1 ICD-9-CM 751.7 is a billable medical code that can be used to indicate a diagnosis on a reimbursement claim, however, 751.7 should only be used for claims with a date of service on or before September 30, 2015. 2  For claims with a date of service on or after October 1, 2015, use an equivalent ICD-10-CM code (or codes).
The myocardium is located between the endocardium and the visceral layer of the serous membrane (epicardium) of the heart.
The myocardium is the heartâs thick middle layer. It is made almost entirely of cardiac muscle tissue and blood vessels, and the inside of it is covered with the endocardium. This thick heart layer makes up the majority of the wall of the heart.