Platypnea-Orthodeoxia Syndrome Due to Atrial Septal Defect with Congenital Variation in the Position of the Atrial Septum and Combined Thoracic Deformities in a Young Man

Platypnea-Orthodeoxia Syndrome Due to Atrial Septal Defect with Congenital Variation in the Position of the Atrial Septum and Combined Thoracic Deformities in a Young Man | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Platypnea-Orthodeoxia Syndrome Due to Atrial Septal Defect with Congenital Variation in the Position of the Atrial Septum and Combined Thoracic Deformities in a Young Man Lixing Hu, Xincao Tao, Xiaoming Zhou, Jingjin Wang, Xiangnan Li, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3893279/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Platypnea-orthodeoxia syndrome (POS) is a rare and complicated clinical entity with low recognition rate. The mechanisms of POS are broadly divided into intracardiac and intrapulmonary, while the detailed pathogenesis is less understood. Here we reported a POS case with atrial septal defect with congenital horizontal position of the atrial septum and combined thoracic deformities in a young man with normal right atrial pressure. This case was useful for understanding the detailed pathogenesis of POS. Platynea-orthodeoxia syndrome Atrial septal defect Thoracic deformities Intracardia shunt Figures Figure 1 Figure 2 Background Platypnea-orthodeoxia syndrome (POS) is a rare clinical entity that causes dyspnea and arterial desaturation in the upright or sitting position, and their pathogenesis is very complicated. The phenomenon was first reported in 1949 by Burchell et al. in a patient with post-traumatic intrathoracic arteriovenous shunt [ 1 ] . The terms ‘platypnea’ and ‘orthodeoxia’ were proposed by Altman et al. and Robin et al in 1969 and 1978 respectively [ 2 , 3 ] . This syndrome is commonly underdiagnosed in clinical practice. We herein report a case diagnosed with Agitated saline contrast echocardiography (ASCE) and Computed tomography, which was useful for understanding the detailed pathogenesis of POS. Case Presentation We presented a case of a 41-year-old man admitted to our hospital for further evaluation of postural dyspnea and desaturation. His height was 140cm and his weight was 59kg. He presented with pulse oxygen saturation (SpO2) of 90% in the supine and 83% in the upright position. Accordingly, Platypnea-Orthodeoxia Syndrome (POS) was suspected. He had congenital achondroplasia complicated by bow legs and pectus excavatum. The electrocardiogram showed sinus rhythm with no signs of ischemia, rhythm disorders, or conduction disorders, except for clockwise rotation. Additionally, pulmonary function tests and pulmonary perfusion imaging yielded nearly normal results. Agitated saline contrast echocardiography (ASCE) was performed via the median vein of the left elbow before the operation and via the right lower extremity vein during the operation, more than 100 microvesicle echoes were seen in the left heart during one cardiac cycle (Fig. 1 A). Transthoracic echocardiography implicated a 12mm atrial septal defect (ASD) (Fig. 1 B) with no tricuspid regurgitation. Computed tomography of the pulmonary artery (CTPA) ruled out lung parenchymal disease, obvious pulmonary embolism, and pulmonary arteriovenous malformation. However, it did reveal overly cardiac dislocation to the left thorax which led to right heart compression by the rib, sternum, and spine (Fig. 2 A). Additionally, Sagittal reconstruction of CTPA showed a depressed sternum (pectus excavatum) and straight dorsal spine (Fig. 2 B), which may also contribute partially to right heart compression. The left atrium and right atrium were arranged up and down with the atrial septum in the horizontal position (Fig. 2 C), as confirmed by the orientation of the occluder (Fig. 2 D). These factors might lead the blood flowing from the superior vena cava (SVC) and inferior vena cava (IVC) via ASD to the left atrium (Fig. 2 E-F). Right heart catheterization ruled out pulmonary hypertension. The right atrial pressure (RAP) was 4mmHg, mean pulmonary artery pressure was 10 mmHg, and the pulmonary vascular resistance was 96.4 dyn.s.cm − 5 . In addition, the ratio of pulmonary (Qp, 4.15 L/min) over systemic (Qs, 5.46 L/min) outflows was 0.76 (< 1), indicating a right-to-left shunt as the cause of the hypoxemia. A 28-mm Occluder (Shanghai Shape Memory Alloy Co., Ltd, China) was successfully implanted percutaneously through the right femoral venous route, resulting in SpO 2 improved to 96% in the supine position. The PO2 levels before and after the operation in the upright position were 57 mmHg and 79.3 mmHg respectively. Pulmonary