Cor Vasa 2008, 50(2):61-68 | DOI: 10.33678/cor.2008.028

Left atrial tachycardia after previous catheter or surgical ablation of atrial fibrillation. Results of mapping and catheter ablation.

Martin Fiala, Jan Chovančík, Dorota Wojnarová, Henryk Szymeczek, Richard Moravec, Radek Neuwirth, Renáta Nevřalová, Otakar Jiravský, Igor Nykl, Libor Škňouřil, Miloslav Dorda, Jaroslav Januška, Jindřich Černý, Alexandra Wodzinská, Jan Indrák, Marian Branny

Oddělení kardiologie, Kardiocentrum, Nemocnice Podlesí a. s., Třinec, Česká republika

Aims:
The aim of the study was to characterize left atrial tachycardia (LAT) after previous catheter or surgical ablation of atrial fibrillation (AF), and to present results of catheter ablation of LAT.

Methods:
Ablation of LAT was performed in 40 patients (11 females, 58 ± 10 years) in 42 procedures. Thirteen, 3, and 22 patients underwent previous ablation for paroxysmal, persistent, and permanent AF, respectively, and 2 patients were after surgical cryo-ablation. Stable LAT was mapped and ablated selectively, unmappable alternating multiple LATs were targeted using a substrate approach. The end point of the procedure was termination of LAT and noninducibility of any tachyarrhythmia.

Results:
Multiple alternating forms of LAT were initially present in 11 (26%) procedures, while stable LAT was mapped in 31 (74%) procedures. In 4 cases, a critical isthmus of a complex reentry could not be determined, and substrate ablation was used. In 2 cases, endocardial mapping did not reveal a clear reentry circuit, and the LAT source was finally found in the coronary sinus. In another 2 cases, an ectopic source of LAT was found in the vicinity of the right lower pulmonary vein. In the remaining 23 cases, different reentry circuits were mapped. Macroreentry was found in 7 cases, localized reentry utilizing less than half of the left atrium in 11 cases, and microreentry from the border of the pulmonary vein antrum in 5 cases. LAT was terminated in 39 patients and 41 procedures. Noniducibility of any tachyarrhythmia was achieved in 33 procedures, while it was not tested in the other 8 procedures. During a follow-up period of 16.4 ± 9.5 months, 35 (88%) patients are free of any arrhythmia in the long term.

Conclusion:
LATs arising after previous catheter or surgical ablation of AF exhibit a predominantly reentry mechanism and can be eliminated by a selective or substrate mapping and ablation strategy with a high long-term efficacy.

Keywords: Atrial tachycardia; Atrial fibrillation; Left atrium; Catheter ablation

Published: February 1, 2008  Show citation