Characterization of temporal electrical activity patterns for detection of critical isthmus regions of recurrent atypical atrial flutter

Figures

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  Figure 1. (A) Left atria, view from the left. “Skyline” tool displays on the right the histogram of global atrial surface activation during AAF cycle length, which shows the relative proportion of the atrial surface area that is activated at each point in time (electrical activity X axis, cycle length Y axis). The green bar (length of 30 ms) marks the minimum (red box) of the skyline, which shows one isthmus (highlighted region, red arrow) in the dorsal wall of LA. (B) Left atria, view from dorsal. One minimum involves two highlighted regions (red arrows) as potential CIR. (C) Example of three minima in the “skyline.” AAF, atypical atrial flutter; CIR, critical isthmus region; LA, left atria.

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  Figure 2. (A) Proportion of detected isthmi, which are part of the AAF re‐entry circuit (61%). (B) PALO and POR of the LP algorithm with respect to the detection of the AAF‐relevant CIR. PALO represents the detection of at least one relevant CIR by LP, which was 98.2%. POR was defined as the detection of only re‐entry‐relevant CIR, which was 12.3% in the unselected all‐over analysis. (C) PALO and POR after applying the preselection criteria: analyzing the smallest electrical activation minimum only (left); selecting the broadest electrical activation minima (right). AAF, atypical atrial flutter; CIR, critical isthmus region; EA, electrical activity; LP, Lumipoint; PALO, probability of identifying at least one CIR; POR, probability of identifying only the relevant CIR.

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  Figure 3. (A) Clinical outcome: Recurrence of AT in the FU of 10 ± 7 months. 20/33 patients have another AT: 30.3% of patients have another AAF, 18.2% have a recurrence of AFib, and 12.1% cases both. Of the patients with recurrent AAF (n = 14), 50% (7/14) undergo reablation, and two patients even twice. (B) Association of potential CIRs detected by the LP algorithm during the index tachycardia in recurrent tachycardias during the index procedure. In total, 13/33 patients showed a second flutter form; two patients develop even a third AAF form during the index procedure. In one case, the CIR is not detected by the LP algorithm. (C) Association of potential CIRs detected by LP algorithm during the index procedure and involvement in recurrent tachycardias during FU. In all de novo AAFs, the potential CIR was already detected by LP during the index procedure. AAF, atypical atrial flutter; AFib: atrial fibrillation; AT, atrial tachycardia; CIR, critical isthmus region; FU, follow‐up; LP, Lumipoint®.