artery pressure was 15/7(11) mmHg before closure, and 15/7(10) mmHg after closure. The follow-up ultrasound showed no residual shunt, pericardial effusion, or postprocedure complications. The patient was discharged from the hospital the next day. Discussion and conclusions Platypnea-Orthodeoxia syndrome (POS) is characterized by dyspnea and arterial desaturation when a patient changes from a supine to an upright position. Since the first POS reported, more than 200 cases have been described. Both intracardiac and intrapulmonary mechanisms are involved in the pathophysiology of POS, and the intracardiac mechanism is involved in more than 80% cases. As to intracardia shunts some patients have elevated RAP, while others with normal RAP have isolated or coexisted aortic, spinal, or other intracardiac changes [ 4 ] . In this case, the ASCE revealed that part of the venous blood from SVC and IVC flowed via ASD to the left atrium. The RAP was normal, and it was accompanied by the horizontal position of the atrial septum and combined thoracic deformities, which could contribute to the symptom. Surgical and percutaneous occlusion of the primary defect are currently considered the definitive treatments to deal with intracardiac shunts. Percutaneous occlusion is preferred due to its faster post-procedural recovery and lower cost, with symptoms relieved in 95% of cases [ 4 ] . In our case, the trans-catheter technique was performed, and the occluder was successfully anchored to the atrial septum with subsequent improvement in SpO2 and no complications. A high level of suspicion for POS is essential in patients presenting with dyspnea, given its subtle and positional nature. POS mechanisms involve cardiac or non-cardiac shunts. ASCE is a simple and practical method in the diagnosis of POS. Appropriate interventions are aimed at correcting the cause and could be potentially curative. Abbreviations POS Platypnea-orthodeoxia syndrome ASCE Agitated saline contrast echocardiography SpO2 Pulse oxygen saturation ASD Atrial septal defect CTPA Computed tomography of the pulmonary artery SVC Superior vena cava IVC Inferior vena cava RAP Right atrial pressure Declarations Ethics approval and consent to participate This study was approved by the Ethics Committee of Fuwai Hospital and based on the declaration of Helsinki. Informed consent was obtained from the patient for both study participation AND publication of identifying information/images in an online open-access publication (when applicable). Consent for publication Not applicable. Availability of data and materials The datasets used and/or analysed during the current case are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding No Funding Author’s contributions Lixing Hu, Xincao Tao and Xiaoming Zhou collected the clinical data. Lixing Hu analyzed and wrote the case. Jingjin Wang provided the ultrasound data. Xiangnan Li provided the computed tomography data. Haibo Hu was the surgeon of atrial septal defect occlusion. Changming Xiong was a major contributor in writing and reviewing the manuscript. All authors read and approved the final manuscript. Acknowledgements We thank Editideas (www.editideas.cn) for its linguistic assistance during the preparation of this manuscript. References Burchell HBHHJ, Wood EH. Reflex orthostatic dyspnea associated with pulmonary hypertension [J]. Am J Physiol, 1949, 159): 563–4.DOI:. Altman MRE. Platypnea (diffuse zone I phenomenon?) [J]. N Engl J Med. 1969;281:1347–8. Robin ELD, Horn D, Theodore J. platypnea related to orthodeoxia caused by true vascular lung shunts [J]. N Engl J Med, 1976, 294): 941–3.DOI:. Salas-Pacheco JL. [Mechanisms of platypnea-orthodeoxia syndrome] [J]. Arch Cardiol Mex. 2022;92(2):274–82. 10.24875/acm.21000171 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3893279","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":270224144,"identity":"cd538857-72a0-4806-8bfd-4b29f727a27f","order_by":0,"name":"Lixing Hu","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Lixing","middleName":"","lastName":"Hu","suffix":""},{"id":270224145,"identity":"865979cc-5f7d-4e6a-80d7-fb9166190756","order_by":1,"name":"Xincao Tao","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Xincao","middleName":"","lastName":"Tao","suffix":""},{"id":270224146,"identity":"aeb446d5-26d8-46aa-91bd-329d4b661bd3","order_by":2,"name":"Xiaoming Zhou","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Xiaoming","middleName":"","lastName":"Zhou","suffix":""},{"id":270224147,"identity":"febb2fd0-6e6e-4072-892c-7b598d8f501c","order_by":3,"name":"Jingjin