Last name change on Indian passport Impact on Visa,I-94,I797

  1. CHILD’s LAST NAME CHANGE:
    I am planning to change my child’s last name in Indian passport from “XXXX YYYY” to “XXXX”…
    So he will get a new Passport with New name.
    What would be the impact to H4 Visa,I-94 and I797 Petition as they have old name “XXXX YYYY”… ?
    (Should we take any action to correct the name on these…?)
    (P.S. He will go to India for vacation during April2015, and may have to go for stamping his H4 Visa)

     2) CHANGE WIFE’s NAME from maiden to married:
     
     Also if wife who is on H4 Visa changes her name in Indian passport from “AAAA BBBB” to “AAAA CCCC” (maiden to married)..
     She will get a new Passport with New name.
     What would be the impact to H4 Visa,I-94 and I797 Petition as they have old name “AAAA BBBB” …. ?
     (Should we take any action to correct the name on these..?)
     (P.S. She will go to India for vacation during April2015, and may have to go for stamping his H4 Visa)
     
     Appreciate your valuable response, as I am really worried about doing this right..
     
     Thanks in Advance