That would be very strange indeed. A heart problem causing a death is about the easiest thing to find in a autopsy. surely they looked at his heart. In spite of other news stories day in day out about unexpected deaths in which coroners and pathologist affirmatively claim to be able to pinpiont the time of death, no one is coming forth with any firm info on this for Heath. If he could be determined to have been alive at 3P, I'll be very, very angry.
This is not necessarily true. A reference I found (I have bolded the relevant parts, just to make it easier for those on this site who are not used to reading medical abstracts):
Med J Aust. 2004 Feb 2;180(3):110-2.
Causes of sudden cardiac death in young Australians.
Doolan A, Langlois N, Semsarian C.
Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Newtown, NSW.
OBJECTIVES: To determine the causes of sudden cardiac death in people aged 35 years or younger. DESIGN AND SETTING: A review of all autopsies erformed between 1 January 1994 and 31 December 2002 at a major Sydney forensic medicine department serving an area with over 2 million people. MAIN OUTCOME MEASURES: Incidence of various types of cardiac disease causing sudden death in those aged <or= 35 years; proportion of deaths in which no cause was found at autopsy.
RESULTS: There were 10 199 autopsies performed during the study period. Of these, 2986 (29.2%) deaths occurred in people aged <or= 35 years; 193 were classified as sudden cardiac deaths.
The cause of sudden death in this group was not established in 60 (31%), and was presumed to be due to primary arrhythmogenic disorders. Coronary artery disease occurred in 46 (24%), hypertrophic cardiomyopathy/unexplained left ventricular hypertrophy in 29 (15%), and myocarditis in 23 (12%).
CONCLUSIONS:
Unexplained deaths, presumed to result from sudden primary arrhythmogenic causes, occur in young Australians with structurally normal hearts. That underlying disease-causing genetic defects may be involved has clinical implications for family members.
I won't overdo you with studies but I found others that seem to have the same ~30% finding. So there is a very real possibility that Heath died of a lethal cardiac arrhythmia not associated with a structural cardiac abnormality, thus not being seen on autopsy.
L