**9.2 Chest radiography**

Findings on chest X-ray are nonspecific, but cardiomegaly due to pleural effusion, pulmonary vascular congestion, or pericardial effusion is seen. Pericardial calcification is seen on chest X-ray in 27% of constrictive pericarditis cases.

### **9.3 Laboratory assessment**

The plasma brain natriuretic peptide (BNP) level can be used for diagnosis. BNP is a determinant of ventricular dysfunction and wall tension. Elevation is typical in many forms of heart failure and cardiomyopathy. In constrictive pericarditis, BNP elevation is less than in cardiomyopathy. Hepatic function tests are abnormal due to congestion.
