Abnormal left ventricular outflow tract fluid dynamics: Relationship to etiology and diagnosis of pediatric heart defects.

摘要

An understanding of fluid dynamics can shed light of problems of clinical interest in the field of pediatric heart disease. The effects of certain congenital and acquired lesions on left ventricular flow fields are investigated, and the consequences for treatment or assessment of patients with these lesions is discussed. Specifically, knowledge of the relevant flow fields can be useful in understanding the etiology of acquired lesions, and in the development of noninvasive techniques for the assessment of defects using Doppler ultrasound.; The first aim of this work is to examine a potential method using color Doppler flow mapping for measuring shunt flow rate across a ventricular septal defect (VSD). It is shown that this method has only limited applicability, and depends on VSD diameter, shunt flow and aortic outflow strength. The second aim of this work examines the potential for the use of Doppler ultrasound to estimate pressure drops across stenotic aortic valves. An approach for reconciling disagreement between this method and catheter measurement, the traditional standard, is proposed based on the peak Reynolds number of the stenotic jet. The third aim of this work examines the potential role of fluid mechanics in the etiology of subaortic stenosis. The fourth aim of this work examines the link between this subvalvular obstruction and aortic regurgitation. Results from these studies can potentially be used in the diagnosis of congenital defects, and in management and surgical planning.