Differences in feasibility and outcomes of catheter ablation using robotic magnetic navigation in patients with congenital heart disease depending on the complexity of the defect

Abstract Introduction & purpose Robotic magnetic navigation (RMN) facilitates catheter ablation in the presence of a difficult cardiac anatomy such as congenital heart diseases (CHD). The objective of this study is to evaluate the feasibility, efficacy and safety of this procedure depending on the complexity of CHD. Methods Thirty-one patients with CHD, who received catheter radiofrequency (RF) ablation of arrhythmia using RMN, were retrospectively included. Echocardiographic, clinical, procedural and follow-up data were obtained. Results Twelve patients (38.7%) had corrected transposition of great arteries, 10 patients (32.3%) - ventricular septal defect, 6 patients (19.4%) - atrial septal defect (Figure 1). Atrial flutter was ablated in 19 procedures (61.3%), atrial tachycardia in 6 procedures (19.4%), accessory pathway – 3 procedures (9.7%), atrial fibrillation and ventricular ectopic beats – 2 (6.5%) each and atrioventricular nodal re-entrant tachycardia – 1 (3.2%). The median procedural time was 325.0 minutes (interquartile range (IQR) 109.0). Median radiation dose was 2.2 mGym2 (IQR 2.0). The median number of RF applications was 32.0 (IQR 26.5), median total time of RF applications was 16.4 min (IQR 14.6). The total procedural time and RF time were significantly greater in severe CHD complexity than in the simple defects (p-values 0.023 and 0.049, respectively). Radiation dose was higher in the severe group compared to the moderate group (p = 0.028). Acute arrhythmia cessation was observed during 92.6% of procedures. Major complications were noted in 2 cases (6.5%) (Table 1). One patient had a pericardial effusion treated conservatively, and one patient had a throat hematoma following a periprocedural transesophageal echocardiography. The median time from the ablation to follow-up was 7.1 months (IQR 6.4). Two patients were lost during follow-up. Arrhythmia recurrence was noted in 6 cases of (20.7%). Partially success, noted as significant reduction in clinical arrhythmia without complete resolution, was achieved in 1 patient (3.2%). Conclusion Severe CHD was associated with higher radiation dose, longer procedural time and longer total time of RF applications. The efficacy of arrhythmia cessation for several months depends on the type of arrhythmia and CHD complexity. RMN is associated with a reasonable low risk of major periprocedural complications in this complex set of patients.