The main characteristic finding of CP is a thickened, fibrotic, and/or calcified pericardium constricting the heart and impairing cardiac filling. Diseases that reduce myocardial compliance such as RCM are also characterized by impaired ventricular filling. The clinical manifestations of these diseases are similar to that of constrictive pericarditis Distinguishing between the two entities is crucial, because CP can be treated with early pericardiectomy, however medical treatment is recommended for RCM Imaging methods such as CT and MRI can measure pericardial thickness which is usually increased in patients with CP.