Magnetic navigation in left-sided AV reentrant tachycardias: preliminary results of a retrograde approach

A novel magnetic navigation system allows remote guidance of floppy radiofrequency (RF) ablation catheters. We evaluated the feasibility of mapping and ablation of left-sided accessory pathways (APs) using the retrograde transaortic approach with this system. This might open the gate to retrograde ablation of left atrial arrhythmias.

Twenty consecutive patients were included. A Helios II was used in five and in 15 a Celsius RMT RF catheter with higher magnetic mass and different flexibility was used. Mapping and ablation were attempted. The learning curve was analyzed. Ablation was acutely successful in 60% of the patients using the Helios II and in 80% using the Celsius RMT. Median procedure time was 158 minutes, with median patient and physician fluoroscopy times of 26 and 4 minutes. In the last 10 patients, procedure times became significantly shorter (median 122 minutes, only Celsius RMT catheters) and standard catheters had to be used only twice. No complications occurred.

Remote retrograde transaortic RF ablation of left-sided APs is feasible, safe, and reduces the physician's fluoroscopy exposure. There is a very steep initial learning curve, with the success rate increasing from 50% in the first 10 cases to 80% in the last 10 cases. Different catheter configurations may influence the outcome.