The Study On The Relationship Of The Left Ventricular Flow Propagation Velocity And Changes In Left Ventricular Morphology As Well As Left Ventricular Filling Pattern In Patients With Acute Myocardial Infarction

Objective:To evaluate the relationship of the left ventricular flowpropagation velocity and changes in left ventricular morphology as well as leftventricular filling pattern in patients with acute myocardial infarction, fullyrecognize the the predictive value of Vp in the occurrence of adverse events inthe process of AMI.Methods:1A total of74patients with AMI were enrolled in this study, including46males and28females. AMI diagnostic criteria accord with the standardsestablished by the Chinese cardiovascular disease society in2001[1]:(1) thetypical clinical symptoms of ischemic chest pain;(2) the ECG hadcharacteristic graphics of dynamic evolution;(3) cTnT or myocardial enzymeselevated,all patients must have more than two of the above criteria or twobefore being selected.Infarction location:Anterior wall:24cases, extensiveanterior wall:11cases, inferior wall:23cases and inferior wall and rightventricular:16cases.Cardiac function Killip classification: grade Ⅰ:31cases,grade Ⅱ:23cases, grade Ⅲ:12cases, grade Ⅳ8cases.All the research objectwere sinus rhythm, and excluded valvular lesions and obvious valvularregurgitation, combined with other heart diseases, etc.2According to reference[2]method: the left ventricular filling pattern of74patients with AMI is divided into: normal filling, EDT is140-240ms, Vp≥45cm/s; impaired relaxation, EDT≥240ms; pseudo-normalization, EDT140-240ms, Vp <45cm/s; restrictive filling, EDT <140ms.3Record the gender, age, history of hypertension, systolic pressure, diastolicblood pressure and heart rate of all subject,at the same time the venous blood of all the subject were collected within12hours after admission to test CKMBlevel.4All subjects were done transthoracic echocardiography within24-48hoursafter admission.A set of color Doppler ultrasonic system(ACUSON SC2000)was used,and the3D-function analysis software was available for quantitativeanalysis of LVA.All echocardiography studies were performed with thesubjects lying in the left lateral decubitus position connected withelectrocardiogram(ECG),all the echocardiography views and measurementswere made according to the standard view of echocardiography. Finally，during a brief breath hold，the3D-mode was activated and the apicalfour-chamber view was got，a full-volume3D image of the left ventricle wasacquired (2beats) and all the datesets were saved on a hardware for analysis.5Image analysis and parameters measurement5.1Parameters of conventional two-dimensional echocardiography and Vp5.1.1Pulse doppler echocardiography：Two-dimensional echocardiography apical four-chamber view was taken,placed pulsed Doppler sample volume in the mitral valve, and flow directionparallel to the sound beam, recording diastolic mitral flow spectrum, earlydiastolic mitral and late peak flow velocity (E, A), E/A, E-wave decelerationtime (EDT).5.1.2Color M-mode Doppler echocardiography: Apical four-chamber view,showed the mitral valve with a smaller color flow and gain adjustment to thesampling frame does not appear noise. M-mode scanning lines placed in themitral valve to the apex of the left ventricular outflow tract in the center.Adjust color doppler baseline below the Nyquist velocity of blood flow to thehighest limit the center for blue Flow propagation velocity (Vp) is a measureof the speed of the first reversal of early filling slope measured from the planeof the mitral valve to the left ventricular cavity at4cm[3].5.2Tissue Doppler imaging:Tissue Doppler sample volume placed in the apical four-chamber view ofthe left side of the mitral annulus, access mitral annulus tissue pulsed Doppler recording ventricular early diastolic mitral annulus tissue