正常人额面QRS电轴的年龄趋势以及对肢体导联QRS波振幅的影响

目的调查和评估正常人额面QRS电轴的年龄趋势以及对肢体导联QRS波振幅的影响。方法采集5360例(男性3614例、女性1746例,年龄范围18～84岁)正常健康人12导联心电图分为5个年龄组,计算和分析各年龄组额面QRS电轴的中位数以及肢体导联QRS波振幅的中位数和96%的正常范围上、下限。结果随年龄增长,男、女额面QRS中位数电轴一致性地逐渐向左(上)偏移大约27°(从70°偏移到43°,P＜0．001)。Ⅰ和aVL导联的R波振幅随年龄增长显著增加(P＜0．001),而下壁导联Ⅱ、Ⅲ和aVF的R波振幅随年龄增长显著降低(P＞0．001)。肢体导联R波振幅随年龄的变化趋势与额面QRS电轴的年龄趋势相一致。结论正常人额面QRS电轴随年龄增长逐渐向左(上)偏移,呈现明确的年龄趋势。QRS电轴的生理性演变可引起肢体导联QRS波振幅呈现明显的年龄差异。显然,把一个相同的左心室肥大心电图诊断标准应用到不同年龄组人群是不合适的。     

成人健康人群心电图正常范围的调查

目的 调查和评估我国成人健康人群心电图的正常范围.方法 采集5360例(男性3614例,女性1746例,年龄范围18～84岁)健康人12导联同步心电图并按性别分为5个年龄组,计算和分析男、女各年龄组心电图参数的中位数及96%范围的正常上、下限,并比较其年龄和性别差异.结果 PR间期、QTc间期、额面QRS电轴呈现明确的年龄趋势(P＜0.001).PR间期、QRS波时限、QTc间期及不同导联QRS波和T波振幅存在明显的性别差异(P＜0.001).男性PR间期上限值约为200 ms,女性PR问期上限值从180ms随年龄增长逐渐增加到200 ms.男性QRS波时限上限值为120 ms,女性为109 ms.各年龄组男、女性QTc间期上限值均＞440 ms,女性QTc间期＞440 ms的发生率(12.8%)明显高于男性(6.2%).男性QRs电轴的正常范围为-37°～+94°,女性为-27°～+91°.Q波时限正常范围有明确的导联依赖性.在胸前导联,男性T波幅度的正常值不超过1.44 mV,女性不超过0.9 mV;在肢体导联,男性不超过0.54 mV,女性不超过0.45 mV.值得注意的是,肢体导联QRS振幅随年龄增长的变化规律与额面QRS电轴随年龄增长逐渐向左(上)偏移相一致;女性V5导联的R波振幅随年龄增长而增加.结论 我国成人健康人群心电图参数存在明显的年龄及性别差异,适当调整传统的正常标准,可望进一步提高心电图诊断的质量.     

中国人群心电图T波参数正常范围的调查

调查和评估中国人群 12导联心电图T波参数的正常范围以及年龄、性别和导联差异。采集 5 36 0例 (男 36 14例、女 174 6例 ,年龄范围 18～ 84岁 )健康人 12导联心电图 ,分别按性别分为 5个年龄组 ,计算男、女各年龄组T波幅度和额面T波电轴的中位数及 96 %范围正常上、下限 ,以及各导联负向T波的发生率。结果 :男性各导联T波幅度随年龄增长而逐渐下降 ,呈现明确的年龄趋势 ,尤其在胸导联 (P <0 .0 0 1) ;而女性的年龄趋势并不十分明确。男、女T波振幅的性别差异主要发生在胸导联 (P <0 .0 0 1) ,且T波幅度的性别差异随年龄增长趋向减小。在肢体导联 ,T波振幅的正常上限值在男性为 0 .5 4mV ,女性为 0 .4 5mV ;而在胸导联 ,男性为 1.4 4mV ,女性为 0 .9mV。绝大多数导联女性负向T波发生率高于男性 ;在Ⅰ、Ⅱ及V4～V6导联 ,负向T波最大发生率不超过 1.6 4 % ;在V1导联 ,男性负向T波发生率为 12 .19% ,而女性为 4 6 .79% ;在V2 导联 ,男、女负向T波发生率分别仅为 0 .33%和 2 .4 %。男、女T波中位数电轴均随年龄增长逐渐向左上偏移 ,6 0岁以后又转向左下 ;各年龄组T波中位数电轴的性别差异几乎相同 ,均约为 6°(P <0 .0 0 1)。结论 :中国人群心电图T波参数存在明确的年龄、性别和导联差异。有必要制定与年龄?     

