Not necessarily
He could have had massive total heart block.....conduction cutoff between atrium and ventricular halves down the HIS pathway
You go down like dropping a towel on the bathroom floor
Total utter collapse which on a bed meant nothing moved especially if already on his back
A arterial blockage to the heart muscle can also be just as sudden and overwhelming especially in ones sleep
My grandfather was found slouched with lucky strike burned down between his fingers and newspaper in his lap....no struggle by his housekeeper on the veranda after breakfast in 1962
He was almost 80 and it was his time
A fine death to a stellar life in all probability
Massive transhemispheric stroke or a true pulmonary clot or sudden ruptured aorta north of the big bend can also result in CSD
CARDIAC SUDDEN DEATH
everyone doesn’t mimic Fred Sanford or Phil Leotardo and their TV heart attacks chest clawing and screaming
Phil Leotardo didn’t die of a heart attack. You must have missed the episode where the SUV backs over his head.