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

BACKGROUND

High-density automated mapping of regular atrial tachycardias (ATs) requires accurate assessment of local activation times (LATs).

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 ConfiDENSEۛ high-density mapping module (Carto 3 v4) allowing manual reannotation (edited maps). For each AT, unedited automated maps were reconstructed offline by three algorithms: maximum unipolar slope (LAT ), bipolar peak (LAT ), and a new hybrid annotation algorithm (LAT ). 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 ± 46 ms, activation points 955 ± 421) were successfully ablated using LAT 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 LAT maps showed the highest accuracy in defining the tachycardia mechanism (LAT : 49% vs. LAT : 27% vs. LAT : 28%, P < 0.001) and ablation target (LAT : 65% vs. LAT : 39% vs. LAT : 31%, P < 0.001). Overall, LAT -annotated maps were graded as "easier to interpret" by the experts (difficulty score 2.3 ± 0.9) versus LAT (2.8 ± 1) and LAT (3.2 ± 0.8) (P < 0.001). Only 12% of the LAT maps were annotated as uninterpretable compared to 31% of LAT and 45% of the LAT maps (P < 0.001).

CONCLUSION

Automated LAT annotation allows better and easier recognition of the tachycardia mechanism compared to automated LAT and LAT algorithms, although fully automated mapping still requires further improvements.