多普勒超声检测胎儿心脏机械性PR间期的临床意义研究

目的应用多普勒超声技术测量胎儿心脏机械性PR间期并探讨其临床意义。方法选取经胎儿超声心动图检出的83例疾病组胎儿,分别为先天性心脏病及心律失常。正常对照组为100例中、晚孕胎儿。应用彩色多普勒引导脉冲多普勒取样容积记录左心室流入道及流出道血流频谱,测量从舒张期二尖瓣A峰起始至收缩期主动脉射血起始的心房到心室的传导时间(PR间期),并同时测量收缩期主动脉射血起始至二尖瓣A峰起始的时间(VA间期)。结果 83例疾病组胎儿中先天性心脏病69例,心律失常12例,双胎输血综合征1例(双胎儿)。其中54例多普勒超声测量PR间期延长(131～220ms),并检出自身免疫性抗体阳性和弱阳性5例。正常对照组100例的中、晚孕孕妇均无自身免疫系统疾病,并经超声排除胎儿先天性心脏病、心律失常及其他胎儿异常,多普勒超声测量PR间期值均≤130ms。两组PR间期、VA间期比较差异有统计学意义(P0.01)。结论本研究结果表明,除孕妇患自身免疫性疾病可引起胎儿传导系统受损外,胎儿患先天性心脏病、心律失常等疾病时,其窦房结、房室结传导功能的易损性明显高于正常胎儿。其影响因素与心脏解剖结构异常和传导系统发育不良的相关性有待进一步研究。     

产前超声心动图诊断胎儿Ⅰ度房室传导阻滞

目的 探讨产前应用多普勒超声技术测量胎儿心脏机械性PR间期并诊断胎儿Ⅰ度房室传导阻滞的临床意义.方法 选取经胎儿超声心动图检测出的100胎心脏疾病胎儿(疾病组),应用彩色多普勒引导脉冲多普勒取样容积记录左心室流人道及流出道血流频谱,测量PR间期及VA间期,并与120名正常胎儿(正常对照组)比较.结果 疾病组胎儿中先天性心脏病83胎、心律失常13胎、双胎输血综合征4胎,其中多普勒超声测量PR间期延长(131～220 ms)75胎.疾病组的PR、VA间期与正常对照组比较,差异有统计学意义(P<0.001).结论 多普勒超声心动图技术可以更好地获得房室传导时间的定位取样,且简便易行,对测量胎儿心脏机械性PR间期并诊断胎儿Ⅰ度房室传导阻滞有重要的临床价值.     

胎儿期Ⅰ°房室传导阻滞的诊断性研究分析

目的：选择较理想的指标及临界值点用于筛查胎儿Ⅰ°房室传导阻滞。方法：对62例晚孕孕妇（均大于38周）,进行组织多普勒成像（TDI）检测,记录Aa-IV（心房收缩期起点至等容收缩期起点的时间间隔）及Aa-Sa（心房收缩期起点至心室收缩射血期起点的时间间隔）,作为胎儿房室传导时间的评价指标。出生后一周内行新生儿心电图检查,测量PR间期。应用直线回归分析,比较Aa-IV、Aa-Sa与PR测值的相关性。绘制受试者工作特征曲线（ROC曲线）,分析比较Aa-IV、Aa-Sa的诊断准确性。结果：Aa-IV与PR的相关性更好。ROC曲线显示Aa-IV具有中等诊断意义;Aa-Sa诊断价值较低。根据敏感度及特异度分析,认为Aa-IV≥93.7 ms可作为筛查胎儿Ⅰ°房室传导阻滞的最佳临界值。结论：Aa-IV更适用于胎儿Ⅰ°房室传导阻滞的诊断,筛查胎儿Ⅰ°房室传导阻滞的最佳临界值为Aa-IV≥93.7 ms。     

