Box Isolation of the Confluence of 3 Pulmonary Veins, a Rare Variant of the Common Pulmonary Vein

A 60-year-old man with paroxysmal atrial fibrillation (AF) was referred to hospital for catheter ablation. 3D imaging using contrast-enhanced multidetector computed tomography (CT) revealed confluence of 3 pulmonary veins (PVs), the left superior PV (LSPV), left inferior PV (LIPV), and right inferior PV (RIPV), at their junction towards the posterior left atrium (LA) (Figure A,B). Radiofrequency (RF) ablation was performed under the guidance of 3D ultrasound geometry and 3D merged CT using the CARTO 3 system (Biosense Webster). The voltage map revealed myocardial sleeves towards the common trunk and right superior PV (RSPV) (Figure C). To avoid both stenosis of the common trunk and electrical connection between the carina of the right PVs and LA, box isolation including the RSPV anterior wall, bottom line, left lateral ridge of the left atrial appendage side, and roof line was performed (Figure D). Bidirectional conduction block was confirmed by complete electrical silence and the loss of atrial activation by pacing in the box isolation lesion. No recurrence of AF was observed after the procedure.

Figure.

Posteroanterior (A) and inner view (B) of the common trunk, 3D CT merged voltage map (C) before ablation, and isolation line (D). The dashed and solid line in (B) indicates the intended ablation line. LAA, left atrial appendage; LIPV, left inferior pulmonary vein; LSPV, left superior PV; RIPV, right inferior PV; RSPV, right superior PV.

Anatomic variants including the left, right, and inferior common PVs have been reported and PV isolation is usually achieved ipsilaterally or segmentally.¹ We report a rare case of confluence of 3 PVs for which box isolation was useful for PV isolation of this anatomic variation.

IRB Information

Toyama Prefectural Central Hospital, Ethics Committee. No. 58-109.

Disclosures

The authors declare no conflicts of interest.

Reference

• 1.   Kanaji Y, Miyazaki S, Iwasawa J, Ichihara N, Takagi T, Kuroi A, et al. Pre-procedural evaluation of the left atrial anatomy in patients referred for catheter ablation of atrial fibrillation. J Cardiol 2016; 67: 115–121.