正常人右胸导联心电图QRS波群振幅性别、年龄差异研究

目的探讨正常人右胸导联心电图（RCLECG）QRS波群振幅性别、年龄差异规律。方法测量331名正常人右胸导联（RCL）QRS波群r、s波振幅,比较性别、年龄差异。结果男女各年龄组V3R～V6R导联r、s波振幅依次递减。同导联各年龄组之间：男性V3R-V6R导联r波振幅与年龄增长具有非常显著的负相关（P〈0．01）。V3R、V4R导联S波振幅与年龄增长呈负相关（P〈0．05）。女性r、s波振幅与年龄增长无显著的负相关（P〉0．05）。同年龄组男女之间：V3R—V6R导联QRS波群r、s波振幅均男性大于女性（P〈0．01）。结论正常人RCL ECG中QRS波群振幅性别、年龄差异显著,应引起临床注意。     

儿童心电图Cornell指数诊断左心室肥厚的价值

目的 通过比较Cornell指数与Sokolow指数在儿童心电图中诊断左心室肥厚(LVH)的性能来评估两者的诊断价值.方法 分析我院自2008至2010年的儿童患者共1082例,根据年龄分为1月～3岁组(男232人,女184人),3 ～13岁组(男198人,女143人)及13 ～17岁组(男186人,女139人),每组根据超声心动图测定的左心室内径(LVD)分为正常组和LVH组,计算Cornell指数和Sokolow指数的诊断特异性、灵敏性和准确率.结果 在1月～3岁年龄组中,Cornell指数的男女的特异性、灵敏性及准确率均高于Sokolow指数;在3～ 13岁年龄组及13 ～17岁年龄组中,特异性差别不大,均＞95％,但Cornell指数的灵敏性及准确率高于Sokolow指数.结论 Cornell指数在儿童心电图中诊断LVH的性能要高于Sokolow指数.     

中国人群心电图时间参数的年龄和性别差异

目的：调查和评估中国人群心电图时间参数（P波和QRS波时限、PR间期、QT及QTc间期）的年龄和性别差异。方法：采集5360例（男3614例,女1746例）健康人心电图并按性别分为5个年龄组,计算男、女各年龄组时间参数的平均值、标准差及96％范围上、下限。结果：各年龄组男性的P波时限、PR新时期以及QRS波时限均大于女性,而女性的QTc间期均大于男性;各年龄组时间参数的性别差异均具有极显性（P＜0．0001）。男性P波时限和PR间期上限值分别比女性平均长6ms和12ms;男性QRS波时限上限值为120ms,女性为109ms;女性QTc间期上限值比同年龄组男性长16－20ms,且女性QTc间期＞440ms的发生率（12．8％）明显高于男性（6．2％）。除QRS时限外,男、女其他时间参数上限值均随年龄增长而增加,显示明确的年龄趋势。比较各时间参数年龄组之间差异均具有极显性（P＜0．001或P＜0．0001）。结论：中国人群心电图时间参数存在明显的年龄及性别差异,有必要建立与年龄和性别相关的正常值标准。     

12导联∑QRS诊断高血压左心室肥大的价值

目的探讨常规心电图（ECG）12导联QRS总振幅（∑QRS）指标诊断左心室肥大（LVH）的价值。方法对286例原发性高血压患者根据超声心动图（UCG）检查结果有无LVH进行分组,并描记常规12导联心电图,将∑QRS与Sokolow、Cornell两种心电图指标进行对比分析。结果①∑QRS与Sokolow、Cornell指标差异都具有统计学意义。②∑QRS用于诊断LVH具有较高的敏感性（79．29％）和准确性（86．36％）,优于Sokolow和Cornell指标。结论12导联∑QRS是诊断左心室肥大较好的指标。     

