Impaired exercise capacity in heart transplant recipients during aerobic exercise involving a small muscle mass
Bibliographic record
Abstract
Background: Heart transplant recipients (HTR) have impaired exercise tolerance when performing aerobic exercise involving a large muscle mass. Aim: To assess cardiac function and reserve during small muscle mass aerobic exercise in 5 clinically stable HTR (53±6 yrs) and 5 healthy controls (HC 53±7 yrs). Subjects performed unilateral knee extensor exercise (UKE, 3 watts·min −1 ) with expired gas analysis, impedance cardiography, and cuff blood pressure to measure: heart rate (HR); stroke volume (SV); cardiac output (Q), oxygen consumption (VO 2 ); arteriovenous oxygen difference (a‐vO 2diff ); mean arterial pressure (MAP) and systemic vascular resistance (SVR). Peak exercise and reserve function (peak – rest) data are presented. Results: Peak VO 2 (HTR: 0.9±0.2 vs HC: 1.6±0.5 L·min −1 ), Q (HTR: 9.4±1 vs HC: 12.1±2 L·min −1 ), SV (78±4 vs HC: 95±12 ml·beat −1 ) and a‐vO 2diff (HTR: 9.8±1.6 vs HC: 12.7±2.3 ml·100ml −1 ) were significantly lower in HTR vs. HC. The lower VO 2 reserve in HTR (0.6±0.2 vs HC 1.3±0.5 L·min −1 p<.05) was due to a blunted HR (HTR: 27±11 vs HC: 52±27 beats·min −1 p=.09), Q (HTR: 3.8±0.9 vs HC: 6.4±2.0 L·min −1 p<.05) and a‐vO 2diff reserve (HTR: 4.1±0.7 vs HC: 7.4±2.5 ml·100ml −1 p<.05). Peak HR, MAP, SVR and reserve SV, MAP and SVR were not different between groups. Conclusion: HTR have reduced VO 2peak during UKE. The impaired VO 2peak and VO 2 reserve during UKE is due to a blunted Q and a‐vO 2diff reserve resulting in reduced oxygen delivery and utilization by the active muscles.
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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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".