Defying Occam's Razor: A Case of Pulmonary Embolism Masked By Cardiac Tamponade

BACKGROUND Occam's razor instructs physicians to assume one single cause for multiple symptoms, whereas Hickam's dictum encourages them to suspect multiple concurrent pathologies. Although the general practice is to follow Occam's razor, occasionally Hickam's dictum reigns supreme. Here we present one such case, where the concurrent presence of two life-threatening pathologies posed clinical challenges in diagnosis and management. CASE REPORT Although cardiac tamponade and pulmonary embolism (PE) are known complications of malignancy, their concomitant existence is rare. Here we report a patient who presented with shortness of breath found to have both cardiac tamponade and submassive PE. Although the cardiac tamponade was initially diagnosed in the Emergency Department by bedside ultrasound and treated with pericardiocentesis, only a few hours later, when she deteriorated, the submassive PE was diagnosed, which was treated with heparin infusion and subsequently transitioned to a newer oral anticoagulant. The patient was later diagnosed as having primary breast cancer and metastatic lung adenocarcinoma. Why Should an Emergency Physician Be Aware of This? This raised unique diagnostic challenges, as both cardiac tamponade and PE present with obstructive shock. The increased right heart pressure from the PE could have paradoxically protected the patient from the tamponade effects of the pericardial effusion. Furthermore, the presence of cardiac tamponade may also mask the typical echocardiographic features of PE. The concurrent presence of two pathologies raised challenges and dilemmas in management. This case shows that physicians should maintain a high degree of suspicion of two pathologies when the patient deteriorates after the first pathology has been appropriately treated.

as reported in: J Emerg Med. 2022 Jan 5 [Epub ahead of print]