Fig. 7.
Computer simulation of the changes in AP shape by altered properties of hERG, INa and ICaL channels. (A) Changes in AP shape by applying the altered inactivation of hERG (Fig. 6) and the decrease in Na+-channel density (75% of control) to the computational model. By this modification, the APD90 of reconstructed action potential was prolonged from 208.7 to 230.7 msec, and the peak amplitude of phase 0 was decreased, similar with the results from Fig. 1. (B) When the conductance of ICaL was reduced (80% of control) in addition to the above changes in hERG and INa, the plateau potential was also affected reproducing the results from the cardiac Purkinje fiber of rabbits. The degree of prolongation in APD90 (ΔAPD90=15.5 ms) was rather small compared with the results (ΔAPD90=22.0 msec) in (A).