In developing countries, constrictive pericarditis is most commonly due to which cause?

• A. TB
• B. Idiopathic viral illness
• C. Bacterial pneumonia
• D. Sarcoidosis

Answer: (A)

Tuberculosis is the most common cause of constrictive pericarditis in developing countries. TB pericarditis often leads to chronic inflammation of the pericardium that progresses to fibrosis and thickening, producing a stiff, noncompliant pericardium that restricts diastolic filling. This pericardial constriction creates the characteristic hemodynamic pattern and right-sided heart failure signs seen in constrictive physiology. In contrast, in developed countries constrictive pericarditis more often stems from idiopathic or viral pericarditis, and bacterial pneumonia is not a typical direct cause, with sarcoidosis being much less common.