Platypnea orthodeoxia pathophysiology on screen

A 64-year-old lady lying in supine position because multiple sclerosis, suffered a major stroke with no other plausible reasons but a huge right-to-left shunt confirmed by transthoracic echocardiography as a patent foramen ovale (PFO) with atrial septal aneurysm (ASA). Further examination with transesophageal echocardiography was not possible because of hostile esophageal tract. During rehabilitation exercise protocol in upright position, the patient developed severe dyspnoea and hypoxaemia. The patient was taken into the catheterization lab and a right heart catheterization with intracardiac echocardiography and eventual closure of the interatrial communication was planned. Intracardiac echocardiography with mechanical 9F 9MH probe (UltraICe Boston Scientific Inc.) in two orthogonal planes revealed a huge ASA and virtual right atrium (RA) compared to the left atrium (LA) (Figure 1), impinged by an aneurismal extra-rotated ascending aorta (AO), possibly increasing the blood flow shunting through the PFO, despite normal pulmonary pressure on right heart catheterization. In platypnea-orthodeoxia patients, transcatheter closure can be usually performed with hypoxaemia improvement or abolition.