DISCRIMINATION OF ATRIAL-FIBRILLATION FROM REGULAR ATRIAL RHYTHMS BY SPATIAL PRECISION OF LOCAL ACTIVATION DIRECTION

This study tests the hypothesis that atrial fibrillation (AFib) can be discriminated from regular atrial rhythms by a measure of the variati on in local activation direction, Human endocardial atrial recordings of AFib, sinus rhythm, atrial flutter, and supraventricular tachycardi a were collected using a catheter with orthogonally placed electrodes, and the direction of each activation was calculated using methods pre viously described by our laboratory. Each recording was divided into s egments containing 100 activations, and the spatial precision for each segment was calculated in three dimensions, as well as in each of the three two-dimensional (2-D) planes, The three-dimensional (3-D) spati al precision for 1161 segments of AFib in 11 recordings ranged from 0. 09-0.85 (mean = 0.45), whereas the spatial precision far 138 segments of regular rhythms in 28 recordings was greater than or equal to 0.91 in all but four instances, The 2-D spatial precision values overlapped for all rhythms. The results indicate that 3-D spatial precision of l ocal activation direction is a useful discriminator of AFib.