Familial atrial fibrillation is an inherited condition that disrupts the heart's normal rhythm. This condition is characterized by uncoordinated electrical activity in the heart's upper chambers (the atria), which causes the heartbeat to become fast and irregular.hese resources address the diagnosis or management of familial atrial fibrillation and may include treatment providers. 1  Genetic Testing Registry: Atrial fibrillation, familial, 1. 2  Genetic Testing Registry: Atrial fibrillation, familial, 2.