Massive Right Atrial Thrombus Masquerading as Cardiac Tamponade

A 61-year-old male with a medical history of metastatic leiomyosarcoma was brought to the emergency department with complaints of worsening dyspnea for 2–3 weeks in the setting of increasing lower extremity edema. His leiomyosarcoma, diagnosed 3 years previously, was treated at an outside facility, where he underwent multiple regimens of chemotherapy. He reported that he was in his usual state of health until these symptoms presented. He denied fevers, chills, chest pain, cough, or sputum. He was in moderate respiratory distress, but comfortable enough to speak in full sentences. His heart sounds were distant, his lungs were clear, and he had jugular venous distention. His initial heart rate was 110 beats/min, his respiratory rate was 25 breaths/min, his oxygen saturation was 95% while breathing room air, he was afebrile, and his blood pressure was 92/65 mm Hg.

Supplemental oxygen was administered via facemask and intravenous access was obtained. While awaiting portable chest radiography, a bedside echocardiogram was performed by the emergency physician using a 5–2 MHz curvilinear array transducer (Siemens G60, Siemens Corp., New York, NY) to evaluate for pericardial effusion and suspected cardiac tamponade. On the parasternal long-axis view, a large mass was visualized in the right atrium with extension into the right ventricle and significant compression of the left atrium (Figure 1 and Video Clip S1, available as supporting information). There was no pericardial effusion.

Figure 1.  Parasternal long-axis view demonstrates a giant mass (asterisk) in the right atrium. ao = descending thoracic aorta; lv = left ventricle; rm = right ventricle.

Collateral information from the patient’s oncologist confirmed a right atrial thrombus with extension into the inferior vena cava on computed tomography imaging 1 month prior. The patient was subsequently admitted to the intensive care unit, where he developed worsening hemodynamic instability. His blood pressure was maintained with intravenous fluids and pressor support. Given his poor prognosis, his resuscitation status was addressed, and he agreed to a do not resuscitate order. He expired on hospital day 3.