Former Democratic Unionist leader and First Minister Ian Paisley has had a pacemaker fitted after he became ill at a House of Lords meeting on Wednesday night.
The peer, aged 84, who is now Lord Bannside, was initially treated by parliamentary paramedics, then at St Thomas' Hospital in London. His son, North Antrim MP Ian Paisley Junior, said doctors were exemplary and the pacemaker was put in place.
"It was very successful, he had it fitted and was discharged on Friday," he said.
He was at home at the weekend and is now back at work.
Mr Paisley was first elected in April 1970 to the old Stormont parliament and then in the same year to Westminster.
During the following decades, he was centre stage in Northern Ireland politics.
Famed for his firebrand oratory, Mr Paisley was a founding member of the Free Presbyterian Church in Ireland in 1951. His evangelical theology heavily influenced his political views and throughout the Troubles he denounced Catholicism and the papacy.
During the Troubles, he was a fierce critic of power-sharing with nationalists and of the Republic of Ireland having a say in Northern Ireland's affairs. But in his later political life, the hardline unionist shifted towards an accommodation that finally saw him enter office with his long-time enemy, Sinn Fein.
His decision to accept the position of First Minister alongside Deputy First Minister Martin McGuinness in 2007 saw him hailed as a peacemaker by moderates but criticised by many former followers.
He stepped down as Stormont First Minister in 2008.