长效二氢奎尼丁、普罗帕酮、美托洛尔对心室晚电位影响的临床研究

通过短期观察信号平均心电图（ＳＡ－ＥＣＧ）的重复性及比较心室晚电位（ＶＬＰ）阳性患者服药前后ＳＡ－ＥＣＧ指标变化，以了解长效二氢奎尼丁（ｓéｒéｃｏｒ）、普罗帕酮、美托洛尔对ＶＬＰ阳性患者ＳＡ－ＥＣＧ指标的影响，及是否具有逆转ＶＬＰ的作用，结果表明：（１）ＳＡ－ＥＣＧ各定量指标的重复性良好，ＶＬＰ阳性组自然转阴率仅为７．７％。（２）ｓｅｒｅｃｏｒ不能逆转ＶＬＰ，而具有选择性延长ＱＲＳ终末部４０μＶ的低振幅信号持续时间（ＬＡＳ）的作用。（３）普罗帕酮不能逆转ＶＬＰ，仅延长滤波后ＱＲＳ－时限（ＱＲＳ－Ｄ）。（４）美托洛尔显著逆转ＶＬＰ，使ＱＲＳ－Ｄ、ＬＡＳ缩短，综合导联滤波的ＱＲＳ终末４０ｍｓ处综合向量电压（ＲＭＳ_（４０））增加。讨论了三种抗心律失常药物对ＶＬＰ影响的不同效应。     

继发孔房间隔缺损与全肺静脉异位引流的心电图和血流动力学比较

观察１１２例房间隔缺损（ＡＳＤ）和３９例全肺静脉异位引流（ＴＡＰＶＣ）的ＥＣＧ，若ＱＲＳ电轴正常、左偏或右偏伴Ｖ１呈ｒＳ，可排除ＴＡＰＶＣ。电轴右偏，Ｒｖ１≥１５ｍｍ，Ｖ１呈单纯Ｒ或ｑＲ型，而Ｖ５～６导联为ｒＳ型伴ＰⅡ≥０．２５ｍＶ高度提示ＴＡＰＶＣ。ＴＡＰＶＣ的心导管检查诊断依据：１．ＳａＱ２８０～９０％，且与肺动脉血氧饱和度相近，２．轻度肺动脉高压（≥４．１ｋＰａ）伴大的左向右分流（Ｑｐ／Ｑｓ＞３∶１），３．导管进入异常途径并采血化验血氧含量高于正常，４．肺动脉选择造影右房提早显影。     

心电向量图RX＋SZ对诊断左室肥厚的研究

为提高心电向量图诊断左室肥厚的敏感性，对１４６例患者作心电图、心电向量图与二维超声心动图检测对照研究，提出应用心电向量图ＲＸ＋ＳＺ的测量方法对左室肥厚进行判断。通过对ＱＲＳ环的最大左向力与最大后向力及其角度的测量和分析，可增加诊断信息，弥补心电图及常规心电向量图对左室肥厚诊断的不足，提高诊断率。     

信号平均心电图对冠心病的诊断价值

本文观察信号平均心电图（ＳＡＥＣＧ）对冠心病的诊断价值，对老年冠心病组和老年对照组的ＳＡＥＣＧ进行分析。老年冠心病组滤波后ＱＲＳ波时限（ＴＱＲＳ）、滤波后ＱＲＳ电压低于４０μＶ的时限（ＬＡＳ４０）、滤波后ＱＲＳ终末４０ｍｓ的平均平方根电压（ＲＭＳ４０）分别是１０４．４５±２０．０１ｍｓ、３０．６９±７．７１ｍｓ、３８．８８±６．７１μＶ，与老年对照组相比明显差异（分别为Ｐ＜０．０５、Ｐ＜０．０１、Ｐ＜０．０１）；在非老年人群中，超声运动负荷试验阳性（ＥＸＥ．Ｐ）组与对照组和超声运动负荷试验阴性（ＥＸＥ．Ｎ）组的ＴＱＲＳ、ＬＡＳ４０、ＲＭＳ４０对比，前组较后２组也存在明显差异（分别为Ｐ＜０．０１、Ｐ＜０．０５、Ｐ＜０．０１）。表明ＳＡＥＣＧ作为无创伤性和安全的方法，对冠心病的诊断具有一定的临床价值。     

