Comparisons of right ventricular strain between repaired tetralogy of fallot and isolated pulmonary regurgitation
Bibliographic record
Abstract
Abstract Background: Pulmonary regurgitation leading to right ventricular enlargement may occur after repaired tetralogy of Fallot (rTOF) or balloon dilation for pulmonary valve stenosis. Cardiac magnetic resonance imaging (CMR) guidelines to identify the timing of valve replacement in rTOF are not necessarily applicable to isolated pulmonary regurgitation. This study aims to compare deformation parameters of isolated pulmonary regurgitation and rTOF at comparable right ventricular volume loads. Methods: Adopting a quantitative retrospective analytic framework, CMR was performed in 44 patients (0–30 years), 22 in each of the isolated pulmonary regurgitation and rTOF study arms, matched for age (±12 months), and Right ventricular end-diastolic volume z -score (±1). Right ventricular longitudinal strain/strain rate and circumferential strain/strain rate were measured. Comparisons between groups were analysed using two-tailed T -tests and one-way ANOVA. Results: Both groups showed predominance of longitudinal over circumferential strain. Circumferential strain was significantly greater in rTOF compared to isolated pulmonary regurgitation (–26.5% versus –22.3%, p < 0.05). Longitudinal strain did not differ between groups. The longitudinal:circumferential strain ratio was significantly lower in rTOF compared to isolated pulmonary regurgitation (1.24 versus 1.53, p = 0.05). Circumferential and longitudinal strain rates did not differ between groups. Conclusions: The right ventricles in rTOF demonstrate greater reliance on circumferential strain in response to increased volumes. The decrease in longitudinal:circumferential strain ratio suggests rTOF right ventricles display a greater adaptive response to the volume load than isolated pulmonary regurgitation, highlighting the importance of the relative contributions of both circumferential and longitudinal strain in order to understand the mechanisms of right ventricular dysfunction in pulmonary regurgitation.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.002 | 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".