According to Howard LeWine, M.D., of Harvard Medical School and Medical Advisor to MSN Health, sudden cardiac arrest typically occurs in males after the age of 55, so Jackson's death at 50 was somewhat premature.

"If one looks at a 50-year-old man having an episode that one would call sudden death, the most likely problem would be a clot in an artery caused by undiagnosed coronary artery disease. Another possibility is that he had an arrythmic event, meaning that there were some electrical abnormalities that could have predisposed him to having a very fast heart beat--so fast that it couldn't sustain blood flow to the heart muscle," said LeWine.

Gossip about the state of Jackson's health has swirled since his cancellation of the first concerts in a series of shows he was to perform beginning next month and continuing into 2010. There was concern, reports the New York Times, that at 50, Jackson was not physically ready for the demanding concert series. The promoters of the London shows, AEG Live, said in March that Jackson had passed a 4-1/2 hour physical examination with independent doctors