Feasibility of mapping and ablating ectopy-triggering ganglionated plexus reproducibly in persistent atrial fibrillation

Figures

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  Fig. 1. A simplified model of the Tau20 setup. The output impedance (ROUT,TAU, > 300 KΩ by specification) of the Tau20 is much higher than the tissue impedance (RTISSUE ~ 0.2 KΩ based on Langendorff observations) resulting in the stimulating current (ITAU,OUT) being delivered practically in totality to the tissue. Internal Tau20 circuitry prevents the output voltage (VT,TAU) developed across the tissue (typically during HFS stimulation, VT,TAU is the differential voltage across MAP1–2) from exceeding 15 V

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  Fig. 2. Reproducibility of ET-GP sites identified with synchronised HFS using the Tau20 compared to Grass stimulator. The left atrial anatomy (grey) as visualised with the CARTO™ electroanatomic mapping system. Electrogram (EGM) signals from the EP recording system (LabSystem Pro, Boston Scientific) are shown adjacent. ET-GP sites green. Ectopy circled in red solid lines. HFS applied endocardially via the Map catheter from the Grass stimulator with SIU5 (output 100 V) and then the Tau20 (output 50 mA). Arterial line trace top, CS EGMs, MAP EGMs, PV EGMs bottom

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  Fig. 3. Reproducibility of HFS negative sites with synchronised HFS using the Tau20 compared to Grass stimulator. The left atrial anatomy (grey) as visualised with the CARTO™ electroanatomic mapping system. Electrogram signals from the EP recording system (LabSystem Pro, Boston Scientific) are shown adjacent. Negative synchronised HFS test sites in dark blue/purple. HFS applied endocardially via the Map catheter from the Grass stimulator with SIU5 (output 100 V) and then the Tau20 (output 50 mA). Coronary sinus EGMs above, Map catheter EGMs below

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  Fig. 4. The Tau20 can be used to complete a high-density ET-GP map in a patient with persistent AF in Precision™. Main picture: the left atrial anatomy (grey) as visualised with the Precision™ electroanatomic mapping system. HFS applied endocardially via the Map catheter from the Tau20 (output 50 mA). ET-GP (green), HFS-negative sites (blue), incidental phrenic nerve capture (orange). Second picture: HD grid located in the right lower pulmonary vein (RLPV). Coronary sinus EGMs top, Map catheter middle, HD grid EGMs bottom. Ectopy circled in red solid lines

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  Fig. 5. The Tau 20 can be used to identify ET-GP in a patient with persistent AF to guide therapeutic ablation. The left atrial anatomy (grey) as visualised with the Carto™ electroanatomic mapping system. HFS applied endocardially via the Map catheter from the Tau20 (output 50 mA). ET-GP (green), HFS-negative sites (purple). Ablation lesions (red). CS EGMs top, MAP EGMs middle, PV EGMs bottom. Ectopy circled in red solid lines. EGMs left are pre-ablation, and EGMs right are the same sites post ablation confirming efficacy of ablation