VFM评价正常成人左室心腔血流流场运动状态的初步研究

目的:运用VFM( Vector Flow Mapping)成像探讨正常成人左心室腔内收缩期血流流场特征.方法:健康成人志愿者40例(男22例,女18例),二维超声取心尖三腔观左室腔彩色血流信息动态图像存贮并脱机分析,将取样线分别置于左室腔基底段、中尖段和心尖段,获取心动周期内经取样线部位左室腔血流时间速度积分(Time-Flow curve, TF)变化曲线,记录基底段、中间段及心尖段收缩早期速度时间积分(ES-TF)、收缩中期速度时间积分(MS-TF)、收缩晚期速度时间积分(LS-TF).观察收缩期血流流场特征,观察涡流出现时间,测量涡流直径(横径Dx,)及涡流的最大向量速度(Vmax).结果:正常人左室心腔血流流场呈规则变化,收缩早期二尖瓣前叶下方可见涡流显示,收缩中期及晚期涡流消失.收缩早、中、晚期,血流时间速度积分测值由心尖段经中间段至基底段逐渐递增,差异均有统计学意义(P<0.05).收缩早期涡流直径约为(25.74±7.32)mm, 涡流最大向量速度均背离探头,大小为(38.31±14.25)cm/s,朝向探头速度大小为(11.42±6.28) cm/s.结论:应用VFM技术可清晰显示左室心腔内血流流场状态,左室腔血流速度积分测值可直观反应心腔内血流动力学变化.     

Doppler flow velocity measurement to assess changes in inotropy and afterload: a study in healthy dogs

Myocardial contractility and afterload are important factors for adequate circulation. To noninvasively assess changes in inotropy and afterload, ascending aortic blood flow was measured by continuous-wave Doppler echocardiography before and after the administration of an inotrope and a vasodilator in eight open chest dogs. Data were collected in the baseline, at three different doses of epinephrine (0.1, 0.5, and 1 microg/kg/min) and nitroprusside (1, 4, and 8 microg/kg/min) administration, and after a simultaneous infusion of both drugs in various combinations. Epinephrine infusion caused increases in peak velocity (PV), mean acceleration (MA), velocity time integral (VTI), and minute distance without a significant change in afterload. Acceleration time (AT) and ejection time (ET) showed a slight tendency to decrease with an increase in inotropy, but with no significance. Nitroprusside infusion produced dose-dependent decreases in blood pressure and index of systemic vascular resistance (ISVR), which was associated with increases in PV, MA, and minute distance, and with a decrease in AT. The combined infusion of nitroprusside and epinephrine, unless ISVR was elevated, produced synergistic effects on PV, MA, VTI, and minute distance. However, these Doppler parameters tended to diminish with an elevation in afterload. ISVR obtained during nitroprusside infusion had a better correlation with both PV and MA than with VTI or the Doppler time intervals. Our study suggests that Doppler measurement of aortic blood flow velocity and acceleration can be used for the noninvasive assessment of changes in inotropy and afterload.     

Blood flow measurements in the fetal descending aorta: technique and clinics

A combination of two-dimensional and realtime pulsed-Doppler ultrasound provides a noninvasive method of measuring human fetal blood flow without side effects. By not altering the physiological conditions of the fetus, it minimizes external stimuli that might affect blood flow. However, due to the inaccessibility of the vessels under investigation, errors from the ultrasound technique arise and these are still being assessed. Studies of fetal blood flow suggest that the fetal circulation has a low peripheral resistance and that the increase in blood flow found with increasing gestational age is due predominantly to the increase in the actual dimensions of the fetal vasculature. Investigations in abnormal pregnancies, such as small-for-dates and those with cardiac arrhythmias have shown that the fetal cardiovascular system is capable of compensating efficiently to maintain normal physiological conditions, but only within the limits defined by the Frank Starling mechanism.     

