Abstract
BACKGROUND: We describe a patient who was found to have a rare electrocardiogram pattern in the setting of hyperthyroidism and discuss differential diagnoses and pathophysiology. TAKE-HOME MESSAGES: The take home-messages are to recognize the importance of considering endocrine etiology in irregular electrophysiology, and to recognize mimics of structural and ischemic heart disease that can resolve with appropriate therapy. CASE SUMMARY: A 40-year-old man presented with chest pain and questionable lateral lead ST-segment elevations on electrocardiogram and T waves with bifid morphology. Blood pressure and heart rate were 129/66 mm Hg and 98 beats/min, respectively. Laboratory results revealed cardiac troponin of 5 ng/mL, magnesium of 1.6 mg/dL, potassium of 4.3 mmol/L, unremarkable renal function, thyroid stimulating hormone <0.010 ulU/mL, free thyroxine of 2.90 ng/dL, and free triiodothyronine of 376.1 ng/dL.