应用心电监护仪分析急性心肌梗死患者心率变异性的临床意义

目的：探讨急性心肌梗死（AMI）患者应用心电监护仪分析心率变异性（HRV）的临床意义。方法：对70例入住CCU的AMI患者使用装载心率变异性分析软件的心电监护仪进行心电监护和心率变异性分析，并与体检正常者比较，观察HRV与心肌梗死患者病情的关系。结果：AMI患者HRV指标（SDNN，SDANN，SDNNindex，rMSSD，PNN50）较体检正常者显著减低（P〈0．05，P〈0．01），发生心脏事件患者的心率变异性低于未发生心脏事件的患者，大范围心肌梗死患者HRV明显低于小范围心肌梗死者，患者发病初期的HRV明显低于3周后（P〈0．05）。结论：对AMI患者进行即时的HRV检测，能及早发现严重心律失常的发生，可预测病情和预后，为诊断、治疗和护理提供临床依据。     

糖尿病患者心脏自主神经病变的电生理评估

目的：观测心率变异性(heart rate variability，HRV)各频谱参数在糖尿病心脏自主神经病变(cardiovascular autonomic neuropathy，CAN)各阶段的改变，探索糖尿病CAN的早期诊断方法，为有效防止糖尿病CAN的发生、发展提供监测手段。方法：根据传统心脏自主神经功能检查将104例糖尿病患者按CAN程度分为4组：单纯糖尿病组10例(男8例，女2例)，早期CAN组30例(男13例，女17例)，肯定CAN组24例(男10例，女14例)，严重CAN组40例(男13例，女27例)。每例均检测八项HRV频谱参数，同时检查眼底、尿蛋白、周围神经传导速度及心电图。分析HRV各频谱参数在糖尿病各组间的差异及与正常人群间的差异。结果：心率变异性各频谱参数在糖尿病早期CAN组已显著下降，且早于视网膜病变及肌电图改变，与CAN严重程度的相关系数分别为：高频-0．43，低频-0．40，总功率-0．38，R-R间隔的方差(variance of R-R interval，Var)-0．35，极低频-0．34，低频百分率-0．32，P均&;lt;0．01。极低频、高频、总功率、Var与乏氏指数、深呼吸心率差、卧立位30／15比值显著相关(r=0．30-0．46，P&;lt;0．01)。低频与乏氏指数、深呼吸心率差、卧立位30／15比值、卧立位血压差、握拳实验显著相关(r=0．20-0．44，P均&;lt;0．01)。低频百分率与乏氏指数、卧立位血压差、握拳实验相关(r=0．21～0．30，P&;lt;0．05)。结论：HRV频谱检测对糖尿病CAN特异性强，检测参数中高频、低频、总功率、Var、极低频、低频百分率的改变能反映心脏自主神经病变程度，可用于糖尿病CAN的早期诊断；极低频、高频、总功率、Var代表心脏副交感神经功能，低频反映心脏自主神经总体情况，低频百分率主要反映心脏交感神经功能。     

运动疗法在心脏术后康复中的作用

目的：探讨运动疗法在心脏术后康复中的作用。方法：21例心脏手术后患者均接受功率自行车或／和跑台训练为主的康复训练，并采用常规心电运动试验对康复训练前后的各项指标进行比较。结果：运动训练后，运动时间和最大运动负荷显著增加，安静时，心率、血压（包括收缩压和舒张压）、心率－血压乘积均显著下降（P＜0．05，P＜0．01），安静时心电图最大ST段压低明显改善（P＜0．01）；同等负荷量运动时，心率、血压、心率－血压乘积及运动诱发的最ST段压低与安静状态时有相似的改变(P＜0．05，P＜0．01）。结论：心脏术后的康复训练有助于增加体能，减轻心肌缺血，增加心肌储备功能，从而改善了患者的生活质量。     

