Abstract 19544: Rate and Magnitude of Atrial Remodeling in Permanent Atrial Fibrillation
Bibliographic record
Abstract
Background: Atrial fibrillation (AF) is associated with progressive enlargement of atrial size. Yet, the rate of change in left atrial (LA) and right atrial (RA) size is poorly defined. Methods: This cohort study included 51 patients with a history of permanent AF who had serial transthoracic echocardiograms performed between 2005 and 2010 at Vancouver General Hospital in British Columbia, a large university-based tertiary care hospital. Each had at least 3 transthoracic studies completed and had adequate views for assessment of LA and RA volume. Echocardiographic measurements were performed offline by one person using standardized methodology. Apical 4-chamber LA and RA volume by Simpson’s method was used for assessment of atrial size. Linear mixed effects modeling was used in analyzing changes over time. Results: Of the 51 subjects who underwent 183 studies in total, 28 were men (55%). The mean age at study entry was 72±10 yrs (47-85 yrs). The mean follow-up time was 3.2±2.9 years. The findings for the first 3 consecutive studies for these patients are shown in the attached table. There was a significant increase in LA and RA volume; the increases were 2.98 mL/m2 per year (95% CI 1.23-4.73, P<0.0001) and 1.25 mL/m2 per year (95% CI 1.01-1.61, P<0.0001) respectively. In parsimonious models adjusting for age, sex, and length of follow-up, left ventricular ejection fraction of less than 50% at first study was associated with a significantly more rapid increase in LA volume over time (P<0.001). Conclusion: Both LA and RA volume increased over time in patients with permanent AF. The absolute magnitude of increase appeared greater, and the rate of change faster, for LA than RA volume. Further studies are needed to determine the factors that mediate these changes and their reversibility.
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 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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.003 | 0.001 |
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".