右心室间隔部起搏的核素心室显像位相分析及心电图研究

目的 :观察右心室间隔部 (RVS)起搏时的心室激动顺序和双心室同步性 ;评估在接受心室起搏的患者中心电图的演变。　　方法 :慢性心房颤动伴长RR间歇或缓慢心室率需植入永久起搏器患者 10例 ,男性 7例 ,女性 3例 ,平均年龄(64 2 0± 12 61)岁 ,均采用抑制型按需心室起搏 (VVI)模式先后顺序进行右心室心尖部 (RVA)和RVS。记录术前心电图、术中RVA和RVS起搏心电图 ;术后进行核素心室显像位相分析 ,对比自身心律与RVA和RVS起搏时心室激动顺序和双心室同步性的差异。　　结果 :核素心室显像位相分析证实RVA起搏造成心室激动顺序异常和双心室失同步 ;RVS起搏时心室激动顺序、双心室同步性与正常基本一致。RVA起搏时QRS波群较术前自身增宽 [(173 0 0± 14 94)msvs (74 5 0± 7 62 )ms ,P <0 0 0 1] ,差异有非常显著性 ;RVS起搏的QRS波群宽度较RVA起搏缩窄 [(13 6 0 0± 13 5 0 )msvs (173 0 0± 14 94)ms ,P <0 0 0 1) ] ,差异有非常显著性。　　结论 :RVS起搏时心室激动顺序、双心室同步性与正常基本一致 ;与RVA起搏相比RVS起搏时心电轴、QRS波群与正常心电图相似或接近。     

右心功能评价技术研究进展

随着人们对心脏功能的深入研究,右心室在循环系统中的作用日益受到重视。各种评价右心室功能的检测技术———脉冲多普勒超声心动图、二维超声心动图、三维超声心动图、声学定量技术、X线心室造影、放射性核素心室造影、电子束计算机体层成像、磁共振成像在评价右心功能方面所显示出的优势,使人们对右心室在循环系统中的作用有了进一步的了解,充分利用各种检测技术评价右心室功能。     

左心室壁瘤对右心室整体和局部功能的影响

我们采用放射性核素心室造影技术评价左心室壁瘤患者的右心室整体和局部收缩和舒张功能 ,以进一步认识左心室壁瘤形成对心脏功能的影响。1　对象与方法1.1　对象正常对照 (Ｇ0 )组 :15例 ,男 8例 ,女 7例 ,年龄38～ 6 1(42± 3)岁。既往无原发性高血压、血脂异常、糖尿病和其他心肺疾病史 ,体检和辅助检查无阳性发现。心肌梗死组 :6 8例 ,男 6 1例 ,女 7例 ,年龄 4 1～ 72 (5 1± 2 )岁。诊断按ＷＨＯ标准确定。在发病后 1～ 6个月内 ,进行核素心室造影 ,同期检查心电图、超声心动图、Ｘ线左心室造影。从中选出两组患者 :①单纯前壁心肌梗死…     

关于右心室间隔部起搏的双心室电同步性和血流动力学探讨

目的以右心室心尖部起搏为参照,评估右心室间隔部起搏的双心室电同步性和血流动力学效应。方法20例患者植入全自动双腔(DDD型)起搏器,随机分组,一组10例行间隔部起搏(RVS组),一组行心尖部起搏(RVA组);分析两组有效起搏及1、3个月随访时各起搏参数差异;对比术中心室电极到位所需X线曝光时间、术中及术后并发症;比较术前自身心律心电图、术后起搏心电图的QRS波宽度、形态;比较两组术前和术后6个月随访的左心室射血分数(LVEF)、二尖瓣血流E峰和A峰最大充盈速度比值(E/A)差异。结果RVS组和RVA组起搏电压阈值、电极阻抗、R波高度无明显差异(P>0.05)。电极植入后第1、3个月随访,两组起搏参数之间无明显差异,且动态变化相似;心室电极到位所需X线曝光时间:RVA组为(203.0±127.3)s,RVS组为(581.0±124.7)s(P<0.05)。电极植入术中及术后均未出现并发症;术前和术后心电图Ⅱ导联QRS宽度:RVA组分别为(0.11±0.03)s、(0.19±0.02)s(P<0.05);RVS组分别为(0.10±0.02)s、(0.12±0.02)s(P<0.05),术后QRS形态与术前心电图相似。间隔部起搏和心尖部起搏心电图的QRS波宽度对比,前者明显窄于后者(P<0.01)。术前2组LVEF、E/A比值无明显差异。与术前相比,RVA组6个月随访的LVEF、E/A均明显降低(P<0.05),RVS组无明显变化(P>0.05)。6个月随访RVS组LVEF、E/A均明显高于RVA组(P<0.05)。结论右心室间隔部起搏是安全、有效的,比右心室心尖部起搏更有利于双心室电激动的同步性,且不会给心功能带来明显不良影响。     

