A unique case of reversible myocardial ischemia in a hyperthyroid neonate

Area of Science:

• Neonatal cardiology
• Pediatric endocrinology
• Maternal-fetal medicine

Background:

• Neonatal hyperthyroidism is rare but can lead to significant cardiovascular complications.
• Maternal hyperthyroidism can impact fetal and neonatal well-being, though diagnosis in the neonate preceding the mother is unusual.

Observation:

• An 8-day-old preterm neonate presented with heart failure, pulmonary hypertension, and myocardial ischemia.
• These cardiac abnormalities were attributed to untreated hyperthyroidism.

Findings:

• Treatment with beta-blockers and subsequently propylthiouracil led to the reversal of all cardiac abnormalities.
• The mother was diagnosed with hyperthyroidism after her infant's diagnosis, a reversal of the typical diagnostic sequence.

Implications:

• This case highlights the importance of considering neonatal hyperthyroidism in infants with unexplained cardiac dysfunction.
• Early diagnosis and treatment can prevent long-term sequelae, as evidenced by the child's normal 10-year follow-up.
• The successful management of ischemic abnormalities in a neonate due to hyperthyroidism has not been previously reported.