Most common

Less common

Idiopathic―42% to 49% [8]

Other infections

Mediastinal irradiation (5 - 10 years duration)

Neoplasms―5% - 17% (lung―33%, breast―25%, adenocarcinoma of intestine [9] )

Following Cardiac surgery―11% to 37% (post-pericardiectomy―10% to 40%, previous cardiac surgery―0.3%)

Connective tissue disorders (rheumatoid Arthritis, systemic lupus erythematosis, Scleroderma)

Radiotherapy―9% to 31%

Drugs (procainamide, hydralazine, methysergide)

Post-infectious―3% to 6%

Trauma

Tuberculosis

Viral infections (coxsackie virus A and B, Adenovirus, echovirus)

Pyogenic infections

Hereditary―Mulibrey nanism (Mu―muscle, Li―liver, br―brain, ey―eyes, nanism―dwarf) in Finland and United states [10]