曲率半径法研究呼吸对室间隔运动的影响

目的探讨曲率半径法观察室间隔运动的敏感性与可靠性。方法21例健康志愿者,胸骨旁左心室长轴二尖瓣腱索水平记录M型曲线,测量呼气相和吸气相左心室舒张末期内径,计算室间隔相对左心室后壁摆动幅度(室间隔摆动幅度=呼气相左心室舒张末期内径-吸气相左心室舒张末期内径)。于同一水平短轴观分别获取、储存呼气相和吸气相舒张末的二维图像,以备脱机分析;采用自制的测量软件,分别计算吸气相与呼气相时室间隔曲率半径,计算室间隔摆动幅度(室间隔曲率半径变化幅度=吸气相室间隔曲率半径-呼气相室间隔曲率半径)。结果平静呼吸时,M型方法测量室间隔随呼吸摆动幅度为(1.65±1.26)mm;吸气相室间隔曲率半径为(25.91±6.08)mm,呼气相的室间隔曲率半径为(22.30±4.40)mm,两时相测值差异有统计学意义(P<0.0001);曲率半径法测量室间隔随呼吸摆动幅度为(2.95±2.00)mm,较M型测量值,差异无统计学意义。结论曲率半径可以有效地评估室壁摆动、形变,具有良好重复性。     

超声心动图评价平静呼吸对正常人左心室收缩功能的影响

目的观察平静呼吸时胸压变化对左、右心室前后径及左室收缩功能的影响,进一步证实呼吸影响血流动力学机制新假说。方法20名健康志愿者,用Sequoia512彩色超声同步记录呼吸曲线。启动二维及M-型超声心动图记录右室前壁、室间隔及左室后壁活动曲线,测量舒张末期室间隔左室面随呼吸摆动幅度,分别测量呼气和吸气时右室前壁、室间隔、左室后壁的收缩幅度及左、右心室舒张期和收缩期内径,计算左室短轴缩短率、每搏输出量及射血分数,并计算上述指标随呼吸的变化率。结果平静呼吸时,室间隔吸气时摆向左室侧,呼气时摆向右室侧,室间隔随呼吸左右摆动幅度为(1.76±0.50)cm;右室舒张期前后径吸气时较呼气时明显增大,左室变化相反;室间隔及左室后壁收缩期运动幅度及左室每搏输出量呼气时较吸气明显增加,而射血分数及短轴缩短率在呼气和吸气间无明显差别。结论呼吸性胸压变化最终作用到了室间隔上,使左、右室内径及收缩功能发生交替性变化。     

心包积液时呼吸对血流动力学影响的超声心动图研究

目的　观察心包积液时呼吸性胸压变化对血流动力学的影响 ,从临床角度验证笔者提出的关于呼吸影响心功能机制新假说 ,提出心包积液时血流动力学改变程度参考指标。方法　 10例大量心包积液患者 ,采用AcusonSequoia 512和 12 8XP/ 10型超声仪 ,同步记录各瓣口血流速率、心电图和呼吸曲线。分别于呼气相和吸气相连续测量 5个呼吸周期的各瓣口血流速率 ,并分别取呼气相和吸气相平均值 ,计算呼吸性血流速率波动指数 (RVI) ,并与 18例健康志愿者的结果进行比较分析。结果　心包积液组二尖瓣(MV)E峰血流速率RVI值和主动脉瓣 (AV)血流速率RVI值均较正常组明显增大 [MV :(14 .57± 7.89) %对 (9.71± 3 .3 9) % ,P <0 .0 5;AV :(11.61± 4.96) %对 (4.67± 1.79) % ,P <0 .0 0 1] ;三尖瓣 (TV)E峰血流速率RVI值和肺动脉瓣 (PV)血流速率RVI值也均较正常组显著增大 [TV :(2 4.97%± 6.19) %对 (14 .82± 3 .70 ) % ,P <0 .0 0 1;PV :(2 3 .93± 10 .12 ) %对 (5.86± 2 .55) % ,P <0 .0 0 1]。结论心包积液时呼吸性胸压变化对心脏各瓣口血流速率影响明显增大 ,RVI值可以作为心包积液和心包填塞严重程度的衡量指标 ;心包腔内压是决定呼吸对血流动力学影响程度的因素之一     

超声心动图观察呼吸对室间隔运动影响的方法

有实验已经证明室间隔随呼吸摆动.M型超声心动图通过测量左室内径变化来观察室间隔的摆动,但这种方法忽略左室后壁的运动,所以误差比较大.心室压微小的变化就可使心室的曲率半径(心室壁圆弧所对应的半径)发生极为明显的变化,即曲率半径将室间隔的变形放大了.本研究探索将曲率半径法与M型超声心动图法联合起来分析平静呼吸时室间隔变形特征.     

