Synchronous assessment of mechanical charaterization of left and right myocardial band of interventricular septum by dual Doppler tissue imaging

Objective To reveal the potential different longitudinal motion characteristics and differences of left and right muscular band (L-MB,R-MB)of interventricular septum (IVS) during systole and diastole in normal subjects.Methods Dual Doppler tissue imaging was applied for the longitudinal velocity curves of L-MB and R-MB of anterior and posterior interventricular septum(P-IVS,A-IVS) at basal,mid,and apical levels in eighty-two healthy subjects.Peak isovolumetric contraction (VIVC),systolic (Vs),early(Ve) and late (Va) diastolic velocities were measured,and myocardial velocity gradient(MVG)and Ve/Va ratio of each segment of L-MB and R-MB were calculated.Results ①Peak velocity of MB:the VrvC,Vs,Ve and Va of R-MB of both A-IVS and P-IVS were higher than those of L-MB; the VrvC,Vs,Ve and Va were gradually decreased from the base to apex of both A-IVS and P-IVS;the VIVC and Vs of A-IVS were higher than those of P-IVS; the Ve and Va of A-IVS were lower than those of P-IVS.②Correlation and MVG analyses of peak velocity of MB:the systolic and diastolic velocities between L-MB and R-MB of both A-IVS and P-IVS have shown a very strong positive correlation;the isovolumetric systolic MVG1 of L-MBof A-IVS,systolic MVG1 of R-MB of P-IVS and the diastolic MVG1 of both A-IVS and P-IVS were higher than those of MVG2.Conclusions The heterogeneity of longitudinal peak systolic and diastolic velocity and regional myocardial compliance,the consistency of moving direction and positive correlation of longitudinal peak systolic and diastolic velocity between L-MB and R-MB of both A-IVS and P-IVS have been demonstrated in normal subjects. Key words: Echocardiography;  Interventricular septum;  Myocardial band;  Dual Doppler tissue imaging