Review of Cardiac Involvement in Multisystem Inflammatory Syndrome in Children.

Coronavirus disease -2019 (COVID-19) is a recently described infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with significant cardiovascular implications. Although infection with SARS-CoV-2 is usually mild in children, some children later develop a severe inflammatory disease that can have manifestations similar to toxic shock syndrome or Kawasaki disease. This syndrome has been defined by the US Centers for Disease Control and Prevention (CDC) as the Multisystem Inflammatory Syndrome in Children (MIS-C). Although the prevalence is unknown, there have been more than 300 cases reported in the literature. MIS-C appears to be more common in Black and Hispanic children in the US. MIS-C typically occurs a few weeks after acute infection and the putative etiology is a dysregulated inflammatory response to SARS-CoV-2 infection. Persistent fever and gastrointestinal symptoms are the most common symptoms. Cardiac manifestations are common including ventricular dysfunction, coronary artery dilation and aneurysms, arrhythmia and conduction abnormalities. Severe cases can present in vasodilatory or cardiogenic shock requiring fluid resuscitation, inotropic support, and in the most severe cases mechanical ventilation and extracorporeal membrane oxygenation (ECMO). Empiric treatments have aimed at reversing the inflammatory response using immunomodulatory medications. Intravenous immunoglobulin, steroids and other immunomodulatory agents have been frequently used. Most patients recover within days to a couple of weeks and mortality is rare, although the medium- and long-term sequelae, particularly cardiovascular complications, are not yet known. This review describes the published data on MIS-C, focusing on cardiac complications, and provides clinical considerations for cardiac evaluation and follow-up.