He throws his hat into the ring speculating on the cause of death:

SANJAY GUPTA, CNN SR. MEDICAL CORRESPONDENT: There’s a lot we don’t know as well. 1:38 p.m. is when that nurse activated that 911 call. We don’t know how long Anna Nicole Smith had already been down or unconscious at that point. Sounds like what we’re hearing, details that have been coming in saying at the time the paramedics actually showed up, she did not have a heart beat, she was not breathing on her own. They had to try and put a breathing tube down her — into her trachea and try to restart her heart. It sounded like those things were not successful.

You’d think, as physicians, as health care personnel, you try and think about what’s the most likely thing that happened here, and I think you have to really think about the heart as being the most likely culprit.

Why she would have heart problems? Not exactly sure. But some sort of heart problem would be something that the medical examiners would really be looking for.

Also lung problems. Could there have been some sort of a clot? It’s called a pulmonary embolism, that actually traveled up and went into her lungs. Could it have been some sort of medication problem? Either too much medication or an interaction of medications.

Wolf, we also heard the fact that she may have been having flu- like symptoms the last few days. Sometimes, these types of viruses can not only cause fever, but they can actually infect the lining of the heart. She had a nurse with her. Any of these things could have been part of the problem. We don’t know. That’s going to be what the medical examiner is really looking for.

(via Schwitzer health news blog)