Figure 4.

Impact of I_to Current Activation

Epicardial conduction parameters in baseline versus NS5806 perfusion (10 µM) when pacing in epicardial RVFW at 1 Hz, and impact of increasing pacing frequency under NS5806 perfusion (1, 2, and 3 Hz pacing). (A) Activation time maps. (B) a) Binary maps of optical upstroke morphology with b) associated epicardial biphasic upstroke proportions; averaged optical action potential traces from different regions; localizations in B.a are represented in c) for baseline versus NS5806 (1 Hz) and in d) for NS5806 1 Hz versus 2 Hz. (C) Relative optical signal amplitude maps and (D) amplitude variations of nonaveraged optical action potential traces from different regions at 1, 2, and 3 Hz under NS5806 perfusion (localizations of pixels in A). Abbreviations as in Figure 2.