Clinical assessment and comparison of annotation algorithms in high-density mapping of regular atrial tachycardias

Background High-density automated mapping of regular atrial tachycardias (AT) requires accurate assessment of local activation times (LAT). Objective To evaluate high density mapping of ATs and compare the accuracy of different automated LAT annotation algorithms. Methods Fifteen patients underwent AT ablation guided by the automated ConfiDENSE high-density mapping module (Carto 3 v4) allowing manual reannotation (edited maps). For each AT, unedited automated maps were re-constructed offline by three algorithms: maximum unipolar slope (LATSlope), bipolar peak (LATPeak) and a new hybrid annotation algorithm (LATHybrid). Five blinded experts were asked to define the 1) tachycardia mechanism 2) ablation target and 3) level of difficulty of these unedited maps. Results Twenty-one ATs (cycle length 300±46ms, activation points 955±421) were successful ablated using LATHybrid guided ablation with manual editing in a small number of points. At 6 months, 14 (93%) of the patients were free of AT recurrences. Unedited LATHybrid maps showed the highest accuracy in defining the tachycardia mechanism (LATHybrid: 49% vs. LATPeak: 27% vs. LATSlope: 28%, p