Time-of-day variation in cardiovascular response to maximal exercise testing in coronary heart disease patients taking a beta-blocker
Bibliographic record
Abstract
The aim of this study was to investigate the effect of a beta-blocker (atenolol and metoprolol) on exercise heart rate (HR) and rate pressure product (RPP) during a morning and afternoon maximal exercise test (maxET) in patients with coronary heart disease (CHD). Twenty-one CHD patients (59.9 +/- 8.9 years of age) treated with either atenolol or metoprolol participated in this study. All subjects underwent a morning and afternoon symptom-limited maximal exercise test (maxET) 2-3 h and 8-10 h after medication intake. No significant differences in exercise capacity (atenolol: 8.3 +/- 1.9 vs. 8.3 +/- 2.1 metabolic equivalents (METs); metoprolol: 8.8 +/- 2.0 vs. 8.7 +/- 2.0 METs) or rate of perceived exertion (atenolol: 7.4 +/- 1.9 vs. 7.4 +/- 1.7 METs; metoprolol: 7.2 +/- 1.5 vs. 6.8 +/- 0.9 METs) were observed between the 2 maxETs in either group. However, there was a discrepancy in cardiovascular and ischemic responses between morning and afternoon maxET. Subjects treated with atenolol demonstrated better overall control of HR and RPP during the afternoon maxET. The difference between morning and afternoon HRmax (11 +/- 8 vs. 19 +/- 9 beats.min-1; p = 0.05) was significantly higher in the metoprolol group, but did not attain significance for RPP (31 +/- 30 vs. 54 +/- 28 mmHg.beats.min-1.10-2; p = 0.09). Also, nearly one quarter of our subjects who had a normal morning maxET demonstrated an abnormal electrocardiogram response and (or) ischemia when exercise testing was done in the late afternoon. These changes were more prevalent in subjects taking metoprolol. The results of this study suggest that there is considerable time-of-day variation in the cardiovascular response to a maxET in CHD patients treated with a beta-blocker.
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How this classification was reachedexpand
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 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".