Figure 4. Local activation signals – The Mapping catheter
location is shown annotated on the electroanatomical map by the orange X
(A). The catheter was placed in the same location at baseline (B),
following ablation (C), and following conductive hydrogel injection (D).
The steepest negative unipolar deflection corresponds with the sharp
near-field bipolar potential suggesting that this point reflects local
activation. A far-field potentials closely precedes the near-field
activation at baseline. Following ablation there is separation with an
isoelectric interval between far-field and near-field potentials.
Following conductive hydrogel injection, the bipolar potentials
approximate – similar in appearance to the baseline signal.
Figure 5. Hydrogel retention within myocardium – Gross
evaluation of the myocardium from the epicardial surface shows the pale
ablated tissue and black circumferentially injected conductive hydrogel
(A). Orthogonally transected ablation lesions (B & C) demonstrate the
hydrogel mostly retained within the ablated lesion, however, some
hydrogel can be seen extruding into regions of unablated myocardium
(arrows).