B51-04 Refractory Atrial Fibrillation Triggered by Topical Oxymetazoline: A Case Requiring Critical Care Management

Abstract Introduction Oxymetazoline, an imidazoline derivative, is a commonly used over-the-counter nasal decongestant. Although generally considered safe, it has been associated with rare but potentially serious cardiovascular adverse effects, including cardiac arrhythmias. Case Presentation A 64-year-old man with diabetes and hypertension presented with a one-week history of dyspnea and cough. On admission, he was tachycardic up to 100 bpm, with normal blood pressure and oxygen saturation. Laboratory tests, including troponin, B-type natriuretic peptide (BNP), and thyroid-stimulating hormone (TSH), were unremarkable. Electrocardiogram (ECG) showed sinus rhythm with frequent premature ventricular contractions (PVCs) and no ST-T changes. Transthoracic echocardiography demonstrated normal cardiac function without structural abnormalities. The following day, he developed new-onset atrial fibrillation (AF) with a rapid ventricular response up to 170 bpm. Despite oral diltiazem and amiodarone, AF persisted. He developed acute hypoxic respiratory failure due to pulmonary congestion secondary to acute heart failure, requiring intensive care unit (ICU) admission and supplemental oxygen support. Intravenous diltiazem and amiodarone infusions failed to restore sinus rhythm. Electrical cardioversion briefly achieved sinus rhythm before AF recurred. Further history revealed frequent, multiple daily uses of oxymetazoline nasal spray for congestion relief. Discontinuation of the decongestant led to sustained conversion to normal sinus rhythm, which has been maintained without recurrence for six months. The temporal relationship between oxymetazoline use and onset of atrial fibrillation, resolution after discontinuation, and exclusion of other causes supported a probable causal association (Naranjo score = 7). Discussion Oxymetazoline is an α1- and α2-adrenergic receptor agonist that acts on adrenergic and cholinergic axons and post-synaptic central nervous system neurons. When applied locally, it causes vasoconstriction of vascular smooth muscle. Although generally considered safe, oxymetazoline has been linked to cardiovascular effects such as hypertension and bradycardia, while its arrhythmogenic potential is rarely reported. A single case of ventricular tachycardia associated with topical oxymetazoline has been described, and in 2016, two cases of atrial fibrillation linked to tramazoline-containing decongestants were reported, both managed as outpatients. To our knowledge, this is the first documented case of oxymetazoline-induced atrial fibrillation refractory to both pharmacologic and electrical cardioversion requiring ICU-level management. Conclusion This case highlights the potentially serious arrhythmogenic effects of certain sympathomimetic nasal decongestants. Caution and medical supervision are warranted, particularly in patients with cardiovascular comorbidities. Although rare, oxymetazoline-induced atrial fibrillation can cause significant morbidity and may necessitate critical care management. This abstract is funded by: None