肺动脉高压右心室流出道血流频谱与右心功能的关系

目的:探讨肺动脉高压患者右心室流出道血流频谱收缩期切迹与右心室收缩功能的关系。方法:收集88例不同原因导致的肺动脉高压患者的临床、血流动力学及超声心动图的资料。根据右心室流出道血流频谱形态分为无切迹组(no notch;NN)、收缩晚期切迹组(late systolic notch;LSN)、收缩中期切迹组(mid-systolic notch;MSN)。以M型超声在心尖四腔心切面三尖瓣环收缩期位移(TAPSE)数值表示右心室收缩功能。结果:肺血管阻力(PVR)在MSN组最高(9.2±3.5)WU,P<0.001,而LSN组为(5.7±3.1)WU,NN组为(3.3±2.4)WU。与LSN组和NN组相比,MSN组TAPSE明显缩短[MSN=(1.6±0.5)cm,LSN=(1.9±0.6)cm,NN=(2.2±0.6)cm,P<0.05]。右心室流出道多普勒加速时间(AT)在MSN组最短(MSN=67±21,LSN=79±18,NN=113±29;MSN vs.NN,P<0.01;MSN vs.LSN,P<0.01;LSN vs.NN,P<0.05)。结论:右心室流出道血流多普勒频谱收缩期切迹可能提示严重的肺动脉高压(PAH)和右心功能不全。     

重症心脏瓣膜置换术前后右心室功能的研究

目的　观察重症心脏瓣膜置换患者手术前后右心室功能的变化。方法　应用核素心室造影与超声心动图测定 35例重症心脏瓣膜置换术患者手术前后右心室功能。结果　右心室射血分数与肺动脉压呈负相关 (r= 0 5 2 ,P <0 0 5 )、与左室舒张末径呈负相关 (r= 0 5 5 ,P <0 0 5 )、与三尖瓣反流面积呈负相关 (r= 0 77,P <0 0 1) ;术后右心室功能较术前明显改善 (P <0 0 1)。结论　瓣膜病变患者右心室功能不全与三尖瓣关闭不全、左室扩大、肺动脉高压、右心室肥厚等因素有关 ,瓣膜置换术后右心室功能可明显改善。     

