Impairments of Ventilatory Adaptation at the Onset of a Fixed Load Exercise Protocol in Patients with Heart Failure
Bibliographic record
Abstract
1472 The method for assessing exercise capacity in patients with congestive heart failure (CHF) remains controversial. PURPOSE: We critically assessed the O2 requirement of a submaximal fixed load exercise protocol tailored individually at the ventilatory threshold in patients with symptomatic CHF and compared it to healthy subjects. METHODS: The ventilatory parameters of thirty patients with symptomatic CHF caused by ischemic heart disease (n = 13), dilated cardiomyopathy (n = 11), or other causes (n = 6), mean age of 56 ± 12 years and mean LV ejection fraction 26 ± 7% were compared to those of 10 age-matched healthy volunteers. Maximal exercise capacity with gas exchange analysis was performed on a treadmill using a RAMP protocol. Submaximal exercise testing was performed using a constant workload slightly above the ventilatory threshold (VT). RESULTS: There was a delay in attainment of a VO2 steady state during the submaximal test in patients with CHF compared to healthy subjects. This was demonstrated by a delay in the time constant (TC), and delta between VO2 at baseline and at 3 minutes during submaximal testing. Also, the VT is reached at a lower percentage of the VO2 max in controls subjects (73% of VO2 peak) than in patients (79% of VO2 peak) (p = 0.0041). Moreover, during the submaximal test, VO2 reached at the 6th minute within the test and at maximal exhaustion was significantly higher than the VO2 predicted for each work rate (p< 0.05) for both patients and healthy subjects. CONCLUSION: Patients with CHF adapt differently when performing an endurance protocol slightly above the ventilatory threshold. This could be explained by the inability of these patients to reach true maximal oxygen consumption. The use of submaximal exercise testing as a functional measure in CHF is an appropriate alternative to maximal exercise testing.
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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) | 0.001 | 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".