How many different threads do we have to have on this most likely non-issue. Reeves went into comma on Saturday night and died on Sunday. Prior to his heart attack, he was as functional as a quadriplegic can be. Certainly well enough to make a phone call. Unless you got some evidence that the rest of us dont, this is black helicoptor territory.
BTW, do you know what cardiac arrest is? It is the sudden stopping of the heart. One minute your heart is pumping normally. The next minute it's not and you either get some assistance in the next four minutes or your dead.