Enables the transmembrane transfer of a sodium ion by a voltage-gated channel. A voltage-gated channel is a channel whose open state is dependent on the voltage across the membrane in which it is embedded. [ GOC:mtg_transport https://www.worldcat.org/search?q=bn%3A0815340729 ]
Synonyms: voltage-gated sodium ion channel activity voltage-sensitive sodium channel voltage gated sodium channel activity voltage-dependent sodium channel activity