53 Abnormal myocardial strain in adult patients with unrepaired ebsteins anomaly and prediction of impaired exercise tolerance
Bibliographic record
Abstract
Introduction Morbidity and mortality in unrepaired Ebstein’s anomaly (EA) relate to exercise capacity, ventricular dysfunction and congestive cardiac failure. Accurate assessment of ejection fraction is difficult due to geometry of the ventricles and complex anatomy of the tricuspid valve in these patients. Myocardial deformation detects ventricular function before other parameters in other cardiovascular disease and has incremental value in predicting outcome but has not been tested in EA. Objectives 1. To compare myocardial deformation in adult patients with unrepaired EA with control subjects; 2. To investigate the relationship with exercise capacity as a known predictor of outcome in these patients measured using cardio-pulmonary exercise testing (CPEX). Methodology This is a single, centre study of 36 consecutive patients with unrepaired EA (20 females) aged 36.3±13.2 years undergoing cardiovascular magnetic resonance (CMR; 1.5T Avanto, Siemens). 2D RV longitudinal strain (RV GLS) and 3D left ventricular longitudinal (GLS) and circumferential (GCS) strains were obtained using Circle cvi42 (Calgary, Canada). Strain values were compared with normative data obtained from age and sex matched healthy controls using paired samples t test. Pearson correlation was used to study the correlation between strain and cardiopulmonary exercise measures. Results Demographic data and conventional CMR data in EA and controls are displayed in table 1. RV end diastolic volume was increased in EA and the RV and LV ejection fraction were impaired compared to the healthy controls. RV GLS and RA GLS were impaired in EA compared to control subjects, as were LV GLS and GCS (see figure 2). RA peak strain correlated with% predicted VO2 peak (r=−0.472, p=0.017), peak VO2 (r=−0.431, p=0.028) and VE/VCO2 slope (r=0.414, p=0.036 respectively). There was no correlation between severity of tricuspid regurgitation, RV ejection fraction or any RV strain parameters and CPEX parameters. Conclusion In adult patients with unrepaired EA, RV, RA and LV global strains are impaired compared to controls. Functional RA peak strain is related to impaired exercise capacity and future study is needed to establish whether these parameters have independent prognostic value in this cohort.
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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 | 0.001 | 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".