What Caused Michael Jackson's Cardiac Arrest?

It kills more people in the U.S. each year than breast cancer, lung cancer and HIV/AIDS combined. The condition is called sudden cardiac arrest (SCA) – and it only takes minutes to claim a person’s life.

“Sudden cardiac arrest is a real national tragedy,” Dr. Leslie Saxon, chief of cardiovascular medicine at the University of Southern California, told FOXNews.com. “It’s most often due to a sudden, very rapid heart rhythm. The heart goes so fast a person dies right away unless they’re shocked out of it with a defibrillator.”

While it hasn’t been confirmed what caused Michael Jackson to go into full cardiac arrest — the Associated Press reported Friday the singer was with a cardiologist when he collapsed and a person with knowledge of the situation said he appeared to have had a heart attack.

Paramedics arrived at his rented Los Angeles home around 12:30 p.m. Thursday and sources with the Los Angeles Fire Department said he wasn't breathing and had no pulse.

They tried resuscitate Jackson and took him to UCLA Medical Center where he was later pronounced dead.

“Even CPR can only bridge a person to a defibrillation,” Saxon said. “So the big thing about these events is they have to be witnessed. The odds are very good if someone witnesses it and shocks them right away. That’s why people in places such as airports and casinos have a higher rate of survival because there are a lot of people around and a lot of defibrillators.”

Saxon said the problem is – if the sudden cardiac arrest is not witnessed there’s less than 1 to 2 percent survival rate outside of a hospital.

“You only have minutes to restore good blood flow,” she said. “That’s why you have to act early because the brain and organs cannot live without blood flow.”

The fact is – is that it takes just 4 to 6 minutes after cardiac arrest before a person experiences brain death and ultimately complete death.

During sudden cardiac arrest, electrical impulses in the heart become rapid or chaotic, which causes the heart to suddenly stop beating, the American Heart Association said on its Web Site. It’s not the same as a heart attack. A heart attack occurs when the blood supply to part of the heart muscle is blocked. However, a heart attack may cause cardiac arrest.

Other common causes include heart disease, respiratory arrest, electrocution, drowning, choking and trauma. Cardiac arrest can also occur without any known cause.

“Most adults who have sudden cardiac arrest — it’s their first symptom — some people don’t even have chest pain,” Saxon said.

An adverse response to prescription drugs or illicit use of drugs can also cause arrhythmias leading to cardiac arrest.

Brian Oxman, Jackson’s spokesperson and longtime family, hinted that the singer may have had trouble with prescription drugs.

"This was something which I feared and something which I warned about," Oxman told CNN. "I can tell you for sure that this is something I warned about. Where there is smoke there is fire."

Oxman told CNN that the singer was taking drugs to deal with past injuries, such as a broken back and broken leg, which were getting in the way of his concert rehearsals.

Jackson was slated to kick-off a 50 concert tour starting in London July 13th.

An autopsy on Jackson will likely take place Friday.

Was Jackson Suffering From Lupus?

In October 2007, sources close to the pop star confirmed to FOXNews.com that he was suffering from lupus.

“Lupus is a chronic autoimmune disease where the immune system is unable to detect foreign invaders — like viruses – in the body,” Dr. Cynara Coomer, FOX News medical contributor and assistant professor of surgery at Mount Sinai Medical Center told FOXNews.com. “So the body creates autoantibodies – or antibodies that attack the body’s own healthy cells, causing inflammation.”

The inflammation caused by lupus can affect the joints, skin, kidneys, blood cells, heart, lungs and brain.

“Several studies have shown that this inflammatory process can occur in the arteries of the heart leading to the formation of fatty plaques, also known as atherosclerosis. This can result in cardiovascular disease and may lead to heart attack,” Coomer said.

Research estimates that at least 1.5 million Americans have lupus, the Lupus Foundation of America said on its Web site.

There are four different types of lupus, but the most common — and serious — form is systemic lupus erythematosus.

According to the Mayo Clinic, the signs and symptoms of lupus can come on suddenly or develop slowly over time and can include:

— Fatigue

— Fever

— Weight loss or gain

— Joint pain, stiffness and swelling

— Butterfly-shaped rash on the face that covers the cheeks and bridge of the nose

— Skin lesions that appear or worsen with sun exposure

— Mouth sores

— Hair loss

— Anxiety

— Depression

— Memory loss

“There’s no real known cause, but the most common type of patients afflicted are African Americans, American Indians and Asians,” Coomer said. “Certain antibiotics or infections, stress and some medications may lead to lupus.”

Click here for more on the article from 2007.