Nav1.5 is a sodium channel that is primarily found in cardiac muscle where it is responsible for action potential generation/cardiac muscle contraction. Nav1.5 is not a classic cannabinoid receptor but its activity is modulated by cannabinoids. Since cannabinoids have a physiological effect on Nav1.5 it is effectively a cannabinoid receptor.  

Chemical Name: 
Voltage-gated sodium channel 5A, SCN5A
IUPHAR entry: 
Wikipedia entry: 

Nav1.5 is predominantly present in cardiac muscle.

Literature Discussion: 



Hill, A.J., Jones, N.A., Smith, I., Hill, C.L., Williams, C.M., Stephens, G.J., and Whalley, B.J. (2014). Voltage-gated sodium (NaV) channel blockade by plant cannabinoids does not confer anticonvulsant effects per se. Neurosci. Lett. 566, 269–274.