平静呼吸对室间隔缺损左向右分流影响的超声心动图研究

目的应用超声心动图检测室间隔缺损（VSD）患者平静呼吸过程中室水平左向右分流血流速度随呼吸的变化,探讨平静呼吸对VSD患者心功能影响的机制及其临床意义。方法超声记录28例VSD患者平静呼吸时室水平左向右分流的血流速度,同步记录心电图和呼吸曲线。结果平静呼吸时,VSD患者室水平左向右分流的血流速度均于吸气相低于呼气相。结论VSD患者平静呼吸时室水平左向右分流的血流速度随呼吸时相波动而规律性变化,证明了呼吸性胸压变化是导致室间隔缺损分流速度波动性变化的主要原因。     

超声心动图观察呼吸对室间隔运动的影响

目的　应用二维超声心动图法观察室间隔运动受呼吸影响情况 ,进一步验证笔者新近提出的关于呼吸影响心功能的假说 ,为该假说的临床应用提供理论依据。方法　用超声心动图观察 2 0例正常人及 11例心包积液伴有或不伴有心包填塞患者的室间隔随呼吸运动的情况。结果　正常人平静呼吸时 ,室间隔运动轻微 ,较深呼吸时明显 ,吸气时室间隔向左室方向移动 ,呼气时恢复。心包填塞患者的室间隔随呼吸左右摆动的幅度明显增大 ,以致左右室短径及相应的左右心功能呈交替、反时相的周期性变化。结论　研究结果进一步证明 ,呼吸性胸压变化是室间隔呼吸性左右摆动的原动力 ,是呼吸性血流动力学指标周期性改变、舒张期左右心室相互作用的力学基础 ,这为笔者提出的假说的临床应用提供了理论依据     

超声监测呼吸对风湿性心脏病患者二尖瓣血流速度的影响及对相关力学机制的分析

目的探讨呼吸对风湿性心脏病单纯二尖瓣狭窄患者二尖瓣血流速度的影响及其力学机制的研究。方法选取32例风湿性心脏病单纯二尖瓣狭窄患者(风湿性心脏病组)和30例正常成人(对照组),应用经胸超声心动图检查分别获取吸气相与呼气相时二尖瓣和三尖瓣彩色多普勒血流频谱,测量舒张早期血流速度峰值(E、Et)及舒张晚期血流速度峰值(A、At),并比较吸气相与呼气相各参数之间的差异。结果对照组吸气相较呼气相E值减低,Et值增大,差异有统计学意义(P0.01),风湿性心脏病组吸气相较呼气相E和Et值增大,差异有统计学意义(P0.01),两组A和At值均无变化。结论呼吸对正常人成与风湿性心脏病单纯二尖瓣狭窄患者二尖瓣血流速度的影响不同。吸气时胸内负压的直接力学作用与左室舒张方向相同,有利于左室舒张,可能是风湿性心脏病单纯二尖瓣狭窄患者二尖瓣血流速度E峰值增大的原因。     

呼吸对慢性阻塞性肺病左心室充盈的影响及其机制的超声心动图研究

目的探讨超声心动图检测慢性阻塞性肺病（COPD）患者左心室功能和COPD病程的可行性。方法采用Sequoia512彩色超声诊断仪,记录21例COPD患者及50名健康人自然呼吸时二尖瓣口E峰、A峰血流速度,同步记录心电图和呼吸曲线,计算二尖瓣舒张早期E峰血流速度呼吸性波动指数（RVI）及E峰与A峰血流速度比值（E/A）呼吸变化率。结果两组均表现为E峰血流速度、E/A吸气相低于呼气相（P〈0.001）;COPD组A峰血流速度吸气相与呼气相差异无统计学意义（P=0.076）,而健康对照组A峰血流速度吸气相低于呼气相（P〈0.001）。COPD组二尖瓣E峰血流速度RVI及E/A呼吸变化率均较对照组增大（P=0.002）。结论自然呼吸对COPD患者二尖瓣血流影响具有规律性,进一步验证了呼吸影响心功能机制新假说,同时也为利用多普勒技术评价COPD患者左室功能损害程度和肺实质病变严重程度的进一步研究提供更多信息。     

