The Heart Under Pressure: A Case of Tuberculous Cardiac Tamponade

Background Tuberculous pericarditis is an uncommon but potentially life-threatening form of extrapulmonary tuberculosis. Direct microbiologic confirmation from pericardial fluid can be difficult, and diagnosis requires integration of epidemiologic risk, imaging, pericardial fluid characteristics, and microbiologic testing. Case presentation: An 82-year-old man originally from Mexico presented with 3–4 weeks of progressive fatigue, productive cough, dyspnea on exertion, and generalized malaise. He was hemodynamically stable (blood pressure 134/81 mmHg, heart rate 91 beats/min, respiratory rate 18 breaths/min). Transthoracic echocardiography demonstrated a large generalized pericardial effusion with echocardiographic signs of tamponade. Urgent echocardiography-guided pericardiocentesis evacuated approximately 1 L of hemorrhagic fluid. The pericardial fluid was lymphocyte predominant (83% lymphocytes) and subsequently grew Mycobacterium tuberculosis complex despite a negative fluorochrome acid-fast bacillus smear. Sputum specimens were likewise smear negative but culture positive for M. tuberculosis complex. Molecular testing detected M. tuberculosis complex DNA, and susceptibility testing showed susceptibility to first-line agents. Antituberculosis therapy was initiated, and the patient completed his prescribed treatment course with clinical and radiographic improvement. Conclusion This case highlights the diagnostic value of pericardial fluid culture in an older patient with hemorrhagic, lymphocyte-predominant pericardial effusion and tamponade physiology. Tuberculosis should remain in the differential diagnosis when compatible epidemiologic, radiographic, and clinical features are present, even when initial AFB smears are negative.