Former Italian prime minister Silvio Berlusconi is to undergo surgery after being admitted to hospital because of a heart problem.

Doctors said Berlusconi has a serious case of "aortic insufficiency" and is to have surgery to replace a valve.

The 79 year old was admitted to hospital in Milan earlier this week.

The centre-right politician was Italy's prime minister four times. He had a pacemaker implanted in a US hospital when he was 70.