Decreased ventricular reserve in individuals with thoracic aortic disease
Notice bibliographique
Résumé
Abstract Background Thoracic aortic disease (TAD) – including aortic aneurysm and dissection – are life-threatening conditions. In addition to causing acute aortic syndromes, TAD may chronically increase left-ventricular (LV) -arterial loading and adverse cardiac remodeling, potentially causing heart failure. How TAD changes LV function, particularly during exercise (i.e., LV reserve), has received little attention. Purpose To compare changes in LV hemodynamics and effective arterial elastance (Ea) during sub-maximal exercise in individuals with TAD, to age-matched older (OC) and younger controls (YC) without TAD. Methods Clinically stable patients with TAD (n=12 total; 25% female, 66±12 yrs; aneurysm, n=5; dissection, n=7), without contraindications to magnetic resonance imaging (MRI) were enrolled and compared to healthy OC (n=9, 44% female, 66±6 yrs) and YC (n=6, 43% female, 29±6 yrs) without TAD. Supine LV hemodynamic (end-diastolic, end-systolic and stroke volume [EDV, ESV, SV], ejection fraction [EF], and cardiac output [CO]) were assessed from real-time cardiac MRI at rest, and during stages of progressive stepping exercise starting at ~25-30% of their peak upright power output (Stage 1), until they reached a rating of perceived exertion >5/10 (Final Stage). Resting and exercise Ea was calculated as the product of SV x (0.9 x systolic blood pressure) assessed from an MRI-compatible automatic oscillometric blood pressure cuff. Groups were compared using one-way (resting values) or repeated measures ANOVA (exercise responses). Results At rest, all three groups showed comparable LVEF (TAD: 57.5±5.7%; OC: 58.3±5.9%; YC: 55.7±3.9%), LV size (i.e. EDV; TAD: 166±44 mL; OC: 176±46 mL; YC: 187±62 mL), and Ea (TAD: 1.11±0.19 mmHg/m; OC: 1.17±0.34 mmHg/mL; YC: 0.94±0.22 mmHg/mL) - P>0.10 for all. There was a significant group-by-exercise interaction for exercise CO augmentation (P<0.001, Fig 1) with a trend for progressively blunted exercise CO augmentation across YC (+6.7±1.8 L/min) to OC (+5.0±1.4 L/min) and to TAD (+3.6±1.5 L/min). From rest to the final stage of exercise (Fig 2), patients with TAD had a greater relative increase in Ea (+10%) versus OC (-4%, P=0.02) and YC (-2%, P=0.08). This coincided with a lesser decrease in ESV in TAD (-5%) vs. OC (-13%, P=0.03) and YC (-12%, P=0.01) which, combined with a comparable increase in EDV for all groups, resulted in a blunted increase in EF in TAD (+5.3%, P=0.03) compared to OC (+8.1%, P=0.03) and YC (+8.9%, P=0.03). Responses did not differ for TAD patients with or without surgical repair (P>0.10 for all). Conclusions Patients with TAD show decreased cardiac reserve during sub-maximal exercise, secondary to higher effective arterial elastance and a blunted ability to reduce ESV. These features may predispose to adverse cardiac remodeling and heart failure, particularly when afterload is further increased by age- and/or chronic disease-related vascular stiffening.Cardiac output in TAD, OC and YCArterial elastance and LV responses
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».