Figure 4. Alternans in cAF_alt tissue at the onset CL.

The odd (blue) and even (red) beats at the alternans onset CL (400 ms) are shown superimposed. Large Ca²⁺ release occurred during the long beat (blue traces). Top (left to right): transmembrane potential (V_m), intracellular Ca²⁺ ([Ca²⁺]_i), and SR Ca²⁺concentration ([Ca²⁺]_SR). Bottom (left to right): RyR open probability (RyR_o), L-type Ca²⁺ current (I_Ca), Na⁺/Ca²⁺ exchanger current (I_NCX).