连枷样二尖瓣口返流彩色多普勒血流的三维重建(英文)

本研究采用体外血流模型,模拟连枷样二尖瓣（ＦＭＶ）口返流,应用常规彩色多普勒血流显像（ＣＤＦＩ）的返流面积与射流和血流会聚区的三维（３Ｄ）超声重建及实际返流量进行对比研究,评价更复杂的血流（脉冲血流通过ＦＭＶ）状态３Ｄ重建的可行性和准确性。被驱动的血流通过一个模拟ＦＭＶ口,返流口的截面积为０．２４ｃｍ２。仪器使用ＡＴＬ,ＩｎｔｅｒｓｐｅｃＡｐｏｇｅｅ８００彩色多普勒超声仪,探头附着在一种机械臂上,在ＴｏｍＴｅｃ计算机控制下进行０°～１８０°的旋转扫描获得射流和血流会聚区３Ｄ重建的数据。同时磁带记录ＣＤＦＩ图像待后分析。结果显示:ＣＤＦＩＦＭＶ的返流面积与实际返流容积和最大返流量呈中等相关（ｒ＝０．６９,ＳＥＥ＝２．２ｃｍ２,Ｐ＜０．０５和ｒ＝０．６２,ＳＥＥ＝２．５ｃｍ２,Ｐ＜０．０５）。３Ｄ重建后的返流容积与实际返流容积和最大返流量相关良好（ｒ＝０．９６,ＳＥＥ＝７．６ｍｌ,Ｐ＜０．０５和ｒ＝０．９４,ＳＥＥ＝８．４ｍｌ,Ｐ＜０．０１）。血流会聚区３Ｄ重建与实际返流容积相关较好（ｒ＝０．８９,ＳＥＥ＝０．２２ｍｌ,Ｐ＜０．０１）。结论:３Ｄ重建可减低ＣＤＦＩ的某些限制,如增益、贴壁返流和混叠速度等,特别是?     

彩色多普勒血流会聚区法定量评估非偏心性二尖瓣返流的严重程度

本文将应用彩色多普勒血流会聚区（ＦＣＲ）法对５５例显示血流会聚区的非偏心二尖瓣返流患者所测的返流率（Ｆ）与返流束面积（Ｓ＿Ｒ）、返流束面积与左房面积（Ｓ＿ＬＡ）之比（Ｓ＿Ｒ／Ｓ＿ＬＡ）相比较，相关系数分别为０．７３２及０．８２２（均Ｐ＜０．０１）。并按常规将二尖瓣返流分为轻、中、重度三组，分别以ＦＣＲ法测定下值，结果组间差异非常显著（均Ｐ＜０．００１）．表明ＦＣＲ法为一定量评估非偏心二尖瓣返流严重程度较为理想的无创性方法，具有广泛的理论研究及临床应用前景。     

超声心动图对30例经皮穿刺二尖瓣球囊扩张术后左心功能的评价

本文对３０例经皮穿刺二尖瓣球囊扩张术（ＰＢＭＶ）后左心功能进行了追踪，拟期评价ＰＢＭＶ的疗效．方法采用Ｍ型超声心动图的左室短轴缩短百分率（ＦＳ），二维超声心动图（改良Ｓｉｍｐｓｏｎ法）的左室射血分数（ＥＦ）、每搏出量（ＳＶ）和心输出量（ＣＯ）．结果与术前比较；ＦＳ、ＳＶ、ＥＦ和ＣＯ均明显均高（Ｐ＜０．００１）．三个月后ＦＳ和ＥＦ没有进一步改善（Ｐ＝ＮＳ）．在对扩瓣前后二尖瓣口面积的变化与ＦＳ和ＥＦ的变化的直线回归分析中发现，随着瓣口面积的扩大，ＥＦ和ＦＳ出现明显升高（ｒ＝０．６４４，ｒ＝０．５９４）．这表明，瓣口面积的变化是导致左心功能改善的重要因素．     

