INTRACARDIAC THROMBUS IN TRANSIT AND RISK OF PARADOXICAL EMBOLISM

Abstract

SESSION TITLE: Medical Student/Resident Pulmonary Vascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: A thrombus in transit is a rare complication that occurs when a deep venous thrombus migrates from the right to the left side of the heart through an interatrial defect. An intracardiac thrombus in transit poses the risk of paradoxical embolism, cardioembolic stroke and high mortality. We present a case of a patient found to have a large intracardiac thrombus in transit managed with systemic anticoagulation and surgical embolectomy with a good outcome. CASE PRESENTATION: A 30-year-old male presented with one week of chest pain, dyspnea on exertion and chills. His vitals were HR 108 bpm, BP 136/87, T 36.4 C, RR 27, saturating 97% on 3 liters nasal canula. A loud S2 on cardiac auscultation was heard but the rest of his physical exam was unremarkable. EKG showed sinus tachycardia with T wave inversions in V2 to V4. Chest X-ray demonstrated normal cardiac silhouette and was unremarkable for pulmonary pathology. CT pulmonary angiography showed a linear saddle embolus extending across the branch point of the right and left main pulmonary arteries (PA) with filling defects of the right PA to the upper, middle, and lower lobe branches and the left PA to the proximal left upper lobe and left lower lobe branches. The RV/LV diameter ratio was >0.9 suggestive of RV strain and the main PA was dilated. Echocardiogram showed a large thrombus in the RA that extended through either a PFO or a secundum ASD into the LA. The RV was dilated with systolic flattening of the interventricular septum with an estimated RVSP of 52 mm Hg. He was started on intravenous heparin and cardiothoracic surgery was consulted for submassive PE with coexisting thrombus-in-transit. The patient underwent a pulmonary embolectomy with successful removal of the intracardiac thrombus and repair of the ASD. He was discharged home without complications on warfarin. DISCUSSION: A thrombus in transit complicating an acute PE is a medical emergency with in-hospital mortality estimates as high as 45%. Further, a thrombus in transit can lead to paradoxical embolism and cardioembolic stroke leading to poor neurologic outcomes. Optimal management remains controversial, although surgical embolectomy has been favored as it reduces mortality compared with thrombolysis or anticoagulation. Echocardiography remains the gold standard for the diagnosis of a thrombus in transit, although there have also been cases identified by CT as well. The differential diagnosis for an intracardiac thrombus also includes the Chiari network and the Eustachian valve, normal anatomic variants found in the RA that appear as highly mobile snake-like structures. CONCLUSIONS: This case underscores the importance of echocardiography in the early diagnosis of thrombus in transit, which when identified, can be removed before paradoxical embolism and subsequent cardioembolic stroke occurs. Reference #1: Alajaji, W., Macswords, J., Eapen, S., Espinal, E., & Pietrolungo, J. (2019). A Thrombus in Transit Complicating Acute Pulmonary Embolism. JACC: Case Reports, 1(4), 652–656. doi: 10.1016/j.jaccas.2019.09.022 Reference #2: Bernal, A. G., Fanola, C., & Bartos, J. (2020, January 27). Management of PE. Retrieved from https://www.acc.org/latest-in-cardiology/articles/2020/01/27/07/42/management-of-pe Reference #3: Minguito-Carazo, C., Benito-González, T., Echarte-Morales, J. C., Castaño-Ruiz, M., & Fernández-Vázquez, F. (2019). Thrombus in transit through a patent foramen ovale: An unusual cause of cardiac embolism. Journal of the Saudi Heart Association. doi:10.1016/j.jsha.2019.12.001 DISCLOSURES: No relevant relationships by Kristen Burton, source=Web Response No relevant relationships by Alexander Gong, source=Web Response