Study Of Periphery Artery Hemodynamic Changes In Patients With Coronary Atherosclerotic Heart Disease Using Wave Intensity Analysis

The incidence of coronary artery disease （CAD）, which is one of the most commoncardiovascular diseases in the elderly population and one of the most important causes ofchronic heart failure, shows an increasing trend in China. Due to the severity of myocardialischemia, CAD patients may show different clinical symptoms and circulatory functionalstatus. In this study, left ventricular ejection fraction （LVEF）, the iconic indicator to reflectthe systolic function of the left ventricular in CAD patients is acquired with Simpson’smethod, and hemodynamic status of common carotid artery （CCA） is detected with waveintensity （WI） techniques in order to analyze and compare changes in WI parameters ofCAD patients with different contractile function, and to explore the relationship betweenleft ventricular contraction function and common carotid arterial hemodynamic changes inCAD patients.Part1: Study of normal human common carotid arteryhemodynamic using WI technique[Objective]:Normal human carotid artery （CCA） hemodynamic parameters were obtained with WIon the basis of conventional two-dimensional carotid artery ultrasound, and correlationbetween the hemodynamic parameters and left ventricular systolic function was analyzed,to investigate the clinical value of WI technology in the assessment of cardiac vascularfunction, and to provide a reference for further study of the common carotid artery bloodflow hemodynamic changes in CAD patients.[Method]:1. Study subjects:35healthy volunteers, among them23males, and12females, agedfrom40to83years old, average age （61.69±13.48） years, those with cardiovascularsystem diseases were excluded by the routine examinations.2. Methods: Blood pressure of the subjects was measured in a calm state,conventional echocardiography was applied, left ventricular end-diastolic volume （EDV）and end-systolic volume （ESV） were measured using Simpson’s method in the apical four-chamber view, and left ventricular ejection fraction （LVEF） values were calculated.Then carotid intima-media thickness was measured in the long axis view, and the presenceor absence of plaques was recorded. Later in WI mode, limb-lead ECG was connected tosubjects, the dilated part1.5cm to the proximal end of the left common carotid artery（LCCA） was chosen as a collection site, two sampling gates in the B-mode sampling linewere placed at the junction of outer and middle membrane of the anterior and posteriorwall of the artery, the Doppler angle was consistently kept at60°. The instrument wasadjusted to keep displaying a clear image, the select key was pressed to collect sampleimages, and results were frozen when smooth waveform changes of arterial diameterappeared, WI key was pressed to show sampling interface, blood pressure values wereinput, more than5to7consistent waveforms were selected, the next key was pressed toshow report interface. Images were restored into discs, all data were collected for offlineanalysis,such as W1、W2、NA、R-1st、1st-2nd.[Results]:1. Routine ultrasound examination: the heart chamber sizes of normal subjects werenormal, myocardial motion was in coordination, heart valves were in good opening andclosing condition. Average EDV of left ventricular was（82.46±12.99）ml, ESV was（29.43±5.20）ml. Left ventricular ejection fraction （LVEF） was normal, with an averageof （65.75±4.93）%, routine ultrasound of the common carotid arteries showed smoothlumen surfaces, normal carotid intima medial thickness, which was0.67±0.07mm, noplaques were spotted in the lumen, good blood flow filling was observed in the colourdisplay mode.2. WI examination: the measurement results of this group: W1was （11.47±3.50）mmHg×m^-1×s^-2, W2was （3.06±1.36）mmHg×m^-1×s^-2, NA was （35.76±9.24）mmHg×m^-1×s^-1, R-1st was （96.71±18.00）ms,1st-2nd was （259.83±25.38）ms.3. Indicators reflecting the elasticity of blood vessels: β was9.27±2.30, Ep was（126.97±35.22）kPa, AC was （0.69±0.23）mm²/kPa, AI was （14.21±1.77）%, PWVβ was（7.18±1.31）m/s.4. The correlation analysis showed: positive correlation between W1and W2, andbetween W1and LVEF. [Conclusion]:WI parameters can intuitively display real-time normal human carotid artery bloodflow velocity characteristics, and reflect vascular elastic state at the same time, it is easy tooperate, safe and non-invasive, which can provide references for further study of coronaryheart disease in patients with common carotid artery hemodynamic changes. Part2. Study of CAD patients common carotid arterieshemodynamic changes using WI technology[Objective]:On the basis of the first part of the study, WI technology was applied to acquirecommon carotid artery （CCA） hemodynamic parameters of CAD patients, andparameters were compared with the normal group, to discuss the characteristics ofhemodynamic changes under different left ventricular systolic function conditions.[Method]:1. Subjects:41CAD patients diagnosed by coronary artery disease（CAD） in thecardiology department, among them26males and15females, aged45-82years, mean age（59.68±7.61） years old, patients with valvular diseases （including severe valvularregurgitation）, congenital heart diseases, hypertrophic cardiomyopathy, serious arrhythmiawere excluded. LVEF values were divided into two groups: group A （LVEF>50%, n=23,15males and8females）, group B （LVEF≤50%, n=18,11males and7females）2. Methods: The same method with the first part, while the parameters between thecase and control groups were analyzed. [Results]:1. Routine ultrasound examination: left ventricular sizes of CAD patients wereirregularly larger than those of normal group, Average EDV of left ventricular was（89.77±15.61）ml, ESV was（33.56±11.10）ml. while myocardial movement lackedcoordination. left ventricular ejection fractions of group A were still normal （59.61±3.35）%, and a decrease of left ventricular ejection fractions were observed in group Bpatients （38.89±6.17）%, routine ultrasound of the common carotid artery showed roughintimal surface and medial thickening,0.91±0.12mm, visible plaque formation in thelumen of some patients, with filling defects in the color display mode.2. WI examination: W1, W2, of CAD patients were significantly lower than normalgroup, R-W1was increased, with no significant difference between NA and1st-2nd.CAD group W1was （7.07±3.65）mmHg×m^-1×s^-2, W2was（1.65±0.85） mmHg×m^-1×s^-2, NAwas （33.98±12.61）mmHg×m^-1×s^-1, R-1st was113.881±3.78ms,1st-2nd was260.46±5.80ms.3. Indicators reflecting the elasticity of blood vessels: β, Ep, AI of CAD patients weresignificantly higher than those of normal group, while differences in pwvβ and AC werenot statistically significant; CAD group β was11.12±4.39, Ep was （151.98±52.43） kPa, ACwas （0.71±0.32） mm²/kPa,AI was （20.26±13.00）%, PWVβ was （7.55±1.44）m/s.4.Analysis showed positive correlations between W1and W2, W1and LVEF[Conclusion]:WI parameters can reflect hemodynamic changes of common carotid arteries in CADpatients with different LVEF levels, as well as changes in arterial elasticity, as a newintra-arterial hemodynamic technique to reflect cardiac function, it can provide valuablereferences for clinical evaluation of cardiac function, and is expected to play a certain rolein clinical work.