冠心病急性心肌缺血时T环向量的变化及其临床价值

对３９例经冠状动脉造影证实的冠心病患者诱发急性心肌缺血，观察其心向量的Ｔ环向量变化。结果显示，Ｔ环向量的变化趋向是最大向量方位集中分布于第四象限（Ｐ〈０．０５）；最大向量振幅，最大向量振幅与ＱＲＳ环最大向量振幅的比值及其长宽的比值呈现递减性变化（Ｐ〈０．０５）；最大向量与ＱＲＷ环最大向量的夹角显示递增性的改变（Ｐ〈０．０５）。同时，Ｔ环向量这种多指标整体同步的变化亦早于心电图所示的急性心肌缺血。经     

慢性阻塞性肺疾病缓解期患者血浆内皮素变化及其与心肺功能的关系

目的探讨内皮素（ＥＴ）－１在慢性阻塞性肺疾病（ＣＯＰＤ）发展中的临床意义。方法采用ＥＴ－１放射免疫直接法，血气分析仪和肺功能仪等测定３４例ＣＯＰＤ缓解期患者血浆不同部位ＥＴ－１浓度及其血流动力、心肺功能参数。结果肺动脉高压患者血浆ＥＴ－１明显高于肺动脉压正常者和健康人。肺动脉高压患者血浆ＥＴ－１与全肺阻力指数（ＴＰＲＩ）、体循环阻力指数（ＳＶＲＩ）、肺动脉平均压（ｍＰＡＰ）、体循环平均压（ＭＳＡＰ）和肺毛细血管楔压（ＰＣＷＰ）呈正相关，与ｐＨ值、混合静脉血氧分压（ＰｖＯ２）、混合静脉血氧含量（ＣｖＯ２）、小气道功能［５０％肺活量最大呼气流量（Ｖ５０）／２５％肺活量最大呼气流量（Ｖ２５）、（Ｖ２５／ＨＴ）％］呈负相关。肺动脉压正常者血浆ＥＴ－１与ＴＰＲＩ、ｍＰＡＰ、右心每搏功指数（ＲＶＳＷＩ）、左心每搏功指数（ＬＶＳＷＩ）呈正相关，与ｐＨ值、肺活量（ＶＣ）、最大通气量（ＭＶＶ）、Ｖ５０／Ｖ２５、（Ｖ２５／ＨＴ）％呈负相关。结论ＣＯＰＤ缓解期患者血浆ＥＴ－１增高可能仍是肺动脉高压形成的重要因素之一。血浆ＥＴ－１水平与心肺功能互相影响，ＥＴ－１的异常表达和释放可加速病情发展     

特发性室性心动过速QRS波群电轴与成功消融关系的探讨

为探讨特发性室性心动过速（ＩＶＴ）体表心电图ＱＲＳ波群电轴与射频消融成败的关系，对２３例ＩＶＴ进行射频消融治疗，其中左室ＩＶＴ１５例、右室ＩＶＴ８例。在左室ＩＶＴ中，１０例ＱＲＳ波群电轴左偏（－８１°±９°）者均消融成功；５例电轴右偏者（＋１１０°～＋２３０°）中只有１例（＋１１０°）消融成功。电轴左偏与电轴右偏患者的消融成功率比较（１０／１５ｖｓ１／５），差异有显著性，Ｐ＜０．０５。在右室ＩＶＴ中，５例电轴正常或轻度右偏患者均消融成功；另３例电轴左偏患者均消融失败。结果提示室性心动过速（ＶＴ）时ＱＲＳ波群电轴对术前判断ＶＴ的起源部位及消融难易程度会有所帮助。     

吡那地尔防治大鼠低氧性肺动脉高压肺血管重建的实验研究

目的研究钾通道开放剂吡那地尔对低氧性肺动脉高压（ＨＰＨ）及其肺血管重建的影响。方法Ｗｉｓｔｅｒ大鼠４６只,随机分为３组：对照组１５只;低氧组１６只;治疗组（低氧＋吡那地尔）１５只。低氧组及治疗组建立低氧性肺动脉高压动物模型,治疗组于每天缺氧前腹腔注射吡那地尔３ｍｇ／ｋｇ。 ４周后测定各组平均肺动脉压（ｍＰＡＰ）、右心室（ＲＶ）／左心室＋室间隔（ＬＶ＋ Ｓ）比值和肺小动脉病理及其形态计量学。结果（１）低氧组ｍＰＡＰ、ＲＶ／（ＬＶ＋Ｓ）分别为（２８．４ ± ２．８）ｍｍＨｇ和（０．３０±０．０３）,明显高于对照组（１６．２±１．８）ｍｍ Ｈｇ和（０．２２±０．０３）（Ｐ＜０．０１）,管壁厚度与血管外径比值（ＭＴ％）、管壁面积与血管总面积比值（ＭＡ％）分别为（２５．７±２．６）％和（７５．３±５．６）％,亦明显高于对照组（１８．５±２．９）％和（５９．９±６．６）％（Ｐ＜０．０１）,管腔面积与血管总面积比值（ＶＡ％）为（２４．３±５．６）％,明显低于对照组（４０．７±８．１）％（Ｐ＜０．０１）。提示慢性缺氧导致大鼠发生明显肺动脉高压及右心室肥厚和肺小动脉管壁增厚、管腔狭窄等肺血管重建等改变。（２）治疗组ｍＰＡＰ、ＲＶ／     

