Abstract
BACKGROUND: Purulent pericarditis is a rare but severe presentation of acute pericarditis that can rapidly progress to effusive-constrictive pericarditis (ECP), a syndrome characterized by concomitant cardiac tamponade and constrictive pericarditis. CASE SUMMARY: A 62-year-old woman with diabetes presented with chills, dyspnea, and pleuritic chest pain. Despite initial treatment for idiopathic acute pericarditis, she rapidly developed cardiac tamponade. Emergent pericardiocentesis yielded purulent fluid consistent with Streptococcus pneumoniae pericarditis, and postdrainage echocardiogram demonstrated constrictive physiology, supporting a diagnosis of ECP. The patient subsequently underwent partial pericardiectomy, with marked clinical improvement. DISCUSSION: This case highlights the rapid progression of nontuberculous purulent pericarditis to ECP and underscores the importance of serial echocardiography in diagnosing, monitoring, and managing ECP. TAKE-HOME MESSAGES: ECP is a rare but under-recognized complication of purulent pericarditis, requiring a high clinical suspicion. Given the diagnostic challenges, early recognition, close monitoring, and timely intervention are critical to improving outcomes.