Acute pericarditis in diseases classified elsewhere

This code signifies an acute inflammation of the pericardium (the sac surrounding the heart) that is a manifestation or complication of another underlying systemic disease. It indicates that the pericarditis is secondary to a primary condition classified elsewhere in the ICD-9-CM system, rather than being idiopathic or primary.

Apply this code when documentation clearly states acute pericarditis and explicitly links it to an underlying systemic disease, such as a connective tissue disorder (e.g., lupus), metabolic disease, or malignancy. The medical record should identify both the acute pericarditis and the primary causative condition.

• Always sequence the underlying systemic disease first, followed by this code for the acute pericarditis.
• Ensure documentation specifies "acute" pericarditis; chronic forms would be coded differently.
• Do not use this code for idiopathic acute pericarditis or acute pericarditis due to direct infection of the pericardium.