Dressler syndrome, also known as post-myocardial infarction syndrome (when following MI) or more broadly post-cardiac injury syndrome (PCIS) when following any cardiac injury, is an autoimmune-mediated systemic inflammatory disorder characterized by pericarditis, pleurisy, and rarely pneumonitis, occurring weeks (typically 2-10 weeks) after the inciting event. The classical Dressler syndrome incidence following MI has decreased significantly with modern reperfusion therapy (now <1% versus historical 4-7%), but PCIS remains common after cardiac surgery (approximately 10-20%), pacemaker insertion, ablation, and chest trauma.
Pathophysiology involves an autoimmune response triggered by exposure of cardiac antigens (myocardium, pericardium, or both) to the immune system following injury, leading to circulating anti-heart antibodies, immune complex deposition, and inflammatory cascade in the serous membranes (pericardium, pleura) and occasionally lung parenchyma. Predisposing factors include large infarcts, transmural injury, cardiac surgery (especially with pericardial manipulation), and possibly viral coinfection.
The pulmonary component manifests as pleuritic chest pain (sharp, worse with breathing or position), pleural effusions (often bilateral but can be unilateral, lymphocytic or neutrophilic exudate, sometimes hemorrhagic post-surgery), and rarely pneumonitis (interstitial infiltrates, diffusion impairment). Diagnosis requires clinical history (preceding cardiac event), pleural fluid analysis (exudate, may have eosinophilia), echocardiography (often pericardial effusion concurrent), inflammatory markers (elevated CRP, ESR, leukocytosis), and exclusion of alternative diagnoses (heart failure with cardiogenic effusion, infection, pulmonary embolism). Treatment is with NSAIDs as first-line (ibuprofen 600 mg three times daily, indomethacin, aspirin) for 2-4 weeks with taper, colchicine 0.5-0.6 mg twice daily for 3 months reduces recurrence; corticosteroids reserved for refractory cases or contraindications to NSAIDs; therapeutic thoracentesis for large or symptomatic effusions; anticoagulation should be avoided if possible (small risk of hemorrhagic transformation in pericarditis).