ACE2 and cardiac arrhythmia: While ACE2 levels in cohorts A1 and A2 are consistent with recent scientific literature, it is not a known biomarker in Kawasaki disease, despite the fact that cardiac disease (coronary artery aneurysms, myocarditis, pericarditis, congestive heart failure, pericardial effusion, and arrhythmias) is a complication in these patients (Tizard, 2005).