Former Italian Prime Minister Silvio Berlusconi has been placed in intensive care after undergoing an operation to replace a defective heart valve.
The procedure lasted four hours, Milan's San Raffaele hospital said, giving no further details.
But sources told Ansa news agency the operation had been a success. He is likely to take a month to recover.
Berlusconi, 79, served as prime minister four times but has since been convicted of tax fraud and bribery.
He was admitted to hospital last week after suffering a heart attack his doctor said could have killed him.
He is expected to remain in intensive care for another 48 hours.
"Everything is okay guys, now I can speak more calmly," an ally of Mr Berlusconi, Gianni Letta, told AGI news agency.
On Monday, Berlusconi wrote on his Facebook page he was "concerned" by the looming operation.
"But I am also very moved by the very many demonstrations of appreciation, support and affection which I have received from everywhere, even from political rivals," he added.
Once the dominant figure in Italian politics, Berlusconi has seen his political influence wane since his coalition lost power in 2011.