The utility of a novel mapping algorithm utilizing vectors and global pattern of propagation for scar-related atrial tachycardias.

Background Activation maps of scar-related atrial tachycardias (AT) can be challenging to interpret due to difficulty in inaccurate annotation of electrograms, and an arbitrarily predefined mapping window. A novel mapping software integrating vector data and applying an algorithmic solution taking into consideration global activation pattern has been recently described (Coherent™, Biosense Webster "Investigational"). Objective We aimed to assess the investigational algorithm to determine the mechanism of AT compared with the standard algorithm. Methods This study included patients who underwent ablation of scar-related AT using the Carto 3 and the standard activation algorithm. The mapping data was analyzed retrospectively using the investigational algorithm, and the mechanisms were evaluated by two independent electrophysiologists. Results A total of 77 scar-related AT activation maps were analyzed (89.6% left atrium, median tachycardia cycle length of 273 milliseconds). Of those, 67 cases with confirmed mechanism of the arrhythmia were used to compare the activation software. The actual mechanism of the arrhythmia was more likely to be identified with the investigational algorithm (67.2% vs 44.8%, P=0.009). In 5 patients with dual-loop circuits, 3/5 (60%) were correctly identified by the investigational algorithm compared to 0/5 (0%) with the standard software. The reduced atrial voltage was prone to lead to less capable identification of mechanism (P for trend: 0.05). The investigational algorithm showed higher inter-reviewer agreement (Cohen's kappa 0.62 vs 0.47). Conclusions In patients with scar-related ATs, activation mapping algorithms integrating vector data and "best-fit" propagation solution may help in identifying the mechanism and the successful site of termination. This article is protected by copyright. All rights reserved.