连枷样二尖瓣口返流彩色多普勒血流的三维重建

本研究采用体外血流模型,模拟连枷样二尖瓣（ＦＭＶ）口返流,应用堂瞧见彩色多普勒血流显像（ＣＤＦＩ）的返流面积与射流和血流会聚区的三维（３Ｄ）超声重建及实际返流量进行对比研究,评价更复杂的血流（脉冲血流通过ＦＭＶ）状态３Ｄ重建的可行性和准确性。被驱动的血流通过一个模拟ＦＭＶ口,返流口的截面积为０．２４ｃｍ＾２。仪器使用ＡＴＬ,Ｉｎｔｅｒｓｐｅｃ Ａｐｏｇｅｅ８００彩色多普勒超声仪,探头附着在一种机械     

经皮球囊二尖瓣成形术后脉冲多普勒肺动脉频谱时间间期的测定（1）

本研究比较了３５例以二尖瓣狭窄为主的风湿性心脏病患者经皮球囊二尖瓣成形术（ＰＢＭＶ）前后的肺动脉频谱时间间期的改变。结果表明，ＰＢＭＶ术后右室射血前期（ＲＰＥＰ）及ＲＰＥＰ／ＲＶＥＴ明显减小，ＡＴ／ＲＰＥＰ增大；而加速时间（ＡＴ），右室射血期（ＲＶＥＴ），减速时间（ＤＴ）及ＡＴ／ＤＴ则无明显改变。ＰＢＭＶ前后ＲＰＥＰ／ＲＶＥＴ的改变与二维超声心动图测量的二尖瓣口面积改变呈正相关（ｒ＝０．４９６，ｐ＝０．０１），但与Ｇｏｒｌｉｎ公式计算的二尖瓣口面积改变不相关。我们认为ＰＢＭＶ后脉冲多普勒肺动脉频谱时间间期测定有一定变化。     

多普勒超声心动图估测二尖瓣口充盈能量和能量效率

目的：研究二尖瓣口充盈能量和能量效率与瓣口工作效率之间的关系。方法：应用多普勒超声心动图对３种状态即自然瓣、狭窄瓣和机械瓣〔共分为５组即正常组、狭窄瓣组、二尖瓣替换术（ＭＶＲ）后２周组、ＭＶＲ后１．０～４．９年组和ＭＶＲ后５～１０年组〕的二尖瓣口及不同瓣号、瓣型和瓣龄的机械瓣口能量学指标与瓣口功能的定量关系作对比研究。结果：狭窄瓣组较正常组有效充盈能（Ｅｅｆ）和总充盈能（Ｅｔｏｔ）显著增加,能量效率（η）显著降低;ＭＶＲ后２周、１．０～４．９年、５～１０年组较狭窄瓣组Ｅｅｆ和Ｅｔｏｔ显著降低,而η显著增加;η随瓣口狭窄级别和替换瓣龄的增大而进行性下降;机械瓣同号不同瓣型（单叶与双叶）之间η有显著差异,时间－η曲线分离。η与瓣口面积、瓣口阻力和左心房张力成较好的相关关系（分别为ｒ＝０．６７,ｒ＝－０．７２,ｒ＝－０．８２）。结论：瓣口能量效率是衡量不同状态和不同机械瓣龄的二尖瓣口能量分配、利用及工作效率优劣的重要标准。     

彩色多普勒血流显像对心房间隔缺损诊断的评价

目的：探讨彩色多普勒超声心动图诊断心房间隔缺损的临床价值。方法：以彩色多普勒血流显像技术对７５例患者的心房间隔缺损定位及估测缺损大小，并测定肺动脉收缩压。结果：７５例患者中，５２例经手术证实。彩色多普勒超声心动图诊断心房间隔缺损的敏感性达１００％；对缺损的定位准确率为９４．２％（４９／５２）；对缺损大小的估测与手术结果呈显著正相关（ｒ＝０．９５，Ｐ＜０．００１）。对Ｍ型超声心动图显示疑有肺动脉高压的２３例患者用三尖瓣反流压差法估测的肺动脉收缩压与心导管测值密切相关（ｒ＝０．８８，Ｐ＜０．００１）；同时计算肺动脉与主动脉根部内径比值与心导管测值比较，发现肺动脉与主动脉根部内径比值≥１．３５，提示肺动脉高压。结论：彩色多普勒超声心动图对心房间隔缺损有术前诊断价值，并能评价手术效果，可替代有创性检查。     