Wang","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences, Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Jingjin","middleName":"","lastName":"Wang","suffix":""},{"id":270224148,"identity":"1f36f170-6dad-4828-b56a-2882fc29c160","order_by":4,"name":"Xiangnan Li","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Xiangnan","middleName":"","lastName":"Li","suffix":""},{"id":270224149,"identity":"3ddf53f5-009d-4d98-aa63-cd0589d63318","order_by":5,"name":"Changming Xiong","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYDACZgjFz8De2PjwAylaJBt4DjcbS5BimWSDRHqbAA8xSg2OMx97+KVmm4TBzYdtDBIMdnK6DYRMb2ZLN5Y5dlvC4HZi24MChmRjswMEtPAz85hJSzbcrjO7ndhuIMFwIHEbIS1sUC0SZjcPtknwEKMFZIvkR5CWG4xEagH6JU2aAegX+zOJwEA2IMIvBucPH5P8UXNbQrL9+MOHHyrs5AhqAQFmRHQYEKEcBBh/EKlwFIyCUTAKRigAACBrP4Fyn6uVAAAAAElFTkSuQmCC","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":true,"prefix":"","firstName":"Changming","middleName":"","lastName":"Xiong","suffix":""},{"id":270224150,"identity":"18722aa1-1d5e-40b6-bafa-7b2b8abcd96d","order_by":6,"name":"Haibo Hu","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences, Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Haibo","middleName":"","lastName":"Hu","suffix":""}],"badges":[],"createdAt":"2024-01-24 07:22:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3893279/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3893279/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":50565359,"identity":"c4f68f1a-a090-4fdd-ada6-c976867cea66","added_by":"auto","created_at":"2024-02-02 15:08:30","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":46589,"visible":true,"origin":"","legend":"\u003cp\u003eTransthoracic echocardiography. Agitated saline contrast echocardiography showing microvesicle echoes in the left heart during one cardiac cycle (A); 2D with colour Doppler showing ASD (right arrow) (B).\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3893279/v1/3be799fb738781b5d72b8b24.jpg"},{"id":50565360,"identity":"284c2e93-b7e7-4f50-944d-2347e1d5f12b","added_by":"auto","created_at":"2024-02-02 15:08:30","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":573288,"visible":true,"origin":"","legend":"\u003cp\u003eComputed tomography of the pulmonary artery (CTPA) showing overly cardiac dislocation to the left thorax (A). CTPA, sagittal view, showing the depressed sternum and straight dorsal spine (blue arrows) (B). CTPA showing left and right atrium arranged up and down (C). Chest radiography after occlusion, anterior-posterior projection, showing the orientation of the occluder which indicated the spatial relationship of right and left atrium (D). CTPA showing the venous return from SVC and IVC flowed partially to the left atrium through ASD (E-F).\u003c/p\u003e","description":"","filename":"Figure246.png","url":"https://assets-eu.researchsquare.com/files/rs-3893279/v1/5e15d35d605ff971fbb4ac33.png"},{"id":58653941,"identity":"237aacd2-3025-4939-9994-f5b8fca13370","added_by":"auto","created_at":"2024-06-19 10:59:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1125660,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3893279/v1/d14e9a3f-6a69-4108-9825-29ea191bed9e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Platypnea-Orthodeoxia Syndrome Due to Atrial Septal Defect with Congenital Variation in the Position of the Atrial Septum and Combined Thoracic Deformities in a Young Man","fulltext":[{"header":"Background","content":"\u003cp\u003ePlatypnea-orthodeoxia syndrome (POS) is a rare clinical entity that causes dyspnea and arterial desaturation in the upright or sitting position, and their pathogenesis is very complicated. The phenomenon was first reported in 1949 by Burchell et al. in a patient with post-traumatic intrathoracic arteriovenous shunt\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. The terms \u0026lsquo;platypnea\u0026rsquo; and \u0026lsquo;orthodeoxia\u0026rsquo; were proposed by Altman et al. and Robin et al in 1969 and 1978 respectively\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. This syndrome is commonly underdiagnosed in clinical practice. We herein report a case diagnosed with Agitated saline contrast echocardiography (ASCE) and Computed tomography, which was useful for understanding the detailed pathogenesis of POS.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eWe presented a case of a 41-year-old man admitted to our hospital for further evaluation of postural dyspnea and desaturation. His height was 140cm and his weight was 59kg. He presented with pulse oxygen saturation (SpO2) of 90% in the supine and 83% in the upright position. Accordingly, Platypnea-Orthodeoxia Syndrome (POS) was suspected. He had congenital achondroplasia complicated by bow legs and pectus excavatum. The electrocardiogram showed sinus rhythm with no signs of ischemia, rhythm disorders, or conduction disorders, except for clockwise rotation. Additionally, pulmonary function tests and pulmonary perfusion imaging yielded nearly normal results.