Myocarditis in diseases classified elsewhere

This code represents inflammation of the heart muscle (myocardium) that occurs as a manifestation or complication of another underlying disease process. It signifies a secondary myocarditis, where the primary condition is classified elsewhere in ICD-10-CM.

Use this code when documentation clearly links myocarditis to an underlying systemic disease, infectious process, or other condition not specifically listed in the Excludes1 note. The medical record should specify the primary disease causing the myocarditis.

• Always sequence the underlying disease first, followed by this code, to accurately reflect the etiology.
• Carefully review the Excludes1 list; if the underlying disease is listed there, use the specific code provided for that condition's myocarditis.
• Ensure documentation explicitly states the connection between the myocarditis and the primary disease; avoid assuming causality.