The left ventricular intracavitary vortex during the isovolumic contraction period as detected by vector flow mapping

Aims: The purpose of this study was to characterize left ventricular (LV) intracavitary flow during the isovolumic contraction (IVC) period in humans using vector flow mapping. Methods: Color flow Doppler imaging was performed from the apical long‐axis view in 61 patients with heart failure and 58 healthy volunteers. Doppler flow data obtained during IVC were analyzed offline with vector flow mapping. Results: A large vortex was formed from the LV inflow toward the outflow during IVC. In normal subjects, the area of the vortex was sustained, but the flow volume decreased significantly during IVC (P < 0.001). A significant apex‐to‐base flow velocity gradient was shown along the outflow axis on aortic valve opening. However, both the area and flow volume of the vortex decreased more severely during IVC in the patients (P < 0.001). The apex‐to‐base flow velocity gradient along the outflow axis disappeared and a reversed velocity gradient was observed at the basal‐mid level on aortic valve opening. In multivariate models, a decreased LV ejection fraction was the only independent predictor of the percentage decrease in area of the vortex during the IVC (P < 0.001), and a larger QRS width (P = 0.028) and LV end‐systolic long diameter (P = 0.002) were independent predictors of the percentage decrease in flow volume of the vortex. Conclusions: The vortex across the LV inflow–outflow region during IVC facilitates the ejection of blood during early systole, and an unsustained vortex may be associated with impaired cardiac function. (Echocardiography 2012;29:579‐587)     

血流向量图分析左心室射血初速度与舒张晚期涡流的关系

目的 应用血流向量图技术（vector flow mapping,VFM）研究射血前期左心室流出道血流速度与舒张晚期涡流之间关系。 方法 对照组健康人55例,冠心病患者123例分为左心室射血分数（LVEF）> 50%组和LVEF < 50%组。左室长轴切面记录彩色多普勒信号,测量舒张末期前向涡流面积及流量（除以心腔面积进行校正）及流出道射血前期血流速度（V₀）。 结果 对照组V₀与涡流校正前、后流量及二尖瓣口A峰速度中度相关,校正后流量（β = 0.532,P < 0.01）是V₀的独立影响因素（R2 = 0.283,P < 0.01）。LVEF < 50%组涡流面积、流量大于其余两组,校正后流量小于其余两组（均P <0.05）,校正后涡流面积3组之间的差异无统计学意义。LVEF < 50%组V₀小于其余两组（均P < 0.05）,其余两组之间的差异无统计学意义。患者中V₀与涡流校正后流量、左心室大小、LVEF、二尖瓣环收缩和舒张晚期速度s’、a’中度相关,舒张短径（β = -0.329,P<0.01）、a’（β = 0.266,P = 0.01）及涡流校正后流量（β = 0.188,P<0.05）是V₀的独立影响因素（R2 = 0.441,P<0.01）。 结论 左心室射血初速度与涡流密切相关。     

The Evolution of Intraventricular Vortex during Ejection Studied by Using Vector Flow Mapping

Aims: The purpose of this study was to assess the evolution of intraventricular vortex during left ventricular (LV) ejection. Methods: Vector flow mapping was performed in 51 patients with coronary artery disease and LV ejection fraction (EF) >50%, 70 patients with EF <50% (13 with coronary artery disease and 57 with dilated cardiomyopathy), and 62 healthy volunteers. Results: In normals and patients with EF >50%, the intraventricular vortex dissipated quickly during early ejection. In patients with EF <50%, the vortex stayed mainly at apex and persisted for a significantly longer time. The evolution of vortex during ejection was significantly correlated with QRS width, EF, fractional shortening, LV outflow velocity time integral, wall motion score index (WMSI), LV dimensions, left atrial diameter, and diastolic mitral annular velocities. LV end‐diastolic short diameter and WMSI were the independent determinants of the duration of vortex (R² = 0.482, P < 0.001). End‐systolic short diameter and apical WMSI were the independent determinants of duration of vortex corrected for ejection time (R² = 0.565, P < 0.001). End‐systolic short diameter was the independent determinant of percentage change in vortex area during early ejection (R² = 0.355, P < 0.001). End‐systolic short diameter and ejection time were the independent determinants of percentage change in vortex flow volume (R² = 0.415, P < 0.001). Conclusions: In patients with LV systolic dysfunction, the vortex persists during ejection and stays mainly at apex. The vortex evolution during ejection is closely associated with LV dimensions and functions.     

