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).