Figure 5. Ca_i and V_m alternans.

Data from the same rabbit as in Fig. 4A, a and b indicate sites with the earliest Ca_i transient alternans at the peri-infarct zone and at left ventricle base, respectively. B, dominant-frequency map during ventricular fibrillation. The highest dominant frequency was located at the peri-infarct zone (yellow arrow), corresponding to site a in A. C, shows Ca_i (orange) and V_m (black) recordings at sites a and b when the ventricles were paced at pacing cycle lengths of 300 ms, 180 ms and 150 ms. The numbers below each V_m tracings are APD₈₀ values. S, small amplitude; L, large amplitude; 1−(B/A), alternans ratio; R1 and R2, remote zones 1 and 2, respectively.