曲率半径、弧长法与速度向量成像联合评价室间隔形变运动

目的 联合应用曲率半径、弧长法与速度向量成像(velocity vector imaging,VVI)观察室间隔的形变运动.方法 15例健康志愿者,采集胸骨旁左室二尖瓣腱索水平短轴观的动态二维灰阶图像数据储存,并导入VVI工作站,分析获取室间隔心内膜下心肌的环向峰值应变;获取舒张末期和收缩末期左室同一水平短轴观静态图像,储存导出,采用自制的测量软件,分别测量室间隔收缩末期与舒张末期的弧长及对应的曲率半径,计算缩短率.结果 舒张末期室间隔弧长和曲率半径较收缩末期明显增大,差异有统计学意义(P<0.0001);室间隔弧长缩短率与峰值应变比较差异无统计学意义(P=0.123).室间隔峰值应变与室间隔弧长缩短率有相关性(r=0.840,P=0.0001),且Blant-Altman分析图显示二者一致性良好.结论 曲率半径和弧长法可以无创性地评估室壁摆动和形变.     

平静呼吸对肺静脉血流的影响及其机制的超声心动图研究

目的 研究平静呼吸对肺静脉血流的影响及其规律，进一步验证呼吸影响心功能机制新假说，探讨肺静脉血流速度随呼吸变化对评价左心室舒张功能潜在的意义。方法 20名健康志愿者，采用Sequoia 512超声仪，同步记录右上肺静脉血流速度频谱、心电图和呼吸曲线。连续测量5个呼吸周期吸气相和呼气相血流速度及速度时间积分（VTI），取平均值。分别计算吸气相和呼气相肺静脉收缩期S波与舒张期D波的速度比值以及VTI比值。结果 肺静脉收缩期S波血流速度及VTI于吸气相和呼气相之间变化不显著（P=0．221；P=0．090）；舒张期D波血流速度及VTI在吸气相低于呼气相（均P〈0．001）；S波与D波血流速度比值及VTI比值在吸气相高于呼气相（均P〈0．001）。结论 平静呼吸对肺静脉血流影响具有规律性：S波血流速度及VTI于吸气相和呼气相之间变化不显著；D波血流速度及VTI在吸气相低于呼气相；S波与D波血流速度比值及VTI比值在吸气相高于呼气相，其中血流速度比值在吸气相〉1，而在呼气相可〉1，也可≤1。进一步验证了呼吸影响心功能机制新假说。利用肺静脉频谱评价左室舒张功能时如能结合呼吸的影响则可能提供更多信息。     

Reversal of the pattern of respiratory variation of Doppler inflow velocities in constrictive pericarditis during mechanical ventilation.

BACKGROUND: Spontaneous inspiration causes a characteristic decrease of the mitral valve (MV) and pulmonary venous (PV) flow velocities obtained by Doppler echocardiography in patients with constrictive pericarditis (CP). This has been explained by the decrement it causes in the intrathoracic pressure. Positive pressure ventilation (PPV) causes an increment of intrathoracic pressure with mechanical inspiration. Therefore the pattern of respiratory variation produced during PPV may differ from that seen during spontaneous breathing. OBJECTIVE: Our goal was to describe the effect of PPV on the pattern and magnitude of respiratory variation of MV and PV flow velocities in CP. METHODS: We performed intraoperative pulsed Doppler transesophageal echocardiography on 15 patients (13 men, mean age 52+/-15 years) with CP after general anesthesia and before sternotomy and pericardial stripping. The peak velocity and time-velocity integral (TVI) of the mitral inflow E and A waves and the PV systolic and diastolic waves were measured at onset of inspiration and expiration for 3 to 6 respiratory cycles. Respiratory phase was monitored with a heat-sensitive nasal thermistor. The percent change in Doppler flow velocities from mechanical inspiration (INS) to mechanical expiration (EXP) was calculated with the formula %change = INS - EXP / INS x 100. RESULTS: The peak velocity of the mitral inflow E wave was significantly higher during mechanical inspiration than expiration (57 +/-14.5 versus 47+/-13.9 cm/s, P<.001). This represented a percent change of 18%+/-7.9% from expiration to inspiration. The mean TVI of the mitral inflow E was also higher during mechanical inspiration than expiration (P = .02). The peak velocity of the PV D wave was higher during mechanical inspiration than expiration (39+/-17.8 versus 28+/-14.7 cm/s, P<.001). This represented a mean percent change of 28%+/-13.8%. The mean value of the TVI for the PV D wave was also significantly greater during mechanical inspiration than expiration (P <.05). CONCLUSIONS: Positive pressure ventilation reverses the pattern of respiratory variation of the MV and PV flow velocities in CP. The percent change in the peak velocities of the MV and PV flows produced by PPV is the same range reported in CP during spontaneous breathing.     