磁共振电影成像评价左右心室整体收缩功能

目的对照超声心动图研究磁共振(MR)电影成像评价左右心室功能的应用价值。方法应用屏气真实稳定进动快速成像(TrueFISP)电影序列和右室改良定位方法对36名健康成人志愿者进行MRI检查,以及超声心动图左心功能对照检查。MRI图像经Argus心脏功能软件进行左右室功能的分析及评价。结果(1)MRI测量正常组的左心室整体收缩功能各指标:舒张末期容积(EDV)为(101.3±19.2)ml,收缩末期容积(ESV)为(42.1±13.3)ml,每搏输出量(SV)(69.2±9.8)ml,射血分数(EF)(59.1±7.2)%;右心室整体收缩功能EDV(118.9±27.1)ml,ESV(57.6±16.1)ml,SV(61.2±12.7)ml,EF(51.9±4.5)%。(2)MRI测量左心功能与超声心动图检查结果对照:EDV与超声心动图测值[(97.2±17.6)ml]比较,差异无统计学意义;ESV测值大于超声心动图测值[(33.2±9.4)ml],其余指标均低于超声检查[SV为(64.0±11.3)ml,EF为66.1%±6.2%,P<0.01]。两种方法各指标测量值相关性良好(r=0.66～0.80,P<0.05)。(3)右心室短轴定位改良前后心功能指标测值比较:除ESV测值与改良前差异无统计学意义外,EDV、SV、EF均明显大于改良前(P<0.05)。结论MRI是综合准确无创的心脏检查技术。其电影成像技术结合改良定位对左右心室功能测量准确,兼获心脏解剖和形态信息,可以用于心脏疾病的功能评价及疗效监测。     

致心律失常性右心室心肌病临床诊断探讨

目的探讨致心律失常性右心室心肌病的临床诊断标准.方法将19例致心律失常性右心室心肌病患者常规行超声心动图、心电图、X线胸片、24小时动态心电图、心房调搏及心内电生理检查.结果本组19例患者均有心悸,晕厥发作,心电图多为右束支传导阻滞(78.95%),频发室性早搏(89.5%),右心室源性短阵室性心动过速(78.95%),超声心动图右心室50.80±9.88?mm,右心房48.00±8.79?mm,均增大,右心功能减退,射血分数0.294±0.0812.结论致心律失常性右心室心肌病,可根据发作性晕厥,右束支传导阻滞,频发室性早搏及左束支传导阻滞型室性心动过速,右心室、右心房增大,右心室功能减退,并排除其他各类心脏和胸肺疾病后确诊.     

心肌磁共振显像、核素心肌灌注显像、超声心动图与X线左心室造影测定左心室功能的对比研究

目的:评价心肌磁共振显像(MRI)、核素心肌灌注显像和超声心动图对比X线左心室造影(LVG)检测左心室功能的应用价值。方法:46例患者同期分别行左心室造影、心肌磁共振显像、核素心肌灌注显像(30例)及超声心动图(38例)检查,测定左心室功能。将左心室造影作为标准,与其它3种影像学方法比较,行相关性及一致性分析。结果:心肌磁共振显像与左心室造影所测左心室舒张末期容积、收缩末期容积和射血分数的相关系数分别为0.94、0.98、0.96(P均＜0.001),核素心肌灌注显像与左心室造影的相关系数分别为0.82、0.90、0.93(P均＜0.001),超声心动图与左心室造影的相关系数分别为0.66、0.74、0.69(P均＜0.001)。心肌磁共振显像与左心室造影所测舒张末期容积、收缩末期容积和射血分数一致性范围分别为(-21.4±31.8)ml,(-7.7±25.0)ml,(-2.2±8.8)%。核素心肌灌注显像与左心室造影的一致性范围分别为(-36.8±53.1)ml,(-15.2±32.2)ml,(-2.6±11.0)%。超声心动图与左心室造影的一致性范围分别为(-80.9±95.8)ml,(-47.5±96.0)ml,(3.6±21.1)%。结论:心肌磁共振显像检测心功能准确、可靠,与左心室造影相关性明显,一致性好。核素心肌灌注显像与左心室造影亦具有良好的相关性,但一致性偏差。超声心动图左心功能测值较左心室造影有明显偏倚,一致性差。     