冠状动脉粥样硬化性心脏病患者无症状心肌缺血发作特点及其心率变异性分析

目的 探讨冠状动脉粥样硬化性心脏病患者无症状心肌缺血（SMI）发作特点及心率变异性（HRV）与SMI的关系。方法 对69例患者和42例健康人应用动态心电图进行监测,对SMI发作的时间进行分析,病例组HRV与对照组进行比较,观察SMI发作前30分钟、发作时、发作后30分钟心率功率谱的变化。结果 SMI发作多在6：00－22：00,占总数的88．06％,其中6：00－12：00占总数的32．09％,17：00－21：00占总数的26．87％。SMI组SDNN、高频峰均小于对照组（P均＜0．01）,低频峰、低频峰／高频峰均大于对照组（P分别＜0．05,0．01）;低频峰在SMI发作前、发作时均增高,发作后降低,高频峰在SMI发作前30分钟最低,发作后升高。结论 SMI发作的冠状动脉粥样硬化性心脏病患者HRV降低,并且SMI发作有明显的昼夜发作特点,高频峰已经降低,说明SMI患者存在迷走神经兴奋性降低,交感神经性升高,自主神经的功能失调,SMI发作前30分钟交感神经已经兴奋,迷走神经明显抑制。     

急性心肌梗死患者心率变异性的临床观察及护理

目的探讨急性心肌梗死(AMI)患者心率变异性(HRV)的临床意义,以指导临床实施恰当护理.方法对26例AMI患者及25例健康者24小时白天段和夜间段HRV长程时城进行对比分析.结果AMI组HRV各指标均低于健康对照组(P＜0.001).AMI组白天段和夜间段HRV各指标比较均无显著性差异.结论AMI患者HRV降低且HRV昼夜节律性丧失,说明HRV可作为观察AMI患者的病情指标之一.     

太极拳运动中心率变异性指标的检测及意义

检测太极拳爱好者在安静状态下的心率变异性(heart rate variability，HRV)范围，为进一步探索HRV与健身运动的关系打下工作基础。方法：测定49名太极拳拳龄5-15年，年龄45-70岁的中老年太极拳运动爱好者在安静状态下的心电图，由计算机获取RR间期变化，并做功率频谱密度(power spectrum density，PSD)分析。得出正常人在安静状态下的总变异性、低频成分、高频成分以及低频成分／高频成分比值。结果：安静状态下男性心率总变异性为2973．07&;#177;2309．23，低频成分／高频成分为1．09&;#177;1．32；女性的上述两项指标分别为3495．95&;#177;2819.32及1．02&;#177;1．21；男女之间各组数据差异均无显著性意义(P&;gt;0．05)。结论：HRV分析方法具有无创伤、准确定量等其他方法无可替代的优点；本研究检测结果为将HRV作为检测自主神经系统功能的指标应用于运动生理领域打下了工作基础。     

正常人及急性心肌梗死患者心率变异频谱分析

目的：运用心率变异频谱分析法研究正常人和急性心肌梗死患者心脏植物神经功能变化。方法：１１４例正常人和２７例ＡＭＩ患者记记录２４ｈ动态心电图，将人武部窦性心率经计算机ＨＲＶ软件处理后使心电信号转换为心率功率频谱。     

厄贝沙坦时辰化用药控制老年高血压病患者晨峰对心率变异性及 QT 离散度的影响

目的：探讨厄贝沙坦时辰化用药对老年晨峰高血压患者心率变异性（ HRV）及QT离散度（ QTd）的影响。方法62例合并血压晨峰现象的老年高血压患者,睡前口服厄贝沙坦,治疗前及治疗6个月后分别测定患者HRV及QTd并分析比较。结果治疗后24 h平均收缩压、24 h平均舒张压、夜间平均收缩压、夜间平均舒张压及血压晨峰均较治疗前明显降低,差异均有统计学意义（P＜0.05）;治疗后相邻正常RR间期标准差（SDNN）、相邻正常RR间期差值的方差（rMSSD）、相邻正常RR间期差值大于50 ms的窦性心律占心搏总数的百分比（PNN50）、高频功率（HF）明显增加（P＜0.05）,而低频功率（LF）则明显降低（ P ＜0.05）;QTd较前明显下降,差异均有统计学意义（ P＜0.05）。结论厄贝沙坦时辰化用药降低老年高血压病患者血压晨峰对HRV有显著的改善作用,并可有效降低QTd。     