超声心动图评价高血压病患者左心功能

目的运用超声心动图技术综合评价高血压病患者左室收缩功能和舒张功能。方法高血压病组56例和对照组36例,M-型和二维(2D)超声心动图检测:左房内径(LAd),舒张期室间隔厚度(IVST)和左室后壁厚度(PWT),左室舒张末期内径(LVDd),二尖瓣EF斜率,室间隔及左室后壁运动幅度,左室射血分数(EF),左室短轴缩短率(FS),每搏量(SV);脉冲多普勒(PW)检测二尖瓣口舒张早期充盈峰速度(VE),舒张晚期充盈峰速度(VA),E/A比值,等容舒张时间(IVRT)。结果高血压病患者左室壁与室间隔收缩期运动幅度普遍增强,与对照组比较P<0.01;左室收缩功能各项参数(EF、FS、SV)高于对照组(P<0.05),高血压病组左室舒张功能各参数异常,表现为VE减低,VA升高,E/A<1,IVRT延长,MV-EF斜率减慢,与对照组比较P<0.001;左房扩大(P<0.001)。结论超声心动图技术可反映高血压病患者左心结构和功能变化,为临床诊治提供客观依据。     

定量组织速度成像技术评价冠心病左心室局部心肌收缩与舒张功能的研究

目的探讨定量组织速度成像（QTVI）技术评价冠心病（CAD）患者左心室心肌收缩与舒张功能的价值。方法应用QTVI获取35例正常人和35例CAD患者左心室长轴方向不同室壁节段的心肌多普勒速度曲线,分析并比较收缩期峰值速度（Vs）、收缩期加速度（a）、快速充盈期和心房收缩期的速度（Ve和Va）、二尖瓣舒张期血流频谱E／A值、左心室射血分数（LVEF）、左心室质量指数（LVMI）、Vs／Ve、Va／Ve比值。结果CAD患者Vs、Ve、Va、a、Vs／Ve、LVEF均比正常人降低;CAD患者Vs的测值与临床NYHA分级有相关性（r=0．73）,Ve／Va与E／A有明显相关关系（r=0．74）。结论QTVI定量提供了一种较精确的评价CAD患者左心室局部心肌收缩舒张功能变化方法。     

Pulsed Doppler echocardiographic description of a circular flow pattern in spontaneous left ventricular contrast

Pulsed Doppler echocardiography was performed in nine patients with spontaneous intracavitary dynamic echoes, revealing a circular flow pattern. All patients had a severely dilated left ventricle as a result of ischemic heart disease. The sample volume was placed in the apical four-chamber view near the lateral wall and near the interventricular septum, halfway between the mitral valve anulus and apex. A continuous (i.e., during both systole and diastole) positive signal was recorded near the lateral wall and a continuous negative signal at the interventricular septum. This indicates flow continuously toward the transducer along the lateral wall and away from the transducer along the interventricular septum. This is consistent with the circular flow pattern, as demonstrated by the spontaneous intracavitary dynamic echoes. In 22 normal volunteers a positive prominent shift was recorded during diastole near the lateral wall and either a negative (nine of 22) or no (13 of 22) shift at all during systole. Near the interventricular septum a negative systolic shift followed by a positive, early-diastolic shift was consistently recorded. In the large majority (18 of 22) negative waves were recorded during middle and late diastole. A continuous positive or negative Doppler signal was consistently absent in healthy subjects. The angle between the proximal part of the interventricular septum and the anterior mitral valve leaflet during maximal early diastolic opening in the patients was 74 +/- 4.8 degrees (mean +/- SD), which may give rise to a preferential eccentric inflow and the maintenance of the circular apical flow pattern.     