前壁心肌梗死患者左心室血流向量特点及其与收缩功能的关系

目的 应用血流向量成像( VFM)技术分析前壁心肌梗死(心梗)患者左心室涡流和血流向量特点及其与收缩功能的关系.方法 前壁心梗患者(心梗组)31例,对照组20例.记录心尖三腔心彩色多普勒二维图像,VFM技术观察各心动时相左心室涡流和血流速度向量特点.结果 (1)两组在等容收缩期左心室腔内均可见整体涡流;心梗组收缩期及舒张期左心室内均存在涡流,对照组收缩期未见涡流,舒张期左室内可见短暂、局部涡流.(2)心梗组快速射血期心尖部及中部血流速度方向朝向心尖,与基底部血流方向相反,也与对照组相反[(10.6±8.3) cm/s比-(5.8±7.2)cm/s,(19.5±11.8) cm/s比-(16.6±14.7) cn/s];快速充盈期心尖部血流速度低于对照组[(6.8±9.8) cm/s比(17.6±15.8)cm/s,P＜0.01].(3)心梗组心尖部快速射血期血流速度与左心室射血分数(LVEF)呈负相关(r= -0.52,P＜0.05).心梗组LVEF＜ 50％患者快速射血期心尖部血流速度高于LVEF≥50％患者[(13.5±9.0) cm/s比(5.8±5.1) cm/s,P＜0.01].结论 前壁心梗患者左心室内涡流持续时间较对照组延长,心梗组快速射血期心尖部及中部血流向量方向朝向心尖,心尖部血流速度与LVEF呈负相关.     

Blood flow in snake infrared organs: response-induced changes in individual vessels

OBJECTIVE: In the past the microkinetics of blood flow in the infrared pit organs of pit vipers has been studied with Doppler flowmetry using various infrared stimuli such as a human hand or soldering iron at various distances, lasers of various wavelengths, etc. Quick-acting variations in blood flow were recorded, and interpreted as a cooling mechanism for avoiding afterimage in the infrared receptors. However, the Doppler measurements provided only the summation of blood flow in a number of vessels covered by the sensing probe, but did not give data on flow in individual vessels. METHODS: In the present work the authors introduced into the bloodstream of Gloydius and Trimeresurus pit vipers fluorescent microspheres labeled with fluorescein isothiocyanate (FITC) contained in a solution of FITC-dextran in physiological saline. They observed the passage of the microspheres through individual pit organ vessels with a fluorescent microscope to which was attached a high-speed video camera and image intensifier. Output of the camera was recorded before, during, and after stimulus with a 810-nm diode laser. Recording was done at 250 frames/s on high-speed video apparatus and downloaded to a hard disk. Disk files were loaded into proprietary software and particles were tracked and average velocities calculated. The data were then tested for significance by ANOVA with post hoc tests. RESULTS: A significant (p<.05) increase in blood velocity was found at the focal point of the stimulus laser, but not anywhere removed from this point. Proximal severing of the pit sensory nerves caused degeneration of the pit receptor terminals and abolished stimulus-induced blood flow changes, but did not affect normal blood flow. CONCLUSIONS: The authors conclude that the receptors themselves are directly and locally controlling the smooth muscle elements of the blood vessels, in response to heating of the receptors by infrared radiation. They speculate that the heavy vascularization constitutes a cooling system for the radiation-encoding receptors, and further that the agent of control may be a volatile neuromediator such as nitric oxide.     

Coronary flow velocity during coronary angioplasty in regions of myocardial infarction

In patients undergoing angioplasty for angina after myocardial infarction, patterns of post-stenotic coronary blood flow velocity depend not only on satisfactory dilation of the flow-limiting lesion, but also on the vasoregulatory capacity of infarcted myocardium. The case examples demonstrate both normal and persistently abnormal flow velocity patterns following successful coronary angioplasty for post-infarction ischemia. Recognition of collateral flow patterns, easily available using the Doppler angioplasty guidewire, may provide valuable information predicting the viability of post-infarcted myocardium and the resolution of abnormal distal coronary flow patterns. © 1994 Wiley-Liss,Inc..     