关于心电图QRS波的几个新概念

心电图临床应用已百年有余 ,其使用范围和理论还在继续发展。笔者对国人心电图作了较系统的研究 ,该研究选入研究对象 4 32 2例 ,男 32 19例 ,女2 0 0 3例 ,最小年龄为出生后 5min ,最大年龄为 84岁。 <17岁的婴儿、儿童 2 830例 ,18～ 84岁 14 92例 ,按年龄分 2 0个年龄组和必要时合并为较少的组数 ,通过计算机对心电图振幅和时相进行数理统计和分析研究。QRS波是心电图诊断应用最广的指标之一 ,本文就R波和S波过去未曾提及的几个问题进行探讨。1 R波和S波振幅的年龄差异　QRS波是空间QRS向量环 (QRSsE环 )在心电图各导联轴上的投影…     

中国人群额面QRS电轴的正常范围

目的调查和评估国人额面QRS电轴的正常范围及年龄和性别差异。方法采集5360例(男3614例、女1746例,年龄范围18～84岁)正常健康人12导联心电图并分为5个年龄组,计算和分析各年龄组额面QRS电轴的中位数和96%范围的正常上、下限。结果随年龄增长,男、女额面QRS中位数电轴一致性地逐渐向左(上)偏移大约30°(从72°偏移到42°),呈现明显的年龄趋势(P<0.001)。男、女额面QRS电轴的性别差异无显著性。男性额面QRS电轴的正常上、下限范围为-37°～ 94°,女性的正常上、下限范围为-27°～ 91°。结论本研究提示国人采用-30°～ 90°作为额面QRS电轴的正常标准是合理的。     

中国健康人群心电图Q波参数正常范围的调查

目的 :调查中国健康人群 12导联心电图Q波参数的正常范围 ,评估传统的Q波标准。方法 :采集5 36 0例 (男 36 14例 ,女 174 6例 )健康人心电图资料 ,并按性别分为 5个年龄组 ,计算各年龄组Q波时限、振幅和Q/R比例的中位数和正常上限值 ,以及各导联上QS波类型的发生率。结果 :男性Q波时限稍长于女性 ,性别差异为 2～ 5ms。Q波时限正常范围在Ⅰ、V5和V6导联≤ 2 5ms ,在aVL导联≤ 4 5ms ;在下壁导联中 ,Q波时限正常范围在Ⅲ导联 <4 0ms,在Ⅱ和aVF导联 <30ms。各导联的Q波振幅正常上限值在不同年龄组间显示较大的变异。Q/R比例的正常上限值在Ⅰ、Ⅱ导联一般 <2 5 % ,而在V5和V6导联 <15 % ;aVL、Ⅲ和aVF导联的Q/R比例正常上限值在不同年龄组间显示较大的变异。QS波类型在V1导联的发生率为 1.5 % (80 / 5 36 0 ) ,在V2 导联的发生率为 0 .2 % (9/ 5 36 0 )。除Ⅲ和aVL导联外 ,传统的Q波标准的诊断特异性可达到 99%～ 10 0 %。结论 :Q波参数的正常值标准有明显的导联依赖性。适当调整传统的Q波标准 ,可望提高心电图诊断的准确率     

Normal limits of the electrocardiogram in Chinese subjects

BACKGROUND: Accurate normal limits of the electrocardiogram (ECG) are the basis on which diagnostic criteria are developed. The ECG, however, is subject to age- and sex-variations and may also be racially determined. Studies into normal ECG limits for the Chinese, comprising one fifth of the world population, are few and have their limitations. We have undertaken to establish normal limits of the ECG from a large sample of healthy Chinese subjects. METHODS: Standard simultaneous 12-lead ECGs from 5360 apparently healthy Chinese subjects (3614 men and 1746 women, ages ranging from 18 to 84 years) were collected with a modern digital recorder and processed with a well-validated ECG computer program. The medians, lower limits (2nd percentile) and upper limits (98th percentile) of various ECG measurements were calculated and age and sex differences examined. RESULTS: Significant age trends were present in, for example, P-wave duration, QTc interval, and frontal QRS axis, with concomitant changes of R amplitudes in the extremity leads. Sex differences existed for heart rate, interval durations, the Sokolow and Cornell indices, and QRS and ST-T amplitudes in different leads. Notably, left-precordial R-wave amplitudes in women increased with age; the Sokolow index showed a clearer age trend for men than for women, the reverse being true for the Cornell index. Some of these findings are at odds with established diagnostic ECG criteria. CONCLUSIONS: Normal ECG limits of Chinese subjects show marked age and sex differences. This merits the definition and use of age- and sex-specific ECG criteria for a Chinese population.     

