A Case of Atrial Flutter Masking Acute Pericarditis.

Atrial flutter (AFL) is a macro-reentrant tachycardia that can be provoked by numerous factors, including acute pericarditis. We present a case of new-onset AFL masking acute pericarditis in a man with multiple comorbid conditions, including hypertension, chronic kidney disease, and obstructive sleep apnea. After a failed attempt of rate control, the patient underwent successful cardioversion, which revealed electrocardiographic findings consistent with acute pericarditis. Colchicine was avoided in the setting of chronic kidney disease and the patient was treated with a steroid taper. Pericarditis is a rare cause of AFL, and this case demonstrates the diagnostic and management considerations for AFL and acute pericarditis.