Discussion

The incidence of thrombotic complications among patients with COVID-19 is high. In a study of 184 ICU patients with COVID-19 pneumonia, 31% had thrombotic events despite prophylactic dose anticoagulation with pulmonary embolism (PE) being the most frequent (81% of thrombotic events).11Klok FA, Kruip MJHA, van der Meer NJM, et al. Incidence of thrombotic complications in critically ill ICU patients with COVID-19. Thrombosis Research . 2020. https://doi.org/10.1016/j.thromres.2020.04.013 Patients with COVID-19 pneumonia have been found to have PE in the absence of predisposing risk factors.22Danzi GB, Loffi M, Galeazzi G, at al. Acute pulmonary embolism and COVID-19 pneumonia: a random association? Eur Heart J . 2020; https://doi.org/10.1093/eurheartj/ehaa254,33Xie Y, Wang X, Yang P, Zhang S. COVID-19 complicated by acute pulmonary embolism. Radiology: Cardiothoracic Imaging. 2020; 2(2):e200067. We described a case of a previously healthy, young individual critically ill patient with COVID-19 ARDS who developed a large CIT and suffered cardiopulmonary arrest likely because of a massive PE.
Right ventricular thrombi, or clots in transit (CIT), are uncommon and occurring in ~4% of unselected patients with PE but are associated with a considerable 27-45% mortality rate.44Lai E, Alishetti S, Wong JM, et al. Right ventricular thrombus in transit: Raising the stakes in the management of pulmonary embolism.CASE: Cardiovascular Imaging Case Reports . 2019;3(6):272-276.,55Rose PS, Pubjabi NM, Pearse DB. Treatment of right heart thromboemboli.Chest . 2002;121(3):806-814.,66Konstantinides SV, Myer G, Becattini C, et al. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS): The Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC). Eur Heart J . 2020;41(4):543-603. Optimal therapy for CIT is not defined as most data are based on case-series or registry results. However, meta-analysis data suggest superior results with thrombolytic therapy in these patients to alternative treatment modalities.5,77Ferrari E, Benhamou M, Berthier F, et al. Mobile thrombi of the right heart in pulmonary embolism: delayed disappearance after thrombolytic treatment. Chest . 2005;127(3):1051-1053. As our patient was in cardiopulmonary arrest likely because of massive PE, tPA was the indicated therapy.
TEE has been used as a modality to evaluate patients during resuscitation; imaging can effectively diagnose the cause of arrest, alter therapy, and guide chest compressions.88Teran F, Dean AJ, Centeno C, Panebianco NL, Zeidan AJ, Chan W, Abella BS. Evaluation of out-of-hospital cardiac arrest using tranesophageal echocardiography in the emergency department. Resuscitation . 2019;137:140-147.,99Parker BK, Salerno A, Euerle BD. The Use of Transesophageal Echocardiography During Cardiac Arrests Resuscitation: A Literature Review. J Ultrasound Med.2019;38:1141-1151. In a study of 33 patients with out-of-hospital cardiac arrest presenting to the emergency department, 12% of those presumed to be in asystole were found to have fine ventricular fibrillation by TEE. Importantly, the AMC was identified to be over the aortic root or LVOT in 53% of cases.8 TEE imaging has demonstrated the left ventricular stroke volume was correlated with the location of the AMC. LV stroke volume improves when AMC is over the LV and away from the LVOT and the aorta.1010Hwang SO, Zhao PG, Choi HJ, Park KH, Cha KC, Park SM, et al. Compression of the Left Ventricular Outflow Tract During Cardiopulmonary Resuscitation.Acad Emerg Med . 2009;16:928-933. In our case, the AMC of the mechanical CPR device was initially noted on TEE to be malpositioned over the LVOT. Under TEE guidance it was repositioned over the LV to improve chest compressions.