# Neonatal hyperthyroidism with myocardial injury: a case report

## TL;DR

A newborn with neonatal hyperthyroidism showed severe symptoms and myocardial injury, but recovered after treatment with methimazole and propranolol.

## Contribution

This case report highlights the importance of timely diagnosis and treatment of neonatal hyperthyroidism to prevent serious complications.

## Key findings

- Neonatal hyperthyroidism was diagnosed after persistent symptoms and elevated myocardial injury markers.
- Treatment with methimazole and propranolol led to rapid resolution of symptoms.
- Early diagnosis and intervention are critical to prevent complications in neonatal hyperthyroidism.

## Abstract

Neonatal hyperthyroidism (NH) is a rarely reported condition, but inappropriate treatment can have serious consequences. Early diagnosis, treatment, and follow-up are, therefore, essential. We present the case of a male newborn who was admitted to the Pediatrics Department 24 min after birth due to prematurity, presenting with tachypnea and grunting for 20 min. Subsequently, the infant developed increased respiratory rate, tachycardia, crying, and irritability. Bilateral periorbital edema and hyperdynamic heart sounds were also noted. Myocardial injury markers were significantly elevated, indicating myocardial injury. Following treatment with dopamine and dobutamine, the heart rate decreased, but crying, irritability, and periorbital edema persisted. Further history-taking led to a diagnosis of NH with neonatal goiter. The infant was started on oral methimazole and propranolol. Three days after initiation of therapy, the symptoms resolved rapidly, and the patient was discharged.