部分19岁以下正常人心向量图QRS环均值分析

目的探讨不同年龄和性别的QRS环均值参数的变化规律,为应用VCG上QRS环的有关指标,诊断该组人群心脏疾患提供较准确的参考指标.方法在城市随机选择无自觉症状的1个月至19岁不同年龄和性别的正常人群1 950名进行了VCG描记,在VCG上分析QRS环最大方位、电压及总运行时间,得出不同性别及年龄的有关QRS环的均值参数. 结果性别及年龄不同,其QRS环的均值参数也不尽相同.结论在该组人群应用QRS环指标诊断心脏疾患时,最好是根据不同年龄和性别所得出的QRS环指标,从而使诊断才能较为准确.     

山东省部分19岁以下人群心向量图监测分析

通过调查分析城市1个月至19岁正常人群T环的W/L，T／QRS，QRS—T角的均值参数，结果显示，年龄和性别不同其T环的W/L，T／QRS，QRS—T角的有关均值参数也不尽相同。因而，提示在应用VCG上T环的W/L，T／QRS，QES—T角的有关参数诊断19岁以下人群缺血性心脏疾患时，应想到不同年龄及性别对这些均值参数的影响，从而增加诊断的准确性。     

一个月至19岁正常人群心向量图的T环研究

目的：通过对19岁以下正常男女T环的研究，提供对心脏疾患有诊断意义的指标。方法：应用VA-GR型自动VGG随机检查城市1个月至19岁无自觉症状的人群，分析该组人群不同性别及年龄的T环方位、电压及ST向量。结果：性别和年龄不同其T环的有关参数也不尽相同。结论：本研究结果可对19岁下人群不同性别及年龄心脏疾患的诊断提供有价值的参考指标。     

城市1个月至19岁无症状人群的心电向量图分析

目的 分析1个月至19岁无自觉症状城市人群的心电向量图(VCG)，对I临床应用VCG诊断该组人群的心脏疾患提供帮助。方法 应用VA-3GR型自动VCG(联接方法采用Frank导联体系)随机检查1个月至19岁无自觉症状城市人群，分析该组人群在VCG上正常生理变异情况。结果 性别及年龄不同在VCG上的某些诊断数据变异较大。结论 在该组人群应用VCG诊断心脏疾患时不仅要想到性别和年龄不同而引起VCG上各参数的不同，也要想到在这些年龄中可发生一些正常的生理变化而致VCG上的某些诊断数据变异较大。     

19岁以下正常人群的QRS环在不同时间的方位及电压的研究

应用心电向量图(VCG)对1个月至19岁的各年龄组正常男女的QRS环在不同时间的方位和电压进行研究，在目前国内尚未报道。为在临床工作中应用VCG诊断该组人群心脏疾病时提供有用的参考资料，为此，作者进行了这方面的研究，现报道如下。     

慢型克山病室性早搏的心向量图分析

目的 探讨慢型克山病室性早搏在心向量图(VCG)的表现特征。方法 在山东省克山病病区选择慢型克山病有室性早搏的患者进行VCG描记，描记每个患者所发生的各种室性早搏，并对各种室性早搏进行分析。结果 慢型克山病室性早搏的QRS环形态以麻花形和不规则形最多见，QRS环的总运行时间比正常人的明显延长，最大QRS环和T环的电压比正常人的明显增大，最大QRS环和T环的角度无集中的分布范围，QRS-T角有60．9％～73．3％的图形在180度，有63．8％～68．6％的图形有ST向量，并且ST向量的电压较大。结论 慢性克山病室性早搏的QRS环形态、运行时间、最大QRS环和T环的角度及电压、QRS-T角、ST向量的电压和正常人的有明显的不同。     

心向量环体扭曲与Q—T间期离散度分析

目的 探讨Q－T间期离散度（QTd),与心电迥量（VCG）环体扭曲程度的相关性。方法 对130例健康人及肥厚型心肌病（HCM），左室肥大，劳损（冠心病所致），陈旧性心肌梗死（OMI）各20例，用美国国产MACVU002E型心电图机采集VCG及同步12导联ECG进行分析。结果 健康人组的QTd显著小于其它三组（P＜0．01）。HCM珠QTd最大。QTd值与各组VCG中横面和额面的QRS，T环体扭曲程度呈正相关。结论 VCG中横面和额面的QRS，T环扭曲可能导致Q－T间期在各导联上差异增大，使QTd增加。     

山东省部分19岁以下正常人群VCG上的Q/R,S/R,Rx,Ry,Rz值的监测

目的对19岁以下不同年龄和性别正常人群在VCG上的Q/R,S/R值及最大R振幅在X,Y,Z轴上的投影进行研究,探讨不同年龄和性别有关这些项目均值的变化规律.方法在城市1个月至19岁正常人群中,选择经检查无心脏病者1 950名健康人群进行了VCG描记,在VCG上测量与分析Q/R,S/R比值及最大R振幅在X,Y,Z轴上的投影. 结果 Q/R值在性别上区别不明显,但在年龄上稍有所不同,男女的S/R 值在8岁前无性别上的明显区别,8岁后各年龄组男性高于女性;Rx值男性在10岁前,女性在8岁前随年龄增长而增高.男性在10岁～14岁,女性在8岁～14岁随年龄的增长而降低,男女在14岁后稳定在一定范围;在1岁内男女的Ry较小外,其余年龄组在性别和年龄上无明显的区别;Rz值各年龄组的男性均高于女性,男女各年龄组均随年龄的增长而降低. 结论该组人群的VCG各项指标在年龄和性别有所差异,因而应用这些项目监测心脏大小时,应考虑年龄和性别的差异.     

