The plateau (phase 2) of the ventricular myocyte action potential
During the plateau phase (phase 2), the membrane&;s conductance to K+ is low. However, the electrochemical gradient for K+ is so strong that some K+ does leak out. The K+ efflux is balanced by the inward movement of Ca2+ and Na + through the slow Ca2+ channels so that the membrane potential plateaus above 0 mV. Sympathetic stimulation and drugs, which increase the concentration of cytosolic Ca2+ (digitalis), shoen the duration of the plateau phase by increasing K+. Ref - Harrison&;s internal medicine 20e pg 1716
Describes when Ca2+ is the only ion moving through the membrane
Describes when Ca2+ influx is balanced by Na+ efflux
Describes when Ca2+ and Na+ influx is balanced by K+ efflux
Can be prolonged by sympathetic nerve stimulation
C.V.S