Strive for treatment about his heart and go back to (7)
I believe the answer is:
revisit
'go back to' is the definition.
(I've seen this in another clue)
'strive for treatment about his heart' is the wordplay.
'for treatment' indicates an anagram (the anagram must be processed or treated).
'about' means one lot of letters goes inside another.
'heart' indicates the central letters.
The middle of 'his' is 'i'.
'strive' with letters rearranged gives 'revsit'.
'revsit' enclosing 'i' is 'REVISIT'.
'and' acts as a link.
(Other definitions for revisit that I've seen before include "comeback?" , "Go back to (place)" , "repeated call?" , "Reconsider" , "Consider again" .)