- Having received a cardiac MRI which concluded the diagnosis of acute myocarditis according to the usual criteria of the center (Lake Louise criteria changed according to the habits of the center) There myocarditis when at least two of the following criteria are met: hyperintense T2; hyperintense Diffusion; myocardium ratio signal / peripheral muscle Gadolinium> 4; contrast enhancement after injection of gadolinium chelate in cine-steady-state free precession (SSFP); nonischemic type of signal on delayed enhancement. These anomalies are segmental topography typically subepicardial. The analysis is made of the 17 segments of the left ventricle.