超声心动图观察二尖瓣及肺静脉血流参数与左心室舒张末压的关系

测定６０例心导管受检者左心室舒张期压力，经胸脉冲波多普勒超声心动图记录二尖瓣及肺静脉血流参数并与左心室充盈压作相关分析。发现肺静脉血流参数与左心室舒张压比二尖瓣血流更具相关性。肺静脉返流峰和二尖瓣Ａ峰时限差（ＰＡｄ－Ａｄ）与左室舒张末期压（ＥＤＰ）最具相关性（ｒ＝０．７０，Ｐ＜０．０１），肺静脉返流峰时限长于二尖瓣Ａ峰估测ＥＤＰ≥２ｋＰａ（１５ｍｍＨｇ）的敏感性为８６％、特异性为８１％。左室心房收缩前压力与肺静脉收缩分数呈明显负相关（ｒ＝－０．５９，Ｐ＜０．０１）。表明超声心动图能有效地估测左心室舒张期压力，ＰＡｄ－Ａｄ是估测左心室舒张末期压的最佳指标。肺静脉收缩分数减小提示左室心房收缩前压力明显升高。     

脉冲多普勒超声心动检测肺静脉血流与左室舒张压的相关性研究

研究经胸脉冲式多普勒超声心动图所检测的肺静脉血流与左室舒张压的相关性。对35例患者的超声心动图及左室造影进行观察，分析肺静脉血流与二尖瓣血流频谱所获指标与左室舒张庄关系。静脉血流A波间期和二尖瓣血流A波间期之差（d－dif）与左室舒张末压呈显著正相关性（r＝0．5658，P＜0．001），以d－dif判断左室舒张功能不全（LVEDP＞15mmHg）的敏感性为75．0％，特异性为86．7％。d－dif与Pre－A和LVa亦具有正相关性（P＜0．01）。d－dif是一项能够较为准确地反映左室舒张压变化的指标。     

超声心动图对老年冠心病左室舒张末压的评估

目的 探讨老年冠心病患者舒张早期二尖瓣血流速度与二尖瓣环运动速度比值(E/E′)与有创的左室舒张末压(LVEDP)的相关性.方法 30例老年冠心病患者接受心导管检查之前24 h内进行经胸多普勒超声心动图检查;常规测取二尖瓣血流参数、二尖瓣环运动参数.LVEDP由6F猪尾导管测取.结果 线性回归分析表明舒张早期E/E′与二尖瓣环速度比值与LVEDP有较好的相关性(S:r=0.739;P＜0.01;L:r=0.710;P＜0.01));间隔部E/E, ≥10估计LVEDP≥15 mmHg,敏感性为85%,特异性为 89%,左侧壁E/E′≥10估计左室舒张末压≥15 mmHg,敏感性为82%,特异性为 90%.结论 对于老年冠心病患者舒张早期E/E′与LVEDP有良好的相关性,是半定量评估的有效指标.     

多普勒组织成像与脉冲多普勒方法对比评价高血压患者舒张功能

目的应用脉冲多普勒组织成像测量二尖瓣环平均舒张速度,以鉴别高血压患者舒张功能假性正常。方法在健康者(正常组200例)与高血压患者(高血压组47例)中,应用脉冲多普勒技术分别测量二尖瓣口舒张早期峰值速度(E)、舒张晚期峰值速度(A),肺静脉收缩波(S)、舒张波(D)及心房收缩波(Ar)。应用脉冲多普勒组织成像测量二尖瓣环各点舒张早期峰值速率(Ea)、舒张晚期峰值速率(Aa)。结果正常组与对照组患者二尖瓣E、A、E/A差异无显著性意义,肺静脉S、S/D、Ar差异有显著性意义,二尖瓣环平均Ea间差异有显著性意义,Aa间差异无显著性意义。结论二尖瓣环舒张早期速率可用于鉴别高血压舒张功能假性正常。     