Normal limits of the electrocardiogram in a Chinese population

12-lead electrocardiograms (ECGs) from 503 healthy Chinese individuals were computer-analyzed to derive the normal limits of the ECG in a Chinese population. With respect to ECG amplitudes, there were highly significant differences between men and women. The mean S wave amplitude in V2 decreased with increasing age, but the mean R wave amplitude in V5, for example, remained remarkably constant throughout the age groups. The QRS duration was on average 7.6 msec shorter in women than in men. The mean frontal QRS axis shifted superiorly by 17 degrees with increasing age, resulting in an upward trend in R wave amplitude in leads I and aVL. It was concluded that ECG diagnostic criteria for Chinese individuals should be age- and sex-dependent.     

心电图QRS波群复合振幅正常标准

为探讨国人不同年龄和性别心电图QRS波群复合振幅正常范围,计算4322例正常人群各年龄组QRS波群复合振幅(?)±s及百分位数值.结果显示:新生儿期QRS波群复合振幅一般都表现为女性>男性,儿童及成人则为男性>女性,青春期及青年男女振幅不同尤为显著.由于QRS波群振幅数据分布呈轻度正偏态,导致95%区间上限值的P_(97.5)位数值>(?)±1.96s值.研究表明:QRS波群复合振幅有显著的年龄和性别差异,且与国内参用的欧美标准值亦有差别,故临床诊断应分别采用男女标准值,参考欧美标准时应有条件地选择性使用.     

Electrocardiographic detection of left ventricular hypertrophy: development and prospective validation of improved criteria

To develop improved electrocardiographic criteria of left ventricular hypertrophy, individual electrocardiographic voltage measurements were compared with echocardiographic left ventricular mass in a "learning series" of 414 subjects. The strongest independent relations with left ventricular mass were exhibited by the S wave in lead V3, the R wave in lead a VL and the T wave in lead V1 (each p less than 0.001), and by age and sex. Better electrocardiographic detection of left ventricular hypertrophy was achieved by new criteria that stratified QRS voltage and repolarization findings in sex and age subsets. For men, at all ages, left ventricular hypertrophy is suggested by QRS voltage alone when the R wave in lead aVL and the S wave in lead V3 total more than 35 mm. When this voltage exceeds 22 mm, left ventricular hypertrophy is suggested in men under age 40 years when the T wave in lead V1 is positive (greater than or equal to 0 mm), and in men 40 years or older when the T wave in lead V1 is at least 2 mm. For women, at all ages, left ventricular hypertrophy is suggested when the R wave in lead a VL and the S wave in lead V3 total more than 25 mm. When this voltage exceeds 12 mm, left ventricular hypertrophy is suggested in women under 40 when the T wave in lead V1 is positive (greater than or equal to 0 mm), and in women over 40 when the T wave in lead V1 is 2 mm or greater.(ABSTRACT TRUNCATED AT 250 WORDS)     

Race- and sex-associated differences in rate-adjusted QT,QTpeak, ST elevation and other regional measures of repolarization: The Atherosclerosis Risk in Communities (ARIC) Study

Background

Data are limited about race-and sex-associated differences in prognostically important ECG measures of regional repolarization.