有QRS终末向量改变的预激综合征

观察到一例间歇性Ｍａｈａｉｍ型预激综合征，因旁束邻近动脉圆锥，在预激发作时引起ＱＲＳ终末向量改变（Ⅰ、Ⅱ、Ⅴ６导联的终末Ｓ波和ａＶＲ导联的终末ｒ波皆消失）。作者认为凡旁束位于正常心室最晚除极区域的预激综合征，都有可能引起ＱＲＳ终末向量改变。     

Brugada综合征1例报告

患者 ,男 ,30岁。因反复出现胸闷、心前区疼痛来院检查。心电图示 :窦性心律 ,心率 88次 ｍｉｎ ,Ｐ -Ｒ间期 0 16ｓ,Ｑ-Ｔ间期 0 32ｓ,不完全性右束支传导阻滞 (ＩＲＢＢＢ)。Ｖ1 、Ｖ2呈尖峰状或马鞍型抬高 0 2～ 0 3ｍＶ。心电向量图示 :(Ｈ面 )ＱＲＳ环起始于左前 ,逆转至左后终止于右前 ,ＱＲＳ环未闭合偏向左前 ,终末向量略密集 ,ＱＲＳ环总时限≤ 12 0ｍｓ。 (Ｆ面 )图 1　Ｂｒｕｇａｄａ综合征ＱＲＳ环起始于零点 ,顺转由左上至右下呈 8字型逆转至右上形成附加环 ,终止于零点 ,终末向量略密集。诊断为Ｂｒｕｇａｄａ综合征。　…     

Prediction of right ventricular systolic pressure in pulmonary stenosis from combined vectorcardiographic data

In 38 patients with isolated unoperated pulmonary stenosis a systematic search was made for optimal VCG criteria for the prediction of peak systolic right ventricular pressure. Fifty VCG measurements, seven ECG measurements, and age of each patient were entered into a stepwise multiple regression computer program.The best individual predictors were found to be the QRS loop rotation in the horizontal plane and the closely related QRS dislocation along the 135 to 315 degree horizontal plane axis (r = 0.78). Five VCG criteria were better than the best ECG criterion (R V₁, r = 0.72). Thirty-three of the 58 variables showed significant correlations with the pressure (p < 0.01). Since the confidence intervals are large with this sample size and degree of correlation, conclusions regarding the superiority of one predictor vs. another should be drawn with great care.The multivariate equation selected by the computer involved four VCG variables and age; this improved the correlation coefficient to 0.93. This improvement from data combination is larger than in previous studies, probably because all variables were given equal opportunity to enter the equation.The results were tested on a secondary sample of 19 patients with pulmonary stenosis as their main cardiac lesion. Although this sample was less homogeneous, the formula-derived pressure estimates remained reasonably good (r = 0.88). The study suggests that the diagnostic power of ECG and VCG could be increased through the proper combination of easily obtainable measurements.     

New formula for predicting mean pulmonary artery pressure using systolic pulmonary artery pressure

STUDY OBJECTIVES: Mean pulmonary artery pressure (MPAP) and systolic pulmonary artery pressure (SPAP) are used interchangeably to define pulmonary hypertension (PH). We tested the hypothesis that the measurement of MPAP and SPAP is redundant in resting humans over a wide pressure range. DESIGN: Prospective, observational study. SETTING: Catheterization laboratory in a university hospital. PATIENTS: This study involved 31 patients, as follows: primary PH, nine patients; chronic pulmonary thromboembolism, seven patients; venous PH, six patients; and control subjects with normal pulmonary artery pressure, nine patients. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: High-fidelity pulmonary artery pressures were obtained when patients were at rest. Over the wide MPAP range that was under study (10 to 78 mm Hg), MPAP and SPAP were strongly related (r(2) = 0.98). Regression analysis performed on the first 16 subjects (test sample) allowed us to propose a formula (MPAP = 0.61 SPAP + 2 mm Hg), the accuracy of which was confirmed in the remaining 15 subjects (validation sample bias, 0 +/- 2 mm Hg). If PH was defined by an SPAP in excess of 30 or 40 mm Hg, this corresponded to an MPAP in excess of 20 or 26 mm Hg. If PH was defined by an MPAP of > 25 mm Hg, this corresponded to an SPAP of > 38 mm Hg. CONCLUSIONS: In resting humans, MPAP can be accurately predicted from SPAP over a wide pressure range. The new formula may help to refine the threshold pressure values used in the diagnosis of PH. Further studies are needed to test the hypothesis that our formula may allow the noninvasive prediction of MPAP from Doppler-derived SPAP values.     