近端等流速面面积法测算二尖瓣狭窄之瓣口面积

近端等流速面面积（ＰＩＳＡ）法是根据近端血流汇聚（ＰＦＣ）原理，用彩色多普勒血流显像（ＣＤＦＭ）技术测定狭小孔径流量的一种新方法。本研究用ＰＩＳＡ法测算二尖瓣狭窄瓣口的面积（ｃＭ－ＶＡ）与手术标本实测值（ａＭＶＡ）相比较。结果表明，所有病人均可清晰显示二尖瓣口左房侧的ＰＦＣ区，ｃＭＶＡ与ａＭＶＡ具有良好的相关性。本研究证实了ＰＩＳＡ法估测二尖瓣口面积是可行，且精确的，可以在临床应用     

腹膜透析效能的判断及影响因素分析

目的：探讨各种判断腹透效能的指标在临床运用中的意义。方法：前瞻性观察４４例ＣＡＰＤ患者在透析过程中尿素ＫＴ／Ｖ（ＫＴ／Ｖ）、肌酐清除率（ＣＣｒ）、血浆白蛋白（Ａｌｂ）及氮表现的蛋白质水平（ｎＰＮＡ）的变化及彼此间的相关性。结果：４４例患者９４例次的观察显示，ＫＴ／Ｖ与ＣＣｒ在判断透析效能上有明显差异，ＫＴ／Ｖ更大程度上与透析剂量呈正相关，ＫＴ／Ｖ＝１．１６＋０．０００１１×透析剂量（ｒ＝０．２７Ｐ＜０．０５）、与患者的体表面积呈负相关（ｒ＝－０．５９，Ｐ＜０．０１），而ＣＣｒ则与患者的残余肾功能（ＲＲＦ）呈正相关，ＣＣｒ＝４９．３＋１０．２３×ＲＲＦ（ｒ＝０．８４，Ｐ＜０．００１），而与透析时间呈负相关（ｒ＝－０．３６，Ｐ＜０．０５）。此外，ｎＰＮＡ水平的变化与ＫＴ／Ｖ及ＣＣｒ呈正相关（ｒ＝０．２６～０．３３，Ｐ＜０．０５），Ａｌｂ与ＫＴ／Ｖ呈明显相关（ｒ＝０．４０，Ｐ＜０．０１）。结论：尿素ＫＴ／Ｖ和ＣＣｒ完全可以作为反映透析效能的可靠指标，若结合Ａｌｂ及ｎＰＮＡ观察，则更能反映患者的情况。此外，本文还观察到若根据体表面积计算透析液量，不仅可以精确地计算透析需求量，而且还能预测透析效能，减少合并症的产     

经皮二尖瓣球囊扩张术前后血浆降钙素基因相关肽水平研究

为了解经皮二尖瓣球囊扩张术（ＰＢＭＶ）前后血浆降钙素基因相关肽（ＣＧＲＰ）水平，采用放免法测定３０例风湿性二尖瓣狭窄患者ＰＢＭＶ前后的血浆ＣＧＲＰ和内皮素水平，与对照组比较，并与左房内径、二尖瓣口面积和血液动力学参数作相关分析，旨在探讨血浆ＣＧＲＰ水平与二尖瓣狭窄和ＰＢＭＶ的关系。结果显示：术前血浆ＣＧＲＰ水平显著低于对照组（分别为５．６３±１．０１和２２．２９±６．４２ｎｇ／Ｌ，Ｐ＜０．００１），术后第１天明显升高（１２．１５±３．３２ｎｇ／Ｌ，Ｐ＜０．００１），以后继续升高，而血浆内皮素水平则呈相反变化（Ｐ＜０．００１）；ＣＧＲＰ与内皮素的血浆含量呈显著负相关（ｒ＝－０．４２７，Ｐ＜０．０１）；血浆ＣＧＲＰ水平与心脏指数呈显著正相关（ｒ＝０．７０３，Ｐ＜０．００１），与平均肺动脉压、平均右房压和平均左房压呈显著负相关（ｒ分别为－０．６０１、－０．５３５和－０．５９８，Ｐ均＜０．００１）；心功能越差，血浆ＣＧＲＰ水平越低（Ｐ＜０．００１）。提示ＣＧＲＰ在二尖瓣狭窄的病理生理改变中起着重要作用，其血浆水平可作为判断二尖瓣狭窄病情和ＰＢＭＶ疗效的一个指标。     

