Figure 2.

Monophasic (top) and biphasic (bottom) shock episodes resulting in isoelectric window and arrhythmia initiation. Progression of activity from VEP through initiation of intramural activation (transparent view with activation marked by *) to epicardial breakthrough followed by focal activation pattern and ultimately a reentry. Shocks are external of duration 10 ms (6/4 ms for the biphasic shock) and of strengths 16 (monophasic) and 12 (biphasic) V/cm and are delivered at 220 ms coupling interval. Images based on figures published in Ashihara et al.¹