs recurred in 2 out of 39 patients with acute success.  Conclusion · Catheter ablation using RMN for OT-VAs is safe and effective with relatively short operator’s X-ray time. For LVOT-VAs, mapping and ablation guided by RMN through transseptal approach can improve the acute success rate.

Key words: ventricular arrhythmia, catheter ablation, remote magnetic navigation