MILAN (Reuters) - Former Italian prime minister Silvio Berlusconi was placed in intensive care on Tuesday after undergoing heart surgery to replace a defective aortic valve, a hospital statement said.

The surgery lasted around four hours, the statement added without giving more details. It is normal for patients to go into intensive care immediately after heart surgery.

A source from Berlusconi's Forza Italia (Go Italy!) party had earlier told Reuters the operation went well.

(Reporting by Silvia Aloisi; Editing by Mark Bendeich)