Ventricular mechanics in adolescents with Fontan circulation: comparison to healthy controls
Bibliographic record
Abstract
Abstract Funding Acknowledgements Type of funding sources: None. Background While preserved torsion was demonstrated in very young patients with single ventricle (SV) physiology immediately post Fontan completion, there is very limited data about the changes in univentricular mechanics during adolescence and its association with outcomes. Objective We aimed to a) examine changes in ventricular strain and torsion in adolescents and young adults with SV in comparison to healthy controls, and b. examine its association with markers of myocardial fibrosis on cardiac magnetic resonance (CMR). Methods This is a retrospective single center study of adolescents with Fontan circulation in comparison with controls. Speckle-tracking echocardiography was used to assess ventricular strain, torsion, and untwist. Torsion was measured as difference between apical and basal rotations. CMR volumetric and T1 relaxometry data closest to echocardiograms were obtained. Patients were compared to controls in 1:2 match. Results 50 SV patients (27 LV, 17 RV, and 6 co-dominant) were compared to 100 controls. Demographics, echocardiographic, and CMR measurements are shown in table 1. Median duration from Fontan completion was 13.8 (10.6-16.6) years. Compared to controls, adolescents with SV demonstrated reduced global longitudinal strain [-17.1% (-7.4 to -20.1) vs -20.1%(-12.3 to -24.5), p = 0.01], circumferential strain [-15.2% (-9.1 to – 20.3) vs -19.2% (-12.3 to -23.7), p = 0.007], and radial strain [25.2% (15.8 to 54.3) vs 39.4% (25.7 to 62.1), p = 0.01]. Torsion was reduced in patients compared to controls [5.2˚/cm (-4.5 to 16.1) vs 9.2˚/cm (-6.8 to 17.4) vs, p = 0.01] with decreased apical rotation [3.9˚/cm (-10.2 to 14.8) vs 5.7˚/cm (1.6 to 15.6), p = 0.001] and basal rotation [-1.5˚/cm (-7.5 to 3.7) vs -3.9˚/cm (-0.3 to -8.5), p = 0.04], respectively. T1 values were higher in SV patients compared to controls [1009 ± 36ms vs 958 ± 40ms, p = 0.004] and correlated with worse circumferential strain (r = 0.59, p = 0.04) and inversely correlated with torsion (r=−0.71, p = 0.02). Conclusion Adolescents with SV demonstrated a significant decrease in ventricular torsion compared to controls. The increased T1 times and its association with decreased ventricular strain and torsion in SV patients highlights a potential role for myocardial fibrosis in impairment of ventricular mechanics of these patients. Abstract Figure.
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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 | 0.000 | 0.001 |
| 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".