Inhibitory effect of subthreshold high-frequency stimuli: a computer simulation study

A computer model of the ventricular action potential was used to study the effect of trains of subthreshold high-frequency stimuli (TSc) on the prolongation of the effective refractory period (ERP). A zone of ventricular tissue is simulated by a one-dimensional structure. Trains of subthreshold high-frequency stimuli, at different frequencies were applied between the two suprathreshold pulses S1 and S2 and the ERP was measured as a function of TSc frequency. Our simulation results are in agreement with the experimental results. The results suggest that the prolongation of recovery from inactivation of the fast Na/sup +/ current could be partially responsible for the prolongation of the ERP.