Diabetes quality assurance checklist: assessment of inter-rater and intra-rater reliability.

The Diabetes Quality Assurance (DQA) Checklist was developed to measure adherence to standards of diabetes care. Two raters simultaneously scored a convenience sample of 23 charts of patients with diabetes. These raters scored each chart again 5-7 weeks later. Data obtained were used to assess inter-rater and intra-rater reliability. Inter-rater reliability was estimated for basic assessment at Time 1 (r = 0.94, 95% CI 0.86-0.97) and at Time 2 (r = 0.91, 95% CI 0.81-0.96); and for high-risk assessment at Time 1 (r = 0.88, 95% CI 0.73-0.95). Intra-rater reliability for the basic assessment was estimated for Reviewer 1 (r = 0.84, 95% CI 0.65-0.93) and for Reviewer 2 (r = 0.75, 95% CI 0.49-0.89); the high-risk estimate for Review 1 was 0.60 (95% CI 0.25-0.81) and for Reviewer 2 0.97 (95% CI 0.94-0.99). The DQA Checklist is useful for monitoring and assessing diabetes care.     

Accurate, simplified and rapid three-dimensional echocardiographic volume quantifications: Comparison of different algorithms in symmetric and asymmetric left ventricular geometry

OBJECTIVE: A comparative investigation of dynamic three-dimensional freehand echocardiography (D3DFE) and magnetic resonance imaging (MRI) was conducted to determine the accuracy and rapidity of the average rotation method (ARM) and the disk summation method (DSM) for volumetric analysis. METHODS: In 15 patients with an asymmetric left ventricle and 12 normal subjects, end-diastolic and end-systolic left ventricular volumes were assessed by D3DFE and by MRI. Both DSM and ARM were used for volume determination. All echocardiographic readings were performed by two examiners blinded to each other and to the MRI results. The times needed for echocardiographic data acquisition and volumetric analysis with either algorithm were determined. RESULTS: Correlation between ARM and MRI measurements was tighter than between DSM and MRI measurements (end-diastolic volume: r=0.95, P<0.0001 versus r=0.94, P<0.0001 in asymmetric ventricles; and r=0.97, P<0.0001 versus r=0.96, P<0.0001 in symmetric ventricles; end-systolic volume: r=0.94, P<0.0001 versus r=0.93, P<0.0001 in asymmetric ventricles and r=0.96, P<0.0001 versus r=0.94, P<0.0001 in symmetric ventricles). In addition, ARM analysis was less time-consuming than DSM (6.4+/-0.4 min versus 7.6+/-0.3 min, P<0.05). CONCLUSIONS: For D3DFE, ARM is the most accurate and rapid approach to left ventricular volume determination. ARM benefits from advanced two-dimensional imaging and can be easily added to any standard transthoracic echocardiographic examination.     

Assessment of mitral valvar stenosis by echocardiography: utility of various methods before and after mitral valvotomy.

