What Causes Rapid Heart Rate, Head Throbbing, Chest Pain, And Numbness In My Left Hand When Falling Asleep?

Sir,when I just go to sleep means just sleep for few second my heart start pumping fast I feel pumping in head too. It happens only for few seconds and then be come normal ..but whever it happen I feel very scary,my head also ache for few minute..but through out day I am very normal ....sometimes my chest pains slightly ...in sleep my left hand plam also feel numb ....