组织多普勒与脉冲多普勒超声评价胎儿心脏传导时间的定量研究

目的 确立正常胎儿的心脏传导时间参考值,探讨不同孕龄及心率对该值的影响.方法 189例孕妇,分别采用组织多普勒成像(TDI)和脉冲多普勒技术(PD)测量胎儿的房室传导时间(AV)和心室开始收缩到下-心动周期心房开始收缩的时间间期(VA),采用配对t检验比较两种方法测量的一致性,胎儿心脏传导时间与孕周、胎心率进行直线相关分析.结果 TDI测量AV为(126.56±15.33)ms,95% CI(124.10～129.03)ms;VA为(285.22±24.53)ms,95% CI(281.27～289.16)ms;PD测量AV为(127.42±12.88)ms,95%CI(125.35～129.49)ms;VA为(287.42±25.19)ms,95%CI(283.37～291.47)ms.TDI、PD测量胎儿心脏传导时间差异无统计学意义.胎儿心脏传导时间与孕周呈正相关,与胎心率呈负相关.PD、TDI测量AV在不同心率胎儿的比较差异无统计学意义,VA在不同心率胎儿的比较差异有统计学意义;PD、TDI测量AV、VA在不同孕周胎儿的比较差异无统计学意义.17例阵发性心律失常胎儿表现为AV、VA值的改变.结论 TDI、PD均可简单快速地定量测定胎儿心脏传导时间,胎儿心脏传导时间参考值的测定对于胎儿心律失常的评估具有潜在的应用价值.     

多普勒超声心动描记术检测胎儿机械性QT间期

目的 探讨多普勒超声心动描记术在测量胎儿机械性QT间期中的应用价值。 方法 对胎儿心脏无异常的早孕期、中孕期和晚孕期孕妇各100名行胎儿多普勒超声心动描记术检查。记录左心室流入道及流出道血流频谱,测量机械性QT间期,即自二尖瓣舒张期A峰结束至下一个舒张期E峰开始的时间,同时测量胎儿心率。 结果 胎儿机械性QT间期和心率呈正态分布,早孕、中孕和晚孕组胎儿机械性QT间期均值的95%可信区间分别为225.25~231.21 ms、241.21~248.79 ms和253.23~259.45 ms;不同孕期组间胎儿机械性QT间期和心率的差异均有统计学意义(P均<0.01);胎儿机械性QT间期与孕周呈正相关(r=0.499,P<0.01),胎儿心率与孕周呈负相关(r=-0.628,P<0.01)。 结论 应用多普勒超声心动描记术检测胎儿机械性QT间期简便易行,图像清晰且重复性好,可为临床诊断胎儿心律失常提供重要依据。     

定量组织速度成像与频谱多普勒超声心动图对胎儿心脏传导时间间歇的对照研究

目的 探讨定量组织速度成像技术(QTVI)在胎儿心脏传导时间间歇研究中的应用价值.方法 对116例无持续性心律失常的胎儿,分别采用QTVI和脉冲多普勒超声心动图(PD)测量胎儿的房室传导时间(AV)和心室开始收缩到下一心动周期心房开始收缩的时间间期(VA),采用t检验比较2种方法 测量的一致性.胎儿心脏传导时间与孕周、胎心率进行直线相关分析.结果 QTVI测量AV为(120.45±7.00)ms(95%CI,115.67～124.67 ms),VA为(300.31±23.51)ms(95%CI,287.67～316.00 ms);PD测量AV为(122.70±7.39)ms(95%CI,118.33～127.67 ms),VA为(297.85±22.15)ms(95%CI,284.83～310.33 ms).胎儿心脏传导时间与孕周呈正相关,与胎心率呈负相关.不同心率胎儿之间AV比较差异无统计学意义(P＞0.05).不同心率胎儿之间VA比较差异有统计学意义(P＜0.05);不同孕周胎儿之间AV及VA比较差异均无统计学意义(P＞0.05).结论 QTVI可简便快速地测定胎儿心脏传导时间,这在分析胎儿心律失r常方面具有重要的应用价值.     

双腔起搏器患者术后房室间期的程控管理

目的：探讨最佳房室间期（AVD）的设置和管理方法。方法：选择因高度或完全性房室传导阻滞而安置双腔起搏器的患者,研究组（23例）通过超声心动图指导进行感知房室间期的优化,对照组（21例）则常规设置房室间期。对比起搏器植入后1周和7个月2组患者超声心动图的变化以及心房颤动和心力衰竭的发生率。结果：（1）研究组的AVD为（138.7±8.7）ms,对照组的AVD为（124.8±0.8）ms（P〈0.001）。（2）起搏器植入后1周,2组患者的超声心动图指标无显著差异。（3）随访结束时,研究组与对照组相比,左房内径分别为（36±2.8）mm和（38.7±3.4）mm,P=0.008;左室内径分别为（46.7±4.5）mm和（49.4±5.2）mm,P=0.07,对照组的左心房、左心室较研究组相对增大。E波最大血流速度-时间积分分别为（13.2±0.9）和（9.9±1.7）;A波最大血流速度-时间积分分别为（5.1±0.9）和（4.1±0.9）;左心室射血分数分别为（58.6±2.2）%和（55.3±4.1）%;每搏量分别为（63±5.2）mL和（54.9±6.6）mL,对照组患者的心功能明显降低。结论：最佳房室间期起搏有利于患者的心功能,超声心动图是指导房室间期设置的简便而可靠手段。     