Cross-sectional and Doppler echocardiography are currently the most important non-invasive tests for the evaluation of mitral stenosis. Recent experience has, however, shown that parameters that are reliable before mitral valvotomy may not be valid after the procedure. We have studied the validity of estimation of the area of the mitral valve by echo-planimetry, by Doppler pressure half time and the transmitral end-diastolic pressure gradient calculated by continuous wave Doppler in 100 patients (aged 10-30 years) before and after balloon mitral valvoplasty (n = 70) or surgical closed mitral valvotomy (n = 30). These patients underwent cardiac catheterisation and echocardiographic studies before, immediately after and 8-12 (9.3 +/- 2.2) weeks following balloon valvoplasty or closed valvotomy. The area as estimated echocardiographically correlated well with that obtained by the Gorlin formula before (r = 0.80), but not immediately after (r = 0.67) or on follow up after mitral valvotomy. There was good correlation between Doppler pressure half time and the area as estimated by the Gorlin formula before (r = 0.89) and on follow up after valvotomy (r = 0.82), but the correlation was not as good in the immediate period after valvotomy (r = 0.60). The end-diastolic pressure gradients obtained by Doppler examination and at cardiac catheterisation correlated well with each other before (r = 0.94), immediately after valvotomy (r = 0.92) and on follow up (r = 0.94). Hence, the reliability of estimation of the area of the mitral valve by echo-planimetry and by Doppler pressure half time varies according to the time at which the examination is performed following commissurotomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Continuous wave Doppler echocardiographic measurement of prosthetic valve gradients. A simultaneous Doppler-catheter correlative study

Studies correlating prosthetic valve gradients determined by continuous wave Doppler echocardiography with gradients obtained by cardiac catheterization have, to date, been limited to patients with mitral and tricuspid prostheses or have compared nonsimultaneous measurements. Simultaneous Doppler and catheter pressure gradients in 36 patients (mean age, 63 +/- 13 years) with 42 prosthetic valves (20 aortic, 20 mitral, one tricuspid, and one pulmonary) were studied. Catheter gradients were obtained using a dual-catheter technique. The simultaneous pressure tracings and Doppler flow velocity profiles were digitized at 10-msec intervals to derive the corresponding maximal and mean gradients. The correlation between the maximal Doppler gradient and the simultaneously measured maximal catheter gradient was 0.94 (SEE = 6), and that between the Doppler gradient and the simultaneously measured mean catheter gradient was 0.96 (SEE = 3). There were no significant differences in correlation between gradients for the 32 mechanical valves (maximal gradients: r = 0.95, SEE = 6; mean gradients: r = 0.96, SEE = 3) and the 10 bioprosthetic valves (maximal gradients: r = 0.89, SEE = 6; mean gradients: r = 0.93, SEE = 3). In patients with mitral prostheses, Doppler gradients correlated well with the corresponding catheter gradients obtained with direct measurement of left atrial pressure (maximal gradients: r = 0.96, SEE = 2; mean gradients: r = 0.97, SEE = 1.2). A close correlation between corresponding Doppler and catheter gradients also was found in patients with aortic prostheses (maximal gradients: r = 0.94, SEE = 6; mean gradients: r = 0.94, SEE = 3). Thus, continuous wave Doppler echocardiography can accurately predict the pressure gradient across prosthetic valves.     

Accuracy of automated attenuation-based 3-dimensional segmentation: in the analysis of left ventricular function compared with magnetic resonance imaging

We evaluated attenuation-based 3-dimensional segmentation for the analysis of left ventricular function, using as our standard of reference magnetic resonance imaging and dual-source computed tomography with traditional short-axis planimetry.Twenty patients with known or suspected coronary artery disease were examined prospectively. In all magnetic resonance and computed tomographic datasets, global functional values were determined by 2-dimensional planimetry. Computed tomographic scans were further evaluated by automated 3-dimensional segmentation, and the results were compared by Pearson correlation and Bland-Altman analysis.Agreement between magnetic resonance imaging and dual-source computed tomographic 2-dimensional planimetry was good for all values (end-diastolic volume, bias= -4.2, r=0.99; end-systolic volume, bias= -1.7, r=0.99, stroke-volume, bias= -2.4, r=0.98; ejection fraction, bias=0.26, r=0.94; and myocardial mass, bias= 2.5, r=0.90). By contrast, dual-source computed tomographic 3-dimensional segmentation overestimated end-diastolic volume (bias= -19.1, P <0.001), stroke-volume (bias= -16.9, P <0.001), and myocardial mass (bias= -34.4, P <0.001). Moreover, correlation with magnetic resonance imaging proved disappointing for ejection fraction (r=0.72). Results were similar in a direct comparison between dual-source computed tomographic 2-dimensional planimetry and 3-dimensional segmentation (end-diastolic volume, bias= -14.9, r=0.94; end-systolic volume, bias= -0.5, r=0.90; stroke volume, bias= -14.5, r=0.83; ejection fraction, bias= -2.8, r=0.74; and myocardial mass, bias= -36.8, r=0.79).Due to significant overestimation of volumes and poor correlation of ejection fraction with cine magnetic resonance imaging results, attenuation-based 3-dimensional segmentation compares unfavorably with traditional planimetry. Hence this method should be used with caution, and its time benefits should be weighed against its imprecision of functional analysis.     

