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Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography
Published on: March 26, 2020
Patent foramen ovale and hypobaric decompression
M R Powell1, W T Norfleet, K V Kumar
1Space Biomedical Research Institute, NASA Lyndon B. Johnson Space Center (JSC), Houston, TX 77058, USA.
Abstract:
Gas microbubbles were detected in the left ventricle of a supine subject being screened for an atrial septal defect as a participant of a hypobaric decompression study. This determination was made using the saline echocontrast procedure. We found provocation by a Valsalva maneuver not to be necessary in this individual for right-to-left passage of contrast microbubbles into the left heart and middle cerebral artery. When this same individual underwent hypobaric decompression to a simulated altitude of 21,000 ft, numerous gas microbubbles were detected in the right heart, but no gas bubbles were detected in either the left ventricular outflow tract or in the middle cerebral artery. This observation appears to be a novel finding, not previously reported.
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