QT间期离散度与心室晚电位相关性分析

对96例心室晚电位（VLP）检查者测量其同期心电图QT间期离散度（QTd），观察结果显示：VLP阳性组QTd显著高于VLP阴性组（P＜0．05）。其中4例死亡者VLP均为阳性，而且QTd均＞80ms。提示QTd与VLP呈正相关，且与心功能呈负相关。QTd与VLP结合可增加对心电不稳定预测的可靠性。     

56例心梗患者心室晚电位与QT离散度的关系

目的 了解心肌梗死（MI）患心室晚电位（VLP）与QT离散度（QTd)的关系。方法 对56例急性心肌梗死患（AMI）作VLP及QTd检测,进行前瞻性分析。进行前瞻性分析。结果 28例VLP阳性与28例VLP阴性的QTd有显差异。结论 VLP与QTd具有明显的相关性。两对AMI的预后判断均具有一定的临床价值。     

心室晚电位与QTc及QT离散度的相关性分析

心室晚电位(VLP)的检测对预示室速(VT)、室颤(VF)的发作,筛选有心源性猝死(SCD)风险的高危病人,预防SCD发生有重要临床意义。QTc延长是产生致死性室性心律失常的先兆之一,1年内猝死率可达20％;QTc>440ms时的猝     

心肌梗死患者心室晚电位和QT离散度同时检测的临床意义

目的 探讨心肌梗死患者心室晚电位和QT离散度联合检测的临床意义。方法 对86例急性心肌梗死入院第4周后进行同步描记12导联心电图心室晚电位检测后，随即行QT间期检测，测定QT离散度。比较两组心室晚电位阴性与心室晚电位阳性患者的QTd及心律失常、猝死的相互关系。结果 心室晚电位的阴性及QTd在正常范围内的患者无一例猝死，心室晚电位阴性而QTd异常的心肌梗死患者2例猝死，心室晚电位阳性而QTd在正常范围内的患者3例猝死，心室晚电位阳性且QTd异常的患者13例猝死。结论 心室晚电位与QTd联合检测对心肌梗死患者恶性心律失常及猝死有预测意义。     

不稳定性心绞痛心率变异性与QT离散度分析

目的　探讨心率变异性 (HRV )和 QT离散度 (QTd)与不稳定性心绞痛 (UAP)的关系。方法　测定 U AP组 (6 4)例 )和健康对照组 (30例 )的 HRV6项时域指标及与 QTd、校正的 QTd(QTcd) ,并作对比分析。结果　 UAP患者的 2 4小时时域指标及 QTd、QTcd健康对照组比较均有非常显著差异 (P<0 .0 0 1或 P<0 .0 1)。结论　 HRV与 QTd检测是判定 UAP患者心肌缺血、自主神经功能损害程度及预测预后的较有价值的无创性检测手段。     

心室晚电位和QT离散度在缺血性心肌病中的临床意义

缺血性心肌病（isohemic cardiomyopathy，ICM）是由心肌缺血引起纤维化为主的心肌细胞弥散性受损，临床表现为顽固性心力衰竭和易出现室性恶性心律失常（ventricular arrhythmia,VA）和猝死。     

高血压病左室肥厚QT离散度和心室晚电位观察

目的 :探讨高血压病左室肥厚 （L VH）与 QT离散度 （QTd）、心室晚电位 （VL P）之间的联系及其临床意义。方法 :测定 5 0例高血压病不伴 L VH组患者和高血压病伴 L VH组经苯那普利治疗前和治疗 3月后的 VL P,QTd。结果 :1高血压病 L VH组与非 L VH组相比 ,QTd有非常显著差异 （P<0 .0 1） ,VL P阳性率有显著差异 （P<0 .0 5 ）。2高血压病 L VH组治疗前后相比 ,QTd有非常显著差异 （P<0 .0 1） ,VL P阳性率有显著差异 （P<0 .0 5 ） :结论 :高血压病患者伴 L VH,不仅 QTd显著延长 ,而且 VL P阳性率升高 ;随着 L VH治疗好转 ,QTd缩短 ,VL P阳性率降低。     

