Frequent urination
During the early stages of atrial fibrillation, the patient suffers from frequent urination or polyuria, which is most probably due to the secretion of the atrial natriuretic peptide from the fibrillating atria. The patient of atrial fibrillation feels the urge to urinate after every twenty minutes or so. The symptom of frequent urination indicates that there is a decreased blood flow from the heart to the kidneys, which is causing the kidneys to retain more fluid. The excess fluid in the body comes out as urine because the body has to maintain common homeostasis.