The document discusses pericarditis, which is inflammation of the pericardium. Acute pericarditis is the most common disorder and presents with sudden onset chest pain that worsens with breathing or coughing. A pericardial friction rub may be heard on examination. ECG findings include ST segment elevations. Treatment involves NSAIDs which typically resolves symptoms in 2 weeks. Complications include cardiac tamponade and constrictive pericarditis from scarring.