{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T09:34:28Z","timestamp":1771234468580,"version":"3.50.1"},"reference-count":53,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,2,14]],"date-time":"2026-02-14T00:00:00Z","timestamp":1771027200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003243","name":"Ministry of Health, Czech Republic","doi-asserted-by":"publisher","award":["RVO (NNH, 00023884) IG250501"],"award-info":[{"award-number":["RVO (NNH, 00023884) IG250501"]}],"id":[{"id":"10.13039\/501100003243","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Exercise-induced desaturation is an uncommon but clinically significant manifestation of patent foramen ovale, which is present in approximately one-quarter of the general population. Although patent foramen ovale is usually asymptomatic, exertion may provoke transient right-to-left shunting when dynamic changes in venous return and intrathoracic pressure favour intermittent right-to-left transit across the interatrial septum. This narrative review synthesises current evidence on exertion-provoked shunting and its contribution to otherwise unexplained dyspnoea and hypoxaemia. To illustrate these concepts, we present an illustrative case with marked exercise-induced desaturation in the absence of pulmonary disease. The evaluation combined contrast transthoracic and transoesophageal echocardiography with cardiopulmonary exercise testing, and the shunt magnitude was quantified invasively using catheter-based thermodilution at rest and during Valsalva provocation. Six months after percutaneous closure, repeat cardiopulmonary exercise testing showed complete resolution of exercise-induced desaturation without a statistically significant change in exercise tolerance (work performed). Notably, normalisation of oxygen saturation during exercise may occur without a measurable increase in maximal exercise capacity. Overall, patent foramen ovale-mediated right-to-left shunting is an under-recognised yet potentially reversible cause of exertional hypoxaemia; diagnosis typically requires deliberate physiological provocation and integrated imaging, and closure can be considered in carefully selected individuals.<\/jats:p>","DOI":"10.3390\/jcm15041523","type":"journal-article","created":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T08:38:39Z","timestamp":1771231119000},"page":"1523","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Exercise-Induced Desaturation in Patent Foramen Ovale: Mechanisms, Diagnostic Approach, and Resolution After Closure\u2014A Narrative Review with an Illustrative Case"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-4694-2389","authenticated-orcid":false,"given":"Martina","family":"Podolec","sequence":"first","affiliation":[{"name":"Department of Cardiology, 1st Medical Faculty of Charles University and Na Homolce Hospital, Roentgenova 37\/2, 150 30 Prague, Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5389-5555","authenticated-orcid":false,"given":"Ji\u0159\u00ed","family":"Dost\u00e1l","sequence":"additional","affiliation":[{"name":"1st Department of Internal Medicine\u2014Cardioangiology, Faculty of Medicine in Hradec Kr\u00e1lov\u00e9, Charles University, \u0160imkova 870, 500 03 Hradec Kr\u00e1lov\u00e9, Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Petr","family":"Volf","sequence":"additional","affiliation":[{"name":"Department of Cardiology, 1st Medical Faculty of Charles University and Na Homolce Hospital, Roentgenova 37\/2, 150 30 Prague, Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aneta","family":"Dvo\u0159\u00e1kov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Cardiology, 1st Medical Faculty of Charles University and Na Homolce Hospital, Roentgenova 37\/2, 150 30 Prague, Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Mates","sequence":"additional","affiliation":[{"name":"Department of Cardiology, 1st Medical Faculty of Charles University and Na Homolce Hospital, Roentgenova 37\/2, 150 30 Prague, Czech Republic"},{"name":"Department of Internal Medicine, 2nd Medical Faculty of Charles University, V \u00davalu 84, 150 06 Prague, Czech Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"34","DOI":"10.15420\/icr.2018.33.2","article-title":"Patent Foramen Ovale Closure in 2019","volume":"14","author":"Giblett","year":"2019","journal-title":"Interv. Cardiol."},{"key":"ref_2","first-page":"224","article-title":"Desaturaci\u00f3n provocada por el ejercicio asociada a foramen, \u00bfinfrecuente o infradiagnosticada?","volume":"5","year":"2023","journal-title":"REC Interv. Cardiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"416","DOI":"10.1016\/j.jcin.2012.01.011","article-title":"Provoked Exercise Desaturation in Patent Foramen Ovale and Impact of Percutaneous Closure","volume":"5","author":"Devendra","year":"2012","journal-title":"JACC Cardiovasc. Interv."