右心室双部位起搏治疗心力衰竭的疗效和安全性

目的评价右心室双部位(RV-Bi)起搏治疗慢性充血性心力衰竭的疗效。方法 3例心肌病合并心力衰竭患者和3例起搏器综合征患者接受了RV-Bi起搏治疗。比较术前及术后3个月,在RV-Bi起搏、右心室心尖部(RVA)起搏和右心室流出道(RVOT)起搏模式下,患者QRS宽度(QRSd)、QRS电轴(QRSa)和心功能的变化。结果 RV-Bi起搏与RVOT起搏比较,QRSa差异无统计学意义,但与RVA起搏比较,QRSa的差异具有统计学意义;RV-Bi起搏的平均QRSd(143ms)最窄,较RVA起搏(177ms)缩短34ms,较RVOT起搏(155ms)缩短12ms。RV-Bi起搏时心功能优于RVA和RVOT起搏。RV-Bi起博时射血分数(50.4%±3.6%)、每搏量[(65±14)ml]和心输出量[(5.77±0.69)L/min]均较术前射血分数(38.5%±6.2%)、每搏量[(50±18)ml]、心输出量[(4.16±0.55)L/min]及RVA起搏射血分数(34.2%±7.4%)、每搏量[(48±15)ml]、心输出量[(4.12±0.51)L/min]和RVOT起搏时射血分数(45.4%±5.6%)、每搏量[(62±16)ml]、心输出量(5.42±0.63 L/min)显著提高(均为P<0.05)。结论 RV-Bi起搏可改善心室的激动顺序和同步性,可用于慢性心力衰竭和起搏器综合征的治疗,此项技术可作为双室同步起搏技术的替代选择,并具有手术简便和价格低廉的优点。     

Right ventricular volume measurement with single-plane Simpson's method based on a new half-circle model

BACKGROUND: The complexity of right ventricular (RV) shape makes it more difficult for measuring its volume. However, the short-axis view of the right ventricle usually is crescent and might be assumed as half of a circle. This hypothesis can be applied to calculate RV volume by using the single-plane Simpson's method, but the final RV volume should be about half of the original calculated value. The aim of this study was to test the accuracy of RV volume measurement based on this new assumption in human RV casts. METHODS: Fifteen human RV casts were scanned with multislice helical CT and RV sagittal image that corresponds to right anterior oblique view were reconstructed. Single-plane Simpson's method was used to calculate RV volumes. The calculated RV volume was defined as the original calculated value divided by 2. The true RV cast volume was determined by water displacement. RESULTS: The true RV volume was 64.23+/-24.51 ml; the calculated volume was 53.18+/-26.22 ml. The calculated RV correlated closely with true volume with a regression equation of RV actual volume=21.04 0.406 x RV calculated volume (r=0.869, P<0.001), but significantly underestimated the actual volume by 11.05+/-13.09 ml (P<0.006). CONCLUSION: Right ventricular volume could be calculated with single-plane Simpson's method based on the new proposed half-circle model.     

Correlation of right ventricular volume using axial angulated ventriculography to known right ventricular cast volumes in infants and children with congenital heart disease

To calculate right ventricular (RV) volumes from biplane cineangiography obtained in nonstandard views, regression equations were developed from RV casts of known volume. Volumes were calculated using Simpson's rule from casts ranging from 2 to 42 ml from 25 postmortem specimens with various congenital heart diseases. The casts were divided into 2 groups: group 1 (n = 15) with abnormal or group 2 (n = 10) with normal RV hemodynamic measurements. Biplane cinegrams were taken in the anterolateral, anterior and long axis oblique, hepatoclavicular and sitting up projections. The true volume of each cast was determined from its weight and specific gravity. Excellent correlations were obtained between measured and true volumes (r = 0.92 to 0.96) in all projections, although each projection overestimated the true volume (slope value less than 1). The regression equations obtained from group 1 were not statistically different from those in group 2 in any view. Although the application of different regression equations is required in measuring RV volumes by multiple angulated angiography, these regression equations appear not to be affected by the hemodynamic state of the ventricle. These results are important in assessing RV volume in pediatric patients with congenital heart disease using axial angulated ventriculography.     