吸入一氧化氮对犬肺血栓栓塞症再灌注后血气及血流动力学的影响

目的 建立血栓栓塞1周的犬肺栓塞(PTE)模型,观察吸入20 ppm一氧化氮(NO)对取栓再灌注后血气及血流动力学的影响并探讨其可能的机制.方法 对该PTE犬模型行取栓术,观察再灌注0、2、4、6 h后生命体征、血气变化,通过漂浮导管监测肺血流动力学的变化,再灌注6 h后肺泡灌洗液(BALF)中的白蛋白含量(g/L)、肺组织湿干重比值(W/D)、肺泡腔多核中性粒细胞(PMN)数.结果再灌注2 h后与再灌注前比较(下同)平均肺动脉压(MPAP)升高[(3.20±0.53)kPa对(2.27±0.67)kPa,F=63,P=0.02],再灌注6 h后,心率增快最明显[(175±8)次/min对(155±5)次/min,F=38.72,P=0.01],氧合指数下降(41.70±8.04对54.71±3.78,F=48.36,P=0.03);再灌注后2 h,吸入NO组与再灌注组(下同)比较MPAP降低((2.53±0.40)kPa对(3.20±0.53)kPa,F=55,P=0.04],4 h,氧合指数有升高趋势(49.17±7.37对39.71±7.31,F=2.36,P=0.11),再灌注后2、4、6 h,吸入NO组肺血管阻力较再灌注组也有减小趋势(F=1.49,P=0.26),6 h后吸入NO组肺泡腔PMN数低于再灌注组[(19±6)个/10 HPF对(31±11)个/10 HPF,F=98,P=0.01]. 结论 血栓栓塞1周的PTE犬模型再灌注后导致了肺再灌注损伤,再灌注不同时间点对肺组织损伤程度不一.吸入20 ppm NO可降低PTE再灌注损伤导致的升高的肺动脉压,减少PMN向肺组织的迁移而减轻再灌注损伤,可能减轻肺微血管渗漏.     

Usefulness of transcutaneous Doppler jugular venous echo to predict pulmonary hypertension in COPD patients.

Pulmonary hypertension is an important factor that determines the prognosis of chronic obstructive pulmonary disease (COPD) patients. Echocardiography is a noninvasive and useful bedside method for measurement of pulmonary artery pressure. However, this method is sometimes difficult because of the overinflated lungs in COPD patients. This study attempted to estimate pulmonary hypertension in COPD patients using transcutaneous Doppler jugular vein flow velocity recording. The mean pulmonary artery pressure (MPAP) of 64 COPD patients was examined using cardiac catheterization. The right jugular vein flow velocity was measured within 24 h using transcutaneous Doppler echo, after which the ratio of diastolic flow (Df) and systemic flow (Sf) velocity was calculated. Subsequently, the statistical correlation of MPAP and the Df/Sf ratio was examined. MPAP was also measured using standard cardiac echo methods and the results were compared. The Df/Sf velocity ratio showed significant correlation with MPAP in COPD patients (r=0.844, p<0.0001). The sensitivity was 71.4%, and the specificity 95.3% (cut-off ratio= 1.0). Jugular venous Doppler echo could be performed in all patients while other cardiac echo methods could not be performed in all patients. The specificity of the methods used was higher than other cardiac echo methods. Transcutaneous jugular vein flow velocity measurement may be applicable to bedside prediction of pulmonary hypertension in chronic obstructive pulmonary disease patients.     

