Platypnea-orthodeoxia syndrome in patients presenting enlarged aortic root: case report and literature review

Abstract

We describe herein a case of a patient who, when in orthostatic positions, had severe hypoxemia and ventilatory dysfunction. Although the severity of symptoms required hospitalization in an intensive care setting, the initial tests only identified the presence of enlarged aortic root, which did not explain the condition. The association of these events with an unusual etiology, namely intracardiac shunt, characterized the diagnosis of platypnea-orthodeoxia syndrome. The literature review shows that, with advancing research methods, there was a progressive increase in the identification of this condition, and this association should be part of the differential diagnosis of dyspnea in patients with enlarged aortic root.

Platypnoea–orthodeoxia syndrome induced by short-term weight loss: a case series

“…Therefore, intracardiac POS with normal right atrial pressure requires not only anatomic but also functional factors, also known as acquired factors. 3 , 7 These include an enlarged or tortuous ascending aorta, cardiac surgery, pneumonectomy, paraoesophageal hernia repair, and severe kyphosis. 2–5 Joseph et al 3 reported that these factors can reposition the atrial septum or redirect blood flow from the IVC.…”

Patent foramen ovale and ascending aortic aneurysm causing the platypnea-orthodeoxia syndrome

“…This distortion also results in the flap valve of the fossa ovalis moving freely, leading to a spinnaker effect, with the venous flow moving to the left, maintaining the foramen ovale wide open and allowing for persistent right-to-left shunting. [9][10][11][12] In the upright position, there is an increased PFO aperture size and enhanced streaming of blood flow from the inferior vena cava, causing greater shunting due to the effects of gravity. 9,13 Some patients with PFO only become symptomatic in adulthood because aortic dilation, which is a significant component in POS, is often due to longstanding hypertension and age.…”

“…[9][10][11][12] In the upright position, there is an increased PFO aperture size and enhanced streaming of blood flow from the inferior vena cava, causing greater shunting due to the effects of gravity. 9,13 Some patients with PFO only become symptomatic in adulthood because aortic dilation, which is a significant component in POS, is often due to longstanding hypertension and age. 10 Definitive management of POS with identified interatrial communication is surgical or percutaneous closure of the shunt.…”