Islamabad/Washington, Dec 7 (IANS): Pakistan President Asif Ali Zardari's sudden departure from Islamabad for Dubai for medical tests sparked intense speculation Wednesday, with a US media report stating that he has suffered a heart attack and may quit.

The official line was that he had gone to Dubai for medical tests and also to meet his children, but Pakistan Army doctors who carried out a medical check declared him fit. A US magazine quoted a former American official as saying Zardari had a minor heart attack and may resign as president.

Zardari abruptly flew out of Pakistan Tuesday, leading to much confusion and intense speculation. Sources close to the president rubbished reports that he was about to resign and said he would come back after the medical check-up.

Pakistan's official news agency Associated Press of Pakistan reported that Zardari Tuesday evening left for Dubai to visit his children and also to undergo some medical tests. Zardari has three children - Asifa, Bakhtawar and Bilawal.

The president's personal physician Colonel Salman said the proposed medical tests were of routine nature and linked to a previously diagnosed cardiovascular condition.

Zardari's son and ruling Pakistan Peoples Party (PPP) chairman Bilawal Bhutto Zardari met Prime Minister Yousuf Raza Gilani here Wednesday as rumours swirled about the state of the president's health and whether he was stepping down.

Geo News quoted a spokesperson as saying that Bilawal deliberated on the current political situation with Gilani. They also discussed Zardari's health.

The spokesperson said that doctors have termed the president's condition as satisfactory, but newly prescribed medicines could have an adverse affect on his health.

"The president went to Dubai following symptoms related to his pre-existing heart condition," PM's media office said in a statement, adding: "The president will remain under observation and return to resume his normal functions as advised by the doctors."

Though the News International said doctors from the Armed Forces Institute of Cardiology (AFIC) found Zardari completely fit after a check-up, the president's spokesperson Farhatullah Babar denied the report.

The President House Wednesday dismissed as speculative and untrue media reports about Zardari's health and said he was in Dubai for regular medical checks.

Adding a new dimension, the US-based Foreign Policy magazine quoted a former American official as saying that parts of the US government were informed that Zardari had a "minor heart attack" Monday night. He had flown to Dubai by an air ambulance.

Zardari may have to undergo an angioplasty procedure Wednesday and may also resign on account of "ill health", the magazine said.

The ex-official noted the growing expectation inside the US government that Zardari may be on the way out, reported Foreign Policy.

The former US government official told the website that Zardari was "incoherent" when President Barack Obama spoke with him regarding Nov 26 NATO airstrikes killing two dozen Pakistani soldiers.

Zardari had planned to address a joint session of Pakistan's parliament on a controversy over a memo to Washington that claimed he feared a military coup after the May 2 US commando operation that killed Al Qaeda leader Osama bin Laden.

Zardari has been under tremendous pressure since the memo came to light.

"The noose was getting tighter -- it was only a matter of time," the former official was quoted as saying.

In September, Zardari underwent an angiography at a hospital in Britain where doctors gave him a clean bill of health.

Two surgeons from the US too were involved in the medical check-ups along with the British doctors.

Shuja Nawaz, director of the South Asia Center at the Atlantic Council, in a Tuesday interview said a plan would see Zardari step aside.

Nawaz said: "Unfortunately, it means that the military may have had to use its muscle to effect change yet again."

Zardari's wife, late former prime minister Benazir Bhutto, had gone into self-imposed exile to Dubai in 1998.

In her second term, Benazir was toppled in 1996 as prime minister on charges of corruption, and she went to to Dubai. Bhutto returned to Pakistan in October 2007 after an understanding with then president Musharraf.

She was granted amnesty and all corruption charges were withdrawn. She was assassinated in December 2007, after a Pakistan Peoples Party rally in Rawalpindi, just two weeks before the scheduled election of 2008.