应用组织多普勒成像技术测量正常胎儿房室传导时间的初步研究

目的 应用组织多普勒成像测量正常胎儿的房室传导时间,建立正常胎儿的房室传导时间参考值范围,为早期发现房室传导异常提供依据.方法 100名中晚孕超声筛查结果正常的胎儿(15～40孕周),按检查时不同胎龄分为5组进行研究.获得TDI动态图像后脱机软件QLAB分析测定房室传导时间,各组间进行方差分析并将AVCT与心率及孕周进行线性相关及线性回归分析;纳入研究的胎儿出生后尽量进行心电图和超声心动图检查.结果 正常胎儿房室传导时间范围为(123.9±10)ms;胎儿房室传导时间与心率成负相关(Y＝190.261-0.467X, P＜0.01),与孕周无明显相关(Y=0.045X,P=0.66).结论 组织多普勒成像为测量胎儿房室传导时间的良好方法;胎儿房室传导时间与孕周无相关,而与心率呈负相关;正常值的建立将有助于临床早期发现和诊断胎儿房室传导异常.     

左束支传导阻滞对扩张型心肌病左心功能的影响

目的　评价左束支传导阻滞对扩张型心肌病 (DCM )左心功能的影响。方法　对照组、DCM不伴室内传导阻滞组、DCM伴完全左束支传导阻滞 (CLBBB)组各 16例 ,均为窦性心律 ,并伴有相对性二尖瓣反流。应用脉冲和连续多普勒技术 ,测量左室射血前期时间 (PET)、左室射血时间 (LVET)、左室充盈时间 (LVFT)、二尖瓣反流持续时间 (MRT)、心搏做功指数 (MPI)、每搏量 (SV)等参数 ,然后转换为脉冲心肌组织多普勒成像技术 (TDI) ,通过左房室环测量左室收缩期和舒张期电机械运动的时间离散度。结果　与对照组相比 ,DCM伴室内传导阻滞组与不伴室内传导阻滞组 [分别为收缩期 ( 77.9± 13 .6)ms对( 5 2 .1± 13 .2 )ms对 ( 2 8.3± 7.2 )ms ,P <0 .0 0 1;舒张期 ( 92 .0± 18.6)ms对 ( 5 2 .9± 14 .5 )对 ( 3 3 .7±10 .2 )ms ,P <0 .0 0 1]左室电机械运动的时间离散度均明显增大 ,尤以DCM伴CLBBB组更明显。PET、LVFT、MPI三组间差异有显著性意义 ,MRT也有明显延长趋势。结论　使用TDI及频谱多普勒技术可全面评价左心室及左房室间不协调运动情况 ,为临床双心室或双腔起搏治疗充血性心力衰竭提供理论依据     

超声诊断胎儿左心室横纹肌瘤1例

患者女,28岁,孕27周,胎儿胎心律正常。超声检查:胎儿心脏位于脊柱左侧,四腔心可显示,房室连续一致,大动脉与心室连接关系正常。左心室内可见一团状强回声,大小约21mm×20mm,几乎充满左心室(图1、2),左室流出道及二尖瓣口血     

Doppler echocardiographic and electrocardiographic atrioventricular time intervals in newborn infants: evaluation of techniques for surveillance of fetuses at risk for congenital heart block.

OBJECTIVE: To evaluate one novel and two previously reported Doppler flow velocimetric techniques to estimate atrioventricular (AV) time intervals, suggested to be useful for early identification of fetuses at risk for congenital heart block. METHODS: In 22 newborn infants, Doppler tracings were obtained from the mitral valve/aortic outflow and the superior vena cava/ascending aorta, as an ECG was recorded simultaneously. AV time intervals were measured using the onsets of the mitral A-wave/aortic outflow (MV-Ao), superior vena cava a-wave/aortic flow (SVC-Ao), and mitral A-wave/mitral valve closure (MV) as indirect markers of electrical atrial/ventricular activation. RESULTS: Close positive linear relationships to the electrocardiographic PR interval were demonstrated for the MV-Ao (r = 0.82, S(y/x) = 7.4 ms), SVC-Ao (r = 0.85, S(y/x) = 6.8 ms), and MV (r = 0.92, S(y/x) = 3.8 ms) approaches. Both techniques using the aortic flow to indicate ventricular activation overestimated the PR interval: the MV-Ao by + 32 +/- 7.7 ms (mean +/- SD) and the SVC-Ao approach by + 22 +/- 7.0 ms. The new MV approach using mitral closure for the same purpose did not overestimate the PR interval, but there was a trend towards underestimation of the PR intervals as time intervals increased. CONCLUSIONS: When systematic differences between echocardiographic and electrocardiographic AV time intervals are compensated for, all three techniques are useful to get indirect estimates of the PR interval. As MV recordings only need insonation of a single valve, and are thus easier to obtain, this technique may be of value as a first screening method to identify fetuses in need for further surveillance. In cases with AV time prolongation the SVC-Ao method seems superior.     

