Entering through the back-door: remotely navigated ablation of left atrial tachycardia in the presence of a large atrial septal defect occluder

A 43-year-old patient was referred for ablation of symptomatic left atrial tachycardia (cycle length 280 ms) 6 months after surgical cryoablation of paroxysmal atrial fibrillation and mitral valve reconstruction. Since the patient had undergone closure of an atrial septal defect using a large occluder 5 years prior to surgery (Figure 1A), puncture of the interatrial septum was not attempted. A magnetically steerable catheter was inserted through the femoral artery and advanced via the aortic valve into the left ventricle. Trans-mitral access of the left atrium was achieved by remote navigation (Figure 1B). An electroanatomic activation map of the entire left atrium showed centrifugal activation from a micro-reentry circuit at the posterior wall next to the left inferior pulmonary vein (Figure 1C). Ablation at the site of earliest activation with a fractionated signal of low voltage terminated the tachycardia. Although puncture through a closure device has been reported, this was not performed due to safety considerations and the option of an alternative access. We could show that if transseptal puncture is not a valid option, creation of a detailed electroanatomical map of the left atrium via a retrograde aortic trans-mitral approach is feasible using remote magnetic navigation. The full-length version of this report can be viewed at: http://www.escardio.org/communities/EHRA/publications/ep-case-reports/Documents/remotely-navigated-ablation.pdf