Study On Difference Of Left Atrial Function And Dyssynchrony In Patients With Either Dilated Or Ischemic Cardiomyopathy Using Velocity Vector Imaging

Objective:1 To provide another valuable approach in detecting left atrial function and left dyssnchrony by velocity vector imaging.2 Try to find out the difference of left atrial "booster pump "and "reservoir" function and dyssynchrony in patients with either dilated or ischemic cardiomyopathy.Further the more, anaylysis rensaons that LA "booster pump "and "reservoir" function are more depressed in dilated cardiomyopathy than ischemic cardiomyopathy.3 To determine wthether left atrial dyssynchrony is present inpatients with either dilated or ischemic cardiomyopathy and to compare left atrial asynchronous parameters between dilated cardiomyopathy and ischemic cardiomyopathy.Methods:1 The study population consisted of 20 patients with dilated cardiomyopathy(DCMgroup) and 20 patients with ischemic cardiomyopathy (ICM group) and 20 healthy subjects (control group). DCM and ICM group are choosed by WHO/ISFC,DCM group consisted of 13 males and 7 females, mean age of 59.35±4.32 years; ICM group consisted of 15 males and 5 females, mean age of 58.4±5.01 years. The control group consisted of 20 age and gender-matchde normal volunteers consisted 10 males and 10 females,mean age of 55.50±4.5 age.2 A velocity vector imaging ultrasonic systen (Acuson Sequoia 512)and 2.25-4.25MHz transducer was used with WI software workstation.All echocardiography studies were performed with the subjects lying in the left lateral decubitus position in connection with electrocardiogram.Under WI mode, real-time 2D data of left ventricular apical 4-chamber view, apical3-chamber view and apical 2-chamber view were obtained in standard view. ALL the date were recorded in 3 continuous beats and were stored in handware for off-line analysis with VVI software.All eochcardiogrophic parameters were measured and calculated by a single operator.4 Image analysis and parameter measurement:4.1 Left ventricular systolic function parameter measurement:LV end-diastolic volume (LV-EDV) was measured at the point of QRS pave on ECG and LV end-systolic volume (LV-ESV) were measured at the end of T pave on ECG. LV stroke volume and LV ejection force were measured by biplane Simpson method.4.2 Left atrial "booster pump "and "reservoir" function parameter measurement:From 2D echocardiography,in apical 4-chamber view,Left atrial maximal diameter (LATD).Left atrial maximal volume(Vmax) was measured the end of T pave on ECG; Left atrial minimal volume(Vmin) LA volume; at the end of T pave on ECG minmal; pre-atrial contraction LA volume (Vpre) were measured at the point of P pave on ECG. Above LA volumes were calculated using the biplane area-length method as follows:LA volume= 8×(LA area in four-chamber view)×(LA area in two-chamber view)/3Π(LA length).LA volume according to the formulas calculate other parameters of LA:"booster pump" function parameters:active LA emptying volume(AEV), active LA emptying fraction (AEF),LA ejection force(EF);"booster pump"function parameter:LA expansion index (AEI), all parameters were adjusted by body surface area.4.3 Left atrial parameter of the peak strain rate and the time peak to strain rate measurement:In VVI mode, we measured the peak strain rate with reference to the QRS complex during ventricular systolic ("reservoir"), and left ventricular late diastole ("atrial booster pump"), in which plane were selected on the left arial free wall,anterior wall, in ferior wall, posterior wall,atero-aortar wall and interatrial wall along long-axis, each of the wall divided of 2 segme ns (the basal,the moderate).We obtained velocity vector image of the apical 4 chamber view,apical 3-chamber view and apical 2-chamber view.Re gions of interest were placed in the basal and mid-atrial segme nts of the atrial free wall, anterior wall, inferior wall, posteror wall, latero-aorta wall and interatrial wall. Obtaining strain rate curve of 12 segments we measured the peak longitudinal "reservoir" the time to peak strain rate of each segment (T-SRs),calculated the standard deviation of each parameter (T-SD) and the maximal difference of each pa rameter (T-Max).Result:1 Comparison of general parametersThere were no differences between the group in sex, age, HR, and BAS(p>0.05).2 Comparison of LV systolic fuction and LA size volume parameters2.1 LVEDV,LVESV,LVSV and LVEF were increase in DCM group and ICM group than control group,the difference was significant(P<0.01) The difference had no statistical significance between in DCM group and ICM group(P>0.05).2.2 LATD,LAVmax and LAAEV were increase in DCM group and ICM group than control group,the difference was significant(P<0.01).The difference had no statistical significance between in DCM group and ICM group(P>0.05).3 Comparison of LA "booster pump" and "reservoir"fuction parametersLA "booster pump" function parameters:LAEF in DCM and ICM group are both higher than control group, "reserveoir" function parameter:AEI in DCM group and ICM group are both more lower than control group,the difference was significant(P<0.01). LAEF and AEI in DCM group are lower than ICM group(P<0.05).4 Comparison of LA the peak strain rate parameters in"booster pump" and "reservoir" phase left arial free wall,anterior wall,inferior wall,posterior wall,latero-aorta wall,and interatrial wall along long-axis,each of the wall in the basal and the moderate SRs("reservoir") group,the difference was significant(P<0.01).SRs ("reservorvoir") and SRa ("booster pump") in DCM group were lower than ICM group (P<0.05),except the base segments latero-aorta's SRs.5 Comparison of LA dyssynchrony parameters in"reservoir"phaseIn "reservoir"phase,the differential value of the time to peak strain rate in 12 segments of left arial 6 walls T-SRs in DCM and ICM group were lower than control group(P<0.01). T-Sra in DCM group were lower than ICM group (P<0.05).The standard deviation of each parameter T-SD and the maximal difference of each parameter T-Max in DCM and ICM group were lower than control group(P<0.01).T-SD and T-Max in DCM group were lower than ICM group (P<0.05).Conclusion:1 Velocity Vector Imaging appears to be a promising technique to describe the longitudinal,radial and circumferential myocardial fiber architecture.VVI maybe a helpful technique on dectect and assess LA atrial myocardial function and dyssynchrony.2 LA "booster pump","reservoir" fuction, strain rate in patients with dilated cardiomyopathy are more depressed than ischemic cardiomyopathy.3 In "reservoir" phase, LA dyssynchrony exist in in patients with dilated and ischemic cardiomyopathy. Moreover,LA dyssynchrony in dilated cardiomyopathy are higher than ischemic cardiomyopathy.