放松训练对脑卒中后抑郁患者心率变异性的影响

目的：本文旨在对脑卒中后抑郁患者放松训练前后的心率变异性进行前瞻性分析.方法;将59例脑卒中后抑郁患者随机分为观察组30例和对照组29例,2组均接受常规运动疗法,观察组另外接受放松训练;训练前后,采用汉密尔顿抑郁量表对抑郁症的严重程度进行评定,并进行心率变异性（HRV）分析,观察指标有低频成分（LF）、高频成分（HF）、低频高频比（LF/HF）.结果：训练1个月后,观察组抑郁程度较训练前及对照组训练后明显减轻（P＜0.05,0.01）.训练后HRV比较,观察组HF较治疗前及对照组治疗后明显下降,LF/HF较治疗前及对照组治疗后明显上升（P＜0.01,0.05）.结论：放松训练有助于减轻脑卒中后抑郁患者的症状,改善患者的心率变异性,从而降低脑卒中后患者的死亡风险.     

急性心肌梗死早期溶栓治疗效果与心率变异性的关系

目的：探讨急性心肌梗死（acute myocardial infarction,AMI)早期溶栓治疗对心率变异性（heart rate variability,HRV)的影响。方法：264例首次Q波AMI患者按有无接受早期静脉溶栓治疗分为溶栓组11例、非溶栓组145例；溶栓组根据溶栓治疗成功与否又分为溶栓成功组68例和溶栓失败组51例。264例均在起病14日后行24小时动态心电图检查和HRV分析。结果：（1）溶栓成功组HRV时域分析指标24小时正常R－R间期的标准差、24小时内每5分钟节段平均正常R－R间期的标准差、24小时内每5分钟节段正常R－R间期标准差的平均值、连续正常R－R间期差值均方的平方根、差值超过50ms的R－R间期在一定时间内的百分比及频域分析指标总能谱、低能谱、高能谱均大于溶栓失败组和非溶栓组（P＜0．01），溶栓成功组频域分析指标低能谱／高能谱比值小于溶栓失败组和非溶栓组（P＜0．01）；（2）溶栓失败组与非溶栓组所有HRV分析指标均无统计学差异（P＞0．05）。结论：AMI早期溶栓治疗成功能改善病人的HRV，提示AMI早期梗死相关冠状动脉再通能提高心肌电稳定性。     

高血压病人心率变异性研究

目的 :探讨高血压病人心率变异性的特点 ,为护理提供依据。方法 :对 10 2例原发性高血压病人 (EH组 )和 66例健康对照组进行 2 4h心率变异性分析。结果 :EH组时域和频域分析各项指标均减低 ;高血压病人自主神经 2 4h昼夜变化与正常人有差异 ,变频部分夜间明显减低 (P <0 .0 5 ) ;高血压伴糖尿病与无糖尿病者、高血压伴心肌缺血与无心肌缺血者之间高频 /低频比值差异有统计学意义 (P <0 .0 5 )。结论 :高血压病人心率谱 (PSD)昼夜分布与正常人明显不同 ,高血压伴心肌缺血者交感神经活力降低 ,伴糖尿病时交感神经和迷走神经均受损     

Heart rate variability and hemodynamic alterations in canines with normal cardiac function during exposure to pressure support, continuous positive airway pressure, and a combination of pressure support and continuous positive airway pressure

