Citation, DOI & article data
Platypnoea-orthodeoxia syndrome refers to the concomitant occurrence of dyspnea and hypoxemia, respectively, which are precipitated by assuming an upright position and alleviated by assuming a recumbent position 4.
As the name of the syndrome suggests, the hallmark clinical feature is platypnoea - dyspnea when upright that improves in a supine position. Patients may also have clinical features attributable to the underlying etiology of the syndrome, for example, clinical features of a congenital heart defect.
Confirmed clinically by the dynamic change of arterial oxygenation with a positional change from supine/recumbent to seated/upright, quantified as follows:
- decrease in arterial PaO2 by 4 mmHg or more
- decrease in arterial oxygen saturation by 5% or more
Gold standard diagnosis is achieved by cardiac catheterization.
Requires the presence of right-to-left shunting, which is most commonly related to a cardiac etiology i.e. an intracardiac shunt. Extracardiac etiologies have also been described.
- intracardiac shunting
The right-to-left shunting may be exacerbated by hemodynamic perturbations, such as right heart failure and pulmonary hypertension, or anatomic factors predisposing preferential flow of blood toward (and across) the interatrial septum 2.
- extracardiac shunting
Echocardiography may be utilized with agitated saline as a contrast medium ('bubble study') to demonstrate the presence of right-to-left shunting.
- 1. Tsuzuki I, Iigaya K, Matsubara T et al. Platypnea-Orthodeoxia Syndrome in the Right Lateral Decubitus Position: A Case Report. J Med Case Rep. 2017;11(1):109. doi:10.1186/s13256-017-1267-6 - Pubmed
- 2. Klein M, Kiefer T, Velazquez E. Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question. Tex Heart Inst J. 2016;43(3):264-6. doi:10.14503/THIJ-15-5280 - Pubmed
- 3. Henkin S, Negrotto S, Pollak P, Cullen M, O'Cochlain D, Wright R. Platypnea-Orthodeoxia Syndrome: Diagnostic Challenge and the Importance of Heightened Clinical Suspicion. Tex Heart Inst J. 2015;42(5):498-501. doi:10.14503/THIJ-14-4596 - Pubmed
- 4. Salvetti M, Zotti D, Bazza A et al. Platypnea and Orthodeoxia in a Patient with Pulmonary Embolism. Am J Emerg Med. 2013;31(4):760.e1-2. doi:10.1016/j.ajem.2012.12.004 - Pubmed
- 5. Agrawal A, Palkar A, Talwar A. The Multiple Dimensions of Platypnea-Orthodeoxia Syndrome: A Review. Respir Med. 2017;129:31-8. doi:10.1016/j.rmed.2017.05.016 - Pubmed