The effect of orthostatic stress type on cardiovascular control
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
OBJECTIVES: We aimed to compare the cardiovascular responses of a novel orthostatic stress test, the passive seated orthostatic stress test (PSOST), with those during passive head-up tilt testing (HUTT). We hypothesized that cardiovascular responses during PSOST would be similar to those during HUTT (the 'gold standard'). METHODS: We tested 15 healthy volunteers, who underwent both PSOST and HUTT during one session in a random order. We measured beat-to-beat blood pressure, heart rate, peripheral resistance, stroke volume, cardiac output, and middle cerebral artery blood flow velocity during each test. RESULTS: Blood pressure responses were not significantly different between PSOST and HUTT, except for a significantly lower delayed nadir and 15-min recovery value in systolic arterial pressure during HUTT. HUTT elicited a significantly larger increase in heart rate during all test intervals in comparison with PSOST, as well as a larger decline in stroke volume during almost all test intervals. Responses for the other hemodynamic variables were not significantly different between the tests at any test interval. Repeated HUTT has large inherent variability, which was also evident from the variability in the mean differences on comparing PSOST and HUTT. There was a significant bias for larger heart rate increases (P<0.01) and a greater delayed systolic arterial pressure decline during HUTT. CONCLUSION: We have shown that PSOST and HUTT elicit similar blood pressure and cerebrovascular responses in the early stages of the upright phase. We believe that PSOST is a reasonable surrogate for HUTT in assessing orthostatic hypotension in population groups that are unable to stand for prolonged periods of time.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it