Subacute Massive Pulmonary Embolism Diagnosed by Transesophageal Echocardiography
A 78-year-old man presented with a 1 week history of breathlessness. He had no chest pain, cough, hemoptysis or any other symptoms. Past medical history was unremarkable. Initial examination revealed normal blood pressure, resting tachycardia of 140 beats per minute and type I respiratory failure requiring oxygen (FiO2 of 0.35) to maintain normal oxygen saturation. His chest x-ray showed no evidence of pneumonia or pulmonary edema. Admission ECGs showed ST depression and T wave inversion in the precordial leads V1–V5 and also a short run of paroxysmal atrial flutter. His troponin T measured 0.09 μg/L (normal range <0.1 μg/L). It was assumed that he suffered from an acute coronary syndrome, and therefore he was initially treated with low–molecular weight heparin and antiplatelet therapy using aspirin and clopidogrel. Transthoracic echocardiography was performed, but views were suboptimal and showed good left ventricular function, reasonable right ventricular function, and no significant valvular abnormalities. There was, however, an echogenic mass at the base of the right atrium attached to the atrial septum, which did not appear to be freely mobile. A transesophageal echocardiogram was subsequently performed (Figure and online-only Data Supplement Movies I through V). Transesophageal echocardiogram showed an intact atrial septum with no atrial masses, no significant valvular abnormalities, moderate right ventricular hypokinesia, and good left ventricular function, and no filling defects were seen in the inferior vena cava or superior vena cava. However, there was evidence of a large “saddle” pulmonary embolus, measuring approximately 7 cm, at the bifurcation of the main pulmonary artery. An urgent computed tomography pulmonary angiogram scan confirmed this saddle pulmonary embolus and further pulmonary emboli in the more distal pulmonary arteries. He received thrombolysis with tissue plasminogen activator, made a good recovery, and later began taking warfarin.
The online-only Data Supplement, which contains movies, can be found at http://circ.ahajournals.org/cgi/content/full/116/12/e352/DC1.