Introduction: Pulmonary vein isolation (PVI) using standard radiofrequency (RF) catheters is limited by incomplete contiguity and prolonged procedural times. A novel, 9-mm lattice-tip irrigated RF catheter can create wide lesions rapidly in swine atria.
Methods: In five swine, temperature limited (75°C) irrigated RF for 5 seconds/ablation was selected, to isolate seven pulmonary veins (PVs; five right superior and two inferior commons) and create five right atrial lines. After 4 weeks, repeat mapping and additional ablation to create atrial isthmus lesions were performed. The chronic lesions were submitted for histology. This was compared with right superior PVI data using standard 3.5-mm irrigated tip ablation in six swine.
Results: All targeted PVs (seven of seven, 100%) were acutely isolated. Durable isolation was observed in all six of six PVs treated with 5-second applications, but not in one PV inadvertently treated with 4-second applications. For the durably isolated PVs, the mean lesion count/PV and total RF time/PV was 16.3 ± 5.2 applications and 81.3 ± 25.9 seconds for the right superior and 14.5 ± 0.7 applications and 71.1 ± 5.5 seconds for the inferior common PV. Right atrial linear ablation was performed with a lesion count of 12 ± 2.3 applications and RF times of 59.5 ± 12.5 seconds. Cavotricuspid and mitral isthmus linear ablations were transmural along their entire length. All 53 of 53 (100%) sections were transmural on histology.
Conclusion: Rapid and durable PVI and linear atrial ablation is feasible with this novel 9-mm lattice-tip catheter.
Keywords: catheter ablation-atrial fibrillation; durable; isolation; isthmus; pulmonary vein; swine; temperature.
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