Former Prime Minister Dr Mahathir Mohamad is making a quick recovery from his mild heart attack, one of his sons said today.

"He is in good condition. We are convinced in just a matter of time he will be out of the hospital," Mirzan Mahathir told AFP .

"He is fine and he is resting," he added.

Mirzan blamed the attack on Mahathir's recent overseas trips to Saudi Arabia and New Zealand, saying his 81-year-old father had been "tired out".

Mahathir, who ruled Malaysia for 22 years until he handed over to Prime Minister Abdullah Ahmad Badawi in October 2003, was taken to the National Heart Institute (IJN) yesterday after suffering a heart attack.

IJN, in a statement, said Mahathir had undergone blood, x-ray and heart tests early today and was progressing well.

"Dr Mahathir had spent a trouble-free night, having eaten and slept well throughout the first 24 hours of admission," it said.

He also suffered a heart attack in 1989 and the ex-premier underwent coronary artery bypass surgery.

Giving a miss

Mirzan said his father would like to thank everyone for their prayers and messages for a fast recovery.

Mirzan said depending on advise from doctors, Mahathir was expected to remain in hospital for a week and would likely miss next week's Umno annual meeting.

"I don't think he will attend the meeting. He will still be in hospital," he said.

Mahathir is currently involved in an ugly dispute with premier Abdullah whom he has accused of economic mismanagement, corruption and nepotism - charges Abdullah, the Umno president, has repeatedly denied.