Study Of Left Ventricular Flow In Different Phaseof Cardiac Circle In Patients With Coronary Atherosclerotic Heart Disease Using Vector Flow Mapping

Part1. Evaluation of left ventricular flow during different phases of cardiac circle by vector flow mapping[Objective]This study was to observe the changes of left ventricular (LV) flow during different phases of cardiac circle by VFM, analyse the relation between eddy current parameters, vector of different phases of LV and the LV function, and discuss their clinical application.[Methods]1. Study subjects:35healthy volunteers, consisting of13females and22males, aged from40yo to81yo, and average age was59.68±7.61yo. Cardiovascular diseases, respiratory diseases were excluded by physical examination, biochemical examination and electrocardiographic (ECG). Their heart rate was all sinus heart rate.2. Methods:Connecting ECG, the subjects should lay left lateral position with natural breath. The instrument was a-10color Color Doppler Ultrasonic Diagnosis Apparatus, PA52101-cardiac probe, and the frequency range was2.0-5.0MHz. First the routine echocardiographic examination was followed, end-diastolic diameters and end-systolic diameters of the LV were documented by M-mode ultrasound, and end-diastolic volume and end-systolic volume of the LV were recorded by Simpson dual plane method. The maximum velocity of transmitral blood flow during early diastole (E) and late diastole (A) were measured by pulsed Doppler echocardiography and E/A ratio was calculated. The time of isovolumic contraction, ejection period and isovolumic relaxation were recorded. The Tei-index was calculated. The VFM mode was employed, the color doppler image of the LV during three cardiac cycles in a raw were recorded by DSA-RS1, including three and five chamber view. The vortex parameters (transverse and vertical diameters of the vortex, the number of vortex ring) of the period of isovolumic relaxation, early, middle and late diastolic period, the period of isovolumic contraction, rapid and slow ejection were recorded. The comparision between vortex parameters in different phases was performed, and further investigation about the correlation among the vortex parameters, Tei index and EF was carried out. [Results]1. Routine echocardiographic examination:The mean measurements were:LVED (4.41±0.34) cm、LVSD (2.91±0.22) cm、LVEDV (82.46±12.99) ml、LVESV (29.43±5.20) ml、EF (65.82±4.88)%、E (74.51±14.71) cm/s、A (66.41±11.08) cm/s、 E/A (1.04±0.27), IRT (74.66±11.40) ms、ICT (35.11±7.57) ms、ET (317.69±46.7) ms、Tei index0.30±0.04respectively. All para meters were within normal limits.2. VFM results:(1) Blood flow characteristics of the LV:The main form of blood flow in the isovolumic contraction peroid was vortex, and it was laminar flow during the rapid ejection peroid. However, under the mitral valve, there were a few small vortex rings. There was no vortex found in the peroid of slow ejection and isovolumic relaxation. During the mid-diastolic phase the LV cavity was full of large eddies, but there were only a few small vortex in the early-diastolic and late-diastoice peroid.(2) Comparison between the vortex parameters:The mid-diastolic phase had the largest diameters (Vertical and transverse) of the eddy current, followed by isovolumic contraction phase, rapid ejection phase, late-diastolic phase, early diastolic phase, no obvious eddy was observed in slow ejection phase and isovolumic relaxation phase. There were significant differences in vortex parameters of the LV in five different phase which had vortex (P<0.05). Also the mid-diastolic phase had the most vortex ring number, in five vortex phases, the vortex ring numbers were significantly different (P<0.05).The vortex intensity in mid-diastolic phase was26.40±9.24.(3) Comparison between vector values of different phases:In isovolumic contraction phase, rapid ejection phase and early diastolic phase, the vector value showed an increasing tendency from apical segment, middle segment to basal segment. And in early diastolic phase the vector values of the three segments were highest in three phases. There were significant differences (P<0.05) in the same phase of three segments.(4) Correlations between LVEF, Tei-index and vectors, vortex parameters in different segments of related phases:LV vectors of rapid ejection phase in three different segments (apical, middle and basal) were positively relation with LVEF (0.49≤r≤0.58); there was a positive relation between vectors of the middle segment in rapid ejection phase and Tei-index, r=0.5; there was a positive correlation between vectors of the apical segment in early diastolic phase and LVEF, r=0.39; The middle segment in isovolumic contraction, the basal segment of the LV in early diastolic and rapid ejection phase were positively relation with Tei-index (0.3≤r≤0.41); the middle segment and basal segment in ED, the apical and basal segments in isovolumic contraction, the apical segment in rapid ejection phase all showed a weak positive correlation with Tei index (0.1≤r≤0.27). In different phases of cardiac cycle, there was no relation between vortex parameters and LVEF, Tei-index.[Conclusion]The VFM can show the hemodynamic changes in left ventricular dynamically and visually, moreover it can measure the vortex quantitatively and research the blood-flow patterns and hemodynamic change of the normal LV cavity. VFM can be a great tool for future research about complex changes in LV cavity blood flow of CAD patients. Part2. Assessment of left ventricular flow structure at different periods of cardiac circle in CAD patients by VFM[Objective]The purpose of the study was to investigate the flow features of the LV in different phases of cardiac circle in CAD patients by using VFM, and to compare the differences between normal volnteers and CAD patients. The flow structures of LV in CAD patients were demonstrated in four types of VFM diagram, and the changes of LV blood flow in CAD patients were evaluated with vector values and eddy parameters quantitatively, to better understand the intracardiac hemodynamic changes caused by myocardium abnormal motion and change of global heart function in CAD patients, to provide reliable basis for accurate