慢性充血性心力衰竭患者心率变异性及其昼夜节律变化

目的分析慢性充血性心力衰竭(CHF)患者心率变异性(HRV)及其昼夜节律的变化,了解CHF患者自主神经功能损害与心功能的关系。方法用24小时动态心电图分析38例CHF患者,20例心功能代偿的心血管病患者心功能代偿组,16例健康体检者对照组的HRV时域指标。比较三组间HRV指标的差异;计算CHF患者HRV昼夜指标差异,分析CHF患者24小时HRV指标变化与心功能NYHA分级的关系。结果心功能代偿组24小时HRV时域指标SDNN、SDANN和SDNNindex较对照组显著下降P<0.01、0.05和0.05rMSSD和pNN50与对照组无显著差别P>0.05;CHF组的HRV各指标均显著低于对照组均P<0.01且昼夜指标变化无差异;将CHF组分为心功能Ⅱ级组n=20和心功能≥Ⅲ级n=18两个亚组结果发现心功能≥Ⅲ级的HRV各指标明显低于心功能Ⅱ级组P<0.01。结论心血管病患者可能在心功能代偿期时自主神经的平衡就已受到损害当出现CHF时交感活性增强迷走神经张力进一步下降,自主神经调节昼夜节律性丧失,且HRV指标的下降与心功能损害程度相关因此HRV时域指标可作为评价CHF预后指标之一。     

Right lateral decubitus position reduces QT dispersion in patients with chronic heart failure

A greater QT dispersion in patients with chronic heart failure (CHF) appears to be a non-invasive marker of susceptibility to malignant ventricular arrhythmias. We evaluated whether QT dispersion in CHF patients is modified by the patients' recumbent position. In 12 CHF patients, and age and sex-matched 12 normal subjects, a single 12-lead surface ECG was recorded in each postural position [left lateral decubitus position (L), supine position (S), and right lateral decubitus position (R)]. In normal subjects, the QT dispersion was comparable in the three recumbent positions [L: 47+/-15 (SD) ms, S: 40+/-9 ms, R: 38+/-14 ms, P=NS]. In contrast, in CHF patients, QT dispersion was significantly shorter in R than those in L and S (L: 93+/-42 ms*, S: 81+/-29 ms*, R: 63+/-24 ms, *P <.05 vs. R). In conclusion, reclining in R reduces the prolonged QT dispersion in CHF patients.     

原发性高血压的心率变异性分析

目的通过观察原发性高血压患心率变异性（ＨＲＶ）以及高血压患血压昼夜节律正常与异常患ＨＲＶ的变化,了解高血压患心率变异性改变及血压昼夜节律异常与自主神经功能紊乱之间的关系。方法对１００例原发性高血压患进行２４小时动态血压监测,用时域分析法对心率变异性各项指标进行了检测,并与１００例血压正常组进行对照。结果原发性高血压组与血压正常对照组相比,代表心率总变异程度的ＳＤＮＮ、ＳＤＡＮＮＩ和ＳＤＮ     

Heart rate–corrected QT interval in men increases during winter months

BACKGROUND: Sudden cardiac death increases during winter months in both men and women. The heart rate-corrected QT (QTc) interval exhibits circadian variation. However, little is known about QTc interval variation with month of year. OBJECTIVE: We sought to determine whether the QTc interval varies with month of year. METHODS: We retrospectively analyzed a database of 24,370 electrocardiograms (ECGs) to determine seasonal variation in QTc intervals. The analysis data set included 7,976 baseline ECGs, one each for 3,700 men and 4,276 women. ECGs selected for analysis were normal, recorded in regions north of the equator, and taken on subjects >or=18 years old. The QT correction for heart rate (HR) was performed using QTc = QT*(HR/60)(0.4). The monthly mean QTc intervals were compared, for men and women separately, using a one-way analysis of variance with the Bonferroni correction for multiple comparisons. RESULTS: Subject ages ranged from 18 to 95 years. The monthly mean QTc intervals were consistently greater for women than for men by 5.2 +/- 2.3 ms. After correction for multiple comparisons, the difference between the greatest and least monthly mean QTc interval was 6.1 +/- 1.5 ms (P <.01) for men and 3.5 ms (nonsignificant) for women. The maximum monthly mean QTc interval of 413 +/- 18 ms (n = 560; P <.05) occurred in October for men and of 417 +/- 16 ms (n = 350) in March for women, but it was not significant. CONCLUSIONS: Significant seasonal variation in QTc interval exists among male subjects >or=18 years of age with normal baseline ECGs, with the QTc interval being longest in October. No significant variation was seen for women.     

