Case Presentation
A 67-year-old woman with persistent atrial fibrillation (AF) underwent
pulmonary vein isolation using a contact force-sensing catheter
(SmartTouch SF, Biosense Webster, CA). We performed an ablation index
(AI)-guided circumferential energy application (AI of> 400 at the posterior wall roof and> 450 at the anterior wall) with a target lesion
distance of 4 mm. However, the right pulmonary vein (PV) potential
remained after the circumferential lesion. The time difference between
the P-wave onset to the right superior PV (RSPV) remained constant. From
the activation sequence of a circular mapping catheter placed in the
RSPV, the earliest activation site was the anterior carina. Additional
energy applications were delivered just inside the initial anterior
ablation line (Figure 1A) . The right superior and inferior PVs
were individually isolated, but they did not require linear carina
ablation. After 5 months, the patient was readmitted to the hospital for
recurrent AF.
Repeat ablation was performed using a three-dimensional mapping system
(CARTO3, Biosense Webster) and reconnection of the RPV was detected. An
activation sequence of a circular mapping catheter placed in the RSPV
demonstrated the earliest activation site to be the anterior carina. The
time difference between P wave onset and RSPV potential was 48 ms, and a
conduction delay was not apparent despite the previous ablation.
Detailed mapping of the left atrium (LA) was performed using a 1-mm
multi-electrode mapping catheter (PentaRay®, Biosense
Webster) during sinus rhythm. Activation mapping within a
circumferential line demonstrated that the earliest activation site was
the anterior carina. This suggested a conduction breakthrough over the
anterior line where the myocardium was thick (Figure 1B ).
However, a voltage map demonstrated a contiguous circumferential lesion
without an apparent gap (Figure 1C ). Where is the gap and where
should we ablate?