diagnosis, reasonable treatment and estimating prognosis in CAD patients. [Methods]1. Study subjects:43patients with CAD admitted by cardiology department in our hospital In March to June,2012, consisting of15females and28males, aged from45yo to83yo. The average age was61.11±14.56yo. All the patients were examined by ECG, CAG (coronary artery angiography) and echocardiography, CAG showed the stenosis of one or more coronary artery branch was greater than70%. Basic heart rate was all sinus heart rate. Cardiovascular diseases, respiratory diseases, severe hepatical and renal dysfunction patients were precluded.2. Methods:Connecting ECG, the subjects should lay left lateral position with natural breath. The instrument was a-10color Color Doppler Ultrasonic Diagnosis Apparatus, PA52101-cardiac probe, and the frequency range was2.0-5.0MHz. First the routine echocardiographic examination was followed, end-diastolic diameters and end-systolic diameters of the LV were documented by M-mode ultrasound, and erd-diastolic volume and end-systolic volume of the LV were recorded by Simpson dual plane method. The maximum velocity of transmitral blood flow during early diastole (E) and late diastole (A) were measured by pulsed Doppler echocardiography and E/A ratio was calculated. The time of isovolumic contraction, ejection period and isovolumic relaxation were recorded. The Tei-index was calculated. The VFM mode was employed, the color doppler image of the LV during three cardiac cycles in a raw were recorded by DSA-RS1, including three and five chamber view. The vortex parameters (transverse and vertical diameters of the vortex, the number of vortex ring) of the period of isovolumic relaxation, early, middle and late diastolic period, the period of isovolumic contraction, rapid and slow ejection were recorded. The comparision between vortex parameters in different phases was performed, and further investigation about the correlation among the vortex parameters, Tei index and EF was carried out.[Results]1. Routine echocardiographic examination:the increase of heart volume, the reduced E/A ratio, distinctly reduced EF and ET were almost happened in all patientd which was included.Heart volume increased irregularly, reduced E/A ratio, distinctly reduced EF and ET were found in all patients. The time of isovolumic relaxation, the time of isovolumic contraction and Tei-index were increased dramatically. The mean value were:LVED (4.65±0.37)cm, LVSD(3.11±0.31)cm, LVEDV(89.77±15.61)ml, LVESV (33.56±11.10)ml, EF (61.06±3.20)%, E(62.56±16.31)cm/s, A (73.90±15.24)cm/s, E/A (0.87±0.22), IRT (83.30±12.61)ms,ICT(45.79±13.23)ms,ET(292.23±31.35)ms,Tei-index0.48±0.03respectively.2. VFM test results:(1)CAD group:structural features of blood flow in LV in different periods of cardiac cycle Vortex evolution rule was similar to control group, the vast majority of CAD in IVRT and all patients in SE had no obvious vortex. Compared to control group, vortex shape was not regular and the density was nonuniform, the center position of diastolic vortex were closer to mitral annulus.(2)Comparison between the vortex parameters:Comparing with the control group, in CAD group,, the diameters (transverse and vertical) were longer, and the number of the eddy ring were more in the five phases, including IVCT, RE, IVRT,ED and LD; in MD phases the transverse and vertical diameters,the vortex number and the vortex intensity were all less. The vortex vertical diameters in IVCT and the vortex parameters in SE(transverse diameters, vertical diameters and vortex number) had no statistical differences between the two groups (P>0.05). The vortex transverse diameters in IVCT and the vortex vertical diameters in ED and vortex number in MD were statistically different (P<0.05). The vortex number in IVCT, the parameters of vortex (transverse diameters and number) in ED, the parameters of vortex (the diameters of transverse and vertical, vortex strength) in MD and the parameters of vortex (the diameters of transverse and vertical, vortex number) in LD were all statistically significant different between the two groups (P<0.01).(3) Comparison of LV vector value:In CAD group, the vector values showed an increasing tendency from apical segment, middle segmental to basal segment. In early diastolic phase and rapid ejection phase, vector values of the apical, middle and basal segment in CAD group were less comparing with that of control group (PO.05), also the vectors values of the apical segment in IVCT. While the CAD group’s vectors of middle and basal segment in IVCT were greater than control group. Between the CAD group and the control group, vectors of apical and middle segment in early diastolic phase and basal segment in rapid ejection phase had significant statistical difference (P<0.01). Vectors of basal segment in early diastolic phase, apical and middle segment in RE, middle and basal segment in IVCT were statistically different (P<0.05), there was no difference between two groups on the vectors values of apical segmental in IVCT.(4) Correlations between LVEF, Tei-index and vectors, vortex parameters in different segments of related phases:In CAD group LV vectors of basal segment in RE,basal and middle segment in ED and IVCT were turned out to be a negative correlation with Tei-index (0.51≤|r|≤0.6), Vectors of all the apical segment in ED and IVCT, the middle and apical segment in RE were negatively correlated with Tei index (0.31≤|r|≤0.43). Vectors of the basal and apical segment in IVCT and vectors of the apical, middle and basal segments in ED was a positively correlation with LVEF(0.31≤r≤0.40). Vectors of all three segments in RE and vectors of the middle segment in IVCT were weak positively correlated with LVEF(0.14≤r≤0.29).[Conclusion]The parameters of vortex, including diameters of transverse and vertical and number of rings in CAD patients, vortex intensity in middle diastolic phase and vector values of the three segments were different with that of normal ones. VFM technology can visually show the left ventricular vortex changes and quantitatively analyse the vortex for CAD patients. VFM provide a new noninvasive method for evaluate hemodynamic changes of the left ventricular and Ventricular function.