Nats MP, 43, surprised by heart attack

A 43-year-old Victorian MP was taken completely by surprise when he had a serious heart attack while driving to his rural home.

Nationals lower house MP Danny O'Brien says he felt unwell after leaving a conference on Friday and pulled into a Berwick hospital.

He says he was quickly transferred to Monash Medical Centre in Clayton after "what turned out to be a fairly serious heart attack".

"At 43, not overweight, a non-smoker and not a heavy drinker, this was a complete surprise," he said on his Facebook page on Sunday.

"What probably helped me was recognising the symptoms and seeking treatment promptly - as well as the great staff that looked after me."

He's expected to remain in hospital for a few more days and will take a break from his parliamentary duties.

"Danny's experience is a sage reminder to us all of the importance of knowing the signs and symptoms of a heart attack, and of seeking medical help without delay," Nationals leader Peter Walsh says in a statement.