Any dilated cardiomyopathy in which the cause of the disease is a mutation in the DMD gene. The disease is Monarch Disease Ontology entry MONDO_0010542 (dilated cardiomyopathy 3B). Also known as: CMD3B, DMD dilated cardiomyopathy, cardiomyopathy, dilated, type 3B, dilated cardiomyopathy caused by mutation in DMD, dilated cardiomyopathy type 3B.