Carbon monoxide (CO) is one of the leading causes of poisoning; it inhibits oxygen delivery, subsequently causing ischemic changes and ultimately death by multiorgan failure. Furthermore, thromboembolic episodes due to CO poisoning have been reported. However, intracardiac thrombus formation following exposure to CO has been very rarely described. Here, a case of right atrial large thrombus formation after CO poisoning is presented. A previously healthy 24-year-old woman was referred for CO poisoning. She has attempted suicide, and her initial mental status was drowsy with focal memory loss. Her initial CO fraction was 16%, and initial laboratory data showed creatinine kinase-myocardial bound of 90.6 ng/mL (upper limit 5 ng/mL) and troponin I of 1.899 ng/mL (upper limit 1.5 ng/mL). A transthoracic echocardiography was performed 24 h after the accident, revealing a 30 15 mm nodular echogenic mass in the right atrium. Anticoagulation with low-molecular-weight heparin was started along with hyperbaric oxygen therapy. After 7 days of heparinization, the large thrombus in right atrium had resolved. This report describes an intracardiac thrombus formation induced by CO poisoning. Because intracardiac thrombus can result in pulmonary embolism and cerebral embolic infarction, its consideration following CO poisoning is important.

Ryoo, Sohn, Kim, Kwak, Oh, Lim, , , (2013). Intracardiac thrombus formation induced by carbon monoxide poisoning. Human & experimental toxicology, 2013 Nov;32(11):1193-6. https://www.ncbi.nlm.nih.gov/pubmed/23357963