\u003c/p\u003e \u003cp\u003eAgitated saline contrast echocardiography (ASCE) was performed via the median vein of the left elbow before the operation and via the right lower extremity vein during the operation, more than 100 microvesicle echoes were seen in the left heart during one cardiac cycle (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). Transthoracic echocardiography implicated a 12mm atrial septal defect (ASD) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB) with no tricuspid regurgitation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eComputed tomography of the pulmonary artery (CTPA) ruled out lung parenchymal disease, obvious pulmonary embolism, and pulmonary arteriovenous malformation. However, it did reveal overly cardiac dislocation to the left thorax which led to right heart compression by the rib, sternum, and spine (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA). Additionally, Sagittal reconstruction of CTPA showed a depressed sternum (pectus excavatum) and straight dorsal spine (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB), which may also contribute partially to right heart compression. The left atrium and right atrium were arranged up and down with the atrial septum in the horizontal position (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC), as confirmed by the orientation of the occluder (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eD). These factors might lead the blood flowing from the superior vena cava (SVC) and inferior vena cava (IVC) via ASD to the left atrium (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE-F).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRight heart catheterization ruled out pulmonary hypertension. The right atrial pressure (RAP) was 4mmHg, mean pulmonary artery pressure was 10 mmHg, and the pulmonary vascular resistance was 96.4 dyn.s.cm\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e. In addition, the ratio of pulmonary (Qp, 4.15 L/min) over systemic (Qs, 5.46 L/min) outflows was 0.76 (\u0026lt;\u0026thinsp;1), indicating a right-to-left shunt as the cause of the hypoxemia.\u003c/p\u003e \u003cp\u003eA 28-mm Occluder (Shanghai Shape Memory Alloy Co., Ltd, China) was successfully implanted percutaneously through the right femoral venous route, resulting in SpO\u003csub\u003e2\u003c/sub\u003e improved to 96% in the supine position. The PO2 levels before and after the operation in the upright position were 57 mmHg and 79.3 mmHg respectively. Pulmonary artery pressure was 15/7(11) mmHg before closure, and 15/7(10) mmHg after closure. The follow-up ultrasound showed no residual shunt, pericardial effusion, or postprocedure complications. The patient was discharged from the hospital the next day.\u003c/p\u003e"},{"header":"Discussion and conclusions","content":"\u003cp\u003ePlatypnea-Orthodeoxia syndrome (POS) is characterized by dyspnea and arterial desaturation when a patient changes from a supine to an upright position. Since the first POS reported, more than 200 cases have been described. Both intracardiac and intrapulmonary mechanisms are involved in the pathophysiology of POS, and the intracardiac mechanism is involved in more than 80% cases. As to intracardia shunts some patients have elevated RAP, while others with normal RAP have isolated or coexisted aortic, spinal, or other intracardiac changes\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn this case, the ASCE revealed that part of the venous blood from SVC and IVC flowed via ASD to the left atrium. The RAP was normal, and it was accompanied by the horizontal position of the atrial septum and combined thoracic deformities, which could contribute to the symptom.\u003c/p\u003e \u003cp\u003eSurgical and percutaneous occlusion of the primary defect are currently considered the definitive treatments to deal with intracardiac shunts. Percutaneous occlusion is preferred due to its faster post-procedural recovery and lower cost, with symptoms relieved in 95% of cases\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. In our case, the trans-catheter technique was performed, and the occluder was successfully anchored to the atrial septum with subsequent improvement in SpO2 and no complications.\u003c/p\u003e \u003cp\u003eA high level of suspicion for POS is essential in patients presenting with dyspnea, given its subtle and positional nature. POS mechanisms involve cardiac or non-cardiac shunts. ASCE is a simple and practical method in the diagnosis of POS. Appropriate interventions are aimed at correcting the cause and could be potentially curative.