Atrial fibrillation versus ventricular fibrillation. Causes and cures?

VF vs AF. Ventricular is lethal instantly. A fib is not lethal and treated with medications or ablation.
Bottom vs. Top. Ventricular fibrillation is from the bottom chamber; vf is worse; it usually causes cardiac arrest which is often fatal. Atrial fibrillation - from the top chamber- while not as severe, also has significant health risks. It increases the risk of stroke, which can be disabling or fatal.