Echocardiographic indices of Doppler flow patterns compared with MRI or angiographic measurements to detect significant coarctation of the aorta

Evaluation for the presence and severity of coarctation of the aorta (CoA) by two-dimensional echocardiography alone can be difficult. The purpose of this study was to use Doppler velocity and pressure gradient half-time in systole and diastole to estimate CoA severity. Doppler echocardiograms of children with suspected CoA and either an aortic angiogram or thoracic magnetic resonance imaging (MRI) performed within 1 month of the echocardiogram were evaluated. Patients with patent ductus arteriosus, significant aortic insufficiency, long tubular CoA, or CoA outside the thorax were excluded. Measured Doppler variables, indexed for heart rate, included systolic velocity half-time (sVHTi), diastolic velocity half-time (dVHTi), systolic pressure half-time (sPHTi), and diastolic pressure half-time (dPHTi). For each of these variables, sensitivity and specificity to detect a significant CoA were determined. A significant CoA was defined as a ratio of the CoA diameter to the diaphragmatic aortic diameter of < 0.5 as imaged by MRI or angiography. Indexed systolic velocity and pressure half-times were found not to be significant predictors for CoA. For the Doppler parameter dVHTi, using a critical value of > 200 msec indexed, we found a positive predictive value of 87% and a negative predictive value of 80%. The parameter dPHTi, using a critical value of > 75 msec indexed, demonstrated positive and negative predictive values of 92% and 79%, respectively. Measurement of dVHTi is a useful predictor for significant CoA, but the parameter dPHTi has an improved positive predictive value for detection of significant CoA. Systolic measurements of velocity or pressure half-times are not adequate to assess severity of CoA.     

New method for quantitatively determining aortic regurgitant volume using Doppler color flow imaging: experimental validation study

We have developed a method to provide the two-dimensional distribution of blood flow velocity and the blood flow volume rate in the ascending aorta from the cross-sectional Doppler color flow image. Regional blood flow velocities were determined by converting color intensities of the cross-sectional Doppler color flow image into the corresponding flow velocities with the correction with the spatial ultrasound beam incident angle. The spatial ultrasound beam incident angle was estimated from the geometric characteristics of the color flow image contour. The method was validated in a steady flow model circuit comparing the calculated flow volume rates by the method with those simultaneously measured by an electromagnetic flowmeter. We performed an open chest dog experiment and calculated the blood flow volume rate at the ascending aorta before and after the aortic regurgitation was made. The calculated ejection flow volume rate and regurgitant volume were validated by the comparison with those simultaneously measured by an electromagnetic flowmeter. Based on these data, we can conclude that the current method provides accurate measurements of regurgitant volume as well as ejection flow volume rate in the ascending aorta.     

Blood flow and cell-free layer in microvessels

Blood is modeled as a suspension of red blood cells using the dissipative particle dynamics method. The red blood cell membrane is coarse-grained for efficient simulations of multiple cells, yet accurately describes its viscoelastic properties. Blood flow in microtubes ranging from 10 to 40 μm in diameter is simulated in three dimensions for values of hematocrit in the range of 0.15-0.45 and carefully compared with available experimental data. Velocity profiles for different hematocrit values show an increase in bluntness with an increase in hematocrit. Red blood cell center-of-mass distributions demonstrate cell migration away from the wall to the tube center. This results in the formation of a cell-free layer next to the tube wall corresponding to the experimentally observed Fahraeus and Fahraeus-Lindqvist effects. The predicted cell-free layer widths are in agreement with those found in in vitro experiments; the results are also in qualitative agreement with in vivo experiments. However, additional features have to be taken into account for simulating microvascular flow, e.g., the endothelial glycocalyx. The developed model is able to capture blood flow properties and provides a computational framework at the mesoscopic level for obtaining realistic predictions of blood flow in microcirculation under normal and pathological conditions.     