QT离散度昼夜的变化与心率变异性的联系

目的 探讨QT离散度的昼夜改变与心率变异性的关系。方法 测量计算20例正常人24小时动态心电图的QT、QTc、QT与QTc离散度及心率变异参数。结果 发现QT、QTd、QTcd、RR间期、RMSSD、HF、LH/HF存在昼夜的明显差异。QTd、QTcd与RR间期、RMSSD、HF呈现明显的负性相关，与LF/HF呈明显的正性相关。结论 QT离散度的增加与交感神经活动的增加和迷走神经活动的减弱密切相关。     

自主神经对心室晚电位各参数的昼夜影响

采用数字化Holter监测仪对 30例健康人进行连续监测 ,计算其心室晚电位 (VLP)及心率变异性 (HRV)指标的动态变化 ,以评价出两者之间的关系。所有健康受试者 ,均按立体正交导联方式佩戴 2 4h动态心电图 ,分别记录午夜 2时及下午 14时左右这两个时间点的VLP及HRV数值 :夜间LF 4 93.5 7± 15 6 .6 2ms2 ,HF 6 89.73± 172 .19ms2 ,LF/HF 0 .74 3± 0 .118,T QRS 10 0 .1± 12 .79ms ;白天LF 4 14 .75± 176 .6 1ms2 ,HF 318.5 1± 116 .6 1ms2 ,LF/HF 1.399± 0 .2 81,T QRS 90 .0 3± 9.70ms(P <0 .0 5 ) ,结果显示VLP与HRV均存在昼夜的明显变化 ,T QRS与HF在夜间均增高 ,白天均降低 ,且表现出明显的正相关 ;TQRS与LF/HF比值则表现出明显的负相关。结论 :VLP存在与自主神经相关的昼夜规律性变化。     

QT离散度与心率变异性的关系

QT离散度(QTd)主要反映心室肌复极的不稳定性,而心率变异(HRV)主要反映自主神经活性及其平衡协调关系。HRV是公认的非创伤性的评价自主神经活动的一种方法,而QT间期受自主神经活动的调节,显示出昼夜的节律性改变。本文利用24h动态心电图(DCG),分析HRV与QTd的昼夜变化,探讨它们之间的联系。     

经皮冠状动脉介入术对冠心病患者的QT离散度心率变异性和心室晚电位的影响

目的 :探讨冠心病患者经皮冠状动脉介入术 (PCI)治疗后 ,QT离散度 (QTd)、心率变异性 (HRV)及心室晚电位 (VLP)的变化 ,从而估计PCI对冠心病患者预后的影响。方法 :选择 2 0 0 1年 1月～ 2 0 0 2年 1月入院的经冠状动脉造影证实适合PCI的患者 6 0例 ,其中心绞痛组 39例和心肌梗死组 2 1例。在术前第 3天及术后第3天和术后 1个月分别测QTd、HRV和VLP。所获得的数据应用SPSS 10 .0软件分析系统进行分析。结果 :PCI术前 [(4 0 .4 6± 14 .85 )ms]和术后 [(2 8.96± 11.4 2 )、(2 7.85± 9.6 6 )ms]的QTd比较差异有显著性意义 (P <0 .0 1) ,而术后第 3天和术后 1个月的QTd差异无显著性意义 (P >0 .0 5 )。HRV和VLP :PCI术前第 3天[(7.5 3± 7.0 5 )、2 1.6 7% ]、术后第 3天 [(8.2 5± 7.0 3)、2 3.33% ]和术后 1个月 [(7.81± 7.5 2 )、18.33% ]相比差异无显著性意义 (P >0 .0 5 )。结论 :成功的PCI使缺血的心肌重新获得充足的血供 ,QTd缩短 ,但PCI对心率变异性和心室晚电位的改善并不明显。     

Assessment of autonomic function in patients with acute myocardial infarction or diabetes mellitus by heart rate variability, ventricular late potential and QT dispersion.

