Overnight Shift From Obstructive to Central Apneas in Patients With Heart Failure
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
BACKGROUND: Obstructive (OSA) and central sleep apnea (CSA) can coexist in patients with congestive heart failure (CHF). However, the reason why OSA events occur at one time and CSA events at another has not been determined. We hypothesized that a change in PCO(2) would be associated with an alteration in apnea type: a decrease in PCO(2) should lead to CSA. METHODS AND RESULTS: To test this hypothesis, we evaluated minute ventilation (V(I)), transcutaneous PCO(2) (PtcCO(2)), circulation time, and periodic breathing cycle length during overnight polysomnography in 12 patients with CHF and coexisting OSA and CSA. V(I) was significantly greater (mean+/-SEM, 9.4+/-1.3 versus 8.0+/-0.9 L/min; P:<0.05) and PtcCO(2) was lower (39.4+/-1.0 versus 41.9+/-1.1 mm Hg, P:<0.01) during episodes of CSA than of OSA. These changes were associated with significant lengthening of circulation time (23.6+/-3.7 versus 21.1+/-3.6 seconds, P:<0.01) and periodic breathing cycle length (53.7+/-3.5 versus 49.6+/-2.9 seconds, P:<0.01). In addition, the proportion of obstructive events decreased (from 68.5+/-11.4% to 22.5+/-7.2%, P:<0.001) and of CSA events increased (from 31.5+/-11.4% to 77.5+/-7.2%, P:<0.001) from the first to the last quarter of the night in association with a significant decrease in PtcCO(2) (from 42.6+/-0.9 to 40.8+/-0.9 mm Hg, P:<0.01). CONCLUSIONS: In patients with CHF, the shift from OSA to CSA is associated with a reduction in PCO(2). This appears to be related to an overnight deterioration in cardiac function as suggested by the concurrent lengthening of circulation time. Therefore, in CHF patients, alterations in cardiac function may influence apnea type.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| 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