A coupling model of left ventricle and arterial system

A simple left ventricular model and a systemic arterial model of a tapered tube with eight branches are used in this paper which are combined into a mathematical coupling model of heart and arterial system to study the interaction of the heart and the arterial system.     

镧对心肌细胞钾通道的作用研究

用全细胞膜片钳记录方式研究了La^3^+对大鼠心室肌细胞钾通道的作用机理。对酶解分离的大鼠心室肌细胞施一跃迁电压可引出一非钙依赖性电压去激活的外向钾电流。将10μmol/LLa^3^+加入细胞外液后，非钙依赖性电压去激活的外向钾电流明显减小，这提示在大鼠心室肌细胞钾通道上存在La^3^+结合位点。     

MRI analysis of right ventricular function in normal and spontaneously hypertensive rats

Right ventricular structure and function were characterized in spontaneously hypertensive rats (SHR) using non-invasive magnetic resonance imaging (MRI) techniques. These studies therefore complement previous reports preoccupied with left ventricular changes associated with this condition. Eight SHR and eight control normotensive Wistar-Kyoto (WKY) rats were each subdivided into equal age-matched groups of 8 and 12 weeks. The right ventricle was imaged through a series of twelve contiguous 1.37–1.75 mm transverse sections at twelve equally spaced time-points that covered both systole and most of diastole thereby completely reconstructing right ventricular anatomy. This gave measurements of right ventricular myocardial mass that were consistent through all twelve time-points in all four experimental groups throughout their cardiac cycles. However, spontaneous hypertension increased this right ventricular myocardial mass, as well as the end-diastolic (EDV) and end-systolic volumes (ESV). Although stroke volume (SV) was conserved, decreases in ejection fraction (EF), a positive shift in the relationship between SV and EDV, and reduced indices of systolic ejection rates in SHR rats compared with the age-matched normal WKY controls indicated significant systolic dysfunction. Additionally, reductions in the rates of diastolic relaxation suggested the onset of diastolic dysfunction. Thus, the non-invasive nature of MRI has made it possible for the first time to demonstrate alterations in structure of the right ventricle and in quantitative indicators of its systolic and diastolic function in the SHR model of hypertension.     

模糊差异鉴别对室性早搏QRS-T波形态的临床意义

根据模糊集理论和模糊差异鉴别方法,对８９５例单纯室早搏和１８例室性早搏伴室性心动过速心电图的ＱＲＳ－Ｔ波进行测量并作模糊数据处理,发现ＱＲＳ波增宽,尤其是当时限≥０．１６ｓ时,存在心肌损害的可能性越大,这一结论与用经典数理统计方法处理所得结论一致,但与８０年代初由Ｓｃｈａｍｒｏｔｈ所提出的权威的传统鉴别方法的结论有差异。     

Magnetic-resonance-imaging-derived indices for the normalization of left ventricular morphology by body size

Scaling left ventricular (LV) mass and other cardiac dimensions to account for individual body size is important. The traditional method of simple ratio scaling using, for example, body surface area (BSA) assumes a linear and proportional relationship and accurate measurement of both LV mass and BSA. These assumptions can be questioned; hence, we examined the appropriateness of methods and different indices using highly accurate magnetic resonance imaging scans. Cardiac and whole-body scans were performed in 172 young, healthy, male subjects (age range, 17-28 years) to assess LV mass, volume, linear dimensions, lean body mass and fat mass. Height, body mass and BSA were determined anthropometrically. Relationships were examined for linearity and closeness of fit using log-log least-squares linear regression to determine the slope exponent b (where 1.0 indicates linearity). The relationship between LV mass and lean body mass (b=.90+/-.15; r(2)=.66) was linear and geometrically consistent. This was also the case for LV end-diastolic volume (b=.70), although the confidence intervals were broader (+/-0.32) and the r(2) (.31) smaller. The relationships between LV mass, volume and other variables were generally not linear or geometrically consistent. LV linear dimensions did not demonstrate any linear relationships, and in particular, those with BSA were extremely poor (r(2)=.02-.09). In summary, the traditional scaling of LV measurements to BSA does not remove the influence of body size and other techniques should be considered. Lean body mass was the most appropriate variable for simple indexing of LV mass. No body size variable had a linear and proportional relationship with LV linear dimensions, and the use of simple ratio scaling for these is seriously questioned.     

