Enteroviral Neonatal Myocarditis: Diagnostic Challenges and Clinical Implications

Abstract

Neonatal enterovirus infection is generally asymptomatic and self-limited, but in rare cases it may progress to myocarditis, a severe inflammatory condition characterized by rapid clinical deterioration and high lethality. In newborns, the high expression of the coxsackie-adenovirus receptor (CAR) facilitates intense viral replication, contributing to fulminant presentations and hindering early recognition, as clinical manifestations are nonspecific and often mimic sepsis or other infectious conditions. In this context, the present study aimed to critically synthesize the available evidence on neonatal enteroviral myocarditis, emphasizing diagnostic challenges and current gaps in the literature, while integrating clinical manifestations, pathophysiology, disease progression, and therapeutic possibilities. A narrative review was conducted through searches in PubMed/MEDLINE, SciELO and LILACS between April and November 2025, using descriptors in Portuguese, English, and Spanish related to viral myocarditis and neonatal enteroviral infection. Studies published within the last ten years and presenting clinical relevance to the topic were included, whereas research involving only older children or adults, articles without full-text access, or publications not directly related to enteroviral myocarditis were excluded. Analysis of the selected studies showed that although RT-PCR is the most sensitive method for confirming viral infection, diagnosing myocarditis still requires a multimodal approach involving biomarkers, electrocardiography, and imaging exams, all of which lack neonatal-specific standardization. Regarding management, hemodynamic support remains the cornerstone of treatment, and available pharmacological interventions show heterogeneous results. Overall, the current literature reveals significant gaps concerning diagnostic criteria, markers of severity, and optimal therapeutic strategies, reinforcing the need for multicenter studies and neonatal-specific guidelines capable of improving early recognition and clinical outcomes in enteroviral myocarditis.