121 Catheter ablation of atrial tachycardia inducing tachycardia cardiomyopathy in the maternal population: high risk, high reward

Background Haemodynamic, hormonal and autonomic changes of pregnancy confer an increased propensity to arrhythmia. A small proportion of arrhythmias are complicated by tachycardia-induced cardiomyopathy (TCM) which can pose a severe threat to maternal and foetal health. Aim To report experience of catheter ablation in pregnant patients with atrial tachycardia (AT) complicated by TCM. Methods A retrospective review of electronic records of patients who had undergone catheter ablation of AT during pregnancy was performed. Results Three gravid patients (Age 40 ± 6, primigravida = 1, gestational age at symptom onset 23 ± 7 weeks) underwent catheter ablation between 2010 and 2023 for AT complicated by TCM. Of the 3 cases, 2 were twin pregnancies, one assisted by IVF. No patients had any prior cardiac history. Presenting rhythm in all patients was AT, resistant to rate +/- rhythm control. DC cardioversion was unsuccessful in 2 patients. Mean LVEF at presentation was 21 ± 14%. Two patients developed significant haemodynamic compromise pre-procedurally with 1 initiated on VA ECMO with Impella and the other retrieved for consideration of ECMO prior to ablation. Electrophysiology study with electroanatomic mapping (Carto: 2; EnSite: 1) revealed focal AT in all cases. Earliest activation was found at the crista terminalis (n=2) or lateral tricuspid annulus (n=1). Acute intra-procedural success was achieved in all patients with termination of AT following catheter ablation with no post procedural complications. Following restoration of sinus rhythm, LVEF rose to 33 ± 12% at a mean of 3 days and 47 ± 10% at a mean of 921 days post procedure. There was no arrhythmia recurrence at mean follow up of 948 days. Cardiac MRI in 1 patient showed no evidence of scar or fibrosis, indicative of non-ischaemic dilated cardiomyopathy and genetic testing was normal. All patients delivered via caesarean section with live births without foetal complications. Conclusions Catheter of maternal AT complicated by TCM is safe and feasible and requires meticulous pre-procedural planning with the support of a multi-disciplinary team. Where possible zero-fluoroscopic procedures are preferable. Conflict of Interest None