LAUSR

The Fontan operation, followed by the total cavo-pulmonary connection (TCPC), has been the primary technique for surgical treatment of patients with functionally univentricular heart. Post-surgical arrhythmias contribute considerably to the morbidity and mortality within this cohort To demonstrate feasibility and outcome of catheter ablation procedures aided by three-dimensional (3D) image integration combined with advanced technologies in adult Fontan patients, as well as correlation of arrhythmia type. We included adult pts who underwent catheter ablation between 2008 and 2018. Procedures were carried out with electro-anatomical mapping and 3D image integration. Mapping and ablation were performed manually or with remote magnetic navigation (RMN). A retrograde access via the aortic valve was used to reach the atria in TCPC pts. A total of 63 pts were reviewed with either TCPC or Fontan operation (see figure). A total of 215 arrhythmias were inducible (117 in Fontan, 2/procedure, range 1–5; 98 in TCPC, 1/procedure, range 1–5), in 2 pts (3%) no ablation was performed, whereas 8 (3.7%) arrhythmias were not sustained. In TCPC pts 36 (36.7%) were macro-reentrant atrial tachycardia (MRAT) mostly from the right atrium (RA), 31 focal AT (FAT, 31.6%) almost equally from either the RA or the TCPC; 10 (10.2%) were atrio-ventricular nodal re-entrant tachycardia (AVNRT), 7 from twin AV node, and 3 concealed accessory pathways (AP) with AVRT (3%). Nine AT originated from several sites within the left atrium (9.1%). For the MRAT, most of the ablation lines were performed between the TCPC and the tricuspid annulus. In Fontans, all ATs originated from the RA, either MRAT (54, 46.1%) mostly around surgical scars, or FAT (58, 49.6%). Three pts (2.5%) presented in AF, while 1 (0.8%) had a left AP. Irrigated tip ablation resulted in acute success of 78.3% in the TCPC cohort and 76.7% in the Fontan cohort. The mean procedure time was 254±99 min and 255±106 min with a mean fluoroscopy time 2.3±1.9 min and 5.5±4.8 min for each TCPC and Fontan, respectively. During a mean follow-up of 4.2±3.0 years (maximum of 10.8 years), 58% (41–72) of TCPC pts and 22% (10–38) of Fontan pts remained free of symptoms/significant arrhythmia [at 2 years: 69% (55–79) and 31% (18–46), respectively]. Eleven TCPC (26%, 4 new arrhythmias) and 14 Fontan patients (70%, 3 new arrhythmias) needed repeat procedures. In multivariate Cox regression analysis, Fontan operation and female gender were associated with worse outcome, independently of the type of arrhythmia. Advances in 3D mapping, image integration and the introduction of RMN has facilitated a dramatic improvement of ablation outcomes for adult patients after single ventricle repair. Patients with TCPC have fewer arrhythmias than Fontans and are more likely to benefit longterm, whilst transbaffle puncture can be avoided using RMN.