LEFT VENTRICLE EFFICIENCY IN CHILDREN WITH MODERATE AORTIC VALVE REGURGITATION OR MODERATE AORTIC VALVE STENOSIS

Abstract

Patients with congenital aortic valve disease can remain asymptomatic. But the risk of increased left ventricular (LV) wall stress, irreversible myocardial fibrosis and sudden death in untreated patients warrants earlier intervention. The timing for curative therapy for severe aortic valve disease (stenosis or regurgitation) is clearly defined, but the optimal timing for moderate aortic valve disease (moderate aortic stenosis (mod AS) or moderate aortic regurgitation modAR) remains unknown and largely unexplored. The specific objective of this work is to develop a mathematical model in order to evaluate left ventricle performance in patients with moderate aortic valve disease. Thirty pediatric patients were included in this study (healthy = 10; modAS = 11; modAR = 9). A mathematical model has been developed to evaluate patient-specific LV performance. In addition, we have developed a new non-invasive parameter, LV efficiency, evaluating the effect of aortic stenosis and aortic regurgitation on LV function: Elv=(1-Rf)*(Psys/(Psys+TPGmean)) where Rf is the regurgitant fraction, Psys is the systolic arterial pressure and TPGmean is mean transvalvular pressure gradient. Our results show that healthy patients possess a very high LV efficiency (96.4±1.9%). However, modAS patients have a significant reduction in their LV efficiency (82.7±8.4%, p < 0.05). Interestingly, the modAR group was found to have the lowest LV efficiency (72.5±7.3%, p < 0.05). Patients with aortic valve disease even at a moderate severity should be carefully followed because their LV performance is significantly reduced compared to healthy patients. The evaluation of LV efficiency offers a promising avenue for future stratification of aortic valve disease and optimal timing of intervention.