Not so.
Fibrillation means no rhythm at all—the heart balls up and contracts chaotically.
In a heart that young and powerful it’s not a “stopped heart” so much as it is a heart in an unregulated state of spasmodic contractions, causing blood to push out to the extremities, including the head, causing the athlete to pass out, as we saw here.
You’re the expert. But I was taught in medical school, residency, ACLS and other critical care courses that fibrillation is rhythm - not an effective one if it is v fib - people can be do live normally for years in a fib. The lack of a rhythm is asystole. You are confusing rhythm which is electrical with circulation which is mechanical. In fact there is a rhythm called PEA that has an absolutely normal
looking sinus rhythm but is associated with no circulation (pulse). I have treated all there rhythms many times and run multiple codes. But you are the expert so please enlighten. me