Quantitative validation of cineangiographic axial oblique biplane left ventricular volume measurement

Axial oblique left ventriculography allows unique visualization of acquired and congenital cardiac lesions. However, validation of the accuracy of left ventricular (LV) volume with axial oblique projections is limited and clouded by orthogonal violations between biplane projections. Biplane cineradiographic volume measurement of 17 LV casts employing the axial projection 35 degrees right anterior oblique/55 degrees left anterior oblique/30 degrees cranial (35 degrees RAO/55 degrees LAO/30 degrees Cr) was performed and compared to the conventional postero-anterior/lateral (PA/Lat) and 30 degrees right anterior oblique/60 degrees left anterior oblique (30 degrees RAO/60 degrees LAO) views. LV volume was calculated from biplane cineradiograms by area length and Simpson's rule method. True LV volume by water displacement was 33 +/- 28 (mean +/- S.D.), range 15 to 112 ml. LV cast volume calculated by the area length method from cineradiograms was overestimated (p less than 0.002) but no different by Simpson's rule method (pNS). The ideal correlation was best approximated by the 35 degrees RAO/55 degrees LAO/30 degrees Cr biplane view calculated by Simpson's rule, r = 0.99, y = 3.5 + 0.9x, and standard error of estimate (SEE) = 4.3 ml. Biplane LV angiography with the axial projection permitted accurate LV volume measurement, and Simpson's rule provided the best representation of true volume.     

Value and limitations of transesophageal echocardiography in determination of left ventricular volumes and ejection fraction.

Several formulas exist for estimating left ventricular volumes and ejection fraction using conventional two-dimensional echocardiography from transthoracic views. Transesophageal imaging provides superior resolution of endocardial borders but employs slightly different scan planes. The estimation of left ventricular volumes by transesophageal echocardiography has not been validated in human patients. Therefore, the purpose of this study was to compare left ventricular volumes and ejection fraction derived from transesophageal short-axis and four-chamber images with similar variables obtained from ventriculography. End-diastolic and end-systolic volumes and ejection fraction were calculated using modified Simpson's rule, area-length and diameter-length models in 36 patients undergoing left ventriculography. Measurements of left ventricular length were obtained from the transesophageal four-chamber view and areas and diameters were taken from short-axis scans at the mitral valve, papillary muscle and apex levels. Data from transesophageal echocardiographic calculations were compared with end-diastolic volume (mean 172 +/- 90 ml), end-systolic volume (mean 91 +/- 74 ml) and ejection fraction (mean 52 +/- 15%) from cineventriculography using linear regression analysis. The area-length method (r = 0.88) resulted in a slightly better correlation with left ventricular end-diastolic volume than did Simpson's rule (r = 0.85) or area-length (r = 0.84) formulas. For end-systolic volume, the three models yielded similar correlations: Simpson's rule (r = 0.94), area-length (r = 0.93) and diameter-length (r = 0.95). Each of the methods resulted in significant underestimation of diastolic and systolic volumes compared with values assessed with angiography (p less than 0.003). Ejection fraction was best predicted by using the Simpson's rule formula (r = 0.85) in comparison with area-length (r = 0.80) or diameter-length (r = 0.73) formulas. Measurements of left ventricular length by transesophageal echocardiography were smaller for systole (mean 5.7 +/- 1.6 cm) and diastole (mean 7.7 +/- 1.2 cm) than values by ventriculography (mean 9.2 +/- 1.4 and 8.1 +/- 1.6 cm, respectively; p less than 0.0001), suggesting that underestimation of the ventricular length is a major factor contributing to the smaller volumes obtained by transesophageal echocardiography. In conclusion, currently existing formulas can be applied to transesophageal images for predicting left ventricular volumes and ejection fraction. However, volumes obtained by these models are significantly smaller than those obtained with angiography, possibly because of foreshortening in the transesophageal four-chamber view.     