Variations in intrathoracic pressure generated by different ventilator weaning modes may significantly affect intrathoracic hemodynamics and cardiovascular stability. Although several investigators have attributed cardiovascular alterations during ventilator weaning to augmented sympathetic tone, there is limited investigation of changes in autonomic tone during ventilator weaning. Heart rate variability (HRV), the analysis of beat-to-beat changes in heart rate, is a noninvasive indicator of autonomic tone that might be useful in the identification of patients who are at risk for weaning difficulty due to underlying cardiac dysfunction. The authors describe HRV and hemodynamics in response to 3 ventilatory conditions: pressure support (PS) 10 cmH2O, continuous positive airway pressure (CPAP) 10 cmH2O, and a combination of PS 10 cmH2O and CPAP 10 cmH2O (PS + CPAP) in a group of canines with normal ventricular function. Six canines were studied in the laboratory. Continuous 3-lead electrocardiographic data were collected during baseline (controlled mechanical ventilation) and following transition to each of the ventilatory conditions (PS, CPAP, PS + CPAP) for analysis of HRV. HRV was evaluated using power spectral analysis to define the power under the curve in a very low frequency range (0.0033 to < 0.04 Hz, sympathetic tone), a low frequency range (0.04 to < 0.15 Hz, primarily sympathetic tone), and a high frequency range (0.15 to < 0.40 Hz, parasympathetic tone). A thermodilution pulmonary artery catheter measured cardiac output and right ventricular end-diastolic volume to describe global hemodynamics. There were significant increases in very low frequency power (sympathetic tone) with a concomitant significant reduction in high-frequency power (parasympathetic tone) with exposure to PS + CPAP. These alterations in HRV were associated with significantly increased heart rate and reduced right ventricular end-diastolic volume. Although there was a small but significant increase in cardiac output with exposure to PS, HRV was unchanged. These data indicate that there was a relative shift in autonomic balance to increased sympathetic and decreased parasympathetic tone with exposure to PS + CPAP. The increase in intrathoracic pressure reduced right ventricular end-diastolic volume (preload). This hemodynamic alteration generated a change in autonomic tone, so that cardiac output could be maintained. Individuals with autonomic and/or cardiovascular dysfunction may not be capable of this type of response and may fail to successfully wean from mechanical ventilation.     

Effect of diabetes mellitus on heart rate variability in patients with congestive heart failure

This study sought to determine if the severity of autonomic perturbations in patients with heart failure are affected by the presence of diabetes. Decreased HRV is frequent in diabetic patients free of clinically apparent heart disease and has been invoked as a risk factor for sudden cardiac death. However, reduced HRV is also commonly present in patients with left ventricular dysfunction. The effect of diabetes on autonomic dysfunction in this setting is not known. Holter ECGs from 69 diabetic patients and 85 nondiabetic control subjects with heart failure were analyzed. The severity of autonomic dysfunction was assessed using 24-hour time- and frequency-domain HRV analysis. Prognostically important time- and frequency-domain HRV measures (SDNN, SDANN5, total power, and ultra-low frequency power) were not different between the two groups. Time- and frequency-domain parameters modulated by parasympathetic tone (pNN50, RMSSD, and HF power) were depressed to a similar degree in the diabetic and the nondiabetic groups. The low frequency power was significantly lower in diabetic patients (5.8 +/- 0.7 vs 5.3 +/- 1.0, P = 0.02). The ratio of low to high frequency power was substantially lower in the diabetic group (2.2 +/- 0.2 vs 1.4 +/- 0.2, P < 0.0001). These differences were more apparent in insulin-treated diabetics. In the presence of heart failure, HRV parameters that are most predictive of adverse outcome are similar in diabetic and nondiabetic patients. Furthermore, during increased sympathetic stimulation in the setting of heart failure, diabetes does not worsen parasympathetic withdrawal but may mitigate sympathetic activation.     