},{"key":"ref_4","first-page":"733","article-title":"Percutaneous Closure of a Patent Foramen Ovale Causing Exercise Hypoxemia: Case Report and a Review of the Literature","volume":"98","author":"Punzengruber","year":"2021","journal-title":"Catheter. Cardiovasc. Interv."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1354","DOI":"10.1152\/japplphysiol.01246.2010","article-title":"Effect of a Patent Foramen Ovale on Pulmonary Gas Exchange Efficiency at Rest and during Exercise","volume":"110","author":"Lovering","year":"2011","journal-title":"J. Appl. Physiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"137","DOI":"10.3949\/ccjm.74.2.137","article-title":"When and How to Fix a \u201cHole in the Heart\u201d: Approach to ASD and PFO","volume":"74","author":"Krasuski","year":"2007","journal-title":"Clevel. Clin. J. Med."},{"key":"ref_7","first-page":"271","article-title":"Platypnea-Orthodeoxia Syndrome in Interatrial Right to Left Shunt Postpneumonectomy","volume":"74","author":"Bellato","year":"2008","journal-title":"Minerva Anestesiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1258","DOI":"10.1016\/j.amjcard.2013.06.022","article-title":"Effectiveness of Percutaneous Closure of Patent Foramen Ovale for Hypoxemia","volume":"112","author":"Fenster","year":"2013","journal-title":"Am. J. Cardiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1635","DOI":"10.1111\/echo.15500","article-title":"Exertional Desaturations after COVID-19: A Case for PFO Closure","volume":"39","author":"Yogeswaran","year":"2022","journal-title":"Echocardiography"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e47","DOI":"10.1161\/circ.105.6.e47","article-title":"Mechanisms of Platypnea-Orthodeoxia: What Causes Water to Flow Uphill?","volume":"105","author":"Cheng","year":"2002","journal-title":"Circulation"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1016\/j.hrtlng.2007.09.006","article-title":"Hypoxemia-Orthodeoxia Related to Patent Foramen Ovale without Pulmonary Hypertension","volume":"37","author":"Toffart","year":"2008","journal-title":"Heart Lung"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1928","DOI":"10.1016\/j.jcin.2016.07.003","article-title":"Percutaneous Intervention to Treat Platypnea\u2013Orthodeoxia Syndrome","volume":"9","author":"Shah","year":"2016","journal-title":"JACC Cardiovasc. Interv."},{"key":"ref_13","first-page":"e011619","article-title":"Reversible Cause of Heart Failure?","volume":"17","year":"2024","journal-title":"Circ. Heart Fail."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e165","DOI":"10.1016\/j.jcin.2020.05.037","article-title":"Is Hypoxia in Standing Position Mandatory in Defining Platypnea-Orthodeoxia Syndrome?","volume":"13","author":"Shah","year":"2020","journal-title":"JACC Cardiovasc. Interv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1183\/09031936.00103509","article-title":"Unusual Treatment of Patent Foramen Ovale after Pneumonectomy","volume":"35","author":"Welvaart","year":"2010","journal-title":"Eur. Respir. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.ahj.2024.08.001","article-title":"The Pathophysiology of Patent Foramen Ovale and Its Related Complications","volume":"277","author":"Shah","year":"2024","journal-title":"Am. Heart J."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e012724","DOI":"10.1161\/CIRCHEARTFAILURE.124.012724","article-title":"Letter by Shah Regarding Article, \u201cReversible Cause of Heart Failure?\u201d","volume":"18","author":"Shah","year":"2025","journal-title":"Circ. Heart Fail."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Di Muro, F.M., Compagnone, M., Santoro, G., Boccuzzi, G.G., Ielasi, A., Viola, O., Martinucci, P., Della Valle, A., Nardi, G., and Crociani, M.F. (2025). Percutaneous Closure of Patent Foramen Ovale in Patients with Platypnea-Orthodeoxia Syndrome: An Italian Multicenter Experience. Minerva Cardiol. Angiol.","DOI":"10.23736\/S2724-5683.25.06841-3"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"ehaf784.3263","DOI":"10.1093\/eurheartj\/ehaf784.3263","article-title":"Percutaneous Closure of Patent Foramen Ovale in Refractory Hypoxemia and Platypnea-Orthodeoxia Syndrome","volume":"46","author":"Ndiaye","year":"2025","journal-title":"Eur. Heart J."