Objective To assess longitudinal segmental myocardial strain(?),displacement(D) and the changes of the inner dimension of left ventricle(?L),and to establish their spatial correlationship during cardiac pacing and conductive block.Methods The standard apical four chamber view of left ventricle were acquired during cardiac pacing(n=12),right bundle branch block(RBBB,n=13) and sinus rhythm(n=14) using GE Vivid 7 dimension and the M3S probe with(4.0) MHz for the analysis of the longitudinal myocardial segmental(apical and basal segments) ? and D of left ventricle with two dimensional strain analysis software.The maximal and change longitudinal dimension of left ventricle was measured and calculated at end-diastole and end-systole respectively.The differences of the above parameters were compared and the spatial correlationships among them were analyzed.Results The peak ? of the septal basal segment during cardiac pacing was significant higher than that of the apical segment.There were significant differences in the peak D and(?D)(D_(basal)-D_(apical)) at lateral wall among sinus rhythm,RBBB and pacing group(P

Objeetive To evaluate the changes of left ventricular(LV) global and segmental volume, LV outlet pressure and their co-relationship, and to access LV global and segmental systolic function and mechanical asynchrony in different LV electro-mechanical patterns using full volume three-dimensional echocardiography(3DE). Methods Nineteen open-chest canine models were employed for the acquirement of LV full volume dynamic 3DE imaging during right atrial appendage (RAA), right ventricular apical (RVA), LV lateral wall(LVL) and LV apical(LVA). LV outlet end-systolic pressure(ESP) was recorded simultaneously. End-systolic volume (ESV), end-diastolic volume (EDV), global and segmental ejection fraction(EF) and systolic dyssynchrony index(SDI) of LV were measured and calculated using a dedicated workstation. The average ascending rate of LV pressure during systole(+ dp/dt) and the average descending systolic pressure(ESP), + dp/dt and - dp/dt during RVA pacing were lower than those during RAA pacing (P <0.05). SDI during RVA pacing was higher than that during RAA pacing(P<0.05). ESP, + dp/dtand - dp/dt during LVL and LVA pacing were lower than those during RAA pacing (P <0.05). There and LVA pacing was higher than that during RVA pacing (P <0.05),SD1 during LVL pacing was lower than that during RVA pacing (P <0.05), there was no significant difference of SDI between RVA and LVA and LVL pacing. Segmental EF of septum and apex during LVI. pacing were higher than those during LVA pacing (P <0.05). @Segmental EF of anterior and post septum and all apical segments (except lateral wall) during RVA pacing were lower than those during RAA pacing (P <0.05). Segmental EF of lateral and anterior wall during I.VI. pacing were lower than those during RAA pacing (P <0.05). Segmental EF of anterior wall and anterior septum during LVA pacing were lower than those during RAA parameters. Conclusions The global and minority segmental systolic function of LV during RAA pacing could be reduced compared with normal sinus rhythm. All the ventricular pacing worsen LV systolic and diastolic function compared with RAA pacing. LV systolic function during LVL pacing was superior to RVA pacing. During ventricular pacing,the systolic function at nearby segments of the pacing site was depressed.

Objective To assess subendocardial systolic circumferential strain(CS),radial strain(RS)and radial displacement(RD)of left ventricle(LV)in short-axis view and LV global systolic function in open-chest canine model with acute myocardial ischemia using velocity vector imaging(VVI),and to establish their spatial correlationships.Methods Left anterior descending coronary artery(LAD)was ligated for 20 minutes to induce acute myocardial ischemia in 12 open-chest canine model.At baseline and 20 minutes after ischemia,two-dimensional dynamic gray-scale images of three standard left ventricular short-axis views at the levels of mitral annulus,papillary muscle and apex and the images of LV apical fourchamber and two-chamber view were acquired and transfefred to VVI workstation for off-line analysis.Peak systolic CS,RS and RD of eighteen segments and of three global short-axis sections of LV were measured at subendocardium.and LV ejection fraction(LVEF)and stroke volume(SV)were calculated using Simpson's method.The differences and correlationships were analyzed between them.Resuls Compared with the value at baseline,LVEF decreased significantly(P＜0.05)after ischemia.The peak systolic subendocardial CS,RS and RD of the affected segments,global CS,RD at papillary muscle and apex views and global RS at apex view were significantly lower than those at baseline after ischemia(P＜0.05).There was a good linear correlationship between the peak systolic CS and RD of 17 segments(except the middle segment of LV lateral wall after ischemia)and each global short-axis level before and after ischemia(r=0.662-0.995,P＜0.05,P＜0.01 or P＜0.001),The peak systolic RS of six segments and each global short-axis level(except the apex level at baseline)was correlated with RD(r=0.580-0.916,P＜0.05,P＜0.01 or P＜0.001);There was not statistical correlationship between global RDs and SV as well as LVEF.Conclusions Subendocardial circumferential strain and radial displacement may sensitively reflect the changes of regional and global myocardial systolic function induced by acute myocardial ischemia.The significant correlationship between subendocardial circumferential systolic strain and radial displacement might indicate that circumferential deformation of myocardium result in the changes of the radial displacement mainly.

