Background: Algorithms to detect focal (F) and rotational (R) activations have been used to attribute mechanistic relevance to different sites during atrial fibrillation (AF) mapping.
Objective: To correlate F and R activations during rapid pacing and during AF using multielectrode mapping (CARTOFINDER, CF).
Methods: In mongrel dogs (n=6), rapid pacing from the right superior pulmonary vein (RSPV), distal coronary sinus (CS) or both simultaneously was applied to induce fibrillatory conduction with and without AF induction. A 48-multielectrode Octaray® catheter was used to sequentially map both atria. CF maps were constructed using local activation times. F and R sites were identified during pacing with and without AF induction.
Results: A total of 679 movies (479 during pacing with fibrillatory conduction, 200 during induced AF) of 30-second duration were constructed, 4% of which (n=30) showed R (average rotations= 9) while 63% (n=429) showed F. 1) R was more likely to occur in RA than LA (OR=3.5) and more likely to occur during pacing from distal CS than RSPV (OR=6.63) 2) Crista terminalis and RAA harbored the majority (73%) of R detected in the RA (n=16). 3) No major differences in F distribution among the atrial zones were detected (60% vs 65% of RA vs LA maps showed at least one focal source). Pacing with and without induction, and AF had similar overall R and F site distribution.
Conclusion: Similar R and F activations occur during pacing with and without AF induction and do not predict AF induction or maintenance, thus, they might represent an epiphenomenon of site-specific atrial conduction properties and not true AF drivers.