Hamid Khizar, Perinkulam Sathyanarayanan Swaminathan, Hoerschgen Kayla, Ali Mohammad, Yu John C
Internal Medicine, University of South Dakota Sanford School of Medicine, Sioux Falls, USA.
Pathology, University of South Dakota Sanford School of Medicine, Sioux Falls, USA.
Cureus. 2022 Jul 11;14(7):e26754. doi: 10.7759/cureus.26754. eCollection 2022 Jul.
Platypnea-orthodeoxia syndrome (POS) is defined by dyspnea and deoxygenation due to a change in body position from lying down to an upright position. We present a case of a large right atrial (RA) thrombus likely due to a right coronary artery fistula in a patient with a patent foramen ovale (PFO). On imaging, the thrombus was thought to be an atrial myxoma involving the tricuspid valve; however, after surgical excision and histopathological analysis, it was noted to be a cystic thrombus. Red-brown material along with vascular elements was noted on histopathology. Post-surgery, the patient was critically ill and died due to severe tricuspid regurgitation (TR) and hypotension despite using a right ventricle assist device and multiple vasopressors. Reverse Lutembacher syndrome (RLS) is defined as a triad of tricuspid stenosis (TS), elevated RA pressure, and right-to-left atrial shunting. The location of the mass and positional changes could be causing transient RLS from positional TS and interatrial shunting via the PFO causing POS. Cardiac magnetic resonance imaging can help differentiate between intracardiac masses. T1 and T2 signal characteristics and differences in contrast enhancement can help differentiate between a thrombus and a tumor. Treatment options include anticoagulation, thrombolysis, and thrombectomy. If severe TR occurs after surgery, treatment modalities such as caval valves could be an option in the future. Extracorporeal membrane oxygenation to provide right ventricle support in such cases could be considered.
平卧呼吸困难-直立性低氧血症综合征（POS）的定义是，因身体姿势从卧位变为直立位而出现呼吸困难和脱氧。我们报告一例患有卵圆孔未闭（PFO）的患者，其右心房（RA）内有一个可能由右冠状动脉瘘导致的巨大血栓。在影像学检查中，该血栓被认为是累及三尖瓣的心房黏液瘤；然而，经过手术切除和组织病理学分析，发现它是一个囊性血栓。组织病理学检查发现有红棕色物质以及血管成分。术后，尽管使用了右心室辅助装置和多种血管升压药，但患者病情危重，最终因严重的三尖瓣反流（TR）和低血压死亡。反向鲁登巴赫综合征（RLS）的定义为三尖瓣狭窄（TS）、升高的右心房压力和右向左心房分流三联征。肿块的位置和体位变化可能通过体位性TS和经PFO的心房分流导致短暂性RLS，进而引起POS。心脏磁共振成像有助于鉴别心内肿块。T1和T2信号特征以及对比增强的差异有助于区分血栓和肿瘤。治疗选择包括抗凝、溶栓和血栓切除术。如果术后发生严重TR，未来诸如腔静脉瓣膜等治疗方式可能是一种选择。在这种情况下，可以考虑采用体外膜肺氧合来提供右心室支持。