The reliability of angiographic volume determination of the left ventricle using digital image subtraction--significance in stress tests

Using the technique of digital subtraction angiography (DSA), left ventricular volumes can be determined after intravenous injection of contrast medium at rest and during exercise. The significance of the well known errors of angiographic determination of left ventricular volumes was investigated in 22 patients before and during a bicycle exercise test. Before and after exercise 40 ml of contrast medium were injected (18 ml/s) intravenously to calculate left ventricular volumes. Enddiastolic and endsystolic contours of the left ventricle were traced by two investigators (A and B) on five different days. Using these contours, volumes were calculated by a computer system. The first calculation of both investigators (single measurement) and the mean value of all five calculations (repetitive measurements) were compared. In the same procedure left ventricular contours of six patients were calculated after conventional contrast ventriculography (40 ml of contrast medium). No systematic deviations were found in comparing the results of both investigators using the single or repetitive method by means of DSA: (VolB = 0.86 VolA + 12.2, r = 0.97 versus VolB = 0.96 VolA + 9.1, r = 0.99). Compared to single method the residuals (Syx) of the repetitive method were significantly smaller: Syx = +/- 16.3 ml vs +/- 8.9 ml (p less than 0.01). Similar results were found in conventional ventriculography: single method Syx = +/- 18.7 ml and repetitive method Syx = +/- 8.8 ml (p less than 0.01). Comparing the volumes determined by DSA and by conventional ventriculography, respectively, no significant differences were found.(ABSTRACT TRUNCATED AT 250 WORDS)     

Validation of attenuation-corrected equilibrium radionuclide angiographic determinations of right ventricular volume: comparison with cast-validated biplane cineventriculography

To determine the accuracy of attenuation-corrected equilibrium radionuclide angiographic determinations of right ventricular volumes, we initially studied 14 postmortem human right ventricular casts by water displacement and biplane cineventriculography. Biplane cineventriculographic right ventricular cast volumes, calculated by a modification of Simpson's rule algorithm, correlated well with right ventricular cast volumes measured by water displacement (r = .97, y = 8 + 0.88x, SEE = 6 ml). Moreover, the mean volumes obtained by both methods were no different (73 +/- 28 vs 73 +/- 25 ml). Subsequently, we studied 16 patients by both biplane cineventriculography and equilibrium radionuclide angiography. The uncorrected radionuclide right ventricular volumes were calculated by normalizing background corrected end-diastolic and end-systolic counts from hand-drawn regions of interest obtained by phase analysis for cardiac cycles processed, frame rate, and blood sample counts. Attenuation correction was performed by a simple geometric method. The attenuation-corrected radionuclide right ventricular end-diastolic volumes correlated with the cineventriculographic end-diastolic volumes (r = .91, y = 3 + 0.92x, SEE = 27 ml). Similarly, the attenuation-corrected radionuclide right ventricular end-systolic volumes correlated with the cineventriculographic end-systolic volumes (r = .93, y = - 1 + 0.91x, SEE = 16 ml). Also, the mean attenuation-corrected radionuclide end-diastolic and end-systolic volumes were no different than the average cineventriculographic end-diastolic and end-systolic volumes (160 +/- 61 and 83 +/- 44 vs 170 +/- 61 and 86 +/- 43 ml, respectively). Comparison of the uncorrected and attenuation-corrected radionuclide right ventricular volumes demonstrated narrower 95% confidence intervals for the attentuation-corrected right ventricular volume determinations over a wide range of cineventriculographic volumes. Thus we conclude that: (1) attenuation-corrected radionuclide right ventricular end-diastolic and end-systolic volumes compare closely with those obtained by a cast-validated biplane cineventriculographic method and (2) attenuation-corrected radionuclide right ventricular volumes correspond more closely to determinations of biplane cineventriculographic right ventricular volumes and are thus likely to be more accurate than uncorrected radionuclide right ventricular volumes.     