139例健康人心向量与心电图对比分析

目的 了解常规心电图（ECG）与心向量图（VCG）诊断指标的吻合性及临床价值。方法 对139例健康者用美国Macvu-002 UE型机描记的ECG及VCG从表现到结果,进行统计分析。结果 ECG与 VCG在左室高电压、T波的诊断上存在显著差异（P＜0.01）,在低电压的诊断上相关性不大,VCG横面QRS环出现1例呈顺钟向运行。结论 VCG将各面QRS环最大向量的检测结果列为诊断指标欠妥,ECG与VCG联合使用可以起到很好的互补作用。     

T向量环改变对心肌缺血的早期诊断价值

对4组共223例不同检测者的ECG和VCG的T环4项指标进行分析。结果表明:1.心肌缺血时VCG的T环改变比ECG上的T波和ST段改变更为敏感;2.当T环电压小于0.3mV、T环长/宽比值和T/QRS比值变小时结合临床可考虑为早期心肌供血不足。     

右束支传导阻滞T环形态及异常的临床价值探讨

目的 :探讨心电向量图对右束支传导阻滞 (RBBB)的T环形态及异常的临床价值。方法 :对心电图无RBBB的心肌梗死 (MI)患者 (MI组 )、正常人 (对照组 )各 5 0例及心电图RBBB者 (RBBB组 ,6 6例 )进行心电向量图检查 ,分析T向量环形态及临床意义。结果 :对照组T环形态多呈狭长型 ,占 96 % (4 8/ 5 0 ) ;MI组T环多呈圆小型、狭小型和圆长型 ,占 94 % (4 7/ 5 0 )。两组比较差异有统计学意义 (P <0 .0 1)。RBBB组中正常亚组 (31例 ) ,T环形态呈狭长型占 90 .3% (2 8/ 31) ,异常亚组 (35例 )T环形态呈圆小型、狭小型和圆长型 ,占 71.4 % (2 5 /35 )。两亚组比较差异有统计学意义 (P <0 .0 1)。结论 :心电向量图检查可以揭示RBBB的T环改变 ,对心肌缺血病变的早期诊断具有重要意义     

Assessment of left ventricular hypertrophy by ECG and VCG in patients with inferior and posterior myocardial infarction. A comparison with echocardiographic data

Electrocardiographic (ECG) and vectorcardiographic (VCG) QRS voltage criteria have been analyzed in 26 patients with inferior and 17 with posterior myocardial infarction (MI) in comparison with left ventricular (LV) mass and global and regional wall motion as assessed by M-mode and two-dimensional (2D) echocardiography. Transverse plane QRS maximal vector correlated significantly with LV mass in patients with both inferior and posterior MI (r = 0.65 and 0.87, respectively, p less than 0.01). A transverse plane QRS maximal vector greater than 1.5 mV correctly recognized 12 of 15 (80%) and 9 of 12 (75%) patients with respectively inferior and posterior MI and LV mass greater than 221 gm. Of the ECG measurements, S V1-2 + R V5-6 correlated moderately with LV mass in patients with inferior MI (r = 0.47), and R V1-2 + R V5-6 correlated moderately with LV mass in those with posterior MI (r = 0.67). ECG and VCG QRS voltage data did not correlate with global and regional LV function as assessed by M-mode and 2D echocardiography. We conclude that: ECG and VCG QRS voltage parameters can be utilized for assessing non-invasively LV enlargement in patients with postero-inferior MI; ECG and VCG QRS voltage parameters should be utilized with caution for analyzing LV function or MI size in postero-inferior MI.     

Vectorcardiographic criteria for diagnosis of high lateral infarction--supplement for Chou's criteria

The concept of high lateral myocardial infarction (HLMI) has not been clearly defined, so criteria for its vectorcardiographic (VCG) diagnosis have had no firm basis. However, we have reported that HLMI, expressed as abnormal Q waves in lead aVL on the electrocardiogram, corresponds to necrosis of the area usually supplied by the diagonal branches of the left anterior descending coronary artery. Here, we evaluated conventional VCG criteria for the diagnosis of HLMI on the basis of angiographic findings, and selected the criteria of Chou as typical. The frontal plane VCG was analyzed in 46 patients with HLMI on angiograms; other subjects were 233 healthy controls and 194 patients with left ventricular hypertrophy. Chou's criteria had good specificity, but sensitivity was unsatisfactory (32/46, or 70%). Accordingly, we examined various parameters of the QRS and T loops and found that the addition of four new criteria to Chou's improved sensitivity (46/46, or 100%) without impairment of specificity. The additional criteria are; 1) initial counterclockwise rotation of the QRS loop, 2) the ratio of the maximal QRS magnitude to the maximal T magnitude less than 4.5, 3) direction of the maximal T between +60 degrees and +180 degrees, 4) the QRS-T angle between 40 degrees and 135 degrees, all in the frontal plane.     

