Background: Atrial tachycardia (AT) is commonly observed during catheter ablation (CA) in patients with atrial fibrillation (AF) undergoing a stepwise extensive CA. In this study, we examined the hypothesis that the presence of multiple inducible ATs (multiple-ATs), which allow for latent multiple reentrant circuits, might increase the potential for following AT episodes after CA.
Methods and results: The study population consisted of 347 consecutive AF patients undergoing CA with a stepwise approach. A total of 366 ATs (tricuspid isthmus dependent, 101; mitral annulus, 62; septal, 26; roof dependent, 22; left atrial anterior wall, 13; upper loop, 8; surrounding the left pulmonary veins, 6; surrounding the right pulmonary veins, 6; left atrial appendage, 4; and Cs ostium, 3) occurring during the CA were found in 216 (62.2%) of 347 patients. Multiple-ATs (≥2) during the CA were observed in 93 (26.8%) of 347 patients. The incidence of AT episodes significantly increased as the number of inducible ATs increased (no AT, 7.8%; single AT, 13.7%; and multiple-ATs, 24.2%; P < .001), and multiple-ATs were an independent risk factor for AT episodes (3.07 [1.39-6.78]; P = .005). The impact of the multiple-ATs on the AT episodes was pronounced especially in the patients with coinducible residual AF (with coresidual AF vs without coresidual AF, 8.1% vs 47.7%; P < .001).
Conclusions: The presence of an atrial substrate allowing for multiple-ATs was associated with increased AT episodes during follow-up.
Copyright © 2012 Elsevier Inc. All rights reserved.