RESUMO
Congenital hypothyroidism is a clinical condition characterized by lack of thyroid hormone because of thyroid gland developmental and thyroid hormone biosynthesis disorders. The most common cause of permanent hypothyroidism is congenital factors. Prompt diagnosis is critical. However, overt signs of hypothyroidism are rarely present at birth, and 95% of affected babies are asymptomatic. Hypoxemia, apnea, acidosis, increased intracranial pressure, vagal stimulus and central nerve system abnormalities represent the most common causes of bradycardia in the neonate. Bradycardia associated with congenital hypothyroidism is very rare. In this paper, a case of severe congenital hypothyroidism, induced by maternal blocker antibodies, who presented with bradycardia, is reported