Ultrasonography Studing In Left Cardiac Function In Patients With Systemic Lupus Erythematosus

BackgroudSystemic lupus erythematosus(SLE) is a comparatively autoimmune disease, which can involve multisystem;Cardiac involvement in systemic lupus erythematosus is well known.The prognosis of SLE has been obviously improved in recent years by reasonably applying pharmacal,but the case fatality of SLE has reached to 10%.It has been established that the proportionate mortality from myocardial infraction is approximately 10 times greater in patients with SLE than in the general age-and sex-matched population.Ultrasonography as a useful techinque is widely applied in assessing the cardiac complication in patients with SLE,because the ultrasonography has the advantages in evaluating the structure and function of the cardiac and the ventricular wall motion abnormality;detecting hemodynamics ad.There are some reports about SLE-related cardiac complication and left ventricular dysfunction by echocardiography of two-dimensional,M-mode and the tissue doppler imaging,but the study is very few about the left atrium structure and function;the left ventricular systolic synchronicity in patients with SLE.There have many methods in judging myocardium systolic synchronicity by tissue doppler imaging,but in the two-dimensicnal echocardiography,the each segment of ventricular displays in the different cross-section and in the dissimilar cardiac cycle;thus the results may have certain phase errors.Real-time three-dimensional echocardiography(RT-3DE) has been utilized in clinic as a new ultrasonic image technique.RT-3DE overcomes the inadequacy of two dimensional echocardiography(2DE),it can evaluate myocardium systolic synchronicity by displaying the each segments of left ventricular in the same cardiac cycle and observing the variation rule of the each segment volume.ObjectivesThere are four purposes in this study.Firstly,to assess the left ventricular monolithic function using TDI-Tei index and related index of echocardiography in patients with systemic lupus erythematosus in the active stage.Secondly,to evaluate the difference of the function of left atrium in patients with SLE in the active stage by two dimensional echocardiography and related parameters.Thirdly,to study the left ventricular systolic synchronicity in patients with SLE in the active stage by RT-3DE.Methods1.The objects were divided into two groups.SLE group:30 patients satifying the revised criteria of the American Rheumatism Association for classification of SLE in 1997 in hospital during the period February 2008 to July 2008(3 male and 27 female; mean age±SD,29±9 years) were enrolled in this study.Activity of disease was assessed using SLE daily activity index(SLEDAI)scale.Acrossing to the classification of SLEDAI,30 patients were graded as active(mean scores±SD,10±5 scores).Inclusion criteria were:no clinical evidence of present and/or previous cardiac disease;sinus rhythm;no serious valve diease;no obvious clinical symptom;normal renal function.The history of SLE was 1～36 months(mean months±SD,15±12 months).Control group:27 healthy people(3 male and 24 female;mean age±SD,30±8 years)were enrolled in this study.All of them did not have abnormal findings by physical examination,ECG and echocardiography.Sex and age of the objects were matched between two groups.The objects were measured height and body weight;then the body weight index was calculated.The objects were measured systolic blood pressure and diastolic blood pressure in prostration.2.Images were obtained by philips IE33.All of the studying objects in left-lateral position was connected limb lead ECG..At first,the left ventricular ejection fraction(LVEF),left atrium internal diameter at end-diastole(LAIDd),left ventricular internal diameter at end-diastole(LVIDd),interventricular septum thickness(IVST),left ventricular posterior wall thickness(LVPWT) were gained.The relative wall thickness(RWT),left ventricular mass(LVM) and left ventricular mass index(LVMI) were calculated.RWT=(LVPWT+IVST)/LVIDd,LVM(g)=1.04×[(LVIDd+IVST+LVPWT)³-LVIDd³]-13.6,LVMI(g/m²)=LVM/BSA.The parameters of transmitral E,A were measured.3.The maximal systolic velocity of mitral annulus(Sa),the maximal early diastolic velocity of mitral annulus(Ea),the maximal late diastolic velocity of mitral annulus(Aa) of the six walls of mitral annulus were determined with tissue doppler imaging(TDI).The E/A,Ea/Aa,E/Ea,E/(Ea×Sa) were calculated.The parameters of six walls of mitral annulus isovolumic relaxation time(IRT),isovolumic contraction time(ICT),ejection time(ET) were determined;Tei index measured by TDI was calculated as well.The average value of above-mentioned parameters of six