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Abstract 4309: Ventricular Elastic Support Therapy (VEST) Reduces Transmural Pressure and Myocardial Strain

2008· article· en· W185346929 on OpenAlexaff
Paul W.M. Fedak, Cheryl Meek, Rozsa Sas, Israel Belenkie, John V. Tyberg

Bibliographic record

VenueCirculation · 2008
Typearticle
Languageen
FieldMedicine
TopicCardiac Structural Anomalies and Repair
Canadian institutionsLibin Cardiovascular Institute of Alberta
Fundersnot available
KeywordsMedicinePreloadCardiologyInternal medicineSonomicrometryElastic recoilDiastolePericardiumSilasticHemodynamicsBlood pressureLung

Abstract

fetched live from OpenAlex

Background: Transmural pressure (TMP) determines myocardial strain and chamber dimensions. Epicardial ventricular support may improve mechanical function and promote reverse remodeling by reducing TMP. HeartNet (Paracor Medical Inc) is an elastic intra-pericardial ventricular support device currently evaluated in the PEERLESS-HF clinical trial. To explore the mechanism of action of VEST, we directly measured the in vivo effects of HeartNet on regional hemodynamics and myocardial strain. Methods: We instrumented open-chest anesthetized dogs (n=6) with flat silastic-balloon epicardial pressure transducers, intravascular pressure catheters, aortic flow probes, and sonomicronometry crystals. The pericardium was re-approximated. We obtained pericardial, epicardial, LV, and aortic pressures. We measured epicardial segment length (end-diastolic myocardial strain) and LV dimensions throughout the cardiac cycle. Loading conditions were altered by volume infusion, caval occlusion, and LAD ligation to induce regional ischemia / dysfunction. Parameters were obtained in every animal with and without the HeartNet in situ (applied at 45% baseline stretch) and compared. Results: HeartNet epicardial support was 2.8±0.2 mmHg (mean at end-diastole) and was maintained throughout the cardiac cycle and over a wide range of physiologic filling conditions (LVEDP 0 –15 mmHg) indicating that the device is compliant, elastic, and self-adjusting. TMP and end-diastolic strain were significantly reduced (P<0.01) supporting a mechanism of action for the device. After LAD ligation, HeartNet also reduced TMP (−38±8%, P<0.0001) and end-diastolic strain over the anterior wall. Negative regional stroke work was also lowered (−56±2%, P<0.001) suggesting improved overall ventricular mechanical efficiency. Aortic pressure and LV stroke volume (20±2 vs 22 ±3 mL, P=0.20) was maintained. Conclusions: These are the first in vivo data to demonstrate that ventricular elastic support therapy improves regional myocardial mechanics throughout the cardiac cycle by reducing transmural pressure and end-diastolic strain. Elastic support therapy may provide significant benefits on acute hemodynamics and chronic remodeling in the failing heart.

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 imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.353
Threshold uncertainty score0.389

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.017
GPT teacher head0.244
Teacher spread0.227 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations1
Published2008
Admission routes1
Has abstractyes

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