Neonatal Cardiomyopathies

This review aims to provide an updated overview of the genetic basis, pathophysiology, clinical presentation, diagnostic approach, management strategies, and outcomes for cardiomyopathies presenting in the neonatal population. Neonatal cardiomyopathies represent a rare and complex group of disorders that are typically classified by ventricular morphology, with dilated, hypertrophic, and left ventricular noncompaction phenotypes being the most commonly seen in the neonatal population. Advances in genetic testing have revealed a strong and complex genetic basis for neonatal cardiomyopathies, with wide variability in penetrance and phenotypic expressivity, even among family members sharing the same pathogenic variant. Neonates with cardiomyopathy typically present with symptoms of heart failure that may mimic other diseases of childhood, such as respiratory and gastrointestinal illnesses. The intricate etiologies of each cardiomyopathy makes targeted treatment difficult, and heart failure management is largely supportive in nature. Although medications and interventions exist to manage symptoms, heart transplantation remains the final potential therapeutic option for patients with end-stage heart failure. Neonates and infants diagnosed with cardiomyopathy overall have worse outcomes compared to children who are older at the time of diagnosis and carry a high risk of progression to death or need for heart transplant, highlighting the need to better understand the complex interactions leading to the development of cardiomyopathy in neonates and to continue developing treatment options for this vulnerable population.