Digital signal processing and modeling of the upstroke of action potential in cardiac myocytes

A mathematical model was reconstructed based on the upstroke and sodium current separately recorded from enzymatically dispersed ventricular myocytes of a guinea pig, using the patch clamp technique. After holding the membrane potentials ranging from -120 to -60 mV for 500 ms, the upstroke was induced by applying the stimulus through the patch electrode with the constant latency to obtain voltage-dependence of availability for V_max. Phase plane plots (membrane potential vs. dV/dt) were used for optimization of a mathematical model. Experimental results could be reproduced by the model