室性期前收缩频率在阻塞性睡眠呼吸暂停的冠心病者中的临床意义

目的 评价室性期前收缩(VPC)频率及交感活性在惠有阻塞性睡眠呼吸暂停综合征(OSAS)的冠心病患者中的意义.方法 125例中有OSAS的冠心病患者,均行多导睡眠图检查,将患者按AHI值进行分组.睡眠阶段分为清醒组、S1、S2、S34及REM.并对患者心率震荡(HRT)参数进行测量对比.结果 VPC频率受睡眠阶段(清醒期、S2及REM,F=5.8,P<0.005)及AHI(F=8.7,P<0.005)影响;在严重OSAS患者,REM期VPC频率较清醒期为高(P=0.011),相反,中等OSAS患者VPC频率较低,且没有睡眠阶段依赖性(P=0.19).氧失饱和持续间期与AHI成正相关(r2=0.71,P<0.001),且在REM期较非REM期为长(P<0.0001),在REM期HRT参数TS与氧失饱和持续间期成负相关(r2=0.06,P=0.014).结论 REM期高VPC频率可能是阻塞性睡眠呼吸暂停综合症患者夜间高死亡率的原因之一.     

心力衰竭患者的QT间期动态性的特点

目的：研究心衰患者QT间期动态性的特点,为预测心衰患者猝死风险提供参考。方法：从我院心内科住院病人选择80例慢性心衰患者（心衰组）,并另选择50例健康志愿者（健康对照组）,行24h动态心电图、体表心电图及心脏彩超检查,测量其左室射血分数（LVEF）、左心室舒张末期容量（LVEDV）、收缩末期容量（LVESV）、QT间期离散度（QTd）、心率变异性指标：24h正常RR间期标准差（SDNN）、QT／RR相关直线的斜率。结果：与健康对照组比较,心衰组的LVESV[（34．0±8．3）ml比（90．4±15．4）ml]、LVEDV[（86．0±32．2）ml比（150．3±30．4）ml]、OTd[（35．6±8．5）ms比（46．6±10．4）ms]、QTe／RR[（0．136±0．021）比（0．175±0．023）]和QTp／RR[（0．130±0．026）比（0．158±0．033）]斜率显著增大;SDNN[（140．3±53．3）ms比（100．4±40．3）ms]和LVEF[（60．6±8．4）％比（38．5±8．8）％]显著降低（P均〈0．01）。结论：心力衰竭患者心室复极的不稳定性使其QT／RR斜率明显高于正常者。     

Circadian rhythm of the QT interval dispersion in healthy subjects. Correlation with heart rate variability circadian pattern

Circadian variation of QT interval dispersion (QTd) and heart rate variability spectral indices was evaluated in healthy persons in 24-hour 3-lead electrocardiogram. Mean values, SD, and SD/mean were evaluated for 24 hours, each hour separately and in night, day, and morning periods. Table Curve 2D and multiple regression were applied to find correlations between parameters. In 50% of subjects, a significant negative correlation was revealed between QTd and HF. Also, in 50% of persons, a significant positive correlation was found between QTd and low frequency/high frequency. After adjustment for periods, correlations were only observed during morning hours. With Table Curve 2D, 2 models of correlations between QTd and HF were found. Multiple regression analysis revealed relations between mean QTd and R-R as well as mean QTd and HF. It is possible that it is sympathovagal balance, as reflected in heart rate variability, and not the tone of both autonomic components that affects QTd variability.     

室性心律失常患者的心率变异性分析

为研究自主神经系统活动在室性心律失常发生中的作用,分析３５例正常人（对照组）、３４例无器质性心脏病室性心律失常者（无心脏病组）及３５例器质性心脏病室性心律失常者（心脏病组）的心率变异性。结果显示（１）与对照组比较,无心脏病组ＳＤＮＮ、ＰＮＮ５０、ＲＭＳＳＤ、ＨＲＶＴＩ显著降低（Ｐ〈０．０５～０．０１）,ＳＤＡＮＮ、ＳＤＮＮＩｎｄｅｘ无显著差异（Ｐ〉０．０５）;而心脏病组各项指标均非常显著降低（Ｐ〈     

