Utility and limitations of coherent mapping algorithm utilizing vectors and global propagation patterns in atrial tachycardia.

Background: A novel mapping algorithm utilizing vectors and global patterns of propagation (Coherent™, Biosense Webster) has been developed to help identify the mechanism of atrial tachycardia (AT). We aimed to determine the diagnostic accuracy of coherent mapping compared with that of ripple mapping. Methods and results: This study included 41 consecutive patients with 84 ATs (47 reentrant and 37 focal ATs). Two independent electrophysiologists confirmed the diagnoses using coherent mapping before the ripple map-guided ablation. AT termination was achieved in 75 of 84 ATs (89%) at first ablation lesion set. Four of the remaining nine ATs, which were terminated before an index radiofrequency (RF) application, were non-inducible after RF delivery at the first lesion set, whereas the other five ATs were terminated at the second lesion set. Diagnostic agreement between coherent and ripple maps was achieved in 51 of 84 ATs (61%): 28 of the 47 macroreentrant ATs (60%) and 23 of the 37 focal ATs (62%; P = 0.826). In typical macroreentrant ATs, including left atrial roof, perimitral, and cavotricuspid isthmus-dependent ATs, coherent maps achieved diagnostic agreement in 23 of 29 ATs (79%), which was higher than that in other ATs (51%, P = 0.018): 13 of 26 macroreentrant ATs (50%) and 15 of 29 focal ATs (52%, P = 1.000). Conclusion: Ripple map-guided AT ablation achieved a high termination rate in the first lesion set. Coherent mapping yielded a favorable diagnostic accuracy for typical macroreentrant ATs, though its value for diagnosing other ATs was limited.