Fractionated Potential-Guided Slow Pathway Ablation for Slow-Fast Atrioventricular Nodal Reentrant Tachycardia in a Patient With Persistent Left Superior Vena Cava Using Ultra-High-Density Mapping

A 70-year-old man with persistent left superior vena cava (PLSVC) underwent catheter ablation for atrioventricular nodal reentrant tachycardia (AVNRT). The diagnosis of slow-fast AVNRT was verified by a septal VA time <70 ms, V-A-V response to ventricular overdrive pacing with a post-pacing interval and tachycardia cycle length >115 ms with a corrected post-pacing interval (>110 ms) (Figure A). An ultrahigh-resolution activation map of the triangle of Koch was obtained with the RHYTHMIA mapping system (Boston Scientific, Marlborough, MA, USA), and fractional potentials (FPs) were identified by complex activation using the LUMIPOINT module (Boston Scientific). During slow-fast AVNRT, the earliest atrial activation was observed on the anteroseptum, and the FPs were highlighted by the LUMIPOINT module, with 10.0 peaks at the coronary sinus (CS) ostium (#1) and CS roof (#2) (Figure B). The late extrastimuli at site #1 reset the AVNRT with longer coupling intervals as compared with site #2 (Figure C,D). After the conventional radiofrequency approach for the inferior posteroseptal region outside the CS failed to eliminate the slow pathway junction, tachycardia was eliminated by radiofrequency application at site #1.

Figure.

Ventricular overdrive pacing (A) and at ultrahigh-resolution (B) during AVNRT. Late extrastimuli at the CS OS (#1) and CS roof (#2) (C,D). AVNRT, atrioventricular nodal reentrant tachycardia; CS, coronary sinus; HBE, His bundle electrogram; HRA, high right atrium; OS, ostium; PLSVC, persistent left superior vena cava; RV, right ventricle.

Catheter ablation for AVNRT with PLSVC is challenging because of anatomic abnormalities of Koch’s triangle associated with an enlarged CS ostium. However, FPs recorded by ultra-high-density mapping may indicate the slow pathway potential visualized with LUMIPOINT¹ and could serve as a target for AVNRT with PLSVC.

Disclosures

The authors declare no conflicts of interest.

IRB Information

Toyama Prefectural Central Hospital, Ethics Committee (No. 64-101).

Reference

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