Images in Clinical Medicine
Chronic Thromboembolic Pulmonary Hypertension
N Engl J Med 2001; 344:644March 1, 2001
- Article
Figure 1 A previously healthy 35-year-old man had increasing dyspnea on exertion over a period of several months. The results of a physical examination and transthoracic echocardiography suggested that he had pulmonary arterial hypertension and severe tricuspid regurgitation. A contrast-enhanced helical computed tomographic (CT) scan of the chest was obtained to look for evidence of pulmonary thromboembolism and to assess the lung parenchyma. Contiguous axial CT images through the main pulmonary arteries (Panel A) showed eccentric endothelialized thrombi in both pulmonary arteries (arrows). A CT image obtained at the level of the aortic arch (Panel B) showed a disparity in the pulmonary vasculature, with more visible pulmonary-artery branches in the left lung (arrows) than in the right. A CT image obtained at the same level with lung windows (Panel C) demonstrated a mosaic pattern of attenuation; the areas of higher attenuation (arrows) were areas of lung that are normally perfused.
The combined pulmonary findings of eccentric endothelialized thrombi, disparity of the vessels, and mosaic attenuation on thoracic CT images in a patient with pulmonary arterial hypertension suggest the presence of chronic thromboembolic pulmonary hypertension. The CT findings that are characteristic of this disorder differ from those associated with acute pulmonary thromboembolism in that the filling defects (emboli) are eccentrically located within the pulmonary-artery branch rather than centrally located.
In this patient, as in most patients with chronic thromboembolic pulmonary hypertension, the cause of hypercoagulability was not found. Despite the placement of an inferior vena cava filter and treatment with warfarin, the patient's dyspnea progressed. He subsequently underwent pulmonary thromboendarterectomy, which relieved his symptoms. A repeated echocardiogram showed minimal tricuspid regurgitation and a normal right ventricle.
Julie E. Dixon, M.D.
Mark A. King, M.D.
Ohio State University Medical Center, Columbus, OH 43210