walls of mitral annulus were calculated and contrasted between SLE group and normal subjects group.4.Left atrium volume(LAV) was assessed according to the formula 8/3π·L·A1·A2,where A1 is LA area at apical four-chamber and A2 at apical two-chamber views.LAV was calculated at three phases of ventricular cardiac cycle: maximum LAV(V max) at the end-systole just before mitral valve opening,LAV berore atrial contraction(V Pre-A):the last frame before mitral valve reopening,and minimum LAV(V min) at end-diastole just before mitral valve closure.The indices of volume of the left atrium corrected with body surface area were calculated,the indices were LAV_maxi,LAV_pi,LAV_mini.From the three LAV,the following measurements were selected as indices of LA function and calculated according to previous studies: (1) Total Atrial Stroke Volume(TA-SV) defined as Vmax-Vmin,(2) Active Atrial Stroke Volume(AA-SV) defined as VPre A-Vmin,(3)Active Atrial Emptying Fraction(AA-EF) defined as AA-SV/VPre A×100%,(4) Atrial Expansion Index (AEI) defined as TA-SV/Vmin×100%,(5) Passive Atrial Stroke Volume(PASV) defined as Vmax-VPre A,(6) Passive Atrial Emptying Fraction(PA-EF) defined as (Vmax-VPre A)/Vmax×100%,[7]LA kinetic energy(LA-KE):LA-KE was calculated according to the formula 1/2×AA-SV×P×V2,where P=1.06 g cm^-3 (blood density),and(Ⅴ) is the peak velocity of transmitral A wave was measured by pulsed wave Doppler.PA-SV,PA-EF were defined as indices for LA conduit function,AA-SV,AA-EF, LA-KE for LA pump function,and AEI for LA reservoir function.5.Real time three-dimensional echocardiography:the four cavity in apex were obtained by X3-1 probe,and then knocked"Full Volume" function key to obtain orthogonal two pictures in the moment that subjects were required holding their breath to collect the pyramid picture of four cardiac cycle.Analysis of three-dimensions database:Opened the software of Qlab 4.2,the quantitative analysis was carried out by software of 3DQ advanced.The software can draw automatically the endocardium of left ventricular,then three-dimensional model was divided to 17 volume segments,and the time-volume curve of 17 segments of left ventricular,the time to minimal systolic volume(Tmsv) of 16,12-segmental standard deviation(Tmsv16,12-SD),maximal difference(Tmsv16,12-Dif) were also derived, and the above parameters as a percentage of the cardiac cycle with different heart rates between patients also calcutated by the Qlab software,which were Tmsv16, 12-SD%and Tmsv16,12-Dif%respectively.Statistical analysis was executed by SPSS 13.0 software.Results1.The general information such as age,sex,body mass index,heart rate had no statistically significant between two groups.Compared with normal subjects,the SBP, DBP were significantly higher in the SLE group(P＜0.01)2.The parameters of M-mode and two-dimensional echocardiography such as the LVIDd,LVEF,E,A,and E/A had no statistically significant between two groups. LAIDd,RWT,LVMI were significantly higher in the SLE group(P＜0.01).3.The parameter of TDI echocardiography,Sa,ICT had no statistically significant between two groups.Compared with normal subjects,the Aa,Tei index measured by TDI,IRT,E/ Ea,and E/(Ea×Sa) were higher in the SLE group (P＜0.01,or P＜0.05);Ea,Ea/Aa,ET were significantly lower in the SLE group (P＜0.01).E/(Ea×Sa),E/Ea were positively correlated with Tei index measured by TDI r=0.523,P＜0.01;r=0.323,P＜0.05).There had a certain negative correlation among E/(Ea×Sa),E/Ea and Ea(r=-0.605,r=-0.726,P＜0.01).4.Compared with normal subjects,the LAV_maxi,LAV_pi,LAV_mini were significantly higher in the SLE group(P＜0.01);AA-SV,LA-KE,AEI were significantly higher in the SLE group(P＜0.05).5.The parameter of RT-3DE echocardiography,Compared with normal subjects Tnsv16-SD,Tmsv16-Dif,Tmsvl6-Dif/R-R(%),Tmsv16-SD/R-R(%) in SLE group were significantly higher(P＜0.01);Tmsv12-SD,Tmsv12-Dif,Tmsv12-SD/R-R(%), Tnsv12-Dif/R-R(%) were significantly higher(P＜0.05).The normal volume-time curves were regular parabola and arrange in order;the volume-time curves were in disorder in the SLE group.Conclusions1.The left ventricular function in patients with SLE has been damaged.Tei index measured by TDI and E/(Ea×Sa) could be pristine index for accessing the degrade of left ventricular monolithic function in patients with SLE in the active stage.2.The left atrium function in patients with SLE has been changed.LA active blood-pumping function,reservoir function compensationally enhance.3.The patients with SLE have existed the impariment of left ventricular systolic synchronicity;RT-3DE provides a simple,intuitional,noninvasive and new approach tc assess the systolic synchronicity of all the LV segments simultaneously in patients with SLE.