Imaging the "Hot Phase" of a Familiar Left-Dominant Arrhythmogenic Cardiomyopathy.

We describe the case of a young man with an initial diagnosis of acute myocarditis that was finally recognized as a familial left-dominant arrhythmogenic cardiomyopathy. The diagnostic process was also based on demonstration, serial cardiac magnetic resonance imaging, and typical patterns of myocardial damage, including features of the disease's inflammatory "hot phase".