Can af (without an anti-arrhythmic drug) lead to vf. does effective rate control prevent vf?

AF to VF: AF to VF is very uncommon unless WPW conduction is present. Rate control doesn't prevent afib, it just controls the rate of ventricular response when afib is present. Some drugs for rate control like beta blockers can help decrease the frequency of afib

Unlikely: Atrial fibrillation does not usually lead to VF unless the person also has WPW syndrome. If one has not been diagnosed with WPW, the chances of atrial fibrillation going into ventricular fibrillation is very low. Of course, if one has a fast heart rate for a long time, one can develop CHF and then possibly VF, but not because of the AF. Rate control prevents CHF or retards its development.

Not usually.: VF does not usually occur due to uncontrolled AF; however, rate control is the goal of drug therapy. If the rate is uncontrolled, ones BP can fall and one could feel lightheaded or even faint. An alternative to rate-control would be an ablation; however, that procedure should be performed by an electrophysiologist who performs A Fib ablations frequently.

Rarely: Usually it does not, unless the person has a short circuit in the heart , such as WPW syndrome, or if the person has pre-existing ischemia, and the ventricular heart rate is high.

Statistically no.: If one has a propensity to develop Ventricular arrythmias then it is possible that the irregular beat to beat interval could induce ventricular tachycardia. This was seen with interrogation of AICDs. Also lack or rate control can result in a rate related cardiomyopathy. However, more sudden death was seen with in patients with atrial fibrillation on antiarrythmic therapy.

Yes: Very rapid uncontrolled AFib can degenerate into VFib as can happen in WPW. II is a rare but fatal complication.In treated AFib with controlled rate VFib is unlikely and the risk is related to the anti arrhythmic drug use or existing co morbidities.