To compare the efficacy and sensitivity of heart rate variability (HRV), QT dispersion (QTd) and ventricular late potential (VLP) examination in judging autonomic function. Thirty three patients with acute myocardial infarction (AMI) and 33 patients with diabetes mellitus (DM), all of whom were diagnosed with autonomic neuropathy determined by a standard test of cardiovascular autonomic function, were examined by HRV (timing domain methods), QTd and VLP. Thirty three normal individuals served as controls. The mean SD of the normal R-R interval (SDNN) in both the AMI and DM groups was significantly less than that in the control group (p< 0.01); and of course, the QTd of these groups was significantly greater than that of the controls (p< 0.01). The VLP positive rate of the AMI and DM groups were much higher than that of the control group (p< 0.001). SDNN was shown to be significantly negatively correlated to QTd (r= -0.45); and significantly negatively correlated to VLP (r= -0.47); QTd was shown to be positively, though not significantly, correlated to VLP (r=0.48). QTd could be looked as sieving index; HRV could be looked as routine examination of cardiovascular autonomic function, especially SDNN; the combination of HRV and VLP could improve the accuracy of diagnosis.     

慢性胆囊炎患者心血管自主神经功能变化与心率变异性的关系

目的探讨慢性胆囊炎患者心血管自主神经功能(CANF)变化与心率变异性(HRV)的关系。方法对61例慢性胆囊炎患者进行标准CANF试验,据测试结果分成阳性组(CANF+)及阴性组(CANF-)。健康人60例为对照组。记录24h动态心电图并进行HRV分析。结果慢性胆囊炎患者CANF异常的发生率较对照组高(72.1%vs28.3%,P<0.05),且主要表现为迷走神经功能异常;与对照组比较,CANF+组HRV分析中时域指标正常RR间期的标准差、每5min平均RR间期的标准差减少(P<0.05),且反映迷走神经张力改变的指标在CANF+组及CANF-组中均明显增高,低频与高频比值明显降低(P均<0.05)。结论慢性胆囊炎患者存在自主神经功能异常、以副交感神经张力增加为主。HRV分析是临床早期发现慢性胆囊炎患者CANF异常的较好方法。     

Diagnostic value of ventricular late potentials,heart rate variability and QT dispersion in patients with acute myocardial infarction

Late ventricular potentials (LVP), heart rate variability (HRV) and dispersion of QT interval (QTd) were studied in 91 patients with myocardial infarction with various ventricular arrhythmias. Patients with episodes of sustained ventricular tachycardia (group 4) had the following characteristics: prevalence of LVP 73.7%, QTd 82.5 ms, standard deviation of RR intervals (SD) 26.5 ms; spectral analysis of HRV revealed preponderance of sympathetic influences and lowered vagal activity. Frequency of LVP detection, QTd and SD in patients with ventricular extrasystoles (Lown classes 3-5) (group 3) were 33.3%, 72.8 ms, and 42.8 ms, respectively. Patients of group 3 also had augmented sympathetic and lowered parasympathetic influences. These data significantly differed from those obtained in patients with Lown class 1-2 ventricular extrasystoles (group 2) and patients without extrasystoles (group 1). Groups 3 and 4 had significantly different prevalences of LVP and values of some HRV parameters but similar QTd. There was close correlation between presence of severe ventricular arrhythmias and some parameters of HRV and signal averaged ECG. Stepwise regression analysis showed that the following group of parameters was related to the presence of malignant ventricular rhythm disturbances: heart rate, SD and total QRS duration (p<0.05). Thus patients with life threatening ventricular arrhythmias were characterized by the presence of LVP and changes of some parameters of HRV and QTd. Registration of these parameters can apparently be used for prediction of potentially fatal ventricular arrhythmias in patients with myocardial infarction.     