Estimation of the right ventricular volume and ejection fraction by transthoracic three-dimensional echocardiography

Aims. To validate the use of three-dimensional transthoracic echocardiography compared with the magnetic resonance imaging for determination of right ventricular volume and ejection fraction. Methods and results: We recorded transthoracic echocardiographic images starting from the apical four-chamber view in which the RV is clearly visualized in 15 healthy volunteers. The scanning plane of the RV was obtained by the rotational scanning technique in 2 degree angular increments for three-dimensional reconstruction. The RV volumes in end-diastole and end-systole were calculated using a Tomtec three-dimensional reconstruction computer. We also assessed the RV by cine magnetic resonance imaging using the Siemens Magnetom Impact Expert (1.0 T). Cine gradient echo images were obtained in the short axis of the RV. The RV volume at each phase was calculated by Simpson's method. We also calculated the RV ejection fraction. The RV volumes in end-diastole and end-systole were 111±22 ml and 52±13 ml, respectively as determined by three-dimensional echo, and 115±18 ml and 55±14 ml determined by MRI. The right ventricular volumes at end-diastole and end-systole determined by three-dimensional echo were correlated with the volumes determined by MRI (r=0.94 and 0.97, respectively, p<0.001). The RV ejection fraction determined by three dimensional echo was also correlated with the ejection fraction determined by MRI (r=0.90, p<0.01). Conclusions. Three-dimensional transthoracic echocardiography provided reliable calculations of the right ventricular volume and ejection fraction.     

In vitro validation of right ventricular volume and mass measurement by real-time three-dimensional echocardiography

OBJECTIVE: To evaluate initially the feasibility and accuracy of real-time three-dimensional echocardiography (RT-3DE) for quantifying right ventricular (RV) volume and wall mass in an in vitro experimental study. METHODS: In ten excised porcine hearts, measurements of RV volume and free wall mass with RT-3DE were outlined and calculated by 2-, 4-, 8- and 16-plane methods with Tom Tec 4D Cardio-View RT 1.0. The results were compared with those of 2D length method and 2D biplane Simpson method. The values of RV silicone latex cast and free wall mass measured by water displacement were served as reference values. RESULTS: RV shapes of excised porcine hearts with RT-3DE were similar to those of the actual anatomic RVs and RV silicone latex casts. From the findings of analysis of variance and Student-Newman-Keuls test, there was no significant difference between measurements of RV volume with RT-3DE 16-plane (mean 64.05 ml), 8-plane (61.83 ml) and the reference values of RV silicone latex casts (62.94 ml). No significant difference was found between measurements of RV free wall mass with 16-plane (72.81 g), 8-plane (71.05 g) and the reference values of RV free wall masses (76.21 g). However, there was significant difference between measurements of RV volume and free wall mass with 2-plane, 2D biplane Simpson method and the reference values. Furthermore, the measurements of RV volume and free wall mass with 16-plane and 8-plane were better correlated with the reference values than those with 4-plane and 2D length method. CONCLUSIONS: RT-3DE will be a valuable technique for quantifying irregular crescentic RV volume and wall mass.     

Comparison of left ventricular ejection fraction and volumes in heart failure by echocardiography, radionuclide ventriculography and cardiovascular magnetic resonance; are they interchangeable?

