Platypnea–orthodeoxia syndrome combined with constrictive pericarditis after coronary artery bypass surgery

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.

Transcatheter treatment of atrial septal defect presenting with platypnea-orthodeoxia syndrome

A 29-year-old woman was referred to our institute for symptomatic hypoxemia. Her dyspnea was aggravated while sitting or standing and relieved while in supine position. She did not have any pulmonary disease. Transthoracic echocardiography and heart computed tomography revealed an underestimated small atrial septal defect (ASD) with a left-to-right shunt. A cardiac catheterization was performed to evaluate pulmonary hypertension. It revealed a normal pulmonary artery pressure and a large ASD with bidirectional shunt during Valsalva maneuver by intracardiac echocardiogram. Her arterial oxygen saturation decreased from 93% while supine to 79% while at a 15° sitting position. Thus, the patient was diagnosed with platypnea-orthodeoxia syndrome. The ASD was successfully closed with Amplatzer® (St. Jude Medical) septal occluder and both platypnea and orthodeoxia were resolved immediately after the procedure.

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.

Platypnea-orthodeoxia diagnosed by sitting transesophageal echocardiography

Platypnea-orthodeoxia is a rare syndrome presenting with dyspnea and cyanosis induced by an upright position and relieved by recumbency. We report a patient with an excessively enlarged aortic root who had critical hypoxia due to a paradoxical shunt through the patent foramen ovale only when seated. The postural changes of the shunt, caused by changes in posture, were dynamically detected by transesophageal Doppler echocardiography. We believe that this syndrome should be considered when patients with aortic root dilatation present with inexplicable hypoxia, and that transesophageal Doppler echocardiography in the sitting position can be useful for detecting platypnea-orthodeoxia syndrome.

Platypnea and orthodeoxia associated with Pneumocystis jiroveci and Cytomegalovirus pneumonia: a case report

Introduction

Platypnea-orthodeoxia is an uncommon syndrome characterized by dyspnea and deoxygenation accompanying a change to a sitting or standing posture from a recumbent position. It is usually related to interatrial communications, although several other disorders associated with platypnea-orthodeoxia syndrome have been reported. However, the precise mechanisms are unknown.

Case presentation

We present the case of a 75-year-old Caucasian woman with chronic renal failure due to vasculitis who was admitted with fever and respiratory failure. She was found to have both Pneumocystis jiroveci and Cytomegalovirus pneumonia. She was HIV negative. Severe platypnea and orthodeoxia were major features of her illness with no history of respiratory, liver or cardiac disease. Further investigation with contrast echocardiography revealed no intracardiac or intrapulmonary shunts. Although one case involving Pneumocystis jiroveci pneumonia and platypnea has been previously reported, to the best of our knowledge, this is the first time that two opportunistic pathogens have been accompanied by platypnea and orthodeoxia. As both lung bases were predominantly affected and no obvious explanation was found, platypnea and orthodeoxia were attributed to significant areas of low or zero ventilation/perfusion (V/Q) ratio.

Conclusion

Platypnea-orthodeoxia is a rare and usually underestimated syndrome. Intracardiac shunts and anatomic pulmonary vascular shunts are the most common etiologic associations. However, if a detailed examination reveals no obvious intracardiac or intrapulmonary shunting combined with extensive pulmonary lesions, then severe V/Q mismatching should be considered as the probable explanation.