Objective To evaluate the mechanical homogeneity pattern of isolated carotid atherosclerotic plaque intima on longitudinal axis view using ultrasonic velocity vector imaging.Methods Fourty six patients with 48 isolated plaques were undergone the high frequency ultrasound scanning,the real-time two-dimensional longitudinal-axis gray scale view at the maximal thickness of the plaque was obtained in three complete cardiac cycles.A dedicated velocity vector imaging(ⅤⅤⅠ)workstation was used for the off-line dynamic two-dimensional gray-scale image analysis and mechanics parameter(i.e.,the peak strain and the absolute difference of the peak strain)assessment at the sites of the upper,middle and down stream separately.The length and direction distribution of the velocity vectors at the carotid atherosclerotic plaque intima were observed.Wilcoxon test was utilized for the comparison of the peak strain and the absolute difference of the peak strain between two sites.Results The chaos phenomenon of velocity vector distribution at the sites of plaque intima occurred significantly differed from those uniform velocity vectors at the reference sites.According to the two groups of the higher strain value side and the lower strain value side on the upper stream and the down stream of the plaque intima,the peak strain at the higher strain value side was significantly higher than the lower strain value side(P=0.000).There was a significantly difference between the absolute difference of peak strain from the higher strain value side to the middle stream point of the plaque intima and the absolute difference of peak strain from the lower strain value side to the higher strain value side of the plaque intima(P＜0.017).Conclusions The length and direction distribution of velocity vectors of the isolated carotid atherosclerotic plaque intima on longitudinal axis view are uneven,the mechanical heterogeneity pattern exists at the plaque intima and could be visualized and quantitatively evaluated using ultrasonic velocity vector imaging.

Objective To assess the echocardiographic characteristics of embolism and in-hospital mortality in patients with infective endocarditis using three-dimensional transesophageal echocardiography (3D TEE).Methods Retrospective review of 124 patients with native valve infective endocarditis was performed to examine its characteristics by two-dimensional transthoracic echocardiography (2D TTE),multi-plane and 3D TEE.The primary endpoint was embolism and mortality that occurred within one month before or after operation.The combined simple score was calculated by assigning 1 point each for the presence of large vegetation,abscess or fistula,rupture of valvular chord,moderated or severe valvular regurgitation and perforation or serious valvular destruction.Hosmer and area under the curve was calculated to predict embolism and adverse events with the combined simple score,length of vegetation,serious valvular destruction with abnormal morphology.Results In 124 patients,embolic events occured in 27 cases (27/124,21.77％).Multi-plane and 3D TEE can identify the exact location and length of vegetation compared with 2D TTE,which miss-diagnosed vegetation in left atrium and papillary muscle.The clinical presentation of embolism patients was remarkable for lower hemoglobin level (P＜0.05).The ratio of multi-located vegetation,mortality and serious valvular destruction with abnormal morphology were higher in embolism and adverse events patients than those in non-embolism and adverse events patients (all P＜0.05).The area under the curve of combined simple score,lengh of vegetation for embolisms and adverse events and serious valve destruction with abnormal morphology for embolism and adverse events were 0.65 (P=0.06),0.60 (P=0.19)) and 0.70 (P=0.03).Conclusion Multi-plan and 3D TEE plays a key role in the diagnosis of patients with infecitive endocarditis,especially vegetations in occasional location.Serious valve destruction with abnormal morphology is associated with embolism and adverse events.

Objective To evaluate the changes of left ventricular(LV) 3-dimension peak displacement (3D-D) during different cardiac pacing patterns. To provide a reliable mechanical data base for the optimization cardiac pacing. Methods Cardiac pacings in open-chest Beagle canine models( n = 10) were performed using three patterns[I, e. , right ventricular apical pacing (RVA-P), LV lateral pacing (LVL-P)and LV apical pacing(LVA-P)],3D full volumetric real-time imaging were acquired in a completed cardiac cycle. The 3D-D,3D-D peak time (3D-DTc) and the standard deviation of TC(3D-DTSD) were calculated and analyzed in different pacing patterns for difference and spatial correlationship. Results ① The 3D-D of LVL-P and LVA-P state decreased compared with BASE and RVA-P state, there were significant 3D-D difference of mid anterior,mid anteriorspetal, mid interior,mid posterior, mid lateral between LVL-P and BASE, RVA-P patterns( P ＜0.05). There were significant 3D-D difference of mid anterior,mid lateral,mid posterior between LVA-P and RVA-P patterns groups( P ＜0.05). There were significant 3D-D difference of all segments in apical level between LVL-P,LVA-P and BASE, RVA-P states( P ＜0.05). ② Corrected by the heart rate,the 3D-DTC of different cardiac pacing patterns were shorter than BASE state. ③ There were no significant 3D-DTSD difference between different cardiac pacings and BASE patterns. There were significant 3D-DTSD difference between RVA-P and LVA-P patterns (P ＜ 0.05). Conclusions LV mechanical activation and synchronization could be maintained during RVA-P rather than LVA-P and LVL-P. Echocardiographic study of left ventricular 3D-D can actually reveal myocardial mechanical state during different cardiac pacings and BASE patterns.