Thrombolytic Therapy for Right Atrial and Pulmonary Embolus

A 68-year-old male with a history of hypertension presented to the emergency department with acute onset pain and severe swelling of the left lower extremity. Pleuritic chest discomfort was also noted. He had been traveling by automobile from Canada to the Desert Southwest for 3 days and admitted to very little activity during this period. Physical exam was notable for a swollen, painful left calf with an easily reproducible Homan’s sign. He was noted to have a murmur of tricuspid regurgitation. Shortly after initial evaluation, he became visibly dyspneic with oxygen saturations of 89–90% on 6 liters of supplemental oxygen delivered by nasal canula. He grew progressively more dyspneic and became acutely hypotensive, with systolic blood pressures in the range of 80 mmHg. Lower extremity noninvasive venous studies confirmed the presence of extensive deep venous thrombosis. High-speed multi-detector helical computed tomography of the chest (Figures 1A and 1B) demonstrated the presence of extensive thrombus in the main pulmonary artery. A “saddle embolus” is appreciated in Figure 1A. Transesophageal echocardiography (Figure 3A) revealed a large, multi-lobed thrombus in the right atrium that prolapsed into the right ventricle with each atrial systole. The terminal portion appeared to be relatively stationary in the right atrium. In the superior aspect of the right atrium, there appeared to be a thin filamentous structure contiguous with the thrombus. Because of progressive clinical deterioration, the decision to administer thrombolytics was made and tissue plasminogen activator was infused intravenously over 2 hours. Over the next 3–4 hours, dramatic clinical and hemodynamic improvements were noted, with systolic blood pressures of 120–130 mmHg. Oxygen saturation of 98–99% was achieved on 2 liters of nasal canula oxygen with amelioration of dyspnea. Repeat helical computed tomography of the chest following thrombolytic administration (Figures 2A and 2B) showed complete resolution of the thrombus in the main pulmonary artery as well as the right and left segmental vessels. Repeat transesophageal echocardiography (Figure 3B) revealed complete dissolution of the multi-lobed thrombus in the right atrium. There appears to be a fine filamentous Chiari network in the right atrium, representing the site of attachment on the terminal end of the thrombus. The patient’s hospital course was without further complications. He was committed to long-term antithrombotic therapy and was discharged after achieving therapeutic anticoagulation.