Fig. 5.
Simulations of heart failure remodelling and alternans. A) Action potential in control and heart failure (HF) condition at 1 Hz pacing, showing APD prolongation and loss of notch following the peak in HF. B) Calcium transient in control and HF, showing its prolongation, prolonged time to peak, and reduced amplitude. The calcium transient was normalised between 0 and 1 to facilitate comparison: first, the minimum was subtracted from both calcium transients; second, both calcium transients were divided by the maximum of the control trace, preserving the ratio of amplitude between control and HF. C) Calcium concentration in the network SR showing reduced SR loading in HF. D) Simulation of the effect of heart failure (HF) remodelling and HF + ORM-10962 treatment (50% NCX + 65% ICaL) on alternans development. For each model, the minimum and maximum APD90 achieved over two subsequent beats at the given basic cycle length is given, with bifurcations indicating alternans. Small-amplitude alternans in the HF condition developed already at bcl of 330 ms.