Thanks for the query to H.C.M. Forum.
This is due to radial nerve palsy
( partial ) hence the supplying area of this nerve effected.
The bluish coloration of nail of index finger may be due to hamper in blood supply by any branch of radial artery
, of thumb, index & middle finger ( lateral half of ring finger , not mentioned in query) may be due to radial artery blood supply line damage or effected.
So you have to consult the Cardiologist and get his opinion.