Clin Res Cardiol (2022). https://doi.org/10.1007/s00392-022-02002-5

Typical AVNRT - an underestimated entity after atrial redirection surgery (Mustard/Senning) for d-transposition of the great arteries? Results from 20 years of catheter ablation
S. Neumann1, J.-H. Nürnberg1, C. Frische1, M. Üçer1, A. Wegg1, J. Siebels1, J. Hebe1
1Kardiologie, Elektrophysiologie Bremen, Bremen;

Introduction: In pts with dextro-transposition of the great arteries (d-TGA) Mustard- and Senning-type (M/S) atrial redirection surgery was the standard palliation until the late 80’s. Their mid- to long-term follow up is typically complicated by sinus node dysfunction, failure of the systemic right ventricle, and atrial tachyarrhythmias. Reports of typical AVNRT in this context are scarce. With this retrospective analysis we aimed to depict the prevalence of typical AVNRT in our large single center cohort.

Methods: Included were all pts with d-TGA after M/S atrial redirection surgery who underwent electrophysiology (EP) study and catheter ablation for any tachyarrhythmia at our tertiary referral center between 2001 and 2021 retrospectively.

Results: 161 catheter ablations were performed in 111 pts. In all of these cases 3D-electroanatomical-reconstruction systems (CARTO/NavX) were used in addition to biplane fluoroscopy and angiography of systemic venous atrium (SVA) and pulmonary venous atrium (PVA) initiating the EP procedure. Mean pt age was 31.2 years. Atrial (macro) reentrant tachycardia was found in 92 pts, mostly related to the cavo-tricuspid isthmus within the PVA. Nine pts had non-automatic focal atrial tachycardia, mostly related to baffle-associated scars. Six pts had ventricular tachycardia, 5 pts accessory pathways (AP), one of which multiple AP, 4 pts had atrial fibrillation and underwent pulmonary venous isolation, 2 pts presented with focal atrial automaticity.

Fourteen pts had typical (slow/fast) AVNRT (12.6 %, mean age 28.3 yrs; range 9.6 - 45.4 yrs; female 8 pts; Mustard 8 pts; Senning 6 pts). The target area for slow pathway modification/ablation was accessed from the PVA aspect of the interatrial septum in 10 cases and from both PVA and SVA aspects in the remaining 4 cases. The PVA was accessed retrograde transaortic in 12 and via trans-baffle route in 2 cases. Ablation was successful at initial attempt in 12 of 14 cases. Three pts presented with recurrences of the targeted typical AVNRT after 2 to 12 weeks. We observed one major complication (aneurysm of the femoral artery). There were no procedure related AV blocks or pts requiring pacemaker implantation. In one pt catheter ablation was not performed as AVNRT did not match clinical documentation of tachycardia episodes (this pt was treated for atrial reentrant tachycardia). 

Conclusions: In contrast to published series, our retrospective analysis of two decades of catheter ablation therapy in pts with M/S surgery for dTGA revealed an unexpectedly high prevalence of typical AVNRT. Catheter ablation has shown to be feasible with high success and extremely low complication rates, despite the demanding postoperative anatomy and subsequently challenging access to the relevant ablation target areas. We speculate that the specific baffle-surgery involving inferior regions of the triangle of Koch may facilitate postoperative development of typical AVNRT.


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