室间隔缺损和动脉导管未闭合并中重度肺动脉高压的分期复合治疗

目的 评价经导管介入封堵加择期外科手术的分期复合治疗应用于室间隔缺损和动脉导管未闭合并中重度肺动脉高压患者的安全性及有效性.方法 自2004年7月至2009年7月,对22例室间隔缺损和动脉导管未闭合并中重度肺动脉高压患者进行了先经导管介入封堵动脉导管未闭,随后择期行开胸室间隔缺损修补术的分期复合治疗.术后进行随访,观察心律改变、残余分流、封堵器形态、有无瓣膜反流及主动脉狭窄等情况,测量肺动脉压变化,评价治疗效果.结果 经导管介入封堵治疗后,患者肺动脉收缩压由(76.2±25.8)mm Hg(1 mm Hg=0.133 kPa)降至(55.4±20.6)mm Hg(P=0.005),肺动脉平均压由(53.5±23.5)mm Hg降至(36.2±17.8)mm Hg(P=0.049),全肺动脉阻力由(8.2±4.9)wood单位降至(6.9±4.3)wood单位(P=0.037),肺循环血流量与体循环血流量的比值(Qp/Qs)由2.8±2.3升至3.4±1.7(P=0.045).外科手术后,肺动脉收缩压由(64.5±22.3)mm Hg降至(43.1±18.9)mm Hg(P=0.001),肺动脉平均压由(40.2±18.7)mm Hg降至(29.5±15.8)mm Hg(P=0.040).随访中所有患者均未出现右心衰竭和死亡.结论 室间隔缺损和动脉导管未闭合并中重度肺动脉高压的经导管介入封堵加择期外科手术的分期复合治疗安全、有效.

Abstract：

Objective To evaluate the safety and efficacy of staged hybrid approach in treating ventricular septal defect (VSD) patients combined with patent ductus arteriosus (PDA) and pulmonary artery hypertension (PAH). Methods From July 2004 to July 2009, 22 VSD patients with PDA and PAH were enrolled and received staged hybrid approach treatment( transcatheter PDA occlusion and elective open surgery for VSD several lays after PDA occlusion). All patients were followed up to examine rhythm change,residual shunt, shape of occlude, possible valve regurgitation, and aortic stenosis by echocardiography. Results After transcatheter PDA occlusion, pulmonary arterial systolic pressure decreased from (76. 2 ± 25. 8 ) mm Hg ( 1 mm Hg = 0. 133 kPa) to ( 55.4 ± 20. 6 ) mm Hg ( P = 0. 005 ),mean pulmonary artery pressure decreased from ( 53.5 ± 23.5 ) mm Hg to ( 36. 2 ± 17. 8 ) mm Hg ( P=0. 049), total pulmonary resistance decreased from (8. 2 ±4.9)wood units to (6.9 ±4. 3)wood units (P =0. 037), and pulmonary-to-systemic flow ratio (Qp/Qs) increased from 2. 8 ± 2. 3 to 3.4 ± 1.7 ( P = 0. 045 )post transcatheter interventional PDA occlusion. After VSD repair, pulmonary arterial systolic pressure decreased from (64. 5 ± 22. 3 ) mm Hg to (43. 1 ± 18. 9) mm Hg ( P = 0. 001 ) and mean pulmonary artery pressure decreased from (40. 2 ± 18. 7 ) mm Hg to (29. 5 ± 15. 8) mm Hg ( P = 0. 040). There was no death or right heart failure during the follow-up. Conclusion Staged hybrid approach is an effective and safe strategy for treating VSD patients with PDA and PAH.     

Continuous-wave Doppler in children with ventricular septal defect: noninvasive estimation of interventricular pressure gradient

Continuous-wave Doppler was used to estimate the pressure gradient between the right and left ventricles in 28 children with ventricular septal defect (VSD). Doppler measurement of maximal velocity was performed during cardiac catheterization and the Doppler-predicted gradient was compared with the peak-to-peak gradient measured simultaneously by catheter. Doppler gradients ranged from 10 to 71 mm Hg and correlated well with measured gradient (r = 0.97, p greater than or equal to 0.001). Fourteen patients had isolated VSD, and in these patients Doppler measurements of gradient allowed accurate estimation of right ventricular pressure (r = 0.93). There was an inverse correlation between the ratio of pulmonary to systemic resistance and maximal velocity (r = -0.77). Thus, continuous-wave Doppler is an accurate means of measuring instantaneous VSD pressure gradient in children with congenital heart disease and can be used to estimate the right ventricular and pulmonary artery pressure in children with isolated VSD. This noninvasive method can be used to distinguish restrictive from nonrestrictive VSD.     

