Acute changes of AP prior, during, and after HIFU ablation.

<p>(A) Changes of OAPs amplitude (ΔAPA) at <i>t</i> = 32 s (colored) superimposed on background optical mapping image (gray scale). Black box represents the ROI (6mm×5.6 mm) within the field-of-view of M2D ultrasound imaging. Colored asterisks labeled representative locations inside lesion, border, and normal tissue. (B) Normalized OAPs at the representing locations in (A) with each “spikes” corresponding to single cardiac cycle. Cyan shaded area indicates HIFU duration. Single cycle OAPs at <i>t</i> = 1.8, 8.8, 17.8, and 31.8 s indicated by a, b, c, and d. (C) Normalized OAPs at the representative locations in (A) superimposed at representative times (arrows a – d in B). (D) Spatiotemporal changes of ΔAPA. Blue labeled frames were during HIFU ablation. (E) Spatiotemporal changes of ΔAPD₅₀. (F) Normalized ΔAPA at representative locations (asterisks in D and E). (G) Normalized ΔAPD₅₀ at the same representative locations.