Methods and results

The normal reference group from the Atherosclerosis Risk in Communities (ARIC) study included 8,676 white and African-American men and women aged 40–65 years. Exclusion criteria included cardiovascular disease, hypertension, diabetes and major ECG abnormalities. Notable sex differences (p < 0.001) were observed in the upper 98% limits for rate-adjusted QTend (QT_ea) which was 435 ms in white and African-American men and 445 ms in white and African-American women, and for left ventricular epicardial repolarization time (RT_epi) which was 345 ms in white and African-American men and 465 ms in white and African-American women. These sex differences reflect earlier onset and end of repolarization in men than in women. Upper normal limits for STJ amplitude in V2–V3 were 100 μV in white and African-American women, 150 μV in white men and 200 μV in African-American men (p < 0.001 for sex differences), and for other chest leads, aVL and aVF 50 μV in white women, 100 μV in African-American women, 100 μV in white men and 150 μV in African-American men (p < 0.001 for sex and race differences).

Conclusions

Shorter QT_ea and RT_epi in men than in women reflect earlier onset and end of repolarization in men. STJ amplitudes in African-American men were higher than in other subgroups by race and sex. These sex and race differences need to be considered in clinical and epidemiological applications of normal standards.     

Normal limits of high-resolution signal-averaged ECG parameters of Japanese adult men and women

High-resolution signal-averaged electrocardiography (Hi-Res ECG) has been found useful in measuring ventricular late potentials for identifying patients prone to life-threatening ventricular arrhythmias. Several studies have reported cut-off values (normal limits) of Hi-Res ECG parameters, including sex-specific limits, for adult population. However, there are no such studies reporting such limits in the Japanese population. Hi-Res ECGs were recorded from 482 normal healthy patients (204 men; 278 women) with no cardiac disease and normal electrocardiogram. Three Hi-Res ECG parameters filtered QRS duration (FQRSD), low amplitude signal duration under 40 microV of terminal QRS (LASD), and root mean square voltage in the terminal 40 milliseconds (RMSV) were analyzed. FQRSD was longer in men than in women (P < .0001). RMSV was larger in men than in women (P < .0001). There was no significant difference in LASD between men and women. The upper limit (90th percentile) of FQRSD was 116 milliseconds for women. The upper limit of LASD was 42 milliseconds for both men and women. The lower limit (10th percentile) of the RMSV was 14 microV for both men and women. There was no significant difference in the distributions of the Hi-Res ECG parameters between our study and an earlier study on mostly whites from the United States and Europe. The upper limits (90th percentile) of FQRSD and LASD in the Japanese normal patients were nearly the same as for whites. But, the lower limit (10th percentile) of RMSV in our Japanese normals was significantly smaller than that for whites. Therefore, it may be necessary to use race-specific normal limits for late potential analysis. Criteria for abnormal late potentials (defined as abnormal values in at least 2 of the 3 Hi-Res ECG parameters) were met in 18 of 482 (3.7%) normal healthy patients. Further studies are needed to evaluate the role of these criteria in identifying cardiac patients with life-threatening arrhythmias in the Japanese population.     

Changes in the electrocardiographic response to exercise in healthy women

Changes in the P wave, QRS complex, ST segment, and T wave during and after maximal exercise were quantitatively analysed in 116 healthy women with a mean age of 39. The corrected orthogonal Frank lead electrocardiogram was continuously recorded and computer processed during bicycle ergometry. With exercise, maximal spatial P wave vectors shifted downward. The Q wave amplitude became more negative and the R wave amplitude diminished considerably in leads X and Y: the S wave amplitude decreased only slightly in these leads. The QRS vectors shifted towards right and posteriorly during exertion and a further shift in the same direction was seen in the recovery period. The ST segment amplitude 60 ms after the J point decreased with exertion and became negative at heart rates above 140 beats per minute, in particular in lead Y. ST segment depression increased with age. The T wave amplitude decreased during exercise and increased sharply in the recovery period. Though mean R wave amplitude in leads X and Y became more negative with exercise, this response was unpredictable in individual women. The exercise induced changes in QRS vectors in women resembled those described in men. Changes in the amplitude of the R wave should not be used for the diagnosis of coronary disease in women. ST segment depression was more pronounced in the inferiorly oriented lead Y than in lead X but it was unrelated to changes in the QRS vectors in these leads.