慢性阻塞性肺部疾病的心率变异性分析

为探讨慢性阻塞性肺部疾病与心率变异性的关系,对２４例慢性阻塞性肺部疾病和２４例对照组进行心率变异性分析,并观察其与第ｌｓ用力呼气量的相关性。结果显示：慢性阻塞性肺部疾病患者的ＳＤＮＮ、ＳＤＡＮＮ、ＳＤＮＮＩｎｄｅｘ、ｒＭＳＳＤ、ＰＮＮ５０均明显低于对照组（Ｐ〈０．００５）,且第ｌｓ用力呼气量与上述时域指标呈高度正相关（ｒ＝０．６１～０．８９,Ｐ〈０．０１）。提示心率变异时域指标反映慢性阻塞性肺部疾     

急性脑出血患者24小时心率变异性变化与动态心电图异常

目的：了解急性脑出血对心脏自主神经活性改变，心电图复极改变和心律失常的影响。方法：检测61例急性大脑半球壳核和额顶颞叶出血患者和39例对照的24h动态心电图，分析其心率变异性变化，心电图复极改变和心律失常。结果：右侧壳核和额顶颞叶出血患者急性期室上性快速心律失常和心房颤动发生率明显增高，左侧壳核和额顶颞叶出血患者急性期心电图ST段降低发生率明显增高，右侧壳核和额顶颞叶出血组心率变异性指标HF，RMSSD，PNN50明显下降和LF／HF明显增高，伴室上性快速心律失常者LF／HF高于无室上性快速心律失常者，HF明显低于无室上性快速心律失常者。结论：左侧和右侧大脑半球出血对心脏的影响不高，岛叶病变在其中起着主要作用。     

Aging,heart rate variability and patterns of autonomic regulation of the heart

ObjectivesTo evaluate the effects of aging, gender and body mass index on the heart rate variability (HRV), and to compare the patterns of global autonomic regulation (GAR) and parasympathetic outflow (PO) throughout the aging process.Design, setting and participants: cross-sectionalLarge sample of community-based adults and elderly people. Individuals aged from 40 to 100 years, functionally independent and with satisfactory cognitive function defined as the self-capacity to interact with an interviewer (N = 1743).Material and methodsThe study enrolled individuals of both genders, stratified into five age-groups. We did adjustments for hypertension, dyslipidemia and non-insulin-dependent diabetes, as well as the body mass index (BMI). All groups undertook long-term electrocardiograms and five time-domain HRV parameters were measured, three (SDNN, SDANN, SDNN-index) reflecting the GAR and two (rMSSD and pNN50) the PO.ResultsSDNN, SDANN and SDNN-index decreased linearly with age and BMI, and women had lower values than men (p < 0.001). There was a U-shaped pattern of rMSSD and pNN50, with the nadir between 60 and 69 years for both genders, and women had higher values than men (p < 0.001). The lowest levels of all HRV variables were found in diabetics (p < 0.001). There was no influence of hypertension or dyslipidemia.ConclusionsThe GAR decreased linearly with the age in both genders. It is comparatively lower in women, diabetics and overweight individuals. The PO presented the U-shape in both genders with the nadir at the 7th decade. It was also comparatively lower in men and diabetics. Hypertension and dyslipidemia imparted no significant influence.     

阵发性心房颤动的心率变异性分析

目的：分析阵发性心房颤动与正常对照组之间心率变异性指标的差异，探讨自主神经在阵发性心房颤动中的作用机制。方法：在动态心电图的基础上测量分析25例阵发性心房颤动患者和20例正常人的24h心率变异性指标（SDNN；LF；HF；LF／HF）并对其进行统计学分析，P〈0．05为有差异有显著性。结果：25例阵发性心房颤动患者的SDNN显著增高（172．0±44．95：126．2±19．87，P〈0．05）其余指标LF；HF；LF／HF无显著差异（P〉0．05）。结论：阵发性心房颤动患者存在着自主神经功能的紊乱，迷走神经功能增强可能是阵发性心房颤动发生的重要影响因素之一。     