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePOS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePlatypnea-orthodeoxia syndrome\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eASCE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAgitated saline contrast echocardiography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSpO2\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePulse oxygen saturation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eASD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAtrial septal defect\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCTPA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed tomography of the pulmonary artery\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSVC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSuperior vena cava\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIVC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInferior vena cava\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eRAP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRight atrial pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee of Fuwai Hospital and based on the declaration of Helsinki. Informed consent was obtained from the patient for both study participation AND publication of identifying information/images in an online open-access publication (when applicable).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current case are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo Funding\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor\u0026rsquo;s contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLixing Hu, Xincao Tao and Xiaoming Zhou collected the clinical data. Lixing Hu analyzed and wrote the case. Jingjin Wang provided the ultrasound data. Xiangnan Li provided the computed tomography data. Haibo Hu was the surgeon of atrial septal defect occlusion. Changming Xiong was a major contributor in writing and reviewing the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Editideas (www.editideas.cn) for its linguistic assistance during the preparation of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBurchell HBHHJ, Wood EH. Reflex orthostatic dyspnea associated with pulmonary hypertension [J]. Am J Physiol, 1949, 159): 563\u0026ndash;4.DOI:.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAltman MRE. Platypnea (diffuse zone I phenomenon?) [J]. N Engl J Med. 1969;281:1347\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRobin ELD, Horn D, Theodore J. platypnea related to orthodeoxia caused by true vascular lung shunts [J]. N Engl J Med, 1976, 294): 941\u0026ndash;3.DOI:.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSalas-Pacheco JL. [Mechanisms of platypnea-orthodeoxia syndrome] [J]. Arch Cardiol Mex. 2022;92(2):274\u0026ndash;82. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.24875/acm.21000171\u003c/span\u003e\u003cspan address=\"10.24875/acm.21000171\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Platynea-orthodeoxia syndrome, Atrial septal defect, Thoracic deformities, Intracardia shunt","lastPublishedDoi":"10.21203/rs.3.rs-3893279/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3893279/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePlatypnea-orthodeoxia syndrome (POS) is a rare and complicated clinical entity with low recognition rate. The mechanisms of POS are broadly divided into intracardiac and intrapulmonary, while the detailed pathogenesis is less understood. Here we reported a POS case with atrial septal defect with congenital horizontal position of the atrial septum and combined thoracic deformities in a young man with normal right atrial pressure. This case was useful for understanding the detailed pathogenesis of POS.\u003c/p\u003e","manuscriptTitle":"Platypnea-Orthodeoxia Syndrome Due to Atrial Septal Defect with Congenital Variation in the Position of the Atrial Septum and Combined Thoracic Deformities in a Young Man","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-02 15:08:25","doi":"10.21203/rs.3.rs-3893279/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"46299868-47f5-4bea-a244-a163185d63bc","owner":[],"postedDate":"February 2nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-06-19T10:51:10+00:00","versionOfRecord":[],"versionCreatedAt":"2024-02-02 15:08:25","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3893279","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3893279","identity":"rs-3893279","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}