I searched their entire archive database; no mention of Dr. Atkins dying from a heart attack. As a matter of fact, every report that my search turned up stated that Dr. Atkins died as a result of injuries sustained in his fall, which as I mentioned before was witnessed by several people.
I searched the web for "Dr. Atkins autopsy"...nothing.
I searched Fox News database for "Dr. Atkins heart attack"...only the report from a year before his death and at that time it was reported that Dr. Atkins had undergone a cardiac angiogram and had clear cardiac arteries.
Without a link, there is no way to verify what was or was not said, but if you heard correctly and this doctor was publically giving the results of Dr. Atkins autopsy (if one was actually performed and the only way to verify whether he did or did not have atherosclerosis and it was the true cause of his death would be an autopsy), then I have to wonder if he still has his license because doing so is violating Federal HIPAA laws without written consent from the family. I'm sure the news media would have snatched that up and reported it widely given their current bias against low carb, not just on a weekend show for which I can find no record.