Unreachable: Magnetic guided Ablation of Supraventricular Tachycardia in Patients with Congenital Heart Disease and Complex Vascular Support to the Target Region—A Single-Center Experience

Background: The ablation of supraventricular tachycardia (SVT) in patients with congenital heart disease (CHD), especially transposition of the great arteries (TGA) after atrial switch operation (ASO) or Fontan circulation (FC) is often complicated due to the complex access to the ablation target. To avoid baffle or tunnel puncture, we chose a transaortal retrograde approach to the pulmonary venous atrium, using remote magnetic navigation (RMN). This study takes a look at patients with CHD showing a difficult access to the ablation target. In three of the included patients previous manually guided ablations failed.

Method: From 2012 to 2020, fourteen procedures were performed in 14 patients with CHD and complex vascular support to the ablation target. Nine patients with TGA after ASO, 3 females and 6 males, aged between 19.3 and 42.6 years (median: 35.9 years, SD: 8.9 years) and 5 patients with FC, 3 females and 2 males, aged between 13.0 and 44.7 years (median: 19 years, SD: 12.7 years). All procedures were realized using 3D-navigation and RMN of the ablation catheter. In FC, an electrophysiological examination was performed using a transaortal retrograde ventricular catheter and atrial catheter placement in the tunnel; in ASO, we used venous support for those catheters.

Results: Medium procedure duration was 245.5 min (range: 177–350 min, SD: 55 min), fluoroscopy time of the medium was 4.7 min (range: 0.2–43.0 min, SD: 11.5 min) and radiation dose of the medium was 221.4 cGy cm² (range: 12.1–2,602.0 cGy cm², SD 806.6 cGy cm²). A primary success was seen in all ablations, detected by the non-inducibility of SVT and block of the created ablation line. Follow-up was after 2,113.6 days in average (range: 809–4,288 days, SD: 1,271.9 days). We were able to see tachycardia-free survival in 78.5% after 1 year and 57.1% after 2 years of follow-up. Early recurrence was seen in 3 patients with ASO between 6 and 33 days after ablation of typical flatter. There were 6 patients, 3 after ASO and 3 after FC, without any tachycardia in the follow-up period between 932 and 3,978 days. Only one patient, with underlying bradycardia due to sick sinus syndrome and AV block I to II, had a complication shown as a complete AV-Block.

Conclusion: The RMN ablation is a safe and effective way in the ablation of SVT, also in the catheter manipulation along difficult routes to the target in complex CHD. The radiation exposure is low, and the procedure duration is acceptable. At least it enables an effective ablation without baffle or tunnel puncture in FC or after ASO and avoids risk of complications.

Publication History

Article published online:
28 January 2023