Autonomic Denervation After the Maze Procedure

LÖNNERHOLM, S., et al .: Autonomic Denervation After the Maze Procedure. The Maze III procedure is a surgical operation for curative treatment of AF. The procedure is extensive, however, with multiple incisions in both atria, and its effects on autonomic regulation of the heart rhythm are not known. This study comprises 17 patients, 10 with paroxysmal AF and 7 with chronic AF, who had no concurrent cardiac disease known to affect heart rate variability (HRV). A 24-hour Holter recording was performed preoperatively and 2 months (early) and 7 months (late) after surgery, for analysis of HRV in the time and frequency domains. Early after the Maze procedure all HRV components were markedly reduced compared to baseline (mean ± 1 SD): SDNN   73 ± 13   versus   148 ± 50   (ms), total power   168 ± 126   versus   560 ± 1567   (ms²), low frequency (LF) power   47 ± 67   versus   826 ± 677   (ms²), high frequency (HF) power   47 ± 40   versus   678 ± 666   (ms²), and LF:HF   1.22 ± 0.9   versus   2.55 ± 1.4   . Late after the Maze procedure all variables were still reduced. Only total power increased significantly between early and late follow-up (   168 ± 126   vs   496 ± 435   ms²). Late after Maze surgery, values of the different HRV components did not differ between the patients with paroxysmal AF and chronic AF. Early after the Maze procedure there is a marked decrease of all HRV components, which is maintained 7 months after surgery, a pattern consistent with denervation of the heart. (PACE 2003; 26[Pt. I]:587–592)     

Reproducibility of Time and Frequency Domain Analysis of Heart Rate Variability in Patients with Chronic Stable Angina

Before heart rate variability (HRV) can be used to investigate the effects of drugs or other clinical interventions in chronic stable angina, it is important to establish the stability and reproducibility of HRV indices over time. HRV analysis was performed on two consecutive 24-hour ambulatory ECG recordings in 19 patients with chronic stable angina. Time-domain analysis included average heart rate, variance, SDNN, SDANN5, ASDNN5, and PNN50. The power spectral analysis was computed using fast Fourier transformation for the total power (0.003 and 0.40 Hz), low frequency (0.04–0.15 Hz), and high frequency (0.15–0.40 Hz) bands. No statistically significant differences in the time or frequency domains were found between the two ambulatory ECG recordings. HRV indices in the time and frequency domains are consistent and reproducible in patients with chronic stable angina. Thus, cardiac autonomic tone can be evaluated using HRV analyses, and any significant changes that occur after medical therapy or other clinical interventions can be ascribed to the intervention rather than the lability of cardiac autonomic tone.     

Heart rate variability and its determinants in patients with severe or mild essential hypertension

How cardiac autonomic nervous control is related to the severity of essential hypertension in patients receiving long‐term antihypertensive therapy is not well known. The aim of this study was to examine heart rate variability (HRV), a non‐invasive measure of cardiac autonomic function, in patients with long‐term and medically treated mild and severe essential hypertension and healthy control subjects, and to assess the clinical determinants of HRV in these patients. Thirty‐four patients with severe essential hypertension (SEHT) and 29 with mild essential hypertension (MEHT) as well as healthy age‐ and sex‐matched control subjects were studied. HRV was assessed from 10 min ECG‐recordings during paced (0·2 Hz) breathing at rest and expressed as time and frequency domain measures. In the SEHT group time (SDNN, RMSSD) and frequency domain measures (total power, low‐frequency (LF) power and high‐frequency (HF) power of HRV in absolute units, and LF and HF power of HRV in normalized units) of HRV were significantly lower when compared with those of the control group. The MEHT and control groups did not differ from each other with respect to time or frequency domain measures of HRV. Comparison between the hypertensive groups showed that SDNN, total power, LF power and HF power were lower in the SEHT group compared with the MEHT group (P<0·05 for all). Among hypertensive patients RR‐interval, age, gender, systolic finger blood pressure and diastolic office blood pressure as well as 24‐h blood pressure were significant determinants of HRV. In conclusion, we found that the severity of chronic essential hypertension seems to be related to the severity of impairment of cardiac autonomic control.     

