She had long QT syndrome, a heart signaling disorder that causes “fast, chaotic heartbeats,” according to the Mayo Clinic. The National Organization for Rare Diseases estimates that about 1 in 2,000 people are born with the condition.
Go read another thread about another woman who had a cardiac arrest:
A 30-Year-Old Was Having Lunch When She Collapsed. She’d Had a Cardiac Arrest.
https://freerepublic.com/focus/f-chat/4131851/posts
and long QT syndrome leads to an especially nasty arrhythmia called torsades de pointes or torsades for short. It is very difficult to resuscitate someone with it even when it happens in front of you in an ICU
The question still stands, was she vaxed?