原发性高血压患者血压变异性及昼夜节律与左室肥厚的关系

目的 探讨原发性高血压患者血压变异性及血压昼夜节律与心室肥厚的关系.方法 连续入选2010 年8 月至2012 年1 月,于中国医科大学附属第一医院心血管内科住院的原发性高血压患者共93例,根据超声心动图测量指标计算所得的左心室重量指数(LVMI)分为左心室肥厚(LVH)组与无LVH 组;再根据24 h 动态血压监测获得的结果分为血压晨峰组与无血压晨峰组,杓型血压组与非杓型血压组.分析比较24 h 血压、白昼和夜间血压均值、血压变异性、血压昼夜节律及晨峰与心室肥厚的相关性.结果 ①与无LVH 组相比,LVH 组24 小时收缩压(24 h SBP)、24 小时舒张压(24 h DBP)、白昼收缩压(dSBP)、白昼舒张压(dDBP)、夜间收缩压(nSBP)和夜间舒张压(nDBP)均升高,P<0.01;LVH 组24 小时平均收缩压标准差(24 hSSD)高于无LVH 组,P<0.05,但两组24 小时平均舒张压标准差(24 h DSD)无差别;与无LVH 组相比,LVH组夜间收缩压标准差(nSSD)和夜间舒张压标准差(dDSD)升高,P<0.01;但白昼收缩压标准差(dSSD)和白昼舒张压标准差(dDSD)无差别.②血压晨峰组LVMI 高于无血压晨峰组,P<0.05;血压晨峰组LVH 比率也高于无血压晨峰组,P<0.01;与无血压晨峰组相比,血压晨峰组24 h SBP、dSBP 和nSBP 均增高,P<0.05,但两组24 h DBP、dDBP 和nDBP 无差别.③杓型血压组LVMI 低于非杓形血压组,P<0.05;杓型血压组LVH 比率低于非杓形血压组,P<0.01;与非杓形血压组相比,杓型血压组nSBP、nDBP 均降低,P<0.01;而两组24 hSBP、24 h DBP、dSBP、dDBP 差异无统计学意义.结论 原发性高血压患者LVH 的发生与血压变异性和血压晨峰密切相关.具有血压晨峰的患者和血压昼夜节律消失的非杓型高血压患者更易出现LVH.     

Prognostic value of QT/RR slope in predicting mortality in patients with congestive heart failure

Introduction: Repolarization dynamics, reflecting adaptation of QT to changing heart rate, is considered a marker of unfavorable prognosis in patients with heart diseases. We aimed to evaluate the prognostic value of QT/RR slope in predicting total mortality (TM) and sudden death (SD) in patients with congestive heart failure (CHF). Methods and Results: In 651 sinus rhythm patients with CHF in NYHA class II–III enrolled in the MUSIC study, 24‐hour Holter monitoring was performed at enrollment to assess slope of the QTa/RR (QT apex) and QTe/RR (QTend) during the entire 24‐hour Holter recording and separately during day and night periods. Patients were followed for a median of 44 months, with the primary endpoint defined as TM and the secondary as SD. Analysis of repolarization dynamics was feasible in 542 patients (407M), mean age 63 years, 83% in NYHA class II, 49% with ischemic cardiomyopathy, with mean LVEF 37%. Mean value of QTa/RR slope was 0.172 and QTe/RR was 0.193. During the 44‐month follow‐up there were 119 deaths including 47 SD. Nonsurvivors were characterized by steeper QT/RR slopes. Increased QT/RR slopes during the daytime (>0.20 for QTa and >0.22 for QTe) were independently associated with increased TM in multivariate analysis after adjustment for clinical covariates with respective hazard ratios 1.57 and 1.58, P = 0.002. None of the dynamic repolarization parameters was associated with increased risk of SD in the entire population. Conclusions: Abnormal repolarization dynamics reflected as increased daytime QT/RR slopes is an independent risk stratifier of all‐cause mortality in patients with chronic heart failure     

Effects of aerobic exercise training and irbesartan on blood pressure and heart rate variability in patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVES:

The present pilot study was undertaken to evaluate the efficacy of an aerobic exercise training (AET) program alone or combined with an antihypertensive agent (irbesartan) to reduce blood pressure (BP) and enhance heart rate variability (HRV) in chronic obstructive pulmonary disease patients.

METHODS:

Twenty-one patients were randomly assigned to a double-blind treatment with exercise and placebo (n=11) or exercise and irbesartan (n=10). Subjects underwent 24 h BP monitoring and 24 h electrocardiographic recording before and after the 12-week AET. HRV was investigated using three indexes from the power spectral analysis and three indexes calculated from the time domain. The AET program consisted of exercising on a calibrated ergocycle for 30 min three times per week. Five patients in the placebo group were excluded during follow-up because they were not compliant.

RESULTS:

There was no change in 24 h systolic and diastolic BP before (130±14 mmHg and 70±3 mmHg, respectively) and after (128±8 mmHg and 70±8 mmHg, respectively) exercise training in the placebo group, whereas in the irbesartan group systolic and diastolic BP decreased from 135±9 mmHg and 76±9 mmHg to 126±12 mmHg and 72±8 mmHg, respectively (P<0.02). There were no changes in HRV parameters in either group.

CONCLUSIONS:

The present study suggests that a 12-week AET program is not associated with a significant reduction in BP or enhancement in HRV, whereas an AET program combined with irbe-sartan is associated with a reduction in 24 h BP.     

