Platypnea and orthodeoxia in a patient with pulmonary embolism

Platypnea-orthodeoxia Syndrome Due to Right Ventricular Inflow Tract Obstruction Caused by an Elongated Ascending Aorta: Usefulness of Three-dimensional Cardiac Computed Tomography Imaging in the Sitting Position

An 84-year-old woman presented with dyspnea in the sitting position. Platypnea-orthodeoxia syndrome (POS) was suspected based on arterial desaturation when her posture changed from the supine to the sitting position. Transesophageal echocardiography showed right-to-left shunting enhancement through a patent foramen ovale (PFO) in the sitting position. Three-dimensional (3D) cardiac CT in the sitting position revealed that the elongated ascending aorta compressed the right ventricular inflow tract, resulting in restricted blood flow to the right ventricle and increased right-to-left shunting. This case highlights the role of 3D-CT in the sitting position in the management of POS.

Patent Foramen Ovale and Ascending Aortic Dilatation Causing Platypnea-Orthodeoxia Syndrome

Platypnea-orthodeoxia syndrome (POS) is an underdiagnosed clinical syndrome characterized by dyspnea (platypnea) and hypoxemia (orthodeoxia) in the upright position that resolves when recumbent. POS is often due to an underlying right-to-left shunt. Four broad mechanisms for the shunt have been described: intracardiac shunts, intrapulmonary shunts, hepatopulmonary syndrome, and pulmonary ventilation-perfusion mismatch.

A 68-year-old male with a past medical history of chronic obstructive pulmonary disease (COPD), obstructive sleep apnea, ascending aortic dilation (3.9 cm), myelofibrosis, and status post stem cell transplant complicated by graft versus host disease was found hypoxemic (oxygen saturation: 82%) on routine visit prompting hospitalization. Hypoxemia initially responded to 40% FiO2 but subsequently progressed to refractory hypoxemia on 100% FiO2. A chest computed tomography (CT) scan showed evidence of multiple segmental pulmonary emboli with patent central pulmonary arteries. Hypoxemia out of proportion to pulmonary embolism clot burden and examination findings consistent with orthodeoxia prompted further investigations. Nuclear medicine scan showed radiotracer activity in both brain and kidneys consistent with a small right-to-left shunt (5.9%). Transesophageal echocardiography (TEE) revealed a patent foramen ovale (PFO) with a right-to-left shunt across the atrial septum, with a maximum opening of 3.5 mm and tunnel length of 25 mm. Right heart catheterization (RHC) is consistent with the right-to-left shunt and normal right heart pressures. The degree of the shunt was not significant enough to explain the degree of hypoxemia, but all the diagnostic studies were performed in a supine position, possibly underestimating the degree of the shunt. PFO closure with transcatheter 30-mm Gore device (GORE® CARDIOFORM, Arizona, USA) decreased supplemental oxygen requirement from 75% high-flow nasal cannula (NC) to room air (RA) immediately after the procedure. The patient was subsequently discharged home on a baseline oxygen requirement of 2 L NC at nighttime.

POS should be suspected when a patient develops severe hypoxemia after changing from a recumbent position to a sitting or standing position. The identification and correction of the shunting or mismatch often allow complete resolution of POS. Transthoracic echocardiography with agitated saline, TEE, and RHC are the diagnosis modalities of choice. Left heart cardiac catheterization remains the gold standard, which would demonstrate a mismatch in oxygen saturation between the pulmonary vein and the aorta. Our patient’s PFO was successfully closed by a percutaneous transcatheter closure device leading to the complete resolution of hypoxemia immediately.

Platypnea-orthodeoxia syndrome in a postoperative patient: a case report

Background

We report a case of platypnea–orthodeoxia syndrome observed in a complex clinical situation associating a bilateral pleural effusion, lobar pulmonary embolism, and a partial anomalous pulmonary venous return.

Case presentation

A 57-year-old Caucasian woman developed acute dyspnea in the postoperative course of an elective gynecological surgery for advanced stage ovarian cancer. Preoperative evaluation had failed to reveal any respiratory or cardiac problem. After evidence of a low arterial oxygen saturation, blood gas analysis from the central venous line correctly inserted in the right internal jugular vein revealed a higher oxygen saturation than in the arterial compartment. A thoracic computed tomography showed bilateral pleural effusion, lobar pulmonary embolism, and a drainage of a left pulmonary vein into the left innominate vein. This unique combination resulted in an uncommon cause of platypnea–orthodeoxia syndrome.

Conclusion

Often associated with right-to-left shunting, platypnea–orthodeoxia syndrome may be observed in complex clinical conditions with several factors influencing the ventilation/perfusion ratio. The paradoxical finding of a higher oxygen saturation in a central venous line than in an arterial line should prompt the clinician to look at the possibility of partial anomalous pulmonary venous return. No specific treatment is required in asymptomatic adults, except for an echocardiographic follow-up to detect the onset of pulmonary hypertension.

Platypnea-orthodeoxia syndrome: an unusual presentation of a complex disease

BACKGROUND

Platypnea-orthodeoxia syndrome (POS) is an uncommon disorder characterized by dyspnea (=platypnea) and desaturation (=orthodeoxia) in upright position and improvement of symptoms and blood oxygenation in supine position. Clinical presentation is heterogeneous and often confuses the clinician.

OBJECTIVES

The present case report illustrates a complicated presentation of the underlying syndrome.

METHODS

Description of a POS case in a 73-year-old female with thorough workup and tailored treatment.

RESULTS

In this case report, we describe a rather unusual presentation of POS, with posture-dependent hypoxemic-induced psychiatric symptoms. Further investigations revealed the presence of a patent foramen ovale with atrial septum aneurysm, an aortic root dilatation up to 41 mm and bilateral lower lobe lung emboli. The ventilation-perfusion mismatch aggravated the desaturation in upright position. Since the patient remained symptomatic after treatment of the functional trigger, we choose for the percutaneous closure of the anatomical defect. We used an Occlutech Figulla Flex II UNI 33/33 mm occluder resulting in a perfect closure of the defect.

CONCLUSION

Abnormal shunting in upright position may be the result of different underlying conditions, requiring a thorough workup and a tailored treatment. In case of serious co-morbid conditions, an endovascular procedure to close a patent foramen ovale, after unsuccessful treatment of precipitating conditions, should be considered.

Platypnoea-orthodeoxia syndrome: novel cause for a known condition

A 50-year-old man presented with dyspnoea while sitting, standing and walking but resolved completely in supine position. On cardiorespiratory examinations, fine crackles were noted over bibasal area. Chest X-ray showed bilateral reticulonodular shadows, restrictive pattern on spirometry, elevated alveolar arterial O2 gradient on arterial blood gas. High-resolution CT of the thorax revealed pattern as 'confident' or 'certain' radiographic diagnosis of idiopathic pulmonary fibrosis (IPF). Bubble-contrast echocardiography in recumbent, sitting and upright positions revealed no intracardiac (right to left shunt) or intrapulmonary shunts. This case highlights the necessity of awareness of this syndrome in cases of interstitial lung diseases (ILDs) also. Although 188 cases have been described thus far of platypnoea-orthodeoxia syndrome (P-OS) of various aetiologies, to the best of our knowledge, it is the first ever case of P-OS in ILD/IPF. Both lung bases were predominantly affected in this patient, platypnoea and orthodeoxia were attributed to areas of low/zero ventilation/perfusion (V/Q) ratio (zone 1 phenomena) as no other obvious explanation was found.