New-onset heart failure in infants: when the aetiological diagnosis becomes a challenge.

Abstract

The onset of heart dysfunction in infants can result from either inherited factors or viral infections, both of which may involve inflammation. However, the precise role of EMB and CMR in determining the etiology of such cases remains poorlydefined. While CMR demonstrates high sensitivity in detecting inflammation, our experience suggests that it may not effectively differentiate between these two groups. A comprehensive diagnostic approach is essential when addressing this challenge, which includes considering EMB (with attention to the number of T-lymphocytes and the presence of oedema), specific CMR criteria, notably LGE and tissue mappings, as well as the identification of viral agents in cardiac tissue andtroponin levels. Additionally, genetic tests should be conducted when evaluating these patients. • EMB is the gold standard diagnostic test for myocarditis but it is notuniversally accepted. • The diagnostic value of the 2018-LLC in pediatric patients is still undefined. • Both EMB and CMR may show inflammation in infants with new-onset heart failure of any aetiology. • A global approach should be used when facing this diagnostic challenge, including the EMB (number of T-lymphocytes and oedema), some CMR criteria, specially LGE and mappings, the detection of viral agents in cardiac tissue and troponins. Genetic tests should also be performed when studying these patients.