Figure 9. AP traces and variability of ionic conductances with the population based on the Grandi model in SR at 2.5 Hz.

(A) Accepted models as for 1 Hz pacing are shown in blue, whereas models exhibiting pronounced AP alternans (|APD_90,odd – APD_90,even| >30 ms) and strong AP alternans (|APD_90,odd – APD_90,even| >100 ms) are shown in magenta and black, respectively. (B) Variability of ionic conductances G_K1, G_NaK, G_CaL, G_to, G_Kur and G_NaCa for the models in panel A. Each boxplot represents the range covered by the ionic conductances: the edges of the box are the 1^st and 3^rd quartiles, the whiskers extend to the most extreme datapoints, the estimated median physiological value is the central horizontal line and the notch around the median is the 5% significance level. (Mann-Whitney U test vs. accepted range: *p<0.05; **p<0.01; ***p<0.001).