应用血流向量图比较正常人与心力衰竭患者左心室等容收缩期涡流

目的应用血流向量图(vector flow mapping,VFM)比较心力衰竭(心衰)患者与正常人左室等容收缩期血流动力学特点。方法对照组包括健康志愿者51例,心衰组包括左室射血分数45%的扩张性心肌病患者57例。心尖左室长轴观记录左室彩色多普勒血流信号,应用VFM测量并比较等容收缩期初始帧和终末帧左室腔内涡流流率与面积。结果对照组舒张末期左室涡流经过等容收缩期后面积无显著性变化,但流率显著降低(P0.01);所有涡流范围均达到左室基底部。而心衰组经过等容收缩期后,涡流面积、流率均显著降低(均P0.05);仅有25例(44%)患者涡流范围可达到左室基底部。校正心腔大小的影响后,等容收缩期末左室涡流的面积和流率心衰组均小于对照组(均P0.01)。结论经过等容收缩期后,心衰患者左室涡流的大小与流率均显著降低,且低于正常心脏。     

Assessment of left ventricular energy loss in patients with mild coronary artery stenosis by using vector flow mapping combined with exercise stress echocardiography

Objectives

To evaluate the left ventricular energy loss (EL), energy loss reserve (EL-r), and energy loss reserve rate in patients with mild coronary artery stenosis by using vector flow mapping (VFM) combined with exercise stress echocardiography.

Methods

A total of 34 patients (case group) with mild coronary artery stenosis and 36 sex and age matched patients (control group) without coronary artery stenosis according to coronary angiogram were prospectively enrolled. The total energy loss (ELt), basal segment energy loss (ELb), middle segment energy loss (ELm), apical segment energy loss (ELa), energy loss reserve (EL-r), and energy loss reserve rate were recorded in the isovolumic systolic period (S1), rapid ejection period (S2), slow ejection period (S3), isovolumic diastolic period (D1), rapid filling period (D2), slow filling period (D3), and atrial contraction period (D4).

Results

Compared with the control group, some of the EL in the resting case group were higher; some of the EL in the case group were lower after exercise, and those during D1 ELb and D3 ELb were higher. Compared with the resting state, the total EL and the EL within the time segment in the control group were higher after exercise, except during D2 ELb. In the case group, except for during D1 ELt, ELb and D2 ELb, the total and segmental EL of each phase was mostly higher after exercise (p < .05). Compared with the control group, most of the EL-r and EL reserve rates in the case group were lower (p < .05).

Conclusion

The EL, EL-r, and energy loss reserve rate have a certain value in the evaluation of cardiac function in patients with mild coronary artery stenosis.     

Diagnosis of recurrent left ventricular pseudoaneurysm by echocardiography with color flow imaging

Left ventricular pseudoaneurysms are a rare complication of myocardial rupture. The diagnosis is paramount because of the propensity of pseudoaneurysms to rupture. Color flow imaging has been reported to be an aid in the diagnosis of pseudoaneurysms. We recently studied a patient with a myocardial infarction who developed a left ventricular pseudoaneurysm. Diagnosis was made by two-dimensional imaging with color flow imaging. He subsequently had a repair procedure with a gortex graft. One week after repair, repeat echocardiography with color flow imaging showed flow into the aneurysmal sac at multiple sites, consistent with recurrence of the pseudoaneurysm. Echocardiography with color flow imaging provides a safe noninvasive diagnostic tool for evaluating pseudoaneurysms preoperatively and in assessing the competency of the repair postoperatively.     

