Atrial Tachycardia After Ablation of Persistent Atrial Fibrillation

Abstract

Background-Atrial tachycardia (AT) that develops after ablation of atrial fibrillation often poses a more difficult clinical situation than the index arrhythmia. This study details the use of an impedance-based electroanatomic mapping system (Ensite NavX) in concert with a specialized multielectrode mapping catheter for rapid, high-density atrial mapping. In this study, this activation mapping was combined with entrainment mapping to eliminate ATs developing late after atrial fibrillation ablation. Methods and Results-All study patients developed AT after ablation for atrial fibrillation. The approach to AT ablation consisted of 4 steps: use of a 20-pole penta-array catheter to map the chamber rapidly during the rhythm of interest, analysis of the patterns of atrial activation to identify wave fronts of electric propagation, targeted entrainment at putative channels, and catheter ablation at these "isthmuses." All ablations were performed with irrigated radiofrequency ablation catheters. Forty-one ATs were identified in 17 patients (2.4Ϯ1.6 ATs per patient). Using the multielectrode catheter in conjunction with the Ensite NavX system, we created activation maps of 33 of 41 ATs (81%) (mean cycle length, 284Ϯ71 seconds) with a mean of 365Ϯ108 points per map and an average mapping time of 8Ϯ3 minutes. Of the 33 mapped ATs, 7 terminated either spontaneously or during entrainment maneuvers. Radiofrequency energy was used to attempt ablation of 26 ATs; 25 of 26 of the ATs (96%) were terminated successfully by ablation or catheter pressure. Conclusions-This study demonstrates a strategy for rapidly defining and eliminating the scar-related ATs typically encountered after ablation of atrial fibrillation. (Circ Arrhythmia Electrophysiol. 2008;1:14-22.)

High-Resolution Mapping of Scar-Related Atrial Arrhythmias Using Smaller Electrodes With Closer Interelectrode Spacing

“…These arrhythmias can be challenging to map using standard linear catheters because of significant scar coupled with fractionated and multicomponent electrograms, limiting activation, and entrainment mapping. Patel et al 11 have reported the feasibility to rapidly map and successfully ablate these arrhythmias using the Pentaray multielectrode-mapping catheter in post-pulmonary vein isolation patients with ATs.…”

A Prospective Study of Ripple Mapping in Atrial Tachycardias

“…1 The underlying mechanism of AT can be inferred from isochronal activation maps, which require precise annotation of local activation times at all mapped points within an assigned window of interest (WOI). 2 However, low voltage and fractionated electrograms, commonly found in these atria, are prone to incorrect assignment of local activation time and WOI errors. [3][4][5] Alternatively, the tachycardia mechanism can be located using entrainment, but this risks transforming or terminating the clinical tachycardia and local capture within scarred areas can be difficult.…”

Microreentrant left atrial tachycardia circuit mapped with an ultra-high-density mapping system

“…This compares favorably with other lower-density 3-dimensional mapping systems. For example, in a study using the NavX mapping system, even with the multipolar pentarray catheter, only 365 ± 108 points were collected during an average mapping time of 8 ± 3 minutes 7 . High-resolution electroanatomic mapping systems such as the Rhythmia system enable more accurate and rapid mapping of localized reentrant atrial tachycardia circuits, which may improve success rates in the targeting of post-AF ablation atrial tachycardias.…”