FIGURE 4. Calcium Force Frequency Relationships after cardiac arrest.
A. Plot of force (z-axis), pacing frequency (x-axis) and calcium expressed as ΔF/Fpeak (y-axis) for control cells at slack length loaded with Fluo-5f and simultaneously stretched with CF. n=4 cells from 2 control hearts. The curve showed a steep curve shifted to lower ΔF/Fpeak. The color represents force and is coded from low to high as from blue to red, B. Similar plot in post arrest cells. n=4 cells from 2 control hearts. By comparison to panel A, the curve is shifted to a flatter curve despite also being shifted to higher ΔF/Fpeaks (rightward) at all pacing frequencies. Force was color coded with the same palette as in panel A, and all scale bars were identical.
