First, an identifiable reason. Second, these sorts of things can happen suddenly, even in otherwise healthy young people. It is rare, but not all that uncommon.
There was a thread last night where a woman posted about her teenage son who died of a spontaneous cardiac arrest due to an electrolyte imbalance. It happens.
Alot of seemingly healthy people do suddenly keel over but they usually then find the reason.
Marfan's syndrome hits alot of atheletes and some have undiagnosised arrythmias but after they have a problem it's diagnosised.
Terri didn't have those problems.
I am unable to locate a single case of a healthy young woman collapsing into cardiac arrest in the same circumstances that Terri did. (Getting up from her sleep and keeling over... ) I have asked here before with no response, but I'm still interested. If you know of even one such case, I want to see it.
The #1 cause of injury and death in young women is domestic violence. The casualties from DV (reported) are on the order of three to four million per year. But the odds of collapse due to "chemical imbalance" are zero or infinitesimal. Not an intelligent bet.
The ME effectively ruled it out the "chemical imbalance" theory anyway because the epinephrine, bolus and defibs in the resuscitation could easily account for the short-lived low potassium reading.
The chemical imbalance theory is dead. It was the only alibi Michael had, and now even the ME says it was not worth looking at.
Maybe Michael Schiavo looked at Terri wrong and she sort of hyperventilated in an anxiety attack that she stressed her heart which had an unknown congenital aneurysm. This happens to people all the time. However, if something was wrong, wouldn't you think there would have been a major effort to find out what caused the cardiac arrest and try to correct the problem? I do not think any such effort found anything wrong--do you?