急性肺栓塞患者血浆脑钠肽与右心功能的关系及其预后评估价值

目的研究血浆脑钠肽（BNP）与急性肺栓塞（APE）患者右心室功能不全（RVD）的关系及其预后评估价值。方法采用酶联免疫法测定44例APE患者血浆BNP水平，同时根据超声心动图检查分为RVD组和无RVD组。观察两组间血浆BNP水平差异及血浆BNP水平与不良事件发生率的关系。结果 APE患者RVD组BNP水平[（2352.5±1987.8）pg/ml]高于无RVD组[（349.9±299.4）pg/ml]（P＜0.01）；低BNP者不良事件发生率（10.0％）低于高BNP者（69.2％），差异有统计学意义（P＜0.05）；低BNP者1年生存率高于高BNP者（χ2=6.554,P＜0.05）。结论 BNP可作为反应APE患者RVD的有效手段，对预测患者不良事件及预后有重要作用。     

两种超声检查方法测量心血管疾病患者左心室室壁厚度的对照研究

本文研究二维超声心动图(2DE)与左心声学造影(LVO)两种方法测量心血管疾病患者左心室室壁厚度的准确性.选取心血管疾病患者226例,均行2DE和LVO检测.以LVO检测结果作为对照,分析2DE测量左心室各切面舒张期及收缩期室壁厚度的准确性.结果显示,2DE测量心尖两腔(3、6、9、12、15、18节段)、心尖三腔(4...     

高血压性左室肥厚患者全血镁的测定

通过对比观察了50例高血压性左室肥厚患者和60例高血压性无左室肥厚患者全血镁含量的变化。结果表明,左室肥厚组全血镁明显低于无左室肥大组（P＜0．05）。提示高血压性左室肥厚患者镁的缺乏,可能是形成左室肥厚的因素之一。建议高血压性左室肥厚患者,在降压治疗过程中,同时给予适量补充镁剂,有利于左室肥厚的逆转。     

实时三维超声心动图与640层CT定量评价冠心病患者左心室容积及收缩功能的对比研究

目的应用实时三维超声心动图（RT-3DE）和640层CT（640- MSCT）定量评价左心室容积和收缩功能,探讨两种方法测值的相关性及在左心功能评价中的应用价值。方法选择临床或冠状动脉造影确诊为冠心病的患者42例,分别行RT-3DE和640- MSCT心脏增强（分别采用自动法和手动法）检查,测量指标包括：左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心室每搏输出量（LVSV）和左心室射血分数（LVEF）。将两种方法各测量值的结果进行比较。结果（1）RT-3DE测得左心容积及功能指标与640- MSCT （自动、手动两种方法）测值（LVEDV、LVESV、LVSV及LVEF）间相关性较好（P＜0.01）;（2）640- MSCT与RT-3DE左心室容积与心功能测值之间差别在于：LVEDV、LVESV两项指标640- MSCT测值均高于RT-3DE测值（P＜0.05）,LVSV值640- MSCT测值稍高于RT-3DE测值（P＞0.05）,而LVEF值640- MSCT测值稍低于RT-3DE测值（P＞0.05）。结论640- MSCT与RT-3DE在评价冠心病患者左心容积及功能方面高度相关,RT-3DE可推荐为临床首选影像学检查;根据不同患者的病情和各自特点,将640- MSCT与RT-3DE结合使用,可提高临床的影像学诊断率,为临床提供更多的诊疗信息。