Case presentation
A 54-year-old man with drug-resistant paroxysmal atrial fibrillation (AF) underwent PV isolation using a 28 mm second-generation cryoballoon catheter (Medtronic Inc., MN, USA). Simultaneous isolation of the RSPV and SVC was obtained at 30 s after cryoballoon application and was subsequently followed by an additional freeze-time of 120 s (total 150 s, minimum temperature -44°C).5 Complete PV isolation was achieved without any complications.
The frequency of AF decreased after cryoballoon-based PV isolation, however, a low frequency AF recurrence was noted. A second procedure with radiofrequency catheter ablation was performed 13 months after the first procedure. No phrenic nerve injury nor PV stenosis was observed. Although there was no reconnection of all PVs, sustained fibrillatory potential was recorded in the SVC (Figure A). No dormant reconnection between the RA and SVC was induced by adenosine triphosphate intravenous injection. A three-dimensional voltage mapping using the CARTO-3 system (Biosense Webster Inc., CA, USA) clearly illustrated that the low voltage area around the SVC was consistent with that around the RSPV (Figure B). These findings implied that simultaneous isolation of both the RSPV and SVC had persisted for over a year. Ablation of the left atrial (LA) roof and floor was performed to prevent non-PV triggers from the posterior LA. Complete electrical silence and non-capture of the posterior LA was confirmed in the second procedure.