肺静脉血流识别二尖瓣血流假性正常化的临床研究

目的　探讨肺静脉血流频谱识别二尖瓣血流频谱假性正常化的临床意义及价值。方法　临床确诊为原发性高血压病患者 6 9例。根据超声心动图 ,分为左室肥厚组和非肥厚组。 2 8例正常对照组。应用HPSonos 2 5 0 0超声诊断仪和 2 5MHz的超声探头记录二尖瓣口和右上肺静脉入口处多谱勒血流图。结果　 (1)不同组间二尖瓣血流频谱各指标比较无差别。肺静脉血流的ARD在高血压LVH组较无LVH组及正常组延长(P <0 0 5 ) ;VTIs(VTIs+VTId)在高血压LVH组较其它两组低 (P <0 0 5 ;ARD/AD在高血压LVH组较其它两组高 (P <0 0 5 ) )。 (2 )在左室壁肥厚组 ,二尖瓣血流表现出更高的E/A比值 (P <0 0 1) ;肺静脉血流频谱的ARD、ARD/AD较不肥厚组明显增大 (ARD :P <0 0 5 ;ARD/AD :(P <0 0 1)。结论　综合二尖瓣及肺静脉血流频谱可以识别二尖瓣血流频谱假性正常化 ,更全面反应左室的舒张功能。     

应用左房内径变化评价高血压病患者左室舒张功能不全的研究

目前,超声心动图判断高血压患者左室舒张功能不全最常用的方法是脉冲多谱勒测量二尖瓣口的血流频谱。但是,随着舒张功能的进一步减退,舒张期二尖瓣血流频谱趋于正常,出现舒张功能假性正常化[1]。本研究应用二维超声心动图测量左房内径变化,可以鉴别左室舒张功能假性正常,为临床     

肺静脉血流图鉴别二尖瓣血流图假性正常化的价值

目的 :探讨肺静脉血流图鉴别二尖瓣血流图假性正常化的价值。方法 :通过 69例高血压病 ( EH)患者根据其二尖瓣血流图形态及室壁厚度分组与 15例正常人作对照研究。结果 :二尖瓣血流图正常组 ,肺静脉血流图 S波、D波峰值的比值、S波流速积分与 S波、D波流速积分之和的比值( FVTIs)和 AR波持续时间与 A波持续时的比值 ( ARD/AD)已能显示异常。而二尖瓣血流图异常组 ,肺静脉血流图 FVTIs和 ARD/AD也能显示异常。结论 :肺静脉血流图对识别假性正常化的二尖瓣血流图有重要意义 ,也有助于反映 EH患者左室舒张功能受损的不同阶段 :1二尖瓣血流图正常、肺静脉血流图 FVTIs升高、ARD/AD下降 ;2二尖瓣血流图异常 ;3二尖瓣血流图正常、肺静脉血流图 FVTIs下降、ARD/AD升高 (二尖瓣血流图假性正常 )     

冠心病患者舒张早期左室舒张末压与二尖瓣血流速度/二尖瓣环运动速度比值的相关性

目的探讨冠心病患者舒张早期二尖瓣血流速度/二尖瓣环运动速度（E/E’）比值与左室舒张末压（LV-EDP）的相关性。方法30例冠心病患者在接受心导管检查之前24 h内进行经胸多普勒超声心动图检查;常规测取二尖瓣血流参数、二尖瓣环运动参数。LVEDP由6F猪尾导管测取。结果线性回归分析表明,舒张早期E/E’比值与LVEDP有较好的相关性（间隔部r=0.739,P〈0.01;左侧壁r=0.710,P〈0.01）。间隔部E/E’≥10估计LVEDP≥15 mmHg的敏感性为85%、特异性为89%;左侧壁E/E’≥10估计LVEDP≥15 mmHg的敏感性为82%、特异性为90%。结论舒张早期E/E’比值与LVEDP有良好的相关性,是半定量估计LVEDP的有效指标。     

应用声学定量和多普勒技术评价肥厚型心肌病患者左室舒张功能

应用脉冲波多普勒（ＰＷ）技术获得二尖瓣血流频谱可用来评价左室舒张功能，但易受年龄、心率、心脏前后负荷等因素的影响，当左房压升高、左室早期充盈增加时，二尖瓣血流频谱可出现“假性正常化”，影响了对心脏舒张功能的判定。而肺静脉血流频谱可更准确地评价左室舒张功能。１９９５年以来，我们应用ＰＷ所获得的肺静脉血流频谱及声学定量技术获得的左室容量曲线评价肥厚型心肌病（ＨＣＭ）患者的左室舒张功能，现报告如下。１　对象与方法１１　研究对象　原发性ＨＣＭ患者３２例，男２２例，女１２例；年龄１６～７２岁，平均５３…     

