| With a high incidence and poor prognosis,dilated cardiomyopathy(DCM) is one of the major cardiomyopathy threatening to human health. Previously general heart form, myocardial motion and ventricular function of DCM were detected using conventional two-dimensional color doppler echocardiography(2DCDE), and cardiac movement was observed carefully by doppler tissue imaging(DTI), speckle tracking imaging and velocity vector imaging. Based on 2DCDE and DTI, with vector flow mapping, this research was to study the changes in left ventricular cavity blood flow, observe the different characteristics of stream line map, vortex map, and vector map, compare eddy current parameters and the vector of different segments of left ventricle(LV) in different phases of cardiac circle between DCM group and normal controls, discuss the relationship between these data, the heart chamber morphology and cardiac function, and try to evaluate DCM hemodynamic cardiac function for a new way, provide a reference for clinical diagnosis, treatment and prognosis of DCM.Part 1. Assessment of normal left ventricular flow in different phases of cardiac circle using vector flow mapping[Objective]Reference to some parameters detected by 2DCDE and DTI, this study was to analysis the features of normal left ventricular flow changes in different phases of cardiac circle using VFM, the relationship between VFM parameters and left ventricular systolic and diastolic function, and provide reference indicators for the further study of DCM left ventricular flow.[Methods]1. Study subjects: 48 healthy controls, including 30 males and 18 females, whose age were from 22 to 74 years old, and average age was 52.2±14.3. Heart and lung diseases and the related diseases were excluded by history, physical examination, ECG, laboratory tests and echocardiography.2. Methods: Connecting ECG, after the routine 2DCDE examination, left ventricular end diastolic dimension (LVED ) and left ventricular end systolic dimension (LVSD) were recorded by M-mode ultrasound, left ventricular end diastolic volume (LVEDV) and left ventricular end systolic volume (LVESV) were calculated. Then LVEDV and LVESV were measured by Simpson dual plane method, left ventricular ejection fraction (EF) was obtained, and the EF value obtained by two methods was compared. Spectrum of mitral annular myocardial movement was gained with Doppler Tissue imaging. Mitral annulus of left ventricular wall systolic maximum velocity(Vs), the maximum velocity of early diastole (Ve) and maximum velocity of late diastole (Va), isovolumic contraction time (ICT), isovolumic relaxation time (IRT), ejection time (ET) were measured, and the Tei index were calculated. Then transferred to VFM mode, left ventricular dynamic color doppler flow image of three consecutive cardiac cycle were captured in the apical three-chamber view and five-chamber view, using VFM software DSA-RS1, characteristics of vector map, vortex map and stream map were analyzed, and the vortex parameters (transverse diameters, vertical diameters , number and location) of isovolumic contraction (IVCT), rapid ejection (RE), slow ejection (SE), isovolumic relaxation (IVRT), early diastole (ED), mid-diastole (MD), and late diastole (LD) were measured. The flow vector of apical segment, middle segment, basal segment of left ventricular outflow tract in IVCT and RE, vectors of left ventricular inflow tract in ED were evaluated. The difference of the different segmental vector value in the same phase and the difference of vector parameters in different phases were compared, and the correlation between these parameters and EF, Tei index were investigated.[Results]1. Conventional ultrasonic inspection(2DCDE, DTI): Regular heart shape, normal size and myocardial motion coordination were found in all subjects. All parameters were within normal limits. The mean measurement were: LVED(47.12±2.47)mm,LVSD(32.52±3.01)mm,LVEDV(78.22±24.56)ml,LVESV(28.57±11.42)ml,EF(64.79±5.36)%,Vs(12.44±2.67)cm/s,Ve (15.83±4.25)cm/s,Va(11.45±5.39)cm/s,IRT(76±5)ms,ICT(35±4)ms,ET(322±13)ms , Tei index 0.33±0.08 respectively.2.VFM results:⑴LV blood flow characteristics in different phases of cardiac cycle: The blood flow in isovolumic contraction was mainly vortex. The flow in ejection was mainly laminar flow quickly launched into the aorta. In rapid ejection, small vortex rings of small number were found under the mitral valve, while almost no vortex was found in slow ejection. No vortex but a little low blood flow towards the apical was found in isovolumic relaxation. The blood flow in early diastole and late diastole was mainly laminar flow. Small vortex rings of small number were found under the mitral valve in both phases. While the left ventricular cavity was filled with large and many laps eddy in middle diastole.⑵Comparison of LV vector value: In IVCT, RE and ED, the basal segmental vectors maximum, the middle segmental vectors of the second, and the apical segmental vectors minimum, showed an increasing tendency from apical segment to basal segment. In the same phase vectors of three segments were statistically significant different (P <0.05).⑶Comparison of vortex parameters: Vertical diameters and transverse diameters of the vortex were greatest in MD, while which were less in IVCT, and the least in RE. Vertical diameters and transverse diameters of the vortex in ED relatively close to which in LD. In five vortex phases, vertical diameters, transverse diameters were significantly different (P <0.05). Vortex ring number followed successively by MD, IVCT, ED, LD, RE in descending(P<0.05).