P.036 Delayed orthostatic tachycardia – is the time frame for postural orthostatic tachycardia syndrome arbitrary?
Bibliographic record
Abstract
Background: Postural Orthostatic Tachycardia Syndrome (POTS) is the increase in heart rate (HR) by ≥30 bpm within 10 minutes of upright posture without orthostatic hypotension (OH). This study specifcally investigated patients who develop delayed symptomatic orthostatic tachycardia (i.e. after >10 minutes) without OH. Methods: Clinical histories and laboratory tests of patients assessed for orthostatic intolerance (OI) during last 10 years were reviewed. All patients underwent autonomic tests (sweat test, heart rate variability to deep breathing/Valsalva, 45-minute head up tilt table test (TTT) and quantitative sensory testing. Results: Among 974 patients with OI, 43% (419/974) were diagnosed with POTS whereas 12.4% (121/974) had delayed orthostatic symptoms on TTT alongwith delayed orthostatic tachycardia (DOT; x¯ = 30.3 minutes) without OH. In this cohort, mean HR increase was 51.7 bpm (range: 40-104 bpm). Other findings were significant narrowing of pulse pressure (PP) i.e. ≤25% of systolic pressure (x¯ = 16.2%, range: 6.4% -24.3%), excessive BP oscillations and syncope (9.9%). About 1/3 (37.2%) with DOT had definite small fiber/autonomic neuropathy. Conclusions: Patients with OI may manifest delayed symptoms/DOT and maybe missed on a 10-minute TTT. The marked reduction in PP observed in these pateints signifies reduced cardiac output, possibly from peripheral blood pooling due to small fiber/autonomic neuropathy.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.014 | 0.003 |
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".