Pulmonary venous flow velocity patterns in 404 individuals without cardiovascular disease

OBJECTIVE—To determine the pulmonary venous flow velocity (PVFV) values in a large normal population.
DESIGN—Prospective study in consecutive individuals.
SETTING—University hospital.
METHODS—Among 404 normal individuals, the flow velocity pattern in the right upper pulmonary vein was recorded in 315 subjects using transthoracic echocardiography, and in both upper pulmonary veins in 100 subjects using transoesophageal echocardiography. Subjects were divided into five age groups. The PVFV values were compared between transthoracic and transoesophageal echocardiography within the age groups, and intraindividually between the right and left upper pulmonary veins in transoesophageal echocardiography.
RESULTS—Normal PVFV values for the right upper pulmonary vein in transthoracic and transoesophageal echocardiography are presented. The duration of flow reversal at atrial contraction was overestimated using transthoracic echocardiography (mean (SD): 96 (21) ms in transoesophageal echocardiography, 120 (28) ms in transthoracic echocardiography, p < 0.0001). Systolic to diastolic peak flow velocity ratio (S:D) increased earlier with advancing age with transoesophageal echocardiography than with transthoracic echocardiography. Similar results were found for the corresponding time-velocity integrals. Data from the left and right upper pulmonary veins differed with respect to onset and deceleration of flow velocities, but not for flow durations or peak velocities.
CONCLUSIONS—Normal PVFV values generally show a wide range. The data presented will be of value in assessing left ventricular diastolic function and mitral regurgitation using the PVFV pattern.


Keywords: pulmonary venous flow velocity; Doppler echocardiography; mitral regurgitation     

不同多普勒取样容积对血流速度测量的影响

为探讨脉冲波多普勒不同取样容积（ＳＶ）对最大血流速度（Ｖｍａｘ）测量的影响，我们用内径５．０ｍｍ模拟血管和肝素化人全血，分别以不同血泵流率和ＳＶ为１．５ｍｍ，５．０ｍｍ及１０．０ｍｍ，在仪器其它条件不变的情况下，进行体外模拟脉动血流速度频谱实验。当流率为２００ｍｌ／ｍｉｎ至５００ｍｌ／ｍｉｎ时，ＳＶ为１．５ｍｍ与ＳＶ为５．０ｍｍ和１０．０ｍｍ所测多普勒频谱的Ｖｍａｘ值间差异显著（Ｐ＜０．０１），而ＳＶ为５．０ｍｍ与ＳＶ为１０．０ｍｍｒ测值间差异不显著（Ｐ＞０．０５）。提示在临床工作中，根据所测血管内径，尽可能增大ＳＶ长度，以减少通过时间效应所致频谱增宽，更能准确获得血流速度信息。     

Quantitative demonstration of dipyridamole-induced coronary steal and alteration by angioplasty in man: Analysis by simultaneous,continuous dual doppler spectral flow velocity

In the course of studying the effects of coronary angioplasty on branch vessel flow using two Doppler flow velocity guidewires, we quantitated simultaneous blood flow responses proximal and distal to a stenosis. The alterations of flow documented a horizontal epicardial steal induced during dipyridamole hyperemia, hyperemic flow reversal by intravenous aminophylline, and subsequent normalization of distal hyperemia after endoluminal enlargement by successful angioplasty. The quantitative physiology of the patient described here confirms one postulated mechanism of abnormal myocardial perfusion stress scintigraphy. Continuous dual flowire spectral coronary flow determinations appear to be a valuable method in verifying postulated mechanisms of various pharmacologic and mechanical stimuli influencing coronary blood flow in patients with atherosclerotic coronary artery disease. © 1993 Wiley-Liss, Inc.     

