Thyroid storm in a neonate and young infant: A rare but lethal cause of heart failure.

Neonatal heart failure has varied causes, namely left-sided obstructive lesions such as aortic stenosis, hypoplastic left heart syndrome, and coarctation of the aorta, as well as conditions such as Ebstein's anomaly, supraventricular tachycardia, atrioventricular regurgitation, and large posttricuspid shunts. However, neonatal thyrotoxicosis is a rare but potentially fatal cause of heart failure if left untreated. We present two cases of neonatal thyroid storm manifesting as heart failure and cardiogenic shock, emphasizing the diagnostic challenges, treatment strategies, and transient nature of the disease, which is mediated by maternal thyroid-stimulating hormone receptor antibodies. A literature review is also provided to highlight the clinical approach to this rare but critical condition.