Magnetocardiographic QT dispersion during cardiovascular autonomic function tests

QT dispersion is considered to reflect nonhomogeneity of ventricular repolarization. The autonomic nervous system modulates QT interval duration, but the effect may not be spatially homogenous. Magnetocardiography (MCG) registers the weak magnetik fields generated by myocardial electric currents with high localizing accuracy. We studied the effect of rapid cardiovascular autonomic nervous adjustment on QT dispersion in MCG. Ten healthy male volunteers were monitored during deep breathing, the Valsalva maneuver, sustained handgrip, hyperventilation, the cold pressor test and mental stress. 67 MCG channels and 12 ECG leads were recorded simultaneously. A computer algorithm was used for QT interval measurements. QT dispersion was defined as maximum – minimum or standard deviation of the QT_peak and QT_end intervals. In MCG the QT_end dispersion increased during deep inspiration compared with deep expiration (96±19 ms v 73±27 ms, p=0.05). Magnetic QT dispersion tended to increase during the bradycardia phase of the Valsalva maneuver, but the change was obvious only for QT_end (55±26 ms v 76±29 ms, p<0.05) Other tests had no significant effect on QT dispersion, not even the cold pressor test, although it causes strong sympathetic activation. Magnetic and electric QT_peak and QT_end intervals correlated closely (r=0.93 and 0.91), whereas the QT dispersion measures showed no correlation. In conclusion, magnetic QT dispersion is not modified by rapid changes in autonomic tone, but maneuvers involving deep respiratory efforts and changes in ventricular loading affect QT dispersion measurements. Received: 4 April 2000 Returned for revision: 2 May 2000 Revision received: 20 June 2000 Accepted: 10 July 2000     

Effect of percutaneous transluminal coronary angioplasty on QT dispersion and heart rate variability parameters

Background

The aim of the study was to analyse parameters reflecting the sympathovagal control of ventricular depolarisation and repolarisation [heart rate variability (HRV) and QT interval dispersion (QTd)] in patients undergoing elective percutaneous transluminal coronary angioplasty (PTCA), and determine whether HRV correlates with QT dispersion parameters.

Methods

The study consisted of 26 consecutive patients (16 men, 10 women) with single-vessel coronary artery disease (CAD) who underwent elective coronary angioplasty. HRV analyses of all subjects were obtained with the time- and frequency-domain methods. For frequency-domain analysis, low-frequency HRV (LF), high-frequency HRV (HF) and the LF:HF ratio were measured. For time-domain analysis, standard deviations of the normal-to-normal QRS intervals (SDNN) and square roots of the mean squared differences of successive N–N intervals (rMSSD) were obtained. QT intervals were also corrected for heart rate using the Bazett’s formula, and the corrected QT interval dispersion (QTcd) was then calculated. All measurements (HRV parameters and QTcd) were made before and immediately after PTCA.

Results

QTcd was significantly decreased after PTCA (52.2 ± 3.5 vs 42 ± 3.9 ms). SDNN (94.1 ± 22 vs 123.9 ± 35.2 ms), rMSSD (43.7 ± 20.1 vs 73.4 ± 14.5 ms) and HF (51.1 ± 48.8 vs 64.2 ± 28.6 ms²) were significantly higher after PTCA, whereas LF (142 ± 41.5 vs 157.2 ± 25.9 ms²) and the ratio of LF:HF (3.3 ± 1.9 vs 2.1 ± 1.2) were significantly decreased after PTCA. We observed a significant negative correlation after PTCA between QTcd and LF (r = −0.87, p = 0.01) and between QTcd and the ratio of LF:HF (r = −056, p < 0.05).

Conclusion

Among the patients with CAD undergoing PTCA, QTcd significantly decreased after PTCA, and negatively correlated with LF, the parameter reflecting the sympathetic system.     

