2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Circulatory System 390-459 > Other Forms Of Heart Disease 420-429 > 2006 ICD-9-CM Diagnosis 420 Acute pericarditis View the most recent version of ICD-9-CM 420 420 is a non-specific code that cannot be used to specify a diagnosis 420 Includes acute: mediastinopericarditis myopericarditis pericardial effusion pleuropericarditis pneumopericarditis 420 Excludes acute rheumatic pericarditis (391.0) postmyocardial infarction syndrome [Dressler's] (411.0)