⑷Correlation between vectors, vortex parameters and EF, Tei index: In RE, ED, and IVCT, left ventricular vectors of the apical segment, middle segment and basal segment were positively correlated with EF (0.39≦ r≦ 0.46); vectors of the basal segment in RE were positively correlated with Tei index, r 0.45; vectors of apical segment, middle segment in RE and vector of the three segments in ED, IVCT showed a weak positive correlation with Tei index (0.08≦ r≦ 0.27). Eddy parameters and EF, Tei index were not distinctly related in different phases.[Conclusion]Through stream line map, vortex map, vector map and other modes, VFM can not only show the direction and the size of the basic flow in heart chamber, but also quantitatively measure the vortex, preliminary quantitative study the different blood flow patterns of normal left ventricular cavity in different phases of cardiac cycle. VFM can provide reference indicators for the further study of changes in left ventricular cavity flow of DCM patients. [Objective]Reference to some parameters detected by 2DCDE and DTI, The aim of this study was to analysis the features of DCM left ventricular flow changes in different phases of cardiac circle using VFM, compare the difference between normal and DCM patients, visually display the left ventricular flow structure of DCM through different VFM diagram, and preliminary quantitatively assess the changes of DCM left ventricular flow with vector value and vortex parameters, to learn more about the intracardiac blood flow structure changes and hemodynamic changes of DCM with the enlargement of the heart, myocardial pathologic changes and the systolic and diastolic dysfunction.[Methods]1. Study subjects: 29 patients with DCM, including 19 males and 10 females, whose age were from 18 to 78 years old, and average age was 58.2±15.3. Structural heart disease such as heart valve disease, coronary heart disease etc and image dissatisfied were excluded.2. Methods: Research methods used and the parameters measured were the same as the first part of study, The results were compared with the normal group.[Results]1. Conventional ultrasonic inspection(2DCDE, DTI): Irregular increased heart shape, spherical expansion, and decreased myocardial motion were found in all patients. EF and ET were distinctly reduced. IRT, ICT and Tei index were significantly increased. The mean measurement were: LVED(62.75±5.38)mm,LVSD(42.78±6.19)mm,LVEDV(155.49±60.28)ml,LVESV(98.37±43.65)ml,EF(34.56±8.29)%,Vs(6.93±4.28)cm/s,Ve (9.36±3.76)cm/s,Va(8.52±6.47)cm/s,IRT(128±36)ms,ICT(72±10)ms,ET(240±39)ms,Tei index 0.79±0.26 respectively.2. VFM test results:⑴LV blood flow characteristics in different phases of cardiac cycle: In DCM group, vortices were found in all seven cardiac cycle phases, flow lines were more messy than that in the control group, vortex shape and location were more variable than that in the control group, and diastolic vortex were closer in the lower left ventricle than that in the control group.⑵Comparison of LV vector value: In DCM group, the basal segmental vectors maximum, the middle segmental vectors of the second, and the apical segmental vectors minimum in ED and RE, which showed an increasing tendency from apical segment to basal segment. While in IVCT, vectors of the middle segment of left ventricular outflow tract were maximum, vector of the middle segment were higher than that of the basal segment, and vectors of the basal segment were higher than that of the apical segment, showing a higher in the middle and lower in two ends characteristic (P<0.05). In IVCT, compared with control group, vectors of the middle segment were higher, while the basal segmental vectors were lower in DCM (P<0.05). The difference of apical segmental vectors between two groups was not significant. In ED and RE, vectors of the apical segment, middle and basal segment in DCM group were less than that of the corresponding segments in control group(P<0.05).⑶Comparison of vortex parameters: Compared with control group, in DCM group, the diameters of the transverse diameters and vertical diameters were greater, and number of the vortices were more, the vortex parameters between the two groups were statistically different in MD(P<0.05), and statistically significant different in other phases (P<0.01). Within the DCM group, the transverse diameters, vertical diameters and number of vortex were different in different phases of cardiac circle (P<0.01).In IVCT, the vortex diameters were maximum. Vortex diameters from large to small were IVCT, MD, LD, ED, RE, SE and IVRT, respectively. Vortex number from more to less were IVCT, MD, LD, ED, RE, IVRT, and SE, respectively.⑷Correlation between vector, vortex parameters and EF, Tei index: In RE, DCM left ventricular vectors of the middle segment and basal segment were significantly positively correlated with EF, but negatively correlated with Tei index, r were 0.53,0.56 and -0.41, -0.48 respectively. Vectors of the apical segment in RE and vectors of all three segments in ED and IVCT were positively correlated with EF(0.31≦r≦0.43), and weak positively correlated with Tei index(0.09≦︱r︱≦0.26). Eddy parameters and EF, Tei index were not distinctly related in different phases.[Conclusion]VFM technology can visually show the left ventricular flow structure of DCM patients. Left ventricular eddy size, number of turns and vector value of the different segments were different between normal and DCM patients in different phases of cardiac circle. VFM can not only vividly observe the left ventricular cavity blood flow structure of DCM, qualitatively evaluate changes of the left ventricular blood flow in different phases of cardiac cycle, but also be used for preliminary quantitative evaluation of DCM hemodynamic changes in cardiac chambers. |
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