Former Italian Prime Minister Silvio Berlusconi will undergo further heart checks in a Milan hospital, a day after collapsing during a political rally in Tuscany. Doctors found Berlusconi was suffering from a cardiac arrhythmia and decided to carry out electro-cardiogram tests. His health problems prompted judges in Milan to postpone to Friday the hearing of a trial in which he faces charges of tax fraud, embezzlement and false accounting in connection with his Mediset business. Silvio Berlusconi, Italy's richest man and owner of a media empire, has been leader of the opposition since losing power in elections in April 2006.