he potential charge recorded from ventricular muscle cell Resting potential -90 mv (interior is lower than that of the surrounding medium) Action potential Phase: the rapid upstroke of the action potential depolarizes from -90mv to +2030 mV; Phase 1: a brief period of partial repolarization Fast response +20mV→>0mV, Phase 2:a plateau( persists for about 0. 2 second).ao 3 It is main difference 80 comparing with nerve and skeleton muscle cells 120 0100200300Action potential: Phase 0 : the rapid upstroke of the action potential. depolarizes from -90mV to +20～30 mV; Phase 1 ：a brief period of partial repolarization +20 mV → 0 mV, Phase 2 ：a plateau ( persists for about 0.2 second). the potential charge recorded from ventricular muscle cell Resting potential ： - 90 mV (interior is lower than that of the surrounding medium) It is main difference comparing with nerve and skeleton muscle cells