Molecular function

voltage-gated sodium channel activity involved in SA node cardiac muscle cell action potential, voltage-gated sodium channel activity involved in SAN cardiac muscle cell action potential, voltage-gated sodium channel activity involved in sinoatrial node cardiac muscle cell action potential

Enables the transmembrane transfer of a sodium ion by a voltage-gated channel through the plasma membrane of an SA node cardiac muscle cell contributing to the depolarization phase of an action potential. A voltage-gated channel is a channel whose open state is dependent on the voltage across the membrane in which it is embedded.