He has been shifted to the Armed Forces Institute of Cardiology in Rawalpindi.
He reportedly suffered the heart problem while he was on his way to appear before a court to face trial for the treason case against him, reports said.
The court granted him exemption from appearing before it for Thursday's proceedings. It said that no arrest warrant was issued against the former Prime Minister on medical grounds.
According to reports, authorities are considering to take Musharraf abroad for medical treatment. The hearing into the case has been adjourned till Jan 6.
"An option is under consideration to send General (retd) Pervez Musharraf abroad for medical treatment as the former military ruler suffered from 'heart problem' when he was on his way to appear before the court today (Thursday)," Geo News reported quoting sources.
"The decision whether to send Musharraf abroad or to treat him in the country would be taken after the release of his medical report," the Pakistani news channel said.
Musharraf returned to Pakistan in March last year after years of self-exile in the UK.
Musharraf rose to power in Pakistan in a coup in 1999. He had stepped down from the power in 2008 and was threatened with impeachment, which resulted in his self-exile.
--IBNS (Posted on 02-01-2014)