},{"key":"ref_20","first-page":"701","article-title":"The Effect of Patent Foramen Ovale Closure in Patients with Platypnea-Orthodeoxia Syndrome","volume":"86","author":"Mojadidi","year":"2015","journal-title":"Catheter. Cardiovasc. Interv."},{"key":"ref_21","first-page":"1027","article-title":"Pressure Support Reduces Inspiratory Effort and Dyspnea during Exercise in Chronic Airflow Obstruction","volume":"151","author":"Maltais","year":"1995","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1050","DOI":"10.1136\/thorax.57.12.1050","article-title":"Ambulatory Pulmonary Artery Pressure Monitoring during Sleep and Exercise in Normal Individuals and Patients with COPD","volume":"57","author":"Raeside","year":"2002","journal-title":"Thorax"},{"key":"ref_23","first-page":"120","article-title":"Obstructive Sleep Apnea Diagnosis and Management","volume":"114","author":"Goyal","year":"2017","journal-title":"Mo. Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1006","DOI":"10.1093\/aje\/kws342","article-title":"Increased Prevalence of Sleep-Disordered Breathing in Adults","volume":"177","author":"Peppard","year":"2013","journal-title":"Am. J. Epidemiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1378\/chest.113.1.91","article-title":"Prevalence of Patent Foramen Ovale and Its Contribution to Hypoxemia in Patients with Obstructive Sleep Apnea","volume":"113","author":"Shanoudy","year":"1998","journal-title":"Chest"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1111\/j.1469-7793.2001.00269.x","article-title":"Effect of Hypoxia on the Hypopnoeic and Apnoeic Threshold for CO2 in Sleeping Humans","volume":"535","author":"Xie","year":"2001","journal-title":"J. Physiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1299","DOI":"10.5664\/jcsm.5190","article-title":"Sleep Apnea in Patients with and without a Right-to-Left Shunt","volume":"11","author":"Mojadidi","year":"2015","journal-title":"J. Clin. Sleep Med."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1378\/chest.12-0334","article-title":"Patent Foramen Ovale in Severe Obstructive Sleep Apnea: Clinical Features and Effects of Closure","volume":"143","author":"Shaikh","year":"2013","journal-title":"Chest"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"856","DOI":"10.1093\/sleep\/25.8.21","article-title":"Obstructive Sleep Apnea Can Be Provocative for Right-to-Left Shunting through a Patent Foramen Ovale","volume":"25","author":"Beelke","year":"2002","journal-title":"Sleep"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"880","DOI":"10.1136\/thx.2004.027508","article-title":"CPAP Suppression of Awake Right-to-Left Shunting through Patent Foramen Ovale in a Patient with Obstructive Sleep Apnoea","volume":"60","author":"Pinet","year":"2005","journal-title":"Thorax"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1050","DOI":"10.1161\/HYPERTENSIONAHA.115.06303","article-title":"Patent Foramen Ovale Closure in Obstructive Sleep Apnea Improves Blood Pressure and Cardiovascular Function","volume":"66","author":"Rimoldi","year":"2015","journal-title":"Hypertension"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/S0894-7317(99)70121-5","article-title":"Increased Prevalence of Patent Foramen Ovale in Patients with Severe Chronic Obstructive Pulmonary Disease","volume":"12","author":"Soliman","year":"1999","journal-title":"J. Am. Soc. Echocardiogr."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1164\/rccm.201309-1618OC","article-title":"Patent Foramen Ovale Is Not Associated with Hypoxemia in Severe Chronic Obstructive Pulmonary Disease and Does Not Impair Exercise Performance","volume":"189","author":"Shaikh","year":"2014","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_34","first-page":"547","article-title":"Patent Foramen Ovale Closure for Hypoxemia","volume":"6","author":"Tobis","year":"2017","journal-title":"Interv. Cardiol. Clin."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1016\/j.rmed.2005.08.015","article-title":"Prevalence and Clinical Significance of a Patent Foramen Ovale in Patients with Chronic Obstructive Pulmonary Disease","volume":"100","author":"Hacievliyagil","year":"2006","journal-title":"Respir. Med."},{"key":"ref_36","first-page":"185","article-title":"Significance of Patent Foramen Ovale in Patients with GOLD Stage II Chronic Obstructive Pulmonary Disease (COPD)","volume":"1","author":"Martolini","year":"2014","journal-title":"Chronic Obstr. Pulm. Dis."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1183\/09031936.04.00118303","article-title":"Relationship between Exercise Desaturation and Pulmonary Haemodynamics in COPD Patients","volume":"24","author":"Christensen","year":"2004","journal-title":"Eur. Respir. J."