超声心动图研究正压通气对犬心功能的影响及其机制

目的观察正压通气时心内瓣口血流速度和左、右心功能的变化,研究正压通气影响血流动力学机制的新理论。方法11条杂种犬,用超声心动图测定正压通气时心内各瓣口的血流速度,右室、左室每搏量,左室容积和射血分数的变化。结果三尖瓣和肺动脉瓣口血流速度正压吸气相减低,呼气相增加;二尖瓣和主动脉瓣口血流速度变化与之相反(P<0.05)。与自主呼吸相比,正压吸气时,右室每搏量减少,左室舒张末和收缩末容积减小,射血分数降低(P<0.05)。结论正压通气使室间隔趋于右移,同时,肺血管床回心血量增加,但与自主呼吸时相比,腔静脉回心血量相对减少,故心功能降低。     

Left ventricular wall motion velocities in healthy children measured by pulsed wave Doppler tissue echocardiography: normal values and relation to age and heart rate.

Left ventricular wall motion velocities were measured by pulsed wave Doppler tissue (PWDT) echocardiography in 131 healthy children (mean age 7.5 +/- 5.5 years) at the interventricular septum and the posterior wall in the left ventricular short-axis view, and at the interventricular septum and the lateral wall in the 4-chamber view. The systolic wave (Sw) consisted of 2 components, and the difference between the 2 components was greater in the lateral wall than in the other walls. The peak early diastolic wave (Ew) velocity was also highest in the lateral wall. Most variables during systole correlated with age. The ratio of peak atrial systolic wave (Aw) velocity to peak Ew velocity (Aw/Ew) correlated with heart rate. The Aw/Ew in each wall correlated with the ratio of late (A) to early (E) peak mitral flow, although regression slopes differed among different wall segments. In younger children with increased heart rates, the Aw/Ew ratio increased because the Ew velocity decreased, although the A/E ratio increased because of an increased A velocity. Normal values for the PWDT variables change with heart rate and age in the pediatric population. The data reported in this study can be used as normal values for left ventricular function for PWDT echocardiography.     

QTVI技术结合Tei指数评价风心病单纯性二尖瓣狭窄左室功能

目的探讨定量组织速度成像技术（QTVI）结合Tei指数评价风湿性心脏病单纯性二尖瓣狭窄（MS）患者左室心肌长轴收缩功能的应用价值。方法采用QTVI技术分别测量34例单纯性风湿性二尖瓣狭窄（MS）患者和36例健康志愿者二尖瓣环室间隔、侧壁、前壁、下壁、前间隔、后壁处各点的收缩期峰值运动速度（Vs）,并测量相关时间间期,计算Tei指数。结果MS组左室射血分数（LVEF）64．9±7．01％、对照组左室射血分数（LVEF）68．0±6．8t％,两组间左室LVEF比较差异无显著意义（P〉0.05）。MS组室间隔运动速度4．07±1．44cm／s、侧壁运动速度5．33±1．72cm／s、前壁运动速度4．89±1．71cm／s、下壁运动速度4．28±1．21cm／s、前间隔运动速度3．94±1．46cm／s、后壁运动速度5．19±1．81cm／s、平均峰值运动速度（AVs）4．61±1．62cm/s;对照组室间隔运动速度6．11±0．96cm／s、侧壁运动速度8．74±1．40cm／s、前壁运动速度8．45±1．33cm／s、下壁运动速度6．59±0．94cm／s、前间隔运动速度6．01±1．25cm／s、后壁运动速度7．70±1．46ends、平均峰值运动速度（AVs）7．27±1．63cm／s。MS组与对照组相比较,各节段Vs与平均峰值运动速度（AVs）明显降低,差异有显著意义（P〈O．01）。MS组Tei指数0．50±0．12、对照组Tei指数0．21±3．47,MS组Tei指数明显增高（P〈0．01）。结论LVEF很难准确地反映风湿性单纯性二尖瓣狭窄患者左室收缩功能在亚临床水平上的损害,QTVI技术结合Tei指数能更加敏感、有效地定量评价风湿性单纯性二尖瓣狭窄患者左室心肌长轴收缩功能和左室整体功能的损害。