Mapping pre-ablation, post-ablation, and post-injection
In 4 ex vivo perfused beating canine hearts, a detailed EAM was obtained of the epicardial lateral left ventricle during sinus rhythm at baseline, following ablation, and again following injection of the conductive hydrogel (Figure 3 ). In all 4 animals (100%), we were able to show a disruption of homogeneous baseline conduction by ablation. Following injection of conductive hydrogel, a bridge of improved conduction was demonstrated across the ablated region in all 4 animals (100%).
By placing the mapping catheter on the same site of the muscle in 1 animal, we were able to demonstrate a double potential indicative of far-field and near-field bipolar activation at baseline likely suggestive of endocardial to epicardial activation. Local activation was supported by the steepest negative deflection in the unipolar signal. Far-field and near-field activation appeared to separate with a small isoelectric interval following ablation. Following CNT hydrogel injection, the bipolar signals reapproximated and appeared similar to baseline (Figure 4 ).