To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Video 4 TOE bubble saline contrast injection demonstrating significant right-to-left shunt. View Video 4 at http://movie-usa.glencoesoftware.com/video/10.1530/ERP-17-0055/video-4. An unusual cause of hypoxia: getting to the heart of the matter Daniel Hammersley, Aamir Shamsi, Mohammad Murtaza Zaman, Philip Berry, and Lydia Sturridge 2018. 5:K7-K11 DOI: 10.1530/ERP-17-0055 Download Original Video