Alterations in left ventricular structure and diastolic function in professional football players: assessment by tissue Doppler imaging and left ventricular flow propagation velocity

BACKGROUND: Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler imaging (TDI) and ventricular early flow propagation velocity (Vp) are new tolls in the evaluation of myocardial function. We sought to compare TDI and Vp findings in professional football players and age-adjusted sedentary controls to assess the effect of regular athletic training on myocardial function. METHODS: Twenty-four professional football players and age-, sex-, and weight-adjusted 20 control subjects underwent standard Doppler echocardiography pulsed TDI, performed parasternal four-chamber views by placing sample volume septal and lateral side of mitral annulus and lateral tricuspid annulus. Vp values were obtained by measuring the slope delineated by first aliasing velocity from the mitral tips toward the apex by using apical four-chamber color M-mode Doppler images. RESULTS: Age, body surface area, blood pressure, and heart rate were comparable between two groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter, and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal DTI peak early diastolic (e) velocity (0.22 +/- 0.04 vs 0.19 +/- 0.04, P < 0.05), lateral DTI peak e velocity (0.19 +/- 0.03 vs 0.16 +/- 0.02, P < 0.05) and lateral DTI e/a peak velocity ratio (1.96 +/- 0.41 and 1.66 +/- 0.23, P < 0.05). The ratio of transmitral peak early diastolic velocity (E) to e in both lateral (4.72 +/- 1.20 vs 5.95 +/- 1.38, P = 0.007) and septal (3.90 +/- 0.80 vs 5.25 +/- 1.50, P = 0.002) side of mitral annulus were significantly lower in athletes. In Vp evaluation, we found higher Vp values (60.52 +/- 6.95 in athletes and 56.56 +/- 4.24 in controls, P = 0.03) in football players. CONCLUSIONS: Professional football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function that can be detected by TDI and Vp. These techniques may be new tools to define and quantitate the degree of LV diastolic adaptations to endurance exercise.     

Two-dimensional Doppler color flow mapping in congenital heart disease

The development of a system that images intracardiac anatomy cross-sectionally while simultaneously displaying intracardiac blood flow in realtime has the potential of increasing diagnostic capabilities in the evaluation of congenital heart lesions. This would translate into the ability to visualize intracardiac lesions not identified by standard M-mode, two dimensional (2-D), pulsed, and continuous wave Doppler modalities. A review of 1000 consecutive studies in our laboratory was performed. Doppler color flow mapping was performed in each case after complete segmental analysis by 2-D and Doppler echo. Identification of intracardiac lesions or abnormalities of blood flow by Doppler color flow mapping, not appreciated on routine 2-D/Doppler studies included ventricular septal defect (VSD) (n = 24), atrial septal defect (n = 4), mitral regurgitation (n = 13), tricuspid regurgitation after VSD closure (n = 5), tricuspid regurgitation in association with atrial septal defect (ASD) (n = 7), residual ventricular septal defect after surgery (n = 10), pulmonary insufficiency (n = 4), aortic insufficiency (n = 4), and patent Blalock-Taussig shunt (n = 2). Identification of multiple ventricular septal defects in two patients and the presence of a large left-to-right shunt across an atrial septal defect in the presence of septal aneurysm formation was also aided by Doppler color flow. Use of color flow to identify areas of maximal velocity and turbulence greatly enhanced continuous wave Doppler measurements by directing placement of the Doppler beam within the flow areas.     

Assessment of left ventricular wall motion in diabetic rats using velocity vector imaging combined with stress echocardiography

Objective: The aim of this study was to investigate whether velocity vector imaging (VVI) combined with stress echocardiography could detect potential diffused myocardial impairment of the left ventricle (LV) in diabetic rats. Methods: Thirty-five male SD rats were randomly divided into either the control group or the diabetes mellitus (DM) group (induced with STZ). VVI was performed both at rest and after dipyridamole stress in all rats 12 weeks later. Segmental peak systolic velocity (V_s), diastolic velocity (V_d), radial strain (ɛ_r), circumferential strain (ɛ_c), systolic and diastolic radial strain rate (SR_r), and circumferential strain rate (SR_c) were measured from six segments at the mid-level of the LV. Results: At rest, systolic and diastolic SR_c in the DM group were significantly lower than those in the control group. After dipyridamole stress, all VVI parameters in the DM group were significantly lower than those in the control group, although all values increased significantly after dipyridamole stress compared to those at rest in both groups. Conclusions: The VVI-derived V_s, V_d, ɛ_r, ɛ_c, systolic and diastolic SR_r and SR_c, combined with dipyridamole stress are all effective parameters in evaluating potential myocardial impairment due to ultrastructural alterations of cardiocytes and microcirculation disturbances in DM rats. Systolic and diastolic SR_c may be more sensitive indices that could be useful in detecting myocardial impairment at rest.     

