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.