2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Circulatory System 390-459 > Other Forms Of Heart Disease 420-429 > Acute Pericarditis 420.* > 2006 ICD-9-CM Diagnosis 420.91 Acute idiopathic pericarditis View the most recent version of ICD-9-CM 420.91 420.91 is a specific code that can be used to specify a diagnosis 420.91 contains 7 index entries View the ICD-9-CM Volume 1 420.* hierarchy Alternate Terminology Pericarditis, acute: benign nonspecific viral  Index entries containing 420.91: Pericarditis (granular) (with decompensation) (with effusion) 423.9 acute (nonrheumatic) 420.90 benign 420.91 idiopathic 420.91 nonspecific 420.91 viral 420.91 idiopathic (acute) 420.91 nonspecific 420.91 viral (acute) 420.91