"Upper heart chambers reacted to foreign substance in heart muscle.....filibration as a result. but which can be easily treated."
True enough, but in a 78 year old man, nothing can be taken for granted. If he's in the hospital for a week, there are all sorts of complications that can come up.
It ain't easy being old.
Called a silent heart attack. Wouldn't have been picked up if the doctors hadn't been probing the area.