Dual-chamber open-window mapping for an epicardial accessory pathway through the posterior coronary vein

Figures

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  Figure 1. Surface electrocardiograms and intracardiac electrograms. A: Surface electrocardiograms during sinus rhythm. B: Surface electrocardiograms during atrioventricular reentrant tachycardia (AVRT). C: Intracardiac electrograms during AVRT. The asterisks (∗) indicate the earliest atrial activation site, which was located at the proximal coronary sinus (CS). HBE = His bundle electrogram; HRA = high right atrium; RVA = right ventricular apex.

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  Figure 2. Open-window mapping (OWM) during orthodromic atrioventricular reentrant tachycardia (AVRT) and coronary sinus (CS) venography. A: The OWM of the left atrium. The lower threshold of the early-meets-late (EML) algorithm was set at 30%. No EML gap was observed in the conduction block (depicted as a white line) at the mitral annulus. The earliest atrial activation was noted on the left posteroseptum, where the fragmented potential was recorded. B: The OWM of the left atrium and CS (also refer to Supplemental Video 1). The activation originated from the posterior coronary vein (PCV) and propagated through the CS toward the earliest atrial activation site on the left posteroseptum (indicated by a yellow arrow). Fragmented potential was recorded in the PCV. C: CS venography. The PCV drained into the proximal CS. D: Catheter position during ablation. The ablation catheter was placed in the proximal PCV. E: Surface electrocardiogram and intracardiac electrograms during ablation. Orthodromic AVRT presented as wide QRS tachycardia because of concomitant right bundle branch block. LIPV = left inferior pulmonary vein; LV = left ventricle; RF = radiofrequency application; RIPV = right inferior…