Varying patterns of hyperpnea during Cheyne-Stokes respiration in heart failure: Implication for cardiac function
Bibliographic record
Abstract
In heart failure (HF) patients with Cheyne Stokes respiration (CSR), we have noted 2 patterns of hyperpnea: positive, in which end-expiratory lung volume (EELV) is above functional residual capacity (FRC), and negative, in which EELV falls below FRC [Fig1.a,b]. The latter implies an increase in expiratory intrathoracic pressure, from activation of expiratory muscles. We hypothesized that this may be a compensatory mechanism to support stroke volume (SV) when it is very low, as manifest by longer CSR cycle duration and lung-to-finger circulation time (LFCT) than the positive pattern. Patients with HF underwent polysomnography and were divided into those with a negative or positive pattern. Brain natriuretic peptide (BNP) was measured. In each CSR episode, duration of the apnea-hyperpnea cycle and LFCT were measured. Of 15 patients (14men, 67yr) with CSR, 4 had a negative pattern. There was no difference in age or apnea-hypopnea index between the groups. Patients with a negative pattern had longer cycle lengths (78±14 vs 54±10s, p=0.03) and higher BNP (994±745 vs 92±80pmol/l, p=0.01) than those with a positive pattern. LFCT didn9t differ. HF patients with a negative CSR pattern have longer cycle length and higher BNP suggestive of worse cardiac function. The negative pattern generates greater positive expiratory pressure that might cause a self-resuscitation effect to maintain SV by “squeezing” the heart.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".