FLUID DYNAMICS OF SHUNT FLOWS IN PEDIATRIC CARDIOLOGY: SEPTAL DEFECT

室间隔缺损存在于约30%的所有 先天性心脏病的病例。 室间隔缺损是一个巨大的洞， 分隔心脏左右心室的隔膜。 如果存在室间隔缺损， 部分流出的左心室血液通过缺损进入 右心室，再一次到肺循环。 这样的 条件导致左心室机械效率降低 心 对于中大型VSD， 心脏右侧增加，这可能导致肺 血管疾病（肺小动脉肥大性闭塞）。 这项研究将侧重于VSD的基本流体力学， 实现以下两个具体目标。 (1)了解 近端（左心室）流场会聚到VSD， 汇流和横流之间的相互作用， 收缩期射血 (2)了解远端（右心室） 射流流场及其与横流的相互作用 收缩期流出量 这些目标将通过计算机来实现 使用有限差分技术在Cray Y-MP C90上进行模拟。 基本的理解将允许申请人建立在以前的基础上 在阀的设置方面的理论和实验工作 不足以得出潜在的VSD量化技术。

Ventricular septal defects are present in approximately 30% of all cases of congenital heart disease. A VSD is a variably sized hole in the septum which divides the left and right ventricles of the heart. If a VSD is present, the pressure difference between ventricles forces part of the exiting left ventricular blood through the defect into the right ventricle, and once again to the pulmonary circulation. Such a condition results in decreased mechanical efficiency of the left heart. For moderate to large VSD's, the volume and pressure on the right side of the heart increase which can result in pulmonary vascular disease(hypertrophic occlusion of the pulmonary arterioles). The study will focus on the fundamental fluid mechanics of VSD's and accomplish two specific aims as follows. (1) To understand the proximal(left ventricular) flow field converging in to the VSD and the interaction between converging flow and crossflowing streams due to systolic ejection. (2) To understand the distal(right ventricular) jet flow field and its interaction with crossflowing streams due to systolic outflow. These aims will be accomplished using computer simulations on the Cray Y-MP C90 using Finite Difference Techniques. The basic understanding will allow the applicant to build on previous theoretical and experimental work in the setting of valvular insufficiency to derive potential VSD quantification techniques.