应用血流向量图研究左心室射血期涡流变化

目的 应用血流向量图（vector flow mapping，VFM）技术研究正常人和心功能衰竭患者射血期涡流的变化特点。 方法 扩张性心肌病患者[左心室射血分数(LVEF) < 50%]63例组成心衰组，对照组包括健康志愿者50例。心尖左心室长轴观记录左心室彩色多普勒血流信号用于涡流分析。 结果 对照组射血期左心室涡流迅速消散，消散位置主要位于基底水平二尖瓣下。心衰组射血期涡流持续时间较对照组增加，射血中期涡流面积与流量均大于对照组，差异均具有显著性意义（均P < 0.01）；涡流持续位置主要位于心尖水平。 结论 正常左心室射血期涡流迅速消散，而扩张性心肌病心衰患者涡流持续存在于心尖部，提示射血期涡流的变化与左心室结构、功能密切相关。     

无创性定量左室心腔内涡流的方法及临床应用

定量观察左室腔内涡流,可以评价左室的收缩功能和舒张功能。涡流的形态及位置随心功能减低而发生变化。已经证实,MRI及超声心动图均能够准确观测左室内的涡流。虽然观测方法仍存在一些局限性,借助声学造影的超声心动图方法是能够用于临床的最为准确有效的技术。该方法利用声学微泡流动与涡流的一致性特征对心室重构及心肌做功进行定量研究。敏感参数包括涡流深度比(0.482±0.06)、长度比(0.467±0.05)、宽度比(0.128±0.06)、球形指数(3.66±0.6)、相对强度比(2.10±0.8)、涡流的相对强度(1.19±0.5)和脉动相关系数(1.31±0.5);舒张早期涡流半径(3±1mm)、舒张早期充盈血流前锋速度Vp(47±6cm/s)及Vp/E(0.59±0.07)。但是,由于临床试验研究对象的例数较少,临床应用效果仍缺乏相应的循证医学的依据。     

Color M-mode flow propagation velocity and conventional doppler indices in the assessment of diastolic left ventricular function during isometric exercise

BACKGROUND AND OBJECTIVE: Color M-mode flow propagation velocity (Vp) was shown to be a preload-independent measure of diastolic function. To study the effects of an increase in afterload induced by isometric handgrip exercise on diastolic function assessment in patients with cardiomyopathy, we measured Vp and conventional Doppler indices at baseline and at 30% of predetermined maximum handgrip strength. METHODS: Twenty-four patients with systolic dysfunction were divided into two groups: Group I comprising 12 patients with E/A < 1 (early filling velocity/atrial contraction velocity) and Group II comprising 12 patients with E/A > 1. All the patients underwent measurement of Vp, E velocity, its deceleration time (DT), A velocity, isovolumic relaxation time (IVRT), and pulmonary atrial flow reversal velocity (PFR) at baseline and at 30% of predetermined maximum handgrip strength. Twelve healthy controls underwent these same measurements. RESULTS: When comparing baseline to peak echocardiographic data, no significant changes were noted in Vp in any of the groups while a shift of pulsed Doppler indices of Group I toward a pattern closer to that of Group II was noted and a decrease in E velocity and E/A ratio with an increase in IVRT occurred in healthy controls. CONCLUSIONS: Color M-mode flow propagation velocity seems to be an afterload-independent measure of diastolic function in patients with moderate to severe cardiomyopathy while pulsed Doppler indices are more sensitive to loading conditions induced by isometric exercise.     