Characterization of high-altitude pulmonary hypertension in the Kyrgyz: association with angiotensin-converting enzyme genotype

Previous studies have suggested a genetic component in susceptibility to hypoxia-induced pulmonary hypertension. We therefore estimated the prevalence of high-altitude pulmonary hypertension (HAPH) in a Kyrgyz population and whether the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene associates with HAPH. An electrocardiographic survey of 741 highlanders demonstrated electrocardiogram signs of cor pulmonale in 14% of subjects. Pulmonary artery hemodynamics measured in an independent group of 136 male highlanders with symptoms of dyspnea at altitude revealed established pulmonary hypertension (mean pulmonary artery pressure [MPAP] > or = 25 mm Hg) in 20%. However, 26% of the normal subjects demonstrated an exaggerated response (twofold or greater increase in MPAP) to inhalation of 11% oxygen, and were classified as hyperresponsive. Ten-year follow-up of this group revealed increases in the MPAP, but not in normal subjects. Comparison of ACE I/D genotypes in the catheterized group revealed a threefold higher frequency of the I/I genotype in highlanders with HAPH, compared with normal highlanders (chi2 = 11.59, p = 0.003). In addition, MPAP was higher in highlanders with the I/I genotype (26.9 +/- 4.0 mm Hg) compared with the I/D genotype (20.6 +/- 1.2 mm Hg) or the D/D genotype (18.3 +/- 0.9 mm Hg) (p < 0.05). We conclude that HAPH is associated with ACE I/D genotype among Kyrgyz highlanders and the development of HAPH in this population and may be predicted by hyperresponsiveness to acute hypoxia.     

Portopulmonary hypertension: Results from a 10-year screening algorithm

Portopulmonary hypertension (POPH) is the elevation of pulmonary artery pressure due to increased resistance to pulmonary blood flow in the setting of portal hypertension. Increased mortality has occurred with attempted liver transplantation in such patients and thus, screening for POPH is advised. We examined the relationship between screening echocardiography and right heart catheterization determinations of pressure, flow, volume, and resistance. A prospective, echocardiography-catheterization algorithm was followed from 1996 to 2005. Consecutive transplantation candidates underwent Doppler echocardiography to determine right ventricular systolic pressure (RVSP). Of 1,235 patients, 101 with RVSP >50 mm Hg underwent catheterization to measure mean pulmonary artery pressure (MPAP), flow via cardiac output (CO), central volume via pulmonary artery occlusion pressure (PAOP), and resistance via calculated pulmonary vascular resistance (PVR). Bland-Altman analysis suggested marked discordance between echocardiography-derived RVSP and catheterization results. All-cause pulmonary hypertension (MPAP >25 mm Hg) was documented in 90/101 (90%) patients. Using current pressure and resistance diagnostic guidelines (MPAP >25 mm Hg, PVR > or =240 dynes/s/cm(-5)), POPH was documented in 66/101 (65%) patients. Elevated MPAP was due to increased CO and/or PAOP in 35/101 (35%) patients with normal resistance (PVR <240 dynes/s/cm(-5)). The transpulmonary gradient (MPAP-PAOP) further characterized POPH in the presence of increased volume. Model for end stage liver disease (MELD) scores correlated poorly with MPAP and PVR. In conclusion, right heart catheterization is necessary to confirm POPH and frequently identifies other reasons for pulmonary hypertension (e.g., high flow and increased central volume) in liver transplantation candidates. Severity of POPH correlates poorly with MELD scores.     

The normal pediatric Frank orthogonal electrocardiogram: influence of weight, height and chest circumference

The influence of body weight, height and chest circumference on the pediatric Frank vectorcardiogram (VCG) was investigated in a population of 1317 normal infants, children and adolescents. Simple linear regression analysis showed that 94, 96 and 57 VCG variables were significantly correlated with weight, height and chest circumference, respectively. These numbers were reduced to 10, 18 and 6 VCG variables after a stepwise multiple correlation analysis. The relationship between the VCG and the somatic variables was also studied in ten different age/sex subgroups. Simple regression analysis showed a residual significant correlation between the VCG and all three somatic variables in each group. The multiple correlation analysis allowed us to define a minimum set of VCG variables, from one to six, which could explain all the variation produced by the somatic variables. The coefficient of multiple correlation between VCG and weight was the highest in babies 0 to 6 months old (R = 0.73). For height, the strongest correlation was found in females two to five years old (R = 0.76). In subjects older than two years of age, the correlation between chest circumference and VCG (R = 0.30 to 0.69) was weaker than between VCG and pediatric VCG after stratification for age and sex, especially in the youngest groups.