Michael Jackson, who was with a cardiologist when he collapsed at his rented home in Los Angeles, appeared to have suffered a heart attack, a person with knowledge of the situation told The Associated Press.

The person, who was not authorized to speak publicly and requested anonymity, said Jackson suffered a heart attack, which is a blocking of the arteries that deprives the heart of adequate blood. That can lead to cardiac arrest, an interruption of the normal heartbeat.

Jackson’s brother Jermaine said Thursday that it was believed the pop singer went into cardiac arrest. The Los Angeles County coroner’s office, which completed its autopsy Friday, said determining the cause of death will require further tests that will take six to eight weeks.

The possibility of a heart attack could be a key clue as to why Jackson had a cardiologist at his home while he went through vigorous training for an upcoming series of concerts in London: Heart attacks can indicate a long-term problem, such as heart disease. It would not necessarily rule out another factor, such as drug use, however.

Coroner’s spokesman Craig Harvey said Jackson was taking some prescription medications, but did not specify what they were.

Police earlier today seized the car of Dr. Conrad Murray, a cardiologist who practices in California, Nevada and Texas, who was with Jackson at the time of his death. Police said they believed the car may contain drugs or other evidence.

When autopsies are performed on cardiac arrest victims, as many as three-fourths show signs of heart disease, such as clogged arteries, said Dr. Douglas Zipes, an Indiana University heart specialist and past president of the American College of Cardiology.

Finding signs of a heart attack would not rule out drugs playing a role. For example, injections of the powerful painkiller Demerol can depress normal breathing or cause a sudden drop in blood pressure and trigger a heart rhythm problem, said Dr. Lance Becker, a University of Pennsylvania emergency medicine specialist and an American Heart Association spokesman.

I will wait for the final coroner’s report but I would be surprised when the drugs in his sytem are verified that they did play a major contributing factor to his death – or his long-term drug use.

Demerol and Dilaudad are major respiratory depressants and what kind of pain could Michael Jackson possibly be having to warrant such opiate narcotics?

Michael Jackson’s cardiologist, Dr. Conrad Murray, has a lot of questions to answer.

How about Narcan, doctor?

Stay tuned……

Michael suffered a cardiac arrest earlier this afternoon at his Holmby Hills home and paramedics were unable to revive him. We’re told when paramedics arrived Jackson had no pulse and they never got a pulse back.

A source tells us Jackson was dead when paramedics arrived. A cardiologist at UCLA tells TMZ Jackson died of cardiac arrest.

Once at the hospital, the staff tried to resuscitate him but he was completely unresponsive.

What a damn shame.

Despite all of his troubles, Michael was still the King of Pop – what an artist.

R.I.P.