Study Of Left Ventricle Hemodynamics With Echocardiographic Particle Image Velocimetry

Background:vortex which is the unique existence of flow can be found anywhere. Studies of vortex in fluid mechanic have got rapid development in decades so that human can stimulate and evaluate vorticity. According to cardiac electrophysiology and systole-diastole of myocardium, fluid in left ventricular present complicated vorticity Echocardiography is always used to reflect cardiac function by accessing ventricular wall motion but seldom by evaluating the vorticity in chambers. With the updating and developing of measuring technique and measuring method, studies of fluid dynamic turn into a research hot spot Cardiovascular diseases are closely related to arterial blood. The imbalance of cardiovascular dynamic will lead to disorder and many kind of cardiovascular diseases. Therefore, it’s significative to study cardiovascular fluid.Objectives:To discuss the feasibility of echocardiographic particle image velocimetry in left ventricle hemodynamics.Methods:20normal adults and20people with mild stenosis of mitral valve who had been diagnosed in physical examination from2013.10-2014.4were studied by both conventional echocardiography and EPIV. They were matched with for sex, age. Subjects were imaged in a left lateral position by using an GE LOGIQ E9ultrasound system. In addition to a standard echocardiogram,2-dimensional gray scale images were acquired with high frame rate (60-80s) in all3standard apical views and repeated intravenous administration of a dose of left heart contrast (2.0ml of SonoVue). Images were acquired when cavity contrast distribution was homogeneous and single contrast bubbles could be distinguished. Image loops of3cardiac cycles were digitally stored for subsequent offline analysis with hyperflow software.Results:In patients with mild stenosis of mitral valve,completely different flow patterns were identified which showed significantly higher vortex length、and Maximum vector speed, lower width and depth,higher left ventricular energy dissipation than healthy subjects.All of these parameters above show that the position of vortex in patients with mitral stenosis are more away from mitral orifice but more closer to center of left ventricular.The inner diameter of left atrium, Left ventricular end systolic diameter, end diastolic diameter and EF,FS between experimental group have no significantly statistical difference.Conclusions:It was feasible to quantify LV vorticity arrangement between healthy people and patients with mitral stenosis by CE using particle image velocimetry. and the vorticity imaging by CE may serve as a novel approach to depict vortex.This technology can be widely used in clinical diagnosis、evaluation and reconnaissance.