Hemodynamics and extracardiac causes of cardiac tamponade: a diagnostic and therapeutic dilemma

Mechanical, extracardiac compression by large pleural effusions can impair cardiac filling and cause hemodynamic changes consistent with cardiac tamponade. In this case, a 68-year-old woman presented with fatigue and mild dyspnea on exertion one month following bioprosthetic mitral valve replacement for severe mitral regurgitation. Initial examination revealed hypotension, tachycardia, and pulsus paradoxus. Imaging demonstrated a large right pleural effusion, a small anterior pericardial effusion, and echocardiographic tamponade. After bedside thoracentesis, echocardiographic findings of tamponade resolved, and the patient's symptoms improved. In this patient, a large pleural effusion caused tamponade physiology rather than a pericardial effusion. Increased intrathoracic pressure can impair cardiac filling and result in tamponade physiology, and thoracentesis can resolve tamponade physiology even without pericardiocentesis. This case highlights the importance of recognizing extracardiac factors that may cause cardiac tamponade and warrant a tailored diagnostic and therapeutic approach.