Noninvasive Assessment of Right Ventricular‐Pulmonary Arterial Coupling in Repaired Tetralogy of Fallot by Magnetic Resonance Imaging
Bibliographic record
Abstract
Background Right ventricular (RV) to pulmonary arterial coupling (RVPAc) quantifies RV contractility in relation to its afterload but traditionally requires high‐fidelity catheter derived pressure‐volume loops. We sought to evaluate a noninvasive volume‐based RVPAc parameter in children and adults with repaired tetralogy of Fallot in relation to pulmonary regurgitation (PR), RV outflow tract obstruction (RVOTO), and exercise capacity. Methods We retrospectively studied 92 pediatric and 105 adult patients with repaired tetralogy of Fallot who had cardiovascular magnetic resonance imaging and cardiopulmonary exercise testing within a 1‐year interval. RVPAc was calculated as the ratio of RV end‐systolic volume over stroke volume. RVOTO gradient was obtained by echocardiography; RV ejection fraction, and PR fraction by cardiovascular magnetic resonance imaging. Exercise capacity was measured as the percentage of predicted peak oxygen consumption during cardiopulmonary exercise testing. Subgroups were established depending on the combination of PR‐RVOTO (cutoff defined as PR >30% and RVOTO >25 mm Hg). Results RVPAc was significantly higher in adult versus pediatric patients (1.23 [1.03–1.48] versus 1.00 [0.88–1.15]; P <0.001). RVPAc was comparable in the 4 pediatric hemodynamic subgroups ( P =0.38) but tended to be higher in adults with either RVOTO, PR, or RVOTO+PR ( P =0.05). RVPAc highly correlated with RVEF (r=−0.991, P <0.001) but was not associated with percentage of predicted peak oxygen consumption. Conclusions Worse RVPAc in adult versus pediatric patients with repaired tetralogy of Fallot may signify progressive RV‐PA uncoupling with age‐ or era‐related effects. However, the clinical use of volumetric RVPAc in repaired tetralogy of Fallot appears limited, as it does not provide additional information over RVEF and is not associated with exercise capacity.
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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) | 0.001 | 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".