Atrial fibrillation arising from a silent superior vena cava

Figures

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  Figure 1. Three-dimensional electroanatomical right atrial voltage map (CARTO3) during a sinus rhythm prior to the patient’s second ablation. No superior vena cava (SVC) potential was recorded above the upper border of the sinus node. LAO = left anterior oblique view; RA = right atrium; RAO = right anterior oblique view; SN = sinus node.

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  Figure 2. Superior vena cava (SVC) potential was observed using a multielectrode mapping catheter (PentaRay; Biosense Webster). This figure shows that atrial fibrillation (AF) was provoked from SVC by intravenous adenosine triphosphate (ATP). A: SVC potential prior to ATP injection progressed starting from the intravenous injection of ATP. No SVC potential was recorded prior to ATP injection; however, a firing from the SVC was observed during atrial and ventricular sequential pacing, ie, after blockage of atrioventricular conduction by intravenous ATP (asterisk) (sweep speed 13 mm/s). B: Enlarged view of the black square in Figure 2A. Electrically dissociated pulmonary vein potential was detected (orange arrow). The site of earliest activation initiating AF was in the SVC (black arrow), soon followed by AF resulting from SVC-right atrium (RA) conduction (asterisk) (sweep speed 67 mm/s). C: Fluoroscopic view of RA (anterior-posterior view). PentaRay was located in the SVC. AP = atrial pacing; CS = coronary sinus; RV = right ventricle; VP = ventricular pacing.

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  Figure 3. Effects of adenosine triphosphate (ATP), including atrial fibrillation (AF) induction and dormant superior vena cava (SVC) conduction. A: Conduction blockage by an intravenous injection of ATP. During atrial and ventricular sequential pacing, dormant SVC-right atrium (RA) conduction was induced, but did not provoke AF (red arrows) (sweep speed 33 mm/s). SVC potential was observed using a multielectrode mapping catheter (PentaRay; Biosense Webster). B: At other times, intravenous injection of ATP resulted in rapid firing within the SVC; however, AF was not provoked because of the absence of SVC-RA conduction (black arrowhead). This phenomenon was observed when RV pacing failed owing to atrioventricular reconduction upon attenuation of ATP (sweep speed 67 mm/s). AP = atrial pacing; CS = coronary sinus; RA = right atrium; RV = right ventricle; VP = ventricular pacing.