Pulse noted as children's author has heart transplant (4)
I believe the answer is:
Here is my best explanation:
'pulse' is the definition.
(I've seen this before)
'noted as children's author has heart transplant' is the wordplay.
I cannot quite understand how this works, but
'heart' could be 'h' (card game abbreviation) and 'h' is found in the answer.
The remaining letters 'dal' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).