彩色多普勒超声心动图评价扩张型心肌病左心室舒张功能

目的　用彩色多普勒超声探讨扩张型心肌病患者左心室舒张功能的改变。方法　利用彩色多普勒超声心动图将 37例扩张型心肌病患者分为合并二尖瓣反流组及无二尖瓣反流组 ,观察其二尖瓣及肺静脉血流频谱并与正常人对照。结果　扩张型心肌病无二尖瓣反流组中仅有 41.2 %患者二尖瓣血流频谱 E/ A小于 1,其余均表现为 E/A大于 1,甚至 E/ A大于 2。扩张型心肌病合并二尖瓣反流组 E/ A均大于 2。而扩张型心肌病患者肺静脉血流频谱 ,与正常人组比较有明显差异 ,S峰均明显降低 ,D峰 >S峰 ,结论　扩张型心肌病在收缩功能减退同时有舒张功能异常 ,二尖瓣血流频谱可出现“假性正常化”,掩盖其左心室舒张功能的异常 ,应用肺静脉血流频谱有助于识别二尖瓣血流频谱“假性正常化”,但在评价扩张型心肌病合并二尖瓣反流患者左心室舒张功能时有其局限性     

Color Doppler of Diastolic Flow Converging Into Coronary Ostia by Transthoracic Ultrasound

The flow convergence method is a recently described color Doppler method for determination of flow rate across orifices in patients with valve leaks and ventricular septal defects. For a given geometry, the flow net of the flow convergence region is predictable, which allows one to derive flow rate from the local velocity at given points within the field of convective acceleration proximal to the orifice. This underlying fluid dynamic principle should also apply to coronary ostia. Therefore, we looked to see if the flow convergence region proximal to the coronary ostia can be imaged by color Doppler. In 16 healthy adults we imaged the aortic root by transthoracic color Doppler echocardiography in the parasternal short axis. A low velocity setup was used (PRF 450–2000 Hz, wall filter 50–200 Hz). Eighty-four percent of the coronary ostia was seen (left 15/16; right 12/16). A color signal of the coronary flow convergence region was displayed in 88% of coronary ostia (left 15/16; right 13/16). By quantitative analysis of these color maps the velocity profile across the flow convergence was determined. This always resulted in a steady increase in velocity when approaching the ostium. Within 2 to 18 mm proximal to the orifice, the absolute velocities ranged from 1.2 to 16 cm I sec. The coronary flow convergence region can be imaged by color Doppler. However, the potential estimation of instantaneous diastolic coronary flow rate from these images needs further evaluation.     

Coronary collateral circulation in the pig: correlation of collateral flow with coronary bed size

Summary Coronary bed sizes were measured in pigs. The left anterior descending bed occupies about 31% of the heart, the right coronary bed about 38% of the heart and the left circumflex bed about 31% of the heart is (including atria). The right coronary artery supplies about 81% of the right ventricle and 23% of the left ventricle with its blood supply. The remaining portion of the right ventricle is supplied by the LAD.The collateral circulation was measured in each of the 3 coronary beds using tracer microspheres. Measurements, are in ml/min/100g. Transmural collateral flow in the LC is 5.6, the LAD 1.0, the RC in LV 3.7 and the RC in RV 4.3.Our experiments showed that the coronary bed sizes were relatively uniform in pigs, but that collateral flow was significantly different between the beds.With 4 tablesThis work was supported in part by the Specialized Center on Ischemic Heart Disease, Grant 17682 from NHLBI and USPHS Grant HL 20190.     

Effect of Pentagastrin on Regional Gastric Blood Flow in Conscious Cats

Total gastric flow studies indicated that a transient, considerable flow increase was followed by a more moderate increase of total gastric flow during pentagastrin stimulation in anesthetized cats. In conscious cats regional gastric flow studies, using hydrogen clearance techniques, suggested that raised flow to the corpus region during the stimulation period was accompanied by a moderate decrease of antral flow.     

