Characterizing the repeatability of cardiovascular responses to hypoxic apneas in adults
Bibliographic record
Abstract
Abstract Apneas performed during hypoxia cause pronounced bradycardia and cardiac arrhythmias. What remains unclear is the intraindividual consistency of these responses. Therefore, we assessed the within‐day and between‐day repeatability of responses to hypoxic apneas, including the genesis of arrhythmias or electrocardiogram (ECG) changes. Sixteen participants (8F/8M, 25 ± 3 years, BMI 23.7 ± 3.4 kg/m 2 , mean ± SD) completed four hypoxic apneas per day on consecutive days, time‐matched to a maximal apnea on day 1 (39 ± 16 s). We quantified heart rate (HR) and mean arterial pressure (MAP) repeatability using within‐subject standard deviations (WSSD), [95%CI]. We hypothesized that WSSDs would be <5 bpm and <4 mmHg for HR and MAP. We also assessed the repeatability of arrhythmias or ECG changes. Within‐day, the HR WSSD was 4.4 bpm [3.7, 5.6], and the MAP WSSD was 4.1 mmHg [3.4, 5.1]. Between‐day comparisons had somewhat higher WSSDs: HR was 5.7 bpm [5.0, 6.5] and MAP was 5.0 mmHg [4.4, 5.8]. Arrhythmias or ECG changes occurred during 45% of apneas. These data indicate poor repeatability of electrical conduction changes during apneas. Conversely, our WSSD data indicate good within‐day and between‐day repeatability, albeit somewhat higher than hypothesized. These data therefore indicate that hypoxic apneas are a repeatable laboratory stressor for HR and MAP, but that researchers should exercise caution in interpreting individual‐level arrhythmia data.
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.
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 | 0.001 | 0.004 |
| 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) | 0.001 | 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".