Is having a seizure a sign of atrial fibrillation?

Atrial fibrillation is an irregular heart rhythm that occurs more commonly as we age. If a person had a seizure and was found to be in atrial fibrillation, most likely the two problems are not related. Very rarely, atrial fibrillation can cause an extremely fast heart rate leading to decreased blood flow to the brain. The insufficient delivery of oxygen to the brain could possibly cause a seizure.