The present invention provides an in vitro method for obtaining data useful for diagnosing a cardiomyopathy, measuring the expression levels of two microRNAs in the blood plasma of patients.

Given the absence of methods capable of assuring a degree of acceptable specificity and sensitivity for the diagnosis of myocarditis, particularly during an acute episode, the present invention solves this problem by providing a specific and sensitive assay for diagnosing myocarditis by using blood samples.