Ablation of a focal left atrial tachycardia via a retrograde approach using remote magnetic navigation

A 66-year-old man who had undergone successful ablation of typical atrial flutter subsequently developed a left atrial tachycardia. A trans-septal approach was proposed, but not performed due to risk. He was referred to us with the suggestion that a retrograde procedure could be attempted using a magnetic navigation system (Niobe, Stereotaxis Inc, St Louis, MO, USA) installed in our institution.We performed multi-slice computed tomography (CT) with three-dimensional reconstruction to allow for use of the CARTO RMT Merge system (Biosense Webster, Diamond Bar, CA, USA). The patient was sedated with diazepam and fentanyl. Heparin was used to maintain the activated clotting time of above 300 s. After placing diagnostic catheters, we approached the left atrium (LA) in a retrograde fashion using a 4 mm tip magnetically enabled ablation catheter (Navistar RMT, Biosense Webster), advancing it to just below the subclavian artery manually. The ablation catheter was then manoeuvred across the aortic and mitral …