Real‐Time Magnetic Resonance Imaging to Study Orthostatic Intolerance Mechanisms in Human Beings: Proof of Concept, 2022, Darius A. Gerlach

Abstract

Background
Discerning the mechanisms driving orthostatic symptoms in human beings remains challenging. Therefore, we developed a novel approach combining cardiac and cerebral real‐time magnetic resonance imaging, beat‐to‐beat physiological monitoring, and orthostatic stress testing through lower‐body negative pressure (LBNP). We conducted a proof‐of‐concept study in a patient with severe orthostatic hypotension.


Methods and Results
We included a 46‐year‐old man with pure autonomic failure. Without and during −30 mmHg LBNP, we obtained 3T real‐time magnetic resonance imaging of the cardiac short axis and quantitative flow measurements in the pulmonary trunk and middle cerebral artery. Blood pressure was 118/74 mmHg during supine rest and 58/35 mmHg with LBNP. With LBNP, left ventricular stroke volume decreased by 44.6%, absolute middle cerebral artery flow by 37.6%, and pulmonary trunk flow by 40%.

Conclusions
Combination of real‐time magnetic resonance imaging, LBNP, and continuous blood pressure monitoring provides a promising new approach to study orthostatic intolerance mechanisms in human beings.

https://www.ahajournals.org/doi/10.1161/JAHA.122.026437

 

This is making me wonder if it could be a factor in what astronauts experience in orbit. Because of how dangerous oxygen is, most spacecraft have lower air pressure with a higher oxygen mix to compensate. It's common to experience something like orthostatic issues, resembles dysautonomia even. And could have something with this.

Oh, if only NASA could get on researching this rigorously. This is serious to them because it impacts not only astronaut readiness but also how long they can spend outside a gravity field. It amounts to millions, if not more, astronauts are absurdly expensive to train. Motivated engineers don't stop, don't give up, they keep working the problem in an investigative method until they get something and they're not interested in woo woo.