High reliability rates of spatial pattern analysis by vectorcardiogram in assessing the severity of eccentric left ventricular hypertrophy.

In 33 patients, including 12 control subjects and 21 with eccentric LVH, LV mass determined by angiocardiogram was correlated to 26 VCG measurements (Frank system) calculated from the scalar X, Y, and Z leads. The results demonstrated that the most reliable indices of VCG in assessing the severity of eccentric LVH determined by angiocardiogram were the magnitude of the spatial mean QRS vector and the time of the spatial maximal QRS vector ("spatial VAT"), of which correlation coefficients were 0.93 and 0.93, respectively. Such high correlation coefficients have never been obtained with the usual ECG analysis. These findings strongly suggest that (1) increased QRS voltage and usual prolonged QRS duration in eccentric LVH are due to an increase in LV mass, and (2) prolonged VAT observed in eccentric LVH is closely related to an anatomic alteration, namely, the greater distance of intra-ventricular conducting pathways as the result of LV dilatation, as an increase in LV mass is usually paralleled by the grade of the chamber enlargement in this type of LVH. Regarding the T loop, correlations between the LV mass and the VCG measurements were less as compared to those of the QRS loop. In general, T changes in moderate or severe LVH may be also related to a certain altered cardiac muscle state, in addition to an increase in LV mass. Angiocardiographic and light microscopic findings of a patient with eccentric LVH in whom a widened QRS-T angle was demonstrated to an extent much more than that expected with an increase in LV mass are presented and discussed. The spatial pattern analysis by VCG is very useful and reliable in assessing the severity of eccentric LVH.     

Effect of Heart Rate on Ventricular Repolarization in Healthy Individuals Applying Vectorcardiographic T Vector and T Vector Loop Analysis

Background: Ventricular repolarization (VR) is strongly influenced by heart rate (HR) and autonomic nervous activity, both of which also are important for arrhythmogenesis. Their relative influence on VR is difficult to separate, but might be crucial for understanding while some but not other individuals are at risk for life‐threatening arrhythmias at a certain HR. This study was therefore designed to assess the “pure” effect of HR increase by atrial pacing on the ventricular gradient (VG) and other vectorcardiographically (VCG) derived VR parameters during an otherwise unchanged condition. Methods: In 19 patients with structurally normal hearts, a protocol with stepwise increased atrial pacing was performed after successful arrhythmia ablation. Conduction intervals were measured on averaged three‐dimensional (3D) QRST complexes. In addition, various VCG parameters were measured from the QRS and T vectors as well as from the T loop. All measurements were performed after at least 3 minutes of rate adaptation of VR. Results: VR changes at HR from 80 to 120 bpm were assessed. The QRS and QT intervals, VG, QRSarea, Tarea, and Tamplitude were markedly rate dependent. In contrast, the Tp‐e/QT ratio was rate independent as well as the T‐loop morphology parameters Tavplan and Teigenvalue describing the bulginess and circularity of the loop. Conclusions: In healthy individuals, the response to increased HR within the specified range suggests a decreased heterogeneity of depolarization instants, action potential morphology, and consequently of the global VR. Ann Noninvasive Electrocardiol 2011;16(3):287–294     

Vectorcardiographic changes following coronary artery bypass surgery

Myocardial infarction (MI) has been reported to occur in about 15 per cent of patients following coronary artery bypass (CAB) surgery. Preoperative and postoperative electrocardiograms (ECG) were evaluated in 85 patients. Thirty-four of these patients also had pre- and postoperative vectorcardiograms (VCG). Fifteen additional patients undergoing open heart surgery were used as controls. These included aortic valve replacement (in 4), mitral valve commissurotomy (in 6), mitral valve replacement (in 1), atrial septal defect repair (in 3), and repair SVC to LA shunt (in 1). Pre- and postoperative VCG's were analyzed in three planes. The angle of each 10 msec. vector was measured. The maximal voltage was determined along each axis in each plane. Mean changes in these parameters were determined for the controls. Change exceeding two standard deviations from the control mean was considered abnormal and not explainable by trauma of open heart surgery itself. Excluding the six intraoperative deaths, $\text{19}\text{79}$ (24 per cent) had QRS changes of myocardial infarction by ECG. Changes were considered significant in the postoperative VCG if they occurred in at least two consecutive angles in one plane or in the maximum voltage in one axis. The postoperative VCG depicted MI in 34 per cent ($\text{12}\text{34}$). In the absence of classic criteria for MI a significant change in VCG angle occurred in 26.4 per cent ($\text{9}\text{34}$). The voltage in at least one axis changed significantly in 11.8 per cent ($\text{4}\text{34}$). A change in the postoperative VCG was demonstrated in 73.5 per cent ($\text{25}\text{34}$). The pre- and postoperative VCG is a sensitive method of detecting subtle changes in conduction or loss of myocardium seen in the majority of patients following CAB surgery.