To examine the possibility that syndecan-4 levels could differentiate between subgroups of cardiomyopathies characterized by acute immune responses, we sub-divided patients based on their specific diagnoses, i.e., acute myocarditis (n = 15), acute pericarditis (n = 3) and acute perimyocarditis (n = 23). This evidence concerns the gene SDC4 and acute myocarditis.