母体抗SSA/SSB抗体阳性胎儿完全性房室传导阻滞超声表现

目的 观察母体抗SSA/SSB抗体阳性胎儿完全性房室传导阻滞（CAVB）超声表现。方法 以二维、M型及多普勒超声技术观察7胎母体抗SSA/SSB抗体阳性CAVB胎儿心脏,获取二尖瓣、左心室流入道及流出道、脐动脉（UA）、静脉导管（DV）及大脑中动脉（MCA）血流频谱。结果 7名孕妇抗SSA抗体、抗Ro52抗体均呈阳性,其中4名抗SSB抗体呈阳性。7胎均见房室分离,心房律正常而心室律缓慢,二尖瓣、UA、DV及MCA血流异常;其中4胎心房壁、房间隔、二尖瓣环或腱索回声增强。7胎均未合并其他心内外结构畸形。结论 母体抗SSA/SSB抗体阳性可致胎儿发生CAVB;超声观察胎儿心脏及血流动力学变化有利于判断胎儿预后。     

彩色多普勒超声诊断胎儿左心发育不良综合征

目的探讨彩色多普勒超声诊断胎儿左心发育不良综合征的价值。方法对29436例胎儿进行彩色多普勒超声系统筛查,主要观察心腔大小,二尖瓣和主动脉瓣的活动情况,卵圆孔、室间隔缺损情况,主动脉和肺动脉状况等。结果超声筛查出的15例胎儿左心发育不良综合征中,主要表现为右房、右室明显增大,左心发育不良,二尖瓣狭窄或闭锁,主动脉瓣狭窄或闭锁,二尖瓣或主动脉瓣发育不良等。结论彩色多普勒超声对诊断胎儿左心发育不良综合征具有重要价值。     

全方位M-型与普通M-型超声对比评价左室Tei指数的临床研究

目的 本研究目的旨在比较脉冲多普勒、普通M-型、全方位M-型超声3种方法所得心肌作功指数（Tei指数）的相关性,试图探索一种简便、有效、实用的检测方法。 方法 70例住院患者接受检查。应用脉冲多普勒分别采集二尖瓣口和主动脉瓣口血流频谱,应用普通M-型超声分别记录二尖瓣及主动脉瓣活动曲线,应用全方位M-型超声在同一心动周期内同时记录二尖瓣及主动脉瓣活动曲线,分别测量二尖瓣闭合至下一心动周期开放时间间期（a线）及主动脉瓣开放时间（b线）,计算Tei指数。 结果 普通M-型、全方位M-型与脉冲多普勒超声3种方法测得Tei指数之间的比较差异无统计学意义,且相关性好。 结论 全方位M-型是一种较为简便、理想的测定Tei指数的方法。     

A new and simple Doppler method for measurement of fetal cardiac isovolumetric contraction time.

OBJECTIVES: The fetal cardiac isovolumetric contraction time is defined as the interval between mitral valve closure and aortic valve opening. The objective of this study was to develop a simple and reliable Doppler method for measuring fetal isovolumetric contraction time using a digital filtering and processing system. METHODS: Cardiac Doppler signals were recorded from 40 fetuses at 18-40 weeks' gestation using a continuous-wave ultrasound transducer. The raw signal was digitized, filtered and divided into five different frequency ranges: 250-375, 375-500, 500-750, 750-1000 and 1000-1500 Hz. To determine the most suitable filter setting for detecting mitral valve closure and aortic valve opening signals, we examined whether they were detected clearly in each filter range. RESULTS: Both mitral valve closure and aortic valve opening signals were detected clearly in the 500-1000 Hz range. The atrioventricular flow and outflow noises in the 250-500 and 1000-1500 Hz ranges helped us to identify the signals. It was found that dividing the raw signals into three ranges of 250-500, 500-1000 and 1000-1500 Hz was the most suitable digital-filter setting for measuring isovolumetric contraction time. CONCLUSIONS: We have developed a simple Doppler method for measuring fetal isovolumetric contraction time. The advent of digital processing has simplified the equipment and the simultaneous multidisplay of three different filtered signals enables easy and accurate measurement.     

