NPPB and pericardial effusion: Up to 80% of MIS-C patients have cardiovascular involvement, including signs of myocarditis with an elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and a decreased systolic left ventricular (LV) function, coronary artery dilation, pericardial effusion, arrhythmias, and conduction abnormalities (2–6).