1. What is the most common way a cardiac arrest can occur? Does the person usually experience an abrupt transition from normal sinus rhythm to ventricular fibrillation? Or is it usually an abrupt transition from normal sinus rhythm to ventricular tachycardia and later (possibly long after the person has lost consciousness and clinically died) to ventricular fibrillation?
2. When a person is in v-tach and the v-tach degenerates into v-fib, is the transition abrupt (like the transition from normal sinus rhythm to v-tach) or is it gradual? By gradual, I mean the v-tach becomes progressively finer and faster until eventually it can no longer be defined as v-tach.
I have looked for these stats everywhere but I can't find much of value.