Limited data exist on the efficacy and safety of remote magnetic navigation (RMN) ablation of iatrogenic left atrial flutter (LAF) occurring after atrial fibrillation (AF) ablation.

LAF ablation procedures (proc) were reviewed. Patients (pts) were divided into 2 groups (gr): RMN gr if proc were performed remotely using the Niobe system (Sterotaxis) and conventional gr (CON) if proc were performed with manually driven catheters. Open-irrigated 3.5mm-tip catheters were used in all pts. Activation LA maps were realized in all pts using Carto or EnSite). Acute (defined as sinus rhythm- SR- resumption during ablation) and long-term (defined as SR maintenance) proc success, proc duration, fluoroscopy and radiofrequency (RF) times, and the mechanism of arrhythmias were studied.

In 46 pts (38 males, 60.8±10.19 y) 57 LAF ablation proc were performed. Age and LA size were similar. Activation maps showed: a unique macro-reentrant circuit 46%, multiples successive macro-reentrant circuits 26%, focal pulmonary vein tachycardia 9%, micro-reentrant circuit 19%. Results are showed in the table. Complications occurred in 3 proc: 1 in the RMN gr (groin hematoma) and 2 in the CON gr (1 transient ischemic attack and 1 cardiac perforation with tamponade). Perimitral flutter that occurred at any stage of the proc was associated with significantly higher rate of acute failure (persistent perimitral flutter at the end of the proc, both gr): 44% vs 12% for other types of flutter, p=0.02.
RMN (n=25)CON (n=32)pAcute success80%78%0.86Proc/pt1.2±0.51.2±0.80.74Long-term success (follow-up 12.5±11.3 months)81%66%0.44Fluoroscopy748±377 s1086±772 s0.05Proc time236±68 min201±72 min0.06RF time1291±880 s1181±897 s0.70

As compared to manual proc, RMN guided ablation for LAF after AF ablation provides comparable acute and long-term success rate but is potentially safer.