Acute rheumatic myocarditis

This code signifies inflammation of the heart muscle (myocardium) that occurs as a direct consequence of an acute rheumatic fever episode. It represents a serious cardiac manifestation of the autoimmune response triggered by a Group A streptococcal infection.

Assign this code when documentation clearly indicates acute myocarditis in the context of active rheumatic fever. This typically involves evidence of recent streptococcal infection and clinical signs of cardiac involvement, such as new heart murmurs, cardiomegaly, or heart failure symptoms.

• Always sequence this code after the underlying acute rheumatic fever code (e.g., I00).
• Ensure documentation specifies "acute" myocarditis and its rheumatic origin to differentiate from other forms of myocarditis.
• Do not use this code for chronic rheumatic heart conditions or myocarditis due to non-rheumatic causes.