Sinoatrial cells: Slow response autorhythmic cells Maximal repolarization potential -60mV 0 S 0 3 Threshold potential -40mV Phase 0.3.4 100 0100200300400500 Time(msec) 23• Maximal repolarization potential -60mV • Threshold potential -40mV • Phase 0, 3, 4 Sinoatrial cells: Slow response autorhythmic cells 4 0 3 23