Beneficial effects of delayed ivabradine treatment on cardiac anatomical and electrical remodeling in rat severe chronic heart failure
Bibliographic record
Abstract
We tested the hypothesis that heart rate (HR) reduction, induced by the selective hyperpolarization-activated current inhibitor ivabradine (Iva), might improve left ventricular (LV) function, structure, and electrical remodeling in severe post-myocardial infarction (MI) chronic heart failure (HF). MI was produced in adult male Wistar rats. After 2 mo, echocardiography was performed before the randomization into MI and MI + Iva (10 mg x kg(-1) x day(-1)) groups. After 3 mo of treatment, echocardiography and 24-h telemetry were recorded. Cardiac collagen, mRNA, and protein expressions of angiotensin-converting enzyme (ACE) and ANG II type 1 (AT(1)) receptor were quantified. As a result, at 2 mo post-MI, all rats displayed severe congestive HF signs (ejection fraction < 30%). At 5 mo post-MI, body and heart weights were similar in the MI and MI + Iva groups. LV ejection fraction and LV end-diastolic pressure were worsened in the MI group, whereas both were improved with Iva. Iva reduced HR by 10.4% (P < 0.03 vs. MI) and ventricular premature complexes by 89% (P < 0.03) and improved HR variability (standard deviation of the RR interval) by 22% (P < 0.05). There were no effects of Iva on PR, QRS, and QT durations. Interstitial fibrosis in the MI-remote LV was markedly reduced by Iva (4.0 +/- 0.1 vs. 1.8 +/- 0.1%, P < 0.005). Increases in ventricular gene and protein expressions of ACE and AT(1) receptor in MI were completely blunted by Iva. In conclusion, these data indicated that HR reduction by Iva prevents the worsening of LV dysfunction and remodeling that may be related to a downregulation of cardiac renin-angiotensin-aldosterone system transcripts. Such beneficial effects of Iva on cardiac remodeling open new clinical perspectives for the treatment of severe HF.
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 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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".