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.cardiores.2006.07.004","article-title":"High Altitude-Induced Pulmonary Oedema","volume":"72","author":"Maggiorini","year":"2006","journal-title":"Cardiovasc. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"569","DOI":"10.7326\/0003-4819-114-7-569","article-title":"Intracardiac Shunting across a Patent Foramen Ovale May Exacerbate Hypoxemia in High-Altitude Pulmonary Edema","volume":"114","author":"Levine","year":"1991","journal-title":"Ann. Intern. Med."},{"key":"ref_40","first-page":"871","article-title":"Interaction of PVO2 with PAO2 on Hypoxic Pulmonary Vasoconstriction","volume":"51","author":"Benumof","year":"1981","journal-title":"J. Appl. Physiol. Respir. Environ. Exerc. Physiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2954","DOI":"10.1001\/jama.296.24.2954","article-title":"Patent Foramen Ovale and High-Altitude Pulmonary Edema","volume":"296","author":"Allemann","year":"2006","journal-title":"JAMA"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1152\/japplphysiol.00192.2015","article-title":"Physiological Impact of Patent Foramen Ovale on Pulmonary Gas Exchange, Ventilatory Acclimatization, and Thermoregulation","volume":"121","author":"Lovering","year":"2016","journal-title":"J. Appl. Physiol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1136\/hrt.2006.105262","article-title":"Ebstein\u2019s Anomaly of the Tricuspid Valve: From Fetus to Adult: Congenital Heart Disease","volume":"94","author":"Paranon","year":"2008","journal-title":"Heart"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1186\/s12968-019-0546-3","article-title":"A Simple Measure of the Extent of Ebstein Valve Rotation with Cardiovascular Magnetic Resonance Gives a Practical Guide to Feasibility of Surgical Cone Reconstruction","volume":"21","author":"Hughes","year":"2019","journal-title":"J. Cardiovasc. Magn. Reson."},{"key":"ref_45","first-page":"531382","article-title":"Partial PFO Closure for Persistent Hypoxemia in a Patient with Ebstein Anomaly","volume":"2015","author":"Zuberi","year":"2015","journal-title":"Case Rep. Cardiol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"102283","DOI":"10.1016\/j.jaccas.2024.102283","article-title":"Permanent Pacemaker-Mediated Exertional Hypoxemia in a Patient with Ebstein Anomaly","volume":"29","author":"Shah","year":"2024","journal-title":"JACC Case Rep."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1113\/jphysiol.1984.sp015412","article-title":"Exercise-Induced Arterial Hypoxaemia in Healthy Human Subjects at Sea Level","volume":"355","author":"Dempsey","year":"1984","journal-title":"J. Physiol."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Durand, F., and Raberin, A. (2021). Exercise-Induced Hypoxemia in Endurance Athletes: Consequences for Altitude Exposure. Front. Sports Act. Living, 3.","DOI":"10.3389\/fspor.2021.663674"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1235","DOI":"10.1152\/japplphysiol.00444.2020","article-title":"Is the Healthy Respiratory System Built Just Right, Overbuilt, or Underbuilt to Meet the Demands Imposed by Exercise?","volume":"129","author":"Dempsey","year":"2020","journal-title":"J. Appl. Physiol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"645","DOI":"10.1002\/clc.22301","article-title":"Cardiac Platypnea-Orthodeoxia Syndrome: An Often Unrecognized Malady","volume":"37","author":"Knapper","year":"2014","journal-title":"Clin. Cardiol."},{"key":"ref_51","first-page":"9813038","article-title":"Percutaneous Closure of PFO in Patients with Reduced Oxygen Saturation at Rest and during Exercise: Short- and Long-Term Results","volume":"2020","author":"Pauwels","year":"2020","journal-title":"J. Interv. Cardiol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1080\/24748706.2017.1420274","article-title":"Patent Foramen Ovale Closure, A Contemporary Review","volume":"2","author":"Madhkour","year":"2018","journal-title":"Struct. Heart"},{"key":"ref_53","first-page":"156","article-title":"Healthcare Professional\u2019s Guide to Cardiopulmonary Exercise Testing","volume":"22","author":"Parasuraman","year":"2015","journal-title":"Br. J. Cardiol."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/4\/1523\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T08:55:45Z","timestamp":1771232145000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/4\/1523"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,14]]},"references-count":53,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["jcm15041523"],"URL":"https:\/\/doi.org\/10.3390\/jcm15041523","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,14]]}}}