Cardiovascular Manifestations in the Pediatric Population with COVID-19, What is the Real Relevance?

Although COVID-19 usually has mild manifestations in children, multisystem inflammatory syndrome (MIS) may occur in 0.6% of the cases. MIS in children (MIS-C), already well defined by the World Health Organization (WHO), is characterized by hyperinflammation with cytokine storm and high levels of myocardial injury markers, with involvement of one or more organs of the cardiac, renal, respiratory, gastrointestinal or neurological systems.

The combination of the timing of MIS-C cases with positive serology and negative PCR in most patients suggests that MIS-C is a post-infectious (up to six weeks after the insult), immune-mediated complication rather than of the acute infection. The pathophysiology of MIS-C is thought to be due to a hyperimmune response to the virus in a genetically susceptible child. The symptoms of MIS-C can overlap with those of Kawasaki disease, toxic shock syndrome, macrophage activation syndrome, bacterial sepsis, and cytokine release syndrome (“cytokine storm”). Cytokine storm is characterized by persistent fever, and markedly elevated inflammatory markers and pro-inflammatory cytokines such as interleukin. There increasing evidence on cardiovascular involvement in COVID-19 and MIS-C.^,

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