En-452411-3 are drivers recurring or ephemeral? observations from serial mapping of persistent atrial fibrillation in paced canines

Current treatments for persistent atrial fibrillation are associated with high recurrence. These treatments focus on electrical isolation of the pulmonary veins, but recent studies have identified rotational reentries and ectopic foci, or drivers, outside the pulmonary veins as potential mechanisms for this recurrence. The persistence of drivers across multi-month time scales would be evidence for their structural basis, supporting their ablation, but clinical studies are unable to investigate this development for more than a single electrophysiology study. We evaluated the hypothesis that drivers can recur even multiple months after initial observation. We performed serial electrophysiology studies on paced canines (n=13, 27-35 kg) at 1-, 3-, and 6-months post-initiation of continual persAF. Using an Orion 64-electrode basket catheter and the Rhythmia system, we captured endocardial electrograms in the left atrium (LA) and right atrium (RA). For each measurement site, we held the catheter in place to obtain 4 minutes of recordings before moving to the next site. We continued this until both atria were completely and densely mapped. We identified drivers from movies of dV/dt during the 2 seconds of shortest cycle length for every site and classified sites as having recurring, nonrecurring, or latent drivers. Mean rate of recurring drivers per observed driver was 64% (LA: 69%, RA: 48%). Most likely locations for recurring drivers were the LA appendage (86%), right superior pulmonary vein (86%), LA roof (77%), and LA lateral wall (77%). Some drivers were seen at all 3 studies; we considered these as evidence of “permanent” drivers. Permanent drivers constituted 45% of initially observed drivers with at least one found in 89% of animals. We observed multiple recurrent drivers, confirming our hypothesis, and located anatomical sites where drivers were most likely to recur. We lay groundwork for detection of recurring and permanent drivers, which may provide attractive sites for ablation strategies due to stronger evidence of their structural basis over other drivers.Tabled 1Table 1. Observed drivers by recurrence type and anatomical site in the left atrium with absolute number in parentheses.Left AtrialRecurrence TypeA. Left superior pulmonary veinB. Lateral wallC. Posterior wallD. Atrial septumE. Inferior vein common ostiumF. Right superior pulmonary veinG. Roof wallH. Left atrial appendageI. Anterior wallLatent17%(3)32%(7)23%(5)18%(4)23%(5)23%(5)10%(2)32%(7)19%(4)Non-driver44%(8)9%(2)23%(5)59%(13)59%(13)14%(3)10%(2)5%(1)33%(7)Nonrecurring17%(3)14%(3)14%(3)18%(4)9%(2)9%(2)19%(4)9%(2)33%(7)Recurring22%(4)45%(10)41%(9)5%(1)9%(2)55%(12)62%(13)55%(12)14%(3)Recurring drivers were seen in two consecutive studies, nonrecurring drivers seen in initial study but not later study, and latent drivers seen in later study but not initial study. Sites where greater than 50% of drivers were recurring were the roof, the right superior pulmonary vein, and the appendage. The mean rate of recurring drivers per observed drivers in the left atrium was 61.2%. Open table in a new tab