Preliminary Evaluation Of Left Ventricular Energy Loss In Gout Patients Using Ultrasonic Vector Flow Mapping

Objective: Preliminary estimate left ventricular structure and function in gout patients,and visually qualitative and quantitative analysis flow field applying ultrasonic vector flow mapping(VFM),with exploring correlation among energy loss and left ventricular function.Methods: Enrolled clinically hospitalized gout patients(Gout group,n=45)and healthy subjects(Control group,n=40)aligned for general parameters,like gender,age(AGE),body surface area(BSA),body mass index(BMI),systolic blood pressure(SBP),diastolic blood pressure(DBP)and heart rate(HR),and all had been ruled out complication like hypertension and diabetes.Based on the course of gout(COURSE),the gout were further divided into gout whose COURSE≥5 years(Long-course subgroup,n=24)and gout whose COURSE<5years(Short-course subgroup,n=21).According to their age,the gout were further divided into gout whose age>40 years(Middle-aged gout subgroup,n=22)and gout whose age≤40 years(Young gout subgroup,n=23),while the control were divided into control whose age>40 years(Middle-aged control subgroup,n=20)and control whose age≤40 years(Young control subgroup,n=20).Echocardiography exam was performed with Prosound F75 color Doppler ultrasound apparatus.Conventional echocardiographic parameters are measured and derived on line: left atrial anterior and posterior dimension(LAD),left ventricular diameter(LVD),ventricular septal thickness(IVS),left ventricular posterior wall thickness(LVPW),left ventricular ejection fraction(LVEF),early and late diastolic trans-mitral valve flow peak velocity(E and A),average early diastolic left ventricular parietal and interventricular septum mitral annular peak velocity(e),E/A and E/e.Switch model conversion of echocardiography to VFM,and store two dimensional gray-scale and color doppler transthoracic echocardiographic dynamic images on standard apical four-chamber,three-chamber and twochamber plane.In 2DTT analysis mode,the global longitudinal peak strain(GLS)was offline analyzed and was averaged by three views.In EL analysis mode,the global average energy loss(EL)was offline obtained at 7 phases,which were defined as isovolumic diastole,early diastole,mid-diastole,late diastole,isovolumic systole,early systole and late systole,and named P1-P7 in sequence.EL was averaged by three chambers and corrected by RR interval to ELc.Statistical differences of general,routine echocardiographic,energy loss parameters were statistically compared between Gout group and subgroup and corresponding Control group.And correlation were statistically analyzed between traditional cardiac function parameters and ELc,between age,the course of gout and ELc.Results:1.case control group:There was no significant difference in general parameters between Gout group and Control group(P>0.05).GLS in Gout group was statistically higher than that of Control group(P<0.05).ELc P3,ELc P6 and ELc P7 in Gout group were statistically higher than those of Control group(P<0.05).2.age inter-group:There was no significant difference in general parameters between Middleaged gout and Middle-aged control subgroup,between Young gout and Young control subgroup(P>0.05).E/e in Middle-aged gout subgroup was statistically higher than that of Middle-aged control subgroup,GLS in Young gout subgroup was statistically higher than that of Young control subgroup(P<0.05).ELc P3 in Middle-aged gout subgroup was statistically higher than that of Middle-aged control subgroup,ELc P3 and ELc P6 of Young gout subgroup were statistically higher than those of Young control subgroup(P<0.05).3.age intra-group:AGE and COURSE in Middle-aged gout subgroup were statistically higher than those of Young gout subgroup,BSA in Middle-aged gout subgroup was statistically lower than that of Young gout subgroup,Age in Middle-aged control subgroup was statistically higher than that of Young control subgroup(P<0.05).E/A and E/e in Middle-aged gout subgroup were statistically higher than those of Young gout subgroup,E/A in Middle-aged control subgroup was statistically higher than that of Young control subgroup(P<0.05).ELc P4,ELc P5,ELc P7 in the Middle-aged gout subgroup were statistically higher than those of Young gout subgroup,ELc P4,ELc P5,ELc P7 of Middle-aged control subgroup were statistically higher than those of Young control subgroup(P<0.05).4.COURSE subgroup:AGE and COURSE in the Long-course subgroup were statistically higher than those of Short-course subgroup(P<0.05).E/e in Long-course subgroup was statistically higher than that of Short-course subgroup(P<0.05).ELc P4 and ELc P5 in the Long-course subgroup were statistically higher than those of the Short-course subgroup(P<0.05).5.Correlation analysis:Diastolic parameters: positively correlation existed among ELc P2,ELc P4 with E/e(r=0.306,0.405,P<0.01),and negatively correlation existed between ELc P4 and E/A(r=-0.364 P < 0.01).Besides,positively correlation existed between ELc P2 and E/A(r=0.409,P<0.01).Systolic parameters: positively correlation existed between ELc P6 and LVEF(r=0.306,P<0.01).AGE: positively correlation was demonstrated among ELc P4,ELc P5,with AGE(r=0.622、0.671,P<0.01);COURSE: positively correlation was demonstrated among ELc P4,ELc P5,ELc P7 with COURSE(r=0.433、0.465、0.300,P<0.01).Conclusion:The increased EL in gout and subgroups,compared to the control,suggested that early mild left ventricular dysfunction have occurred in gout,and it might be related with age and the course of gout.VFM technology is expected to be a new technical modality to assess early left ventricular dysfunction in gout.