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On Left Ventricle Stroke Work Efficiency in Children with Moderate Aortic Valve Regurgitation or Moderate Aortic
M Asaadi1,2, W Mawad3, A Djebbari4
1Laboratory of Cardiovascular Fluid Dynamics, Department of Mechanical Industrial and Aerospace Engineering, Concordia University, 1455 de Maisonneuve Blvd. W., Montreal, QC, H3G 1M8, Canada.
Insights
Pediatric patients with moderate aortic valve disease have reduced left ventricular performance, even when asymptomatic. LV stroke work efficiency offers a new way to assess these patients for timely intervention.
Area of Science:
- Cardiovascular Medicine
- Pediatric Cardiology
- Biomedical Engineering
Background:
- Optimal management timing for pediatric moderate aortic valve disease (moderate aortic stenosis or regurgitation) is unclear.
- Untreated moderate aortic valve disease poses risks including left ventricular wall stress, myocardial fibrosis, and sudden death.
- Current risk stratification methods may not adequately identify the need for intervention in asymptomatic pediatric patients.
Purpose of the Study:
- To explore the use of a patient-specific mathematical model for assessing left ventricular (LV) performance in pediatric patients with moderate aortic valve disease.
- To introduce and evaluate Left Ventricular Stroke Work (LVSW) efficiency as a novel, non-invasive parameter for risk stratification.
- To determine if LVSW efficiency can differentiate between healthy controls and patients with moderate aortic stenosis or regurgitation.
Main Methods:
- Generation of synthetic patient data (N=520) for healthy, moderate aortic stenosis (modAS), and moderate aortic regurgitation (modAR) groups.
- Inclusion of clinical data from 25 pediatric patients (9 healthy, 8 modAS, 8 modAR).
- Calculation and comparison of LVSW efficiency between groups using both synthetic and in vivo data.
Main Results:
- Healthy pediatric patients exhibited high LVSW efficiency (synthetic: 91±2%, in vivo: 92±3%).
- Patients with modAS showed significantly reduced LVSW efficiency (synthetic: 78±2%, in vivo: 76±5%, p<0.05).
- Patients with modAR demonstrated the lowest LVSW efficiency (synthetic: 58±3%, in vivo: 66±7%, p<0.05), indicating impaired LV performance.
Conclusions:
- Pediatric patients with moderate aortic valve disease experience significantly reduced LV performance, irrespective of symptoms.
- LVSW efficiency is a promising non-invasive parameter for assessing myocardial function in this population.
- This parameter may aid in future risk stratification and determining optimal timing for intervention in pediatric aortic valve disease.
Abstract:
The optimal timing for management of pediatric patients with moderate aortic valve disease [moderate aortic stenosis (modAS) or moderate aortic regurgitation (modAR)] remains unknown and largely unexplored. Although usually asymptomatic, the risk of increased left ventricular (LV) wall stress, irreversible myocardial fibrosis and sudden death in untreated moderate conditions warrants clearer risk stratification for appropriate timely intervention. In this study, we explore the use of a patient-specific mathematical model to introduce a new evaluative parameter of LV performance in patients with moderate aortic valve disease. Synthetic patient data (N = 520) representing healthy patients, and patients with modAS or modAR were first generated. Then, data from twenty-five pediatric patients were included in this study (healthy = 9; moderate AS = 8; modAR = 8). The effect of modAS or modAR on LV performance was evaluated by LV stroke work (LVSW) efficiency, a new non-invasive parameter. The results demonstrate that healthy patients possess a very high LVSW efficiency (synthetic data: 91 ± 2%, in vivo data: 92 ± 3%). However, modAS patients have a significant reduction in LVSW efficiency (synthetic data: 78 ± 2%, in vivo data: 76 ± 5%, p < 0.05), whereas modAR patients had the lowest LVSW efficiency (synthetic data: 58 ± 3%, in vivo data: 66 ± 7%; p < 0.05). This highlights that patients with moderate aortic valve disease require careful myocardial assessment, regardless of onset of clinical symptoms as their LV performance is significantly reduced. The evaluation of LVSW efficiency offers a promising avenue for future stratification of mixed aortic valve disease for optimal timing of management and intervention.
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