Catheter ablation of right ventricular outflow tract tachycardia: a simplified remote-controlled approach.

ABSTRACT

AIMS: Manual mapping and ablation of right ventricular outflow tract (RVOT) tachycardia may be associated with cardiac perforation and complicated by mechanically induced ventricular extrasystoles (VESs). The aim of this study was to assess remote-controlled magnetic (RCM) mapping and ablation of RVOT ventricular tachycardia (VT)/VES utilizing a soft magnetic catheter. METHODS AND RESULTS: Mapping and ablation of RVOT VT/VES were performed using the magnetic navigation system (MNS, Niobe II, Stereotaxis, St Louis, MO) in conjunction with a cardiodrive motor unit (Stereotaxis). A soft magnetic catheter (Celsius RMT, 4 mm solid tip, Biosense Webster, Diamond Bar, CA) was navigated to the RVOT using a sequence of pre-installed magnetic vectors. The primary endpoint was defined as successful RCM VT/VES ablation. Other parameters observed included RCM RVOT accessibility, mapping-induced mechanical VES, fluoroscopy time, complications, and arrhythmia recurrence. Thirteen consecutive patients (mean age 50 ± 14 years; 10 females, 6 RVOT VT) underwent RCM mapping and ablation. The RVOT was reached in all patients utilizing solely the MNS. Successful RCM RVOT ablation was achieved in {12 of 13} (92.3%) patients. Mean procedure and fluoroscopy times were 116.5 ± 48.9 and 7.5 ± 4.3 min, respectively. Catheter-induced VES during RVOT mapping were observed in {1 in 13} patients (7.7%, three VES). No complications occurred. During a mean follow-up of 252 ± 211 days, clinical arrhythmia recurrence was observed in {1 in 13} (7.7%) patients. CONCLUSIONS: Automatic RCM RVOT access is feasible, while RVOT mapping and ablation appear to be safe, fast, and effective. The soft magnetic catheter rarely induces mechanical VES.