velocity e’, andcalculate E/e’.5.3Three-dimensional echocardiography:The images were extracted from ACUSON SC2000workstation and putinto the LVA automatic analysis software.Following the action menu，parameters including LV global end-diastolic volume (LVEDV)，end-systolicvolumes (LVESV)，and ejection fraction (EF), Left ventricular end-diastolicspherical index(LVEDSI), Left ventricular end-systolic spherical ndex(LVESSI) were measured.Results：1Comparison of general clinical parametersNo significant difference was found in gender and age among the fourgroups, data were comparable.Compared with normal filling, systolic blood pressure were lower (P<0.05), CKMB peak were higher (P <0.01), the incidence of Killip≥grade Ⅱwere higher in pseudo-normal group(P <0.05); systolic and diastolic pressurewere lower (P <0.05or P <0.01), CKMB peak was higher, the incidence ofanterior MI, Q-wave MI and Killip≥grade Ⅱwere higher in restrictive fillinggroup(P<0.05or P<0.01); there was no significant difference of the variousparameters between impaired relaxation group and normal filling group(Table1);2Comparison of echocardiographic parametersCompared with normal filling, LVEDSI、LVESSI、EDT increased（P＜0.01）, E/A、Vp、e,decreased （P＜0.01）in impaired relaxation group;LVEDV、LVEDSI、LVESSI、E/e,increased（P＜0.05or P＜0.01），andLVEF、Vp、e,were lowe（rP＜0.01）in pseudonormal group; LVEDV、LVESV、LVEDSI、LVESSI、E、E/A、E/e,were significantly highter（P＜0.05or P＜0.01），LVEF、A、EDT、Vp、e,were significantly lower in restrictive fillinggroup（P＜0.01）.(Table2)3Correlation analysis3.1Correlation of Vp and left ventricular structural parameters There are the negative correlation between Vp and LVEDSI、LVESSI、LVEDV、LVESV (r=-0.671,-0.680,-0.538,-0.574), and there was a significantdifference（Table3）;3.2Correlation of Vp and left ventricular functional parametersThere are the positive correlation between Vp ratio and LVEF,e，,A,DT（r=0.584,0.609,0.317,0.494）.There are the negative correlation of Vp and E/e，,E,E/A（r=-0.618,0.302,0.412）, and there was a significant difference (Table4)3.3Correlation of Vp and left ventricular filling patternSpearman rank correlation analysis showed the correlation between thechange of Vp and the degrees of left ventricular diastolic dysfunction wasexcellent (r=-0.705,P<0.001),with the aggravating of left ventricular diastolicdysfunction, the Vp decreased.(Table5)3.4Correlation between LVEDSI,LVESSI and left ventricular filling patternSpearman rank correlation analysis showed the correlation between thechange of Vp and the degrees of left ventricular diastolic dysfunction wasexcellent (respectively r=0.662,P<0.001;r=0.645， P<0.001)， with theaggravating of left ventricular diastolic dysfunction, the LVEDSI,LVESSIincreased.(Table5)4Follow-up data comparisonThe average follow-up of3months still alive,68patients underwentechocardiography, compared with the earlier LVESSI decreased, Vpincreasedin impaired relaxation group,but there was no significant difference;LVESSI decreased(P＜0.01), LVESSI did not change significantly(P＞0.05),and Vp increased(P＜0.01)in pseudo-normal group; LVEDSI, LVESSIwas progressively increased (P <0.01), Vp was significantly lower (P <0.05)in restrictive filling group.During flow-up9(0-14)months,14patients died.Compared with survivinggroup,Vp was significantly lower in cardiac death group（P＜0.001）（Table6）Cox analysis illustrated that Vp≤30cm/s was a powerful predictor ofcardiac death(relative hazard coefficient is3.44,P=0.02). Conclusions:1In patients with AMI,the left ventricular morphology changed fromoval to sphere development, the Vp is associated with left ventricular sphericalindex;2As the degree of left ventricular diastolic function impairmentmaggravated, the Vp decreased, the Vp can reflect the severity of left ventriculardysfunction.3Vp is an independent predictor of mortality in patients after acutemyocardial infarction.