Only in a Very Few. Generally, the answer to this is a very solid "no." this is a rare complication of people with another condition (on top of their afib) called wolff-parkinson-white syndrome (or wpw). In certain patients having both conditions, the top chamber is too-well connected to the bottom and can trigger ventricular fibrillation.
Rarely. In rare settings where the usual conduction pathway is not in place atrial fibrillation (af) can lead to ventricular fibrillation (vf) . For example, in WPW an abnormal tract of tissue can conduct impulses directly from the atrium to the ventricle. In rapid af with WPW this abnormal pathway can allow these impulses into the ventricles and cause vf. In af thru a normal av node this will not occur.