Abstract
A 57-year-old male with type 2 diabetes mellitus presented to our emergency department with syncope and shortness of breath. He manifested tachycardia of 120 beats/minute, a blood pressure of 102/68 mmHg, a loud second heart sound and a clear chest on auscultation. His peripheral oxygen saturation was 85% on room air. A 12-lead electrocardiogram demonstrated right bundle branch block and ‘S1Q3T3’ pattern. The plain antero-posterior chest radiograph was unremarkable but plasma D-dimer was elevated. Transthoracic two-dimensional echocardiography showed a dilated right atrium (RA) and right ventricle (RV). There was also severe tricuspid regurgitation, mildly elevated pulmonary artery systolic pressure (42 mmHg) and RV systolic dysfunction.
Interestingly, multiple thromboemboli were appreciated throughout the cardiac cycle in the RA, prolapsing across the tricuspid valve into the RV giving a ‘popcorn’ appearance (Panel A: LV, left ventricle; RA, right atrium; RV, right ventricle). Panels A-1 and A-2 are different phases of the cardiac cycle, showing different size and number of thrombus chunks. These findings confirmed the clinical suspicion of acute massive pulmonary embolus with ‘thromboemboli in transit’. CT pulmonary angiography (axial image) revealed well-defined non-enhancing isodense thromboemboli within the lumen of the RA (top-left [brown] arrow, Panel B), left pulmonary artery (right [red] arrow, Panel B) and at the bifurcation of the main pulmonary trunk with extension into the segmental branch of the right pulmonary artery (bottom [white] arrow; Panel B). Coronal reformatted CT images demonstrated thromboemboli within the right atria (left [yellow] arrow, Panel C-1 and C-2), main pulmonary trunk (right [white] arrow, Panel C-1 and C-2) and its segmental lower lobe branch (bottom-left [brown] arrow, Panel C-2). The patient underwent intravenous thrombolysis with bolus reteplase with excellent recovery and was discharged on oral rivaroxaban.
Free-floating right heart thromboemboli are uncommon and usually represent clots travelling from the legs to the pulmonary arteries, often referred to as ‘thrombi or emboli-in-transit’. They are seen in 4–18% of patients presenting with acute massive pulmonary embolism.1–3 Echocardiography detects and assesses the morphology of the right heart thromboemboli, which are divided into two morphological types: A and B. Type A have a worm-like shape, are extremely mobile and mostly represent peripheral venous clots which temporarily lodge into the right heart. Type B thrombi are morphologically similar to the left heart thrombi, are less mobile, and attach to the right atrial or ventricular wall with a broad-base indicating development within the right heart. The presence of right heart thromboemboli in pulmonary embolism predicts a worse prognosis with a higher mortality rate.4,5 This underscores the importance of a rapid diagnosis and prompt treatment. Treatment includes thrombolysis (intravenous or catheter directed) and surgical removal. Percutaneous removal using a pigtail catheter with simultaneous direct thrombolysis appears promising.
‘Images in vascular medicine’ is a regular feature of Vascular Medicine. Readers may submit original, unpublished images related to clinical vascular medicine. Submissions may be sent to: Heather Gornik, Editor in Chief, Vascular Medicine, via the web-based submission system at http://mc.manuscriptcentral.com/vascular-medicine
Footnotes
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