The mitral gap at 11 + 0 to 13 + 6 weeks: marker of trisomy 21 or artifact?

OBJECTIVES: To investigate the possible association between a particular pulsed Doppler waveform pattern, mitral gap, and trisomy 21 at 11 + 0 to 13 + 6 weeks. METHODS: We performed two studies. The first was a retrospective analysis of pulsed Doppler velocity waveforms of the mitral valve inflow, recorded during specialist fetal echocardiography in 291 chromosomally normal and 144 trisomy 21 fetuses with a nuchal translucency (NT) thickness of 3.5 mm or more. We examined each waveform in each trace to determine whether there was a gap between the E-wave (early diastolic filling) and A-wave (atrial contraction) in the waveform across the mitral valve. We also examined each trace that contained at least one waveform with a mitral gap and, first, noted the order of waveforms with a mitral gap relative to those without and, second, measured the A-wave peak velocity in a representative waveform with a mitral gap and in one without. The second study was a prospective investigation in which Doppler velocity waveforms of the mitral valve inflow were assessed in 227 singleton pregnancies immediately before chorionic villus sampling. RESULTS: A mitral gap was observed in 16 (5.5%) of the chromosomally normal and in 25 (17.4%) of the trisomy 21 fetuses. The incidence of mitral gap was significantly associated with the presence of cardiac defects but not with thickness of NT. The median number of waveforms per recorded image was 6 (range, 3-7) and in 32 (78%) of the 41 traces with a mitral gap only one or two of the waveforms was abnormal. The abnormal waveforms were in the middle or at the end of the trace in 95% of cases and had a lower mean A-wave peak velocity than did the normal waveforms (mean difference 3.7 cm/s; 95% CI, 0.3-7.0 cm/s; P = 0.03). In a prospective study of 10 normal fetuses we could produce a mitral gap deliberately by moving the sample volume out of the center of flow in the atrioventricular valve. In the prospective study of 227 pregnancies undergoing chorionic villus sampling a mitral gap was observed in 26/197 (13.2%) in which the fetal karyotype was subsequently found to be normal, 4/20 (20%) with trisomy 21 and 1/10 with other chromosomal defects. CONCLUSIONS: At 11 + 0 to 13 + 6 weeks, a mitral gap may be more common in fetuses with trisomy 21 than in fetuses with a normal karyotype. However, it is possible that a mitral gap does not reflect an underlying hemodynamic abnormality, but is rather the result of suboptimal positioning of the Doppler sample volume as the fetus moves during acquisition.     

Changes in left heart hemodynamics after technically successful in-utero aortic valvuloplasty.

OBJECTIVE: Severe aortic stenosis in the mid-gestation fetus can progress to hypoplastic left heart syndrome (HLHS). @ In-utero aortic valvuloplasty is an innovative therapy to promote left ventricular growth and function and potentially to prevent HLHS. This study evaluated the effects of mid-gestation fetal balloon aortic valvuloplasty on subsequent fetal left ventricular function and left heart Doppler characteristics. METHODS: We reviewed fetuses with aortic stenosis that underwent attempted in-utero aortic valvuloplasty between 2000 and 2006. Pre-intervention and the latest post-intervention fetal echocardiograms were analyzed to characterize changes in left heart function and Doppler characteristics in utero. RESULTS: Forty-two fetuses underwent attempted aortic valvuloplasty during the study period, 12 of which were excluded from analysis secondary to inadequate follow-up data, termination or fetal demise. Study fetuses (n = 30) underwent pre-intervention echocardiography at a median gestational age of 23 weeks, and were followed for a median of 66 +/- 23 days post-intervention. In 26 fetuses, aortic valvuloplasty was technically successful. Among these 26, left heart physiology was abnormal pre-intervention and improved or normalized after intervention in most cases: biphasic mitral inflow was present in 5/25 (20%) cases pre-intervention and in 21/23 (91%) post-intervention (P < 0.001); moderate or severe mitral regurgitation was present in 14/26 (54%) cases pre-intervention and in 5/23 (22%) post-intervention (P = 0.02); bidirectional flow across the patent foramen ovale was present in 0/26 cases pre-intervention and in 6/25 (24%) post-intervention (P = 0.01); antegrade flow in the transverse arch was present in 0/25 cases pre-intervention and in 17/26 (65%) post-intervention (P < 0.001). The left ventricular ejection fraction increased from 19 +/- 10% pre-intervention to 39 +/- 14% post-intervention (P < 0.001). These changes were not observed in control fetuses (n = 18). CONCLUSION: Fetal aortic valvuloplasty, when technically successful, improves left ventricular systolic function and left heart Doppler characteristics.