Thyrotoxicosis in a Pediatric Patient with Supraventricular Tachycardia and Borderline Features of Thyroid Storm

ABSTRACT Objective The objective of this report was to emphasize the early recognition of thyrotoxicosis in the assessment of a pediatric patient with tachycardia. We present here the case of a 17-year-old female who presented with supraventricular tachycardia and was found to be in a state of severe thyrotoxicosis with borderline features of a thyroid storm. Methods A 17-year-old African American female presented to the hospital with complaints of nausea, vomiting, and diarrhea associated with palpitations for 1 week. Initial workup included electrocardiogram, total blood count, lipase, basic metabolic panel, and thyroid function tests. Results Initial vital signs were significant for a temperature of 100.1°F, and tachycardia with a heart rate (HR) of 180 beats per minute (bpm). Initial telemetry was significant for supraventricular tachycardia with a HR of 180 bpm. Vagal maneuvers including carotid sinus massage were attempted first followed by 6 mg intravenous (IV) push and then 12 mg IV push of adenosine. However, the patient remained tachycardic with a HR in the 150s. Laboratory evaluation confirmed the presence of thyrotoxicosis with a thyroid-stimulating hormone of 0.17 μIU/mL (normal, 0.5 to 4.7 μIU/mL) with a free thyroxine of 4.90 ng/dL (normal, 0.8 to 2.0 ng/dL) and free triiodothyronine >20 pg/mL (normal, 1.95 to 5.85 pg/mL). She was subsequently treated with propranolol, methimazole, and hydrocortisone, which resolved her symptoms in a few hours. Conclusion Due to high mortality rates, severe thyrotoxicosis needs to be recognized and treated early. This case report highlights the importance of early recognition of thyrotoxicosis in the initial management of tachycardia in the pediatric population.