Studies on left ventricular performances pre- and post-percutaneous balloon valvuloplasty in 57 cases

The left ventricular performances (LVP), assessed by two dimensional echocardiography (2 DE) pre- and post-percutaneous balloon mitral valvuloplasty, showed a good linear correlation with those by angiography, the correlative coefficients being 0.94 (left ventricular volume), 0.93 (ejection fraction) and 0.90 (stroke volume), respectively. The results showed that 2 DE may be used in follow-up study of left ventricular performances instead of angiography. Accordingly, it was found that the short-term (6-10 months) effect in LVP of 57 cases post-PBMV assessed by 2 DE in comparison with that pre-PBMV was statistically very significant (t = 3.73-12.92, P less than 0.001); the long-term (12-42 months) effect of 88 cases post-PBMV evaluated by 2 DE compared with that pre-PBMV was statistically very significant (t = -3.73-10.46, P less than 0.001); all these showed that both the short-term and long-term cardiac functions post-PBMV had markedly improved. However, there was a significant difference in statistics (t = 2.41-3.14, P less than 0.05-0.001) between the short-term and long-term cavity area) and radionuclide angiography both during early diastole (r = 0.94) and atrial systole (r = 0.90). The above results were better than those obtained from pulsed Doppler (E area/Total, A area/Total) and radionuclide angiography: during early diastole (r = 0.78) and atrial systole (r = 0.76). Color Doppler can be used as a new method for assessing the pattern of left ventricular filling.     

Quantitative assessment of pulmonary arterial diastolic and mean pressure using continuous wave Doppler

Continuous wave Doppler echocardiographic study was performed almost simultaneously with right heart catheterization in 24 patients with a variety of cardiovascular disorders and evidence of pulmonary regurgitation detected by pulsed wave Doppler. Their pulmonary arterial diastolic and mean pressure (PADP and PAMP) measured during catheterization were ranging from 5 to 70.6 (mean 30.26 +/- 18) mmHg and from 6.7 to 91.14 (mean 42.41 +/- 23.23) mmHg, respectively. The right ventricular end-diastolic pressure was within normal limit in all but one. The peak, mean and end-diastolic pressure gradients of pulmonary regurgitation (PPRPG, MPRPG and PRPGed) were calculated using simplified Bernoulli Equation and their correlations with PADP and PAMP were analysed using linear regression method. There were close correlations between all PRPGs and PADP or PAMP (r = 0.85 - 0.94, P less than 0.0001). The best equation for assessing PADP was MPRPG + 6 mmHg (r = 0.94, P less than 0.0001), for PAMP was PPRPG + 8 mmHg (r = 0.92, P less than 0.0001). It is evident that those constants in the equations should be adjusted in individual patient who has coexisting right heart failure.     

Foot-to-foot bioelectrical impedance analysis: a valuable tool for the measurement of body composition in children.

