Marry Hitch? Perhaps, but it's not indicative of a steady heart (10)

I believe the answer is:

arrhythmic

'it's not indicative of a steady heart' is the definition.
(as in cardiac arrhythmia)

'marry hitch? perhaps' is the wordplay.
'perhaps' indicates anagramming the letters.
'marry'+'hitch'='marryhitch'
'marryhitch' anagrammed gives 'ARRHYTHMIC'.

'but' is the link.

I've seen this clue in The Guardian.

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