Positioning of left ventricular pacing lead guided by intracardiac echocardiography with vector velocity imaging during cardiac resynchronization therapy procedure

LV Lead Positioning Guided by ICE With Vector Velocity Imaging . Introduction: Intraoperative modality for “real‐time” left ventricular (LV) dyssynchrony quantification and optimal resynchronization is not established. This study determined the feasibility, safety, and efficacy of intracardiac echocardiography (ICE), coupled with vector velocity imaging (VVI), to evaluate LV dyssynchrony and to guide LV lead placement at the time of cardiac resynchronization therapy (CRT) implant. Methods: One hundred and four consecutive heart failure patients undergoing ICE‐guided (Group 1, N = 50) or conventional (Group 2, N = 54) CRT implant were included in the study. For Group 1 patients, LV dyssynchrony and resynchronization were evaluated by VVI including visual algorithms and the maximum differences in time‐to‐peak (MD‐TTP) radial strain. Based on the findings, the final LV lead site was determined and optimal resynchronization was achieved. CRT responders were defined using standard criteria 6 months after implantation. Results: Both groups underwent CRT implant with no complications. In Group 1, intraprocedural optimal resynchronization by VVI including visual algorithms and MD‐TTP was a predictor discriminating CRT response with a sensitivity of 95% and specificity of 89%. Use of ICE/VVI increased number of and predicted CRT responders (82% in Group 1 vs 63% in Group 2; OR = 2.68, 95% CI 1.08–6.65, P = 0.03). Conclusion: ICE can be safely performed during CRT implantation. “Real‐time” VVI appears to be helpful in determining the final LV lead position and pacing mode that allow better intraprocedural resynchronization. VVI‐optimized acute resynchronization predicts CRT response and this approach is associated with higher number of CRT responders. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1034‐1041, September 2011)     

Epicardial flow in the right ventricular wall on echocardiography: A sign of chronic total occlusion of left anterior descending artery

Transthoracic coronary Doppler echocardiography (TCDE) can be useful for the detection of chronic total occlusion (CTO) of the proximal left anterior descending coronary artery (LAD) noninvasively, by detecting retrograde flow through the distal LAD or its septal branch. This intriguing case report details the detection of abnormal blood flow in the right ventricular free wall by TCDE. This detection of abnormal flow may be useful to predict CTO of the LAD, even in the absence of retrograde flow in the LAD and its septal branch.     

应用血流向量图研究左心室舒张末期涡流的影响因素

目的 应用血流向量图技术（vector flow mapping,VFM）研究左心室舒张末期涡流的影响因素及与充盈方式的关系。 方法 选择健康志愿者48人、冠心病患者51人、扩张性心肌病患者51人,根据二尖瓣口充盈方式分为正常充盈组29人,松弛受损组85人,假性正常组22人,限制型充盈组14人。心尖左心室长轴观采集左心室彩色多普勒血流图像,VFM技术测量舒张末期左心室涡流面积与流量。 结果 涡流面积与心率、A峰及瓣环a’速度、左心室大小显著相关,其中A峰速度、心率及左心室舒张长径是涡流面积的独立影响因素（P<0.01）。涡流流量与年龄、心率、A峰速度、左心室大小与功能各指标显著相关,其中A峰速度、心率、左心室收缩短径及舒张长径是涡流流量的独立影响因素（P<0.01）。4组之间涡流面积与流量有显著性差异（均P<0.05）,松弛受损组涡流面积显著大于限制型充盈组,正常充盈和松弛受损组流量显著大于假性正常和限制型充盈组。 结论 舒张末期涡流大小与心率、左心室大小及A峰速度有关,不同充盈方式之间具有显著性差异,提示舒张末期涡流可用于鉴别二尖瓣口充盈的假性正常。     

Determination of left ventricular inflow by pulsed Doppler echocardiography: influence of mitral orifice area and blood velocity measurements

Pulsed Doppler echocardiography was performed in 30 patients to assess the influence of mitral orifice area and velocity on the determination of mitral stroke volume and inflow. Aortic forward stroke volume and outflow were measured at the centre of the aortic annulus, and compared with mitral flow measurements calculated by three methods. Both mitral stroke volume and inflow derived from an instantaneous velocity-area method showed an excellent correlation with aortic flow measurements. The other two methods, which determined mitral stroke volume and inflow based on a mean mitral valve area and diastolic velocity integral, significantly underestimated mitral flow measurements. This study indicates that the instantaneous velocity-area method offers a reliable means for quantitating left ventricular inflow.