Lone Atrial Fibrillation Associated with Creatine Monohydrate Supplementation

Atrial fibrillation in young patients without structural heart disease is rare. Therefore, when the arrhythmia is present in this population, reversible causes must be identified and resolved. Thyroid disorders, illicit drug or stimulant use, and acute alcohol intoxication are among these causes. We report the case of a 30‐year‐old Caucasian man who came to the emergency department in atrial fibrillation with rapid ventricular response. His medical history was unremarkable, except for minor fractures of the fingers and foot. Thyroid‐stimulating hormone, magnesium, and potassium levels were within normal limits, urine drug screen was negative, and alcohol use was denied. However, when the patient was questioned about use of herbal products and supplements, the use of creatine monohydrate was revealed. The patient was admitted to the hospital, anticoagulated with unfractionated heparin, and given intravenous diltiazem for rate control and intravenous amiodarone for rate and rhythm control. When discharged less than 24 hours later, he was receiving metoprolol and aspirin, with follow‐up plans for echocardiography and nuclear imaging to assess perfusion. Exogenous creatine is used by athletes to theoretically improve exercise performance. Vegetarians may also take creatine to replace what they are not consuming from meat, fish, and other animal products. Previous anecdotal reports have linked creatine to the development of arrhythmia. Clinicians must be diligent when interviewing patients about their drug therapy histories and include questions about their use of herbal products and dietary supplements. In addition, it is important to report adverse effects associated with frequently consumed supplements and herbal products to the Food and Drug Administration and in the literature.