Circumferential pulmonary vein isolation and linear left atrial ablation as a single-catheter technique to achieve bidirectional conduction block: the pace-and-ablate approach.

BACKGROUND: Pulmonary vein (PV) isolation has become a cornerstone for ablation of atrial fibrillation (AF). Circular mapping catheter (CMC)-guided techniques for detection of lesion gaps are challenging.

OBJECTIVE: The present study describes a new concept of circumferential PV ablation aiming at bidirectional conduction block based on simultaneous pacing and ablation through the tip of a single mapping/ablation catheter.

METHODS: A total of 147 patients with AF received circumferential PV ablation. In persistent AF, a posterior "box" lesion and a mitral isthmus line were added. All procedures were performed in sinus rhythm. Gaps within the left atrial (LA) ablation lines were detected and closed using voltage and pace mapping through the mapping/ablation catheter. Bidirectional conduction block was the procedural end point. Subsequently, the end point was validated by an independent electrophysiologist using a CMC.

RESULTS: Procedural and radiation time measured 188 +/- 55 and 37 +/- 15 min. Bidirectional PV conduction block (lack of PV potentials and lack of LA capture) was found in 140 of 147 (95%) patients with single mapping/ablation catheter and in 138 of 147 (94%) patients with CMC. Early PV reconduction was seen in 22 of 147 (15%) patients. After 12 months follow-up, 84% of the patients were free from AF and/or atrial macro-re-entrant tachycardia. The rate of reablations was 10% and 24% for patients with paroxysmal and persistent AF, respectively.

CONCLUSION: Pacing and ablation from the tip of the mapping/ablation catheter is feasible to detect and close gaps within long atrial ablation lines to consistently achieve bidirectional conduction block.