Prognostic value of duration and variability of QT and RR intervals in general population of Novosibirsk

Increased duration and dispersion of QT interval and lowered variability of RR interval are considered to be probable precursors of dangerous ventricular arrhythmias and sudden death. Standard epidemiological methods were used for the study of a representative sample of nonorganized male population (age 25-64 years) in Novosibirsk in a framework of the MONICA project. Database of the total mortality register was used for verification of deaths. Resting ECGs were analyzed using the Minnesota code criteria blindly relative to other data of the study. Duration and dispersion of QT and QTc intervals as well as temporal parameters of RR variability were determined manually. Assessment of significance of these factors for prognosis was made with the use of methods of survival analysis. Among all characteristics of QTc interval maximal duration and dispersion of QTc were the strongest predictors of death from any cause and cardiovascular death being independent of age, mean blood pressure, ischemic heart disease, body mass index and smoking. Predictive power of these QTc interval parameters was similar in total male population and in subpopulation of patients with cardiovascular diseases. In men without cardiovascular diseases parameters of RR variability on ECG at rest were predictors of cardiovascular death independent of age, mean blood pressure, body mass index, total cholesterol and smoking.     

原发性高血压患者血压变异性与心律失常的相关性

目的:观察原发性高血压(EH)患者的血压变异性(blood pressure variability,BPV)与心律失常的相互关系。方法:根据24h收缩压BPV的总变异系数(coefficient variation,CV)将67例EH患者分为2组:高CV(CV>10.62%)组和低CV(CV≤10.62%)组。应用24h动态血压和24h动态心电图监测观察并比较2组患者的动态BPV与心律失常的相关关系。结果:除夜间舒张压外,2组其他时段动态血压水平及昼夜间QTc值差异均无统计学意义。高CV组除夜间房性期前收缩外,各时段期前收缩的每小时发生次数和复杂室性心律失常的发生率及收缩压BPV(BPVS)和舒张压BPV(BPVD)均明显高于低CV组,且期前收缩的发生次数与BPVS值的大小呈正相关(r=0.7993,P<0.05)。组内比较低CV组昼夜间室性期前收缩每小时的发生次数差异有统计学意义,且具昼夜节律性;而高CV组内差异无统计学意义,且昼夜节律性消失。结论:EH患者心律失常的发生与BPV相关,且昼夜节律性易消失。     

高血压患者胰岛素抵抗与血压昼夜模式改变的关系

目的 探讨原发性高血压时胰岛素抵抗(IR)与血压昼夜模式改变的关系.方法 对41例原发性高血压(EH组)、42例原发性高血压伴IR(EH+IR组)和30例健康志愿者(对照组)分别检测空腹血糖和胰岛素水平,计算胰岛素敏感指数(ISI),并行24小时动态血压监测,计算夜间血压下降率.结果 与EH组比较,EH+IR组血糖、胰岛素明显升高,ISI降低,收缩压及舒张压夜间下降率减少(P均<0.01).ISI与收缩压及舒张压夜间下降率呈负相关(r=0.645和-0.712,P<0.01).结论 IR与血压昼夜模式改变有关.     

原发性高血压患者血压昼夜节律、血压变异性与动脉粥样硬化的相关性研究

目的:探讨原发性高血压患者的血压昼夜节律、血压变异性与动脉粥样硬化的关系。方法:入选原发性高血压患者120例,行24 h动态血压监测,根据血压昼夜节律分为杓型组(n=22)、非杓型组(n=36)和反杓型组(n=62)。分析比较3组的血压变异性、冠心病发生率及颈动脉斑块检出率。结果:反杓型组的24 h收缩压标准差(24hSSD)、24 h舒张压标准差(24hDSD)、白昼收缩压标准差(dSSD)、白昼舒张压标准差(dDSD)、24 h收缩压变异系数(24hSBP-CV)、夜间收缩压变异系数(nSBP-CV)均低于杓型组;反杓型组的24hDSD、dDSD、24hDBP-CV低于非勺型组;反杓型组冠心病发生率及颈动脉斑块检出率较杓型组明显升高(P均<0.05)。结论:原发性高血压患者血压昼夜节律异常对动脉粥样硬化进展可能有促进作用。     

卒中与心率变异性

心率变异性(heart rate variability,HRV)是一种可定量评价心脏自主神经功能的无创性指标,其分析方法 主要包括线性时域分析法、频域分析法和非线性分析法.文章对卒中患者病变类型、病灶部位、神经功能缺损程度、病程与HRV的关系,以及卒中导致HRV的可能机制和干预措施进行了综述.