Blood flow patterns in painful diabetic neuropathy

Summary Peripheral blood flow is known to be qualitatively increased in diabetic patients with neuropathy. We have measured the actual blood flow in the feet of diabetic patients with neuropathy using non-invasive mercury strain gauge plethysmography and Doppler sonogram techniques and shown that it is increased on average five times above normal at an ambient temperature of 20 °–22 °C. Moreover, reduction of this high flow by sympathetic arousal stimuli proved possible in those with severe painful neuropathy contrasting strongly with failure to reverse it in those with severe non-painful sensory neuropathy. Reduction of blood flow was associated with reduction in neuropathic pain. We studied 22 diabetic patients with severe sensory neuropathy and eight with painful neuropathy. High resting foot blood flows were demonstrated in both groups with neuropathy. The big toe flow in those with severe sensory neuropathy was 29.3±9.2 ml · min^–1 · 100 ml^–1 (mean±SD) and in the painful neuropathy group, 25.9±7.5, compared with 5.2±2.4ml · min^–1 · 100ml^–1 in the non-diabetic control subjects (p<0.001). High foot skin temperatures were also recorded in the groups with neuropathy, reflecting the high blood flow. The subjects with painful neuropathy retained the ability to constrict peripheral blood vessels in response to arousal stimuli, and reduce peripheral flow on average by 32% compared with the patients with sensory neuropathy who responded on average by only 10%. The demonstration of a peripheral sympathetic defect, responsible for the high blood flow and the potential reversal of such flow in painful neuropathy may be important in our further understanding of the aetiology of such pain and its treatment.     

“正常”冠状动脉慢血流现象与血浆同型半胱氨酸水平的相关分析

目的:探讨冠状动脉慢血流现象(SCF)与血浆同型半胱氨酸(Hcy)水平的相关关系.方法:选择我院行冠状动脉造影(CAG)显示心外膜主要冠状动脉无明显病变的患者64例.通过校正TIMI血流计帧法(cTFC)计算各支冠状动脉的TIMI帧数.冠状动脉平均帧数大于27帧定义为SCF,将患者分为SCF组(24例)和对照组(40例).应用t检验和卡方检验比较2组各项临床资料的差异,并采用多元逐步回归和Logistic回归分析方法对相关因素进行分析.结果:2组患者性别、高血压、糖尿病、吸烟所占比例、血脂水平、血糖水平的差异无统计学意义,而SCF组的Hcy水平显著高于对照组[(12.55±2.65)μmol/L∶(8.39±1.98)μmol/L,P＜0.001],年龄小于对照组[(53.25±8.67)岁∶(57.85±8.08)岁,P=0.036].多元逐步回归方程:cTFC=9.979+2.256×Hcy-0.14×年龄(F=122.268, P＜0.001).Logistic回归分析表明Hcy是影响SCF的危险因素(OR2.214,P＜0.001).结论:Hcy与SCF有关,Hcy可能参与了SCF发生的病理生理过程.     

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)     

老年冠状动脉慢血流患者的影响因素分析

目的 探讨老年冠状动脉慢血流(CSF)患者的临床影响因素.方法 从2017年1月～2019年8月于滨州医学院附属医院行冠状动脉造影检查的1260例患者中,选择年龄≥60岁的冠状动脉无明显狭窄患者286例,将CSF的98例作为CSF组,血流正常的188例作为对照组.回顾性分析2组患者临床资料,用相关性分析,采用多因素lo...     

养阴通脑颗粒对麻醉犬脑血流量的影响

目的 :观察养阴通脑颗粒对麻醉犬脑血流量的影响。方法 :将 2 9只犬随机分为 5组 ,养阴通脑颗粒大剂量组（2 .0 g/kg） ;中剂量组 （1.0 g/kg） ;小剂量组 （0 .5 g/kg）及阳性药维脑路通组 （维脑路通 0 .0 2 5 g/kg） ,空白对照组给等量的生理盐水。结果 :养阴通脑颗粒 （0 .5 ,1.0 ,2 .0 g/kg）可增加麻醉犬的脑血流量 ,中剂量组在 30～ 90 m in时增加更明显 ,与维脑路通组比较 ,在 30 min时 ,大、中剂量组的脑血流量比维脑路通组明显 （P<0 .0 5 ）。结论 :养阴通脑颗粒扩张脑血管的疗效比小剂量的维脑路通好。