Abstract 244 Characterization of Atrial Tachycardia using the novel Coherent Mapping Module: the CARTO-AT study

Clin Res Cardiol (2022). https://doi.org/10.1007/s00392-022-02002-5
Characterization of Atrial Tachycardia using the novel Coherent Mapping Module: the CARTO-AT study
J. Steinfurt¹, K. Schmidt², A. Haas², S. Kochhäuser³, L. Trolese¹, A. Gressler¹, T. Faber¹, R. Wakili³, A. Luik²
¹Klinik für Kardiologie und Angiologie I, Universitäts-Herzzentrum Freiburg - Bad Krozingen GmbH, Freiburg im Breisgau; ²Med. IV, Schwerpunkt Kardiologie, Angiologie und Internistische Intensivmedizin, Städtisches Klinikum Karlsruhe gGmbH, Karlsruhe; ³Klinik für Kardiologie und Angiologie, Universitätsklinikum Essen, Essen;
Aims: Despite high-resolution, mapping of complex atrial tachycardia (AT) can be challenging. A novel algorithm displaying vectors for wavefront direction and conduction velocity, considering a global best-fit solution, could simplify the interpretation of such complex AT mechanisms. The aim of this study was to evaluate the impact of the novel Coherent mapping algorithm compared with the established Confidense® algorithm in complex ATs in a multicenter setting. Methods: Patients with stable AT who had been successfully mapped and ablated with the Carto3 system were included in the study. The AT mechanism had to be clearly traceable. For high-resolution mapping, a Lasso^TM, Pentaray^TM or Octaray^TM catheter were allowed. Cases were recorded at three centers, anonymized, and submitted to the other centers for review. The cases were randomly evaluated either as Confidense or Coherent Map. Reviewers were blinded to ablation points or other individual points. The tachycardia were evaluated with regard to the mechanism (macro, micro or localized re-entry, or focal) and ablation strategy (anatomical line, critical isthmus, or focal). Results: Thirty patients (median age 64 (55/73) years, 63% females ) were included into the study. A total of n=30 ATs (73% left atrium, median cycle length 260 (240/300) ms) were analyzed. The most frequent AT mechanism was macro re-entry (60%) followed by localized re-entry (17%), micro re-entry (13%), and focal (10%). No rotors were found. Confidense showed more focal mechanisms, whereas the Coherent algorithm differentiated those as localized re-entries (Figure 1), micro re-entries or truly focal ATs. Conclusion: The Coherent algorithm is a valuable tool to interpret complex ATs and was particularly useful to detect localized re-entries. For macro re-entry ATs both modules provide complementary information. The “global best-fit" Coherent solution quickly confirms a macro re-entry while the LAT histogram and extended early meets late (EEML) feature are useful to adjust the window of interest and incorporate lines of block in order to identify critical isthmus sites as target for AT termination. Figure 1: Localized re-entry detected by the novel Coherent algorithm The Coherent vectors indicate counterclockwise (ccw) wavefront propagation anterior of the coronary sinus (CS) ostium within a small area (1.5 cm²) of patchy scar. Complete ccw activation (left panel) covering the entire tachycardia cycle length (TCL) (middle panel) was traced through a channel of relatively higher voltage (right panel) along corresponding ripple bar locations around the low-voltage center. Despite uni- and bipolar scar thresholds set to zero mV (i.e. virtually no scar), Coherent calculated the correct AT mechanism and the AT became non-inducible after limited ablation.
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