OBJECTIVE: To determine the accuracy of foot-to-foot bioelectrical impedance analysis (BIA) and anthropometric indices as measures of body composition in children. DESIGN: Comparison of foot-to-foot BIA and anthropometry to dual-energy X-ray absorptiometry (DEXA)-derived body composition in a multi-ethnic group of children. SUBJECTS:: Eighty-two European, NZ Maori and Pacific Island children aged 4.9-10.9 y. MEASUREMENTS: DEXA body composition, foot-to-foot bioelectrical impedance, height, weight, hip and waist measurements. RESULTS: Using a BIA prediction equation derived from our study population we found a high correlation between DEXA and BIA in the estimation of fat-free mass (FFM), fat mass (FM) and percentage body fat (PBF) (r=0.98, 0.98 and 0.94, respectively). BIA-FFM underestimated DEXA-FFM by a mean of 0.75 kg, BIA-FM overestimated DEXA-FM by a mean of 1.02 kg and BIA-PBF overestimated DEXA-PBF by a mean of 2.53%. The correlation between six anthropometric indices (body mass index (BMI), ponderal index, Chinn's weight-for-height index, BMI standard deviation score, weight-for-length index and Cole's weight-for-height index) and DEXA were also examined. The correlation of these indices with PBF was remarkably similar (r=0.85-0.87), more variable with FM (r=0.77-0.94) and poor with FFM (r=0.41-0.75). CONCLUSIONS: BIA correlated better than anthropometric indices in the estimation of FFM, FM and PBF. Foot-to-foot BIA is an accurate technique in the measurement of body composition.     

New approaches to noninvasive assessment of pulmonary artery pressure

Direct measurement of pulmonary artery pressure (PAP) was performed in 36 patients; right ventricular (RV) isovolumic relaxation time (IRT) and RV systolic output acceleration time (AcT) values were assessed by pulsed Doppler and 2-M echocardiography. There was a fairly good correlation between RV IRT and systolic PAP (r = 0.898; SEE = 7.8 mmHg) and a somewhat weaker one between RV AcT and systolic PAP (r = -0.880; SEE = 8.37 mmHg). Correlation coefficients were the highest between systolic PAP and the [formula: see text] (r = 0.972; SEE = 4.14), and also between mean PAP and the 10-RV AcT/100 predictor: y = 158x + 6.7 (r = 0.951; SEE = 3.48 mmHg). With +/- 5 mmHg deviations, systolic PAP measurements were accurate in 78% and those of mean PAP in 98% of the patients. The double-blind assessment of the reproducibility of the suggested noninvasive PAP measurement was performed in 18 subsequent patients; the interstudy variability of the measurement was 0.88 +/- 0.94 mmHg and 1.22 +/- 1.23 mmHg (p > 0.05), whereas interobserver variability was 1.90 +/- 1.70 mmHg and 1.67 +/- 1.63 mmHg, respectively (p > 0.05). Thus, a combined use of the most informative intervals of RV cycle--IRT and AcT--contributes to the accuracy of noninvasive PAP measurement.     

Comparative echocardiographic volume determinations using a dynamic heart model

Using a dynamic and symmetrical cardiac phantom different echocardiographic mathematical models (Simpson 7 slices, area-length method, Simpson 2 slices and method according to Teichholz) were compared. 9 different end-diastolic (EDV) and end-systolic (ESV) volumes, 9 different stroke volumes (SV) and ejection fractions (EF) were used. EDV and ESV varied between 39-298 ml; SV between 29-100 ml and EF between 14-46%. In addition 10 fixed volumes of the same shape were evaluated using the same echocardiographic mathematical models. While symmetrical fixed volumes can be assessed correctly (r = 0.97-0.98), apart from the formula according to Teichholz (r = 0.89, significant underestimation of volumes), the correlation coefficients decrease using a dynamic cardiac phantom. In the modification of Simpson with 7 slices the best correlation was found for all parameters (EDV: r = 0.93; ESV: r = 0.94; EF: r = 0.87; SV: r = 0.81). The biplane area-length method has no advantages over Simpson's rule with 2 slices in the short axis; for symmetrical models both methods are comparable, both having high correlation coefficients (for volumes r = 0.85 and r = 0.88; for EF 0.78 and 0.84). Using the method according to Teichholz symmetrical volumes can be well assessed (r = 0.90), for the determination of EF the correlation coefficient decreases to r = 0.65 and for stroke volume to 0.33, reflecting no significant correlation to the actual SV. Possible causes for a poorer correlation are discussed for moving objects as opposed to the fixed volumes.