What could have caused Jackson's death?

Michael Jackson died on Thursday

Michael Jackson has died after he stopped breathing and suffered a cardiac arrest.

But what would cause sudden death in a man of his age?

The details are scarce, and a post-mortem will be carried out to determine exactly what happened - because cardiac arrest is simply another way of saying someone's heart has stopped.

There are numerous potential causes. One of those is a heart attack - although they are not interchangeable terms.

I suspect he had a fairly bizarre and weird lifestyle Professor John Reid, British Hypertension Society

When a heart attack occurs, the heart does not always stop beating and the person does not always die.

Most are caused by the build up of fatty deposits in arteries (coronary heart disease), which causes them to narrow and block the blood supply to the heart.

How severe the heart attack is depends on exactly where it is and how big the blockage is.

Cathy Ross of the British Heart Foundation said: "If a heart attack is big enough, it can cause the heart to go into an abnormal rhythm, which can lead to cardiac arrest."

People in their 40s or 50s do die suddenly from heart attacks, but these are usually due to being overweight and smoking - not risk factors for Michael Jackson.

The post-mortem will look at Michael Jackson's body to see if he had any kind of underlying disease, most likely of the brain or the heart itself, which could have contributed to his death.

They will also look for evidence of any drugs - legal or illegal - in his system.

Resources

Cardiac arrest is caused by electrical malfunction and the heartbeat becomes erratic. It can happen at any age.

Cardiac arrest can be caused by many things Cathy Ross, British Heart Foundation

Cathy Ross said: "It can be caused by many things, including underlying heart disease, a blood clot which can lead to a pulmonary embolism, or diabetes.

"There are a number of genetic conditions to do with electrical activity in the heart, such as long QT syndrome which can cause sudden death."

She added: "Anorexics and bulimics who abuse eating can experience electrolyte imbalances.

"If you don't eat the right things, levels of blood electrolytes such as potassium can become depleted. They are very important for heart rhythm, which could then lead to cardiac arrest.

The pop superstar was in preparation for his comeback concert tour, his first performances in many years, and it would have placed great demands on his physical and mental health.

But heart expert Professor John Reid, a past-president of the British Hypertension Society, said that it was unlikely stress would have been a factor.

"This is a man who has been living with stress for many years. He must have had many resources to deal with its manifestations."

It has been reported that Michael Jackson's physician was with him when he died.

Dr Terry McCormack, editor of the British Journal of Cardiology, said that suggested his death was due to an illness.

"It suggests he became unwell, maybe having experienced chest pain."

Medication

There have been persistent rumours for many years that Michael Jackson had a painkiller addiction, and experts say the use of many kinds of drugs can be linked to heart problems.

Professor Reid said: "Drugs and other substances can mimic cardiac arrest - or cause one."

One of the commonest is cocaine. It can cause cardiac arrhythmia, and can cause sudden death.

"It is also possible that opiates, such as morphine, could cause sedation and breathing to stop which would cause respiratory arrest, and then cardiac arrest," said Professor Reid.

"But even prescription drugs can cause death. Antidepressants, which are so widely used, are associated with increased risk of heart attack."

And he added: "I suspect he had a fairly bizarre and weird lifestyle."

Michael Jackson's health - along with his music - has been the focus of attention throughout his adult life. Whatever the post-mortem reveals, this is not likely to change with his death.

Dr McCormack said: "The family have so far been very pedantic about giving specific details of his death, probably because they don't want people to speculate, so we're likely to get a very detailed breakdown of what the post-mortem said.

"But no doubt there will be numerous conspiracy theories about his death, just as there have been with Elvis."