Occurs when normally elastic pericardium becomes thickened and fibrotic
Can be infectious, post-cardiac surgery, inflammatory, idiopathic or related to radiation exposure
Impairs diastolic filling of heart
Must distinguish from restrictive cardiomyopathy
Constrictive pericarditis
Dilated cardiomyopathy
Pericarditis
Hypertrophic cardiomyopathy
Restrictive cardiomyopathy
Peripartum cardiomyopathy
Myocarditis 
Takotsubo cardiomyopathy