Tau20-RETROmapping System Identifies Driver-Like Activation Patterns in Real-Time During Persistent Atrial Fibrillation
Oliver Jones, Nick Linton, Stewart Bissett, Simos Koutsoftidis, Jamie Kay, Huiyi Wu, Ji-Jian Chow, Norman Qureshi, Tina Baykaner, Junaid Zaman, Thorsten Lewalter, Anil Demircali, Qindong Zheng, Fergus Heaney, Ivin Jose, Louisa Malcolme-Lawes, Michael Koa-Wing, Boon Lim, Ahran Arnold, Nicholas Peters, Daniel Keene, Fu Siong Ng, Zachary Whinnett, Burak Temelkuran, Emmanuel Drakakis, Prapa KanagaratnamBACKGROUND:
Conventional activation mapping of atrial fibrillation (AF) during clinical procedures is limited by low-amplitude, fractionated electrograms and cycle length variability. The Tau20-RETROmapping stimulator-recorder system (TauRhythm Therapies, United Kingdom) is an investigational device used to identify nonpulmonary vein AF drivers by real-time, high-density activation mapping of uniform wavefronts during AF. We validated the accuracy of the system and applied it to left atrial mapping for evidence of AF drivers.
METHODS:
Left atrial geometry was acquired using a 3-dimensional electroanatomic mapping system with high-density mapping catheters (CARTO 3 with Optrell, or EnSite X with HD Grid). Electrograms were recorded for 30 seconds at multiple left atrial sites. The Tau20-RETROmapping system generates activation maps of organized wavefronts. System performance was manually validated against randomly sampled local electrograms using a grid sweep of thresholds to identify Pareto-optimal parameters in sinus rhythm, atrial pacing, atrial tachycardia (AT), and AF. The system was then applied to identify putative driver activation patterns during persistent AF.
RESULTS:
We studied 24 patients undergoing pulmonary vein isolation for AF. Six patients presented in sinus rhythm or AT, in whom the system demonstrated a sensitivity of 100.0% (95% CI, 80.5%–100.0%) and a specificity of 100.0% (85.2%–100.0%). Eighteen patients were mapped in AF: the system had a sensitivity of 94.4% (86.2%–98.4%) and a specificity of 97.1% (89.9%–99.6%) when identifying organized AF wavefronts, and accurately identified the earliest activation in 89.6% (79.7%–95.7%) of waves. Stable propagation originating from the left atrial appendage (LAA) was observed in 3/18 patients, while 8/18 demonstrated competing propagation toward and away from the LAA. Conduction away from the LAA was detected along the anterior (8/18 patients), lateral (8/18 patients), and posterior (7/18 patients) walls. No propagation near the LAA was observed in 6/18 patients.
CONCLUSIONS:
The Tau20-RETROmapping system enables real-time activation mapping of AF, with the most convincing driver-like areas being identified around the LAA.