The Cardiac Transmembrane potential Dependends mainly on k, Nat, and ca Each phase of the action potential is associated with a change in conductance to one or more ions The Resting Potential Is Determined by lonic Diffusion A K K 150 mEg/L 5 mEg/L Electrostatic Chemical 615log(K+/K+1The Cardiac Transmembrane Potential Dependends Mainly on K+ , Na+ , and Ca++ Each phase of the action potential is associated with a change in conductance to one or more ions. The Resting Potential Is Determined by Ionic Diffusion