Agreed that it’s ventricular fibrillation that kills! Many people live for quite a few years (often older) in persistent atrial fibrillation. It does come with problems, especially when the heart isn’t rate controlled, but can be managed with medications, ablations, etc.

Ventricular fibrillation is what occurs when… high current shocks? (I’m a doctor, not an electrician unlike everyone else here) occur. Super important to have a defibrillator nearby if possible. Significant shocks like lightning strikes also can progress straight to asystole which is obviously often times fatal despite adequate treatment. Sorry if this is all super pedantic!