Characterization of Extracellular Signal-Regulated Kinase 5 Levels in Human Umbilical Vein Endothelial Cells Exposed to Disturbed and Uniform Flow

Extracellular signal-regulated kinase 5 (ERK5) has been reported to regulate endothelial cell integrity and protect from vascular dysfunction under continuous laminar flow. However, the effect of flow on ERK5 levels has not been determined. Confluent human umbilical vein endothelial cells (HUVECs) were seeded on fibronectin coated glass slides and serum starved for 2 hours with 1% fetal bovine serum (FBS). HUVECs were then exposed to to and fro flow (TFF), pulsatile forward flow (PFF), or continuous laminar flow (CLF) in a parallel plate flow chamber for up to 2 hours. At the end of experiment, cell lysates were prepared and immunoblotted with antibodies to total ERK5. Both CLF and TFF exhibited a decrease in ERK5 after levels after 2-hour exposure. However, the level of ERK5 for PFF remained the same. Disturbed, but not uniform pulsatile, flow decreases ERK5 levels in HUVECs.     

冠状动脉内支架术对冠状动脉血流储备的远期影响

目的　采用经胸多普勒超声心动图冠状动脉 (冠脉 )血流显像技术观察冠脉支架置入术对冠脉血流储备 (CFR)的远期影响。方法　对 34例冠心病患者分别于支架术术前、术后 72h内及随访期 [( 6 .7± 1.5 )个月 ]记录病变血管远端静息舒张期血流峰速 (r Vd)、注射潘生丁及等长握力实验时最大舒张期血流峰速 (d Vd)及CFR。每例患者于随访期复查冠脉造影。结果　随访期造影无再狭窄 2 8例。据术后 72h内CFR分为CFR受损组 ( 10例 ,CFR≤ 2 .5 )及CFR未受损组( 18例 ,CFR >2 .5 )。术后近期CFR受损组r Vd较CFR未受损组明显增高 (P <0 .0 1) ;随访期时CFR受损组CFR升高至CFR未受损组水平 (P >0 .0 5 )。随访期出现再狭窄 6例 ,CFR均 <2 .0 ,降至术前水平。结论　 ( 1)成功的支架术后部分患者存在暂时性CFR降低 ,CFR的降低及其恢复与r Vd的一过性增高及恢复有关 ;( 2 )再狭窄患者冠脉血流储备于随访期显著降低 ,达到术前水平。经胸冠脉血流显像技术可作为冠脉介入治疗后一种简便、安全、无创的随访方法。     

Peak Expiratory Flow Associated with Change in Positioning of the Instrument: Comparison of Five Peak Flow Meters

To determine if peak expiratory flow (PEF) is altered by incorrect positioning of five peak flow meters (PFMs), 16 adults with clinically stable persistent asthma were evaluated. After inhaling two puffs of albuterol via AeroChamber, patients were instructed over the next 15 min in correct PFM technique and two incorrect techniques (PFM angled 20° left in mouth and PFM pointed 20° downward as patient leaned forward with maximal exhalation). Order of use of five peak flow meters and correct vs. incorrect techniques were random. Although mean values generally indicated no clinically meaningful effect of positioning of the PFM, inaccurate PEFs were recorded for several subjects with both incorrect methods and all PFMs.     

Experimental studies to define the geometry of the flow convergence region. Laser Doppler particle tracking and color Doppler imaging

The color flow convergence method for calculating volume flow through regurgitant or forward flow restrictive orifices has gained significant interest and a number of in vitro studies have suggested that this method is accurate, even in pulsatile models. Clinical application of the method over a wide range of conditions will require improved understanding of the effect of orifice size, flow geometry, and flow rate on the flow convergence geometry. In this study, we performed laser particle tracking investigations to allow visualization of streamlines into stenotic orifices. These streamlines are theoretically perpendicular to the isovelocity surfaces used for flow convergence calculations. We compared those observations to color flow map, flow convergence images obtained with a Toshiba 160A for orifices 5 to 15 mm 2 with flow rates of 1.5 to 9.7 L/min. Our results show that for large orifices, low flow rates, and/or low pressure gradients, more oblique streamlines in the velocity of the orifice correspond to nonhemispherical, but more elliptical, flow convergence geometries. This can be corrected for by using lower Nyquist limits and calculating flow convergence at greater distances from the orifice. Under high flow and high gradient conditions, increased Nyquist limits and shorter aliasing radii are more suitable. Our studies yield insights into flow convergence geometry and yield corrective procedures to improve volume flow calculation.