AIMS: To prospectively compare the agreement of left ventricular volumes and ejection fraction by M-mode echocardiography (echo), 2D echo, radionuclide ventriculography and cardiovascular magnetic resonance performed in patients with chronic stable heart failure. It is important to know whether the results of each technique are interchangable, and thereby how the results of large studies in heart failure utilizing one technique can be applied using another. Some studies have compared cardiovascular magnetic resonance with echo or radionuclude ventriculography but few contain patients with heart failure and none have compared these techniques with the current fast breath-hold acquisition cardiovascular magnetic resonance. METHODS AND RESULTS: Fifty two patients with chronic stable heart failure taking part in the CHRISTMAS Study, underwent M-mode echo, 2D echo, radionuclude ventriculography and cardiovascular magnetic resonance within 4 weeks. The scans were analysed independently in blinded fashion by a single investigator at three core laboratories. Of the echocardiograms, 86% had sufficient image quality to obtain left ventricular ejection fraction by M-mode method, but only 69% by 2D Simpson's biplane analysis. All 52 patients tolerated the radionuclude ventriculography and cardiovascular magnetic resonance, and all these scans were analysable. The mean left ventricular ejection fraction by M-mode cube method was 39+/-16% and 29+/-15% by Teichholz M-mode method. The mean left ventricular ejection fraction by 2D echo Simpson's biplane was 31+/-10%, by radionuclude ventriculography was 24+/-9% and by cardiovascular magnetic resonance was 30+/-11. All the mean left ventricular ejection fractions by each technique were significantly different from all other techniques (P<0.001), except for cardiovascular magnetic resonance ejection fraction and 2D echo ejection fraction by Simpson's rule (P=0.23). The Bland-Altman limits of agreement encompassing four standard deviations was widest for both cardiovascular magnetic resonance vs cube M-mode echo and cardiovascular magnetic resonance vs Teichholz M-mode echo at 66% each, and was 58% for radionuclude ventriculography vs cube M-mode echo, 44% for cardiovascular magnetic resonance vs Simpson's 2D echo, 39% for radionuclide ventriculography vs Simpson's 2D echo, and smallest at 31% for cardiovascular magnetic resonance-radionuclide ventriculography. Similarly, the end-diastolic volume and end-systolic volume by 2D echo and cardiovascular magnetic resonance revealed wide limits of agreement (52 ml to 216 ml and 11 ml to 188 ml, respectively). CONCLUSION: These results suggest that ejection fraction measurements by various techniques are not interchangeable. The conclusions and recommendations of research studies in heart failure should therefore be interpreted in the context of locally available techniques. In addition, there are very wide variances in volumes and ejection fraction between techniques, which are most marked in comparisons using echocardiography. This suggests that cardiovascular magnetic resonance is the preferred technique for volume and ejection fraction estimation in heart failure patients, because of its 3D approach for non-symmetric ventricles and superior image quality.     

Quantitation of right ventricular volumes and ejection fraction by three-dimensional echocardiography in patients: comparison with magnetic resonance imaging and radionuclide ventriculography

Three-dimensional echocardiography (3DE) provides volumetric measurements without geometric assumptions. Volume-rendered 3DE has been shown to be accurate for the measurement of right ventricular (RV) volumes in vitro and in animal studies; however, few data are available regarding its accuracy in patients. This study examined the accuracy of 3DE for quantitation of RV volumes and ejection fraction (EF) in patients, compared to magnetic resonance imaging (MRI) and radionuclide ventriculography (RNV). Twenty patients underwent MRI, gated equilibrium RNV, and 3DE using rotational acquisition from both the transesophageal and transthoracic approaches. RV volumes and EF were calculated from the 3DE data using multislice analysis (true Simpson's rule). RV volumes calculated by MRI (end-diastolic volume (EDV) 109.4 +/- 34.3 mls, end-systolic volume (ESV) 59.6 +/- 31.0 mls, and EF 47.7 +/- 17.1%) agreed closely with 3DE. For transesophageal echocardiography, EDV was 108.1 +/- 29.7 mls (r = 0.86, mean difference 1.3 +/- 17.8 mls); ESV was 62.5 +/- 23.8 mls (r = 0.85, mean difference 2.8 +/- 15.1 mls); and EF was 43.2 +/- 11.7% (r = 0.84, mean difference 4.5 +/- 9.7%). For transthoracic echocardiography, EDV was 107.7 +/- 27.5 mls (r = 0.85, mean difference 1.6 +/- 18.2 mls); ESV was 59.7 +/- 22.1 mls (r = 0.93, mean difference 3.2 +/- 19.6 mls); and EF was 45.2 +/- 11.5% (r = 0.86, mean difference 2.0 +/- 9.4%). There were close correlations, small mean differences and narrow limits of agreement between RNV-derived EF (43.4 +/- 12.1%) and both transesophageal (r = 0.95 mean difference 0.2 +/- 3.7%) and transthoracic 3DE (r = 0.95, mean difference 1.8 +/- 5.4%). Three-dimensional echocardiography is a promising new method of calculating RV volumes and EF, comparing well with MRI and RNV. The accuracy of transthoracic 3DE was comparable to that of the transesophageal approach. Three-dimensional echocardiography has the potential to be useful in the clinical assessment of RV disorders.