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Abstract 12770: Left-Atrial Contractile Contribution to Left Ventricle Filling is Preserved in Moderate Chronic Heart Failure

2014· article· en· W4246742838 on OpenAlexaff
Brendan Putko, Ian C. Paterson, Richard B. Thompson, Justin A. Ezekowitz, Jason R.B. Dyck, Todd J. Anderson, Gavin Y. Oudit

Bibliographic record

VenueCirculation · 2014
Typearticle
Languageen
FieldMedicine
TopicCardiovascular Function and Risk Factors
Canadian institutionsUniversity of CalgaryUniversity of Alberta
Fundersnot available
KeywordsMedicineCardiologyInternal medicineEjection fractionHeart failureVentricleSinus rhythmDiastoleSystoleAtrial fibrillationStroke volumeBrain natriuretic peptideBlood pressure

Abstract

fetched live from OpenAlex

Introduction: The extent that left atrium (LA) functional remodeling is impacted by left ventricle (LV) systolic function or clinical history in patients with chronic heart failure (HF) is unresolved. Cardiac imaging and plasma biomarkers may provide valuable information in this regard. Hypothesis: Elastic and active contributions to LV stroke volume (LV SV) are variable, independent of LV systolic function and reflected in natriuretic peptide measurements. Methods: We recruited 27 controls without overt cardiovascular disease and 68 patients with moderate HF, including preserved and reduced LV ejection fraction (LVEF). Cardiac MRI was used to evaluate LV volumes at end diastole and end systole, and LA volumes at end diastole, diastasis and end systole to determine passive and active volume changes. Plasma mid-region pro-atrial and N-terminal pro-brain natriuretic peptides (MR-proANP and NT-proBNP, respectively) were measured. Results: Elastic LA contribution to LV SV was significantly lower in HF (median, IQR: 14%, 8-23%) than controls (24%, 17-30%; p=0.001), but active contribution was not (23%, 0-34% vs 24%, 21-31%; p=0.163). In patients with HF, active LA contribution to LV SV was negatively associated with history of hypertension (β=-0.41, p=0.007) and positively associated with aging (β=0.40, p=0.008) in a multiple linear regression model. Seven of nine subjects with HF and a history of atrial fibrillation (AF), but in sinus rhythm (SR) on the day of study, had active LA contributions to LV SV >15%. Increased LA volume at end diastole (β=0.51, p=0.001) and LVEF (β=-0.33, p=0.008) were independently associated with NT-proBNP (β=0.51, p=0.001) in a model that included age and history of AF. Similarly, LA volume at end diastole (β=0.48, p=0.001) was independently associated with MR-proANP in a model that included age and history of AF. Notably, natriuretic propeptides were not associated with elastic or active LA contributions to LV SV. Conclusions: Heart failure is characterized by preserved LA active contribution to LV SV, regardless of LVEF, which increases with age, and is modifiable by hypertension and AF. Imaging-based assessment can elucidate the contribution of LA function in HF and may provide insight into the impact of AF in patients with 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 machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation 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 score0.002
Threshold uncertainty score0.008

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.001
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)0.0020.000

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 head0.015
GPT teacher head0.256
Teacher spread0.241 · 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 source (direct Gemma or distilled Codex), 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".

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Citations0
Published2014
Admission routes1
Has abstractyes

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