高血压病左室肥厚QT离散度与心率变异性分析

目的；探讨高血压病左室肥厚（LVH）与QT离散度（QTd）、心率变异性（HRV）的关系。方法：测量70例高血压非LVH（组Ⅰ）、62例高血压病LVH患者（组Ⅱ）和80例健康人（组Ⅲ）的QTd与校正的QTd（QTcd）及心率变异指数（HRVI），并对各组进行比较分析。结果：组ⅡQTd、QTcd较组Ⅰ、Ⅲ显著延长（均P＜0．01），组ⅠHRVI较组Ⅲ显著减低（P＜0．01），组Ⅱ较组Ⅰ、Ⅲ的HRVI显著减低（均P＜0.01）。结论：高血压病LVH的发生及其易出现各种并发症的原因可能与其QTd、QTcd的延长及HRVI的减低有关。     

糖尿病合并冠心病患者室性心律失常和心室晚电位以及QT间期离散度的变化

目的　探讨 2型糖尿病 (T2DM )合并冠心病 (CHD)患者室性心律失常 (VA)和心室晚电位 (VLP)与QT间期离散度 (QTcd)的变化。　方法　对选择性冠状动脉造影阳性的 186例单纯CHD与 178例T2DM合并CHD患者的VA阳性率、VLP阳性率与QTcd进行比较分析。　结果　T2DM合并CHD组VA的阳性率、VLP的阳性率明显高于CHD组 (P <0 0 1) ,QTcd明显增加 (P <0 0 1)。　结论　CHD患者VA的阳性率、VLP阳性率与QTcd增加不仅与CHD血管病变有关 ,且与DM所致心脏血管结构和功能改变有密切关系.     

扩张性心肌病心率变异性及QT离散度和心功能的关系

目的:探讨扩张型心肌病(DCM)患者,心率变异性(heart rate variability,HRV)及QT离散度(QTdispersion,QTd)与心功能的相关性。方法:45例临床诊断DCM患者,按NYHA心功能标准分级,A组(心功能Ⅰ～Ⅱ级)16例,B组(Ⅲ～Ⅳ级)29例;检测各组HRV时域指标、QTd、左室射血分数(LVEF)及左室舒张末期内径(LVDd),与正常对照组比较.并检测其相关性。结果:与正常对照组比较,DCM患者HRV各项时域指标显著降低(P<0.05～<0.001),QTd显著增加(P<0.001);且随着心功能恶化,HRV时域指标下降,QTd增加越趋明显(P均<0.001);HRV各时域指标与QTd及LVDd呈显著负相关(P<0.001),与LVEF呈显著正相关(P<0.001);QTd与LVEF及LVDd也育显著相关性(P<0.001)。结论:HRV和QTd变化与DCM患者的心功能恶化是一致的,对预测DCM患者预后有较高价值,是一种简单的无创评定方法。     

麝香保心丸对冠心病心绞痛患者QT离散度 心率变异性及心功能的影响

目的探讨麝香保心丸对冠心病心绞痛患者QT离散度、心率变异性及心功能的影响。方法将2015-03~2016-08收治的冠心病心绞痛患者106例纳入研究,根据抽签法分为对照组和观察组各53例。对照组予以硝酸异山梨酯+辛伐他汀+阿司匹林治疗,观察组在对照组基础上加服麝香保心丸,治疗4个月。比较两组治疗后QT离散度、心率变异性及心功能。结果观察组QT离散度低于对照组,短时程平均NN间期的标准差(SDANN)、NN间期标准差(SDNN)、连续NN间期均方差值的均方根(RMSSD)、心肌缺血总负荷、心绞痛发作频率及心绞痛持续时间等均优于对照组,差异有统计学意义(P0.05)。结论对冠心病心绞痛患者予以麝香保心丸治疗的效果确切,可以明显改善患者的心功能及心率变异性,降低QT离散度。