Syncope.....simply means,,FAINTING.
I don't know what he died of.
\\\ He did complain of a pain in his head and side about 2 minutes before he dropped down dead\\\
That may give us a clue in that he may have had a cerebral bleed..STROKE.
We know nothing about his "heart diagnosis" but that could have been the origin of a blood clot, travelling to his brain......STROKE.
So my money..........he died of a STROKE.
\\\Also I notice that in that same male line going back 6 generations, no male lived beyond the age of 66\\\
In that era, there was TB, syphilis and cardiovascular disease to knock you off, so hereditary would be way down the league.