Cardiac autonomic dysfunction in diabetic children.

OBJECTIVE: Adults with type 1 diabetes may have abnormal alterations in heart rate variability (HRV) due to cardiac autonomic neuropathy. This prospective study was performed to determine whether HRV can be used to detect subclinical autonomic neuropathy in diabetic children. RESEARCH DESIGN AND METHODS: We examined five time domain and three frequency domain HRV indices determined from 24-h Holter recordings in 73 diabetic children and adolescents aged 3-18 years (mean 12.1 years) with a mean duration of diabetes of 55 months. The measures were compared with normal ranges. Z scores were established for each parameter and were compared with classic risk factors of other diabetic complications. RESULTS: Most HRV indices were significantly depressed in children aged > or = 11 years, and the levels of HRV abnormalities were significantly correlated with long-term metabolic control (mean GHb for 4 years) in that age-group. In younger patients, HRV indices were within the normal range and were not correlated with the level of metabolic control. Illness duration and microalbuminuria but not short-term metabolic control (most recent GHb) were also independently predictive of HRV abnormalities. CONCLUSIONS: These results suggest that early puberty is a critical period for the development of diabetic cardiac autonomic dysfunction. Therefore, all type 1 diabetic patients should be screened for this complication by HRV analysis beginning at the first stage of puberty regardless of illness duration, microalbuminuria, and level of metabolic control.     

Heart rate variability and diastolic heart failure

Diastolic heart failure accounts for up to 40% of patients with congestive heart failure (CHF), and is associated with a better prognosis as compared to patients with systolic dysfunction. Nevertheless, patients with diastolic dysfunction have a significantly higher mortality as compared to the normal population. Reduced heart rate variability (HRV), a marker of autonomic dysfunction, is associated with increased mortality in patients with systolic heart failure. We therefore sought to determine to what extent HRV is altered in a population of patients with diastolic heart failure. Twenty-four hour ambulatory (Holter) recordings were performed in 19 consecutive patients with diastolic heart failure, in 9 patients with systolic heart failure, as well as in 9 healthy volunteers (normal controls). Time and frequency domain HRV variables were obtained for all three groups of patients. Both Time and Frequency domain variables were found to be reduced in both heart failure groups compared to normal controls. When compared with each other, patients with diastolic function had relatively higher values of HRV variables, compared to those with systolic dysfunction (SDNN, Total power, ULF power, all P 相似文献   

老年高血压患者同型半胱氨酸水平与心率变异的相关性

目的探讨老年高血压患者同型半胱氨酸(Hcy)水平与心率变异(HRV)之间的关系。方法根据Hcy水平将106例高血压患者分为正常组和升高组2组。通过24 h动态心率变异性(HRV)频谱分析技术测定2组患者HRV,并与Hcy作相关性分析。结果 (1)与健康对照组相比,Hcy升高组的5 min平均心率的标准差、爱丁堡指数、正常R-R间期的标准差、相邻R-R间期之差的均方根值均偏低,两组数据差异有统计学意义(P0.05);(2)Hcy升高组中频域分析指标:高频(HF)和低频(LF)低于健康对照组,差异有统计学意义(P0.01),Hcy升高组中交感—迷走神经平衡指标(LF/HF)较正常组升高(P0.05);(3)Hcy升高者HRV指数较正常组有所下降,空腹血糖、Hcy水平是心率变异危险因素(OR值分别1.57、1.37,P0.05)。结论 Hcy升高是老年高血压患者自主神经病变的危险因素,对早期发现自主神经病变有益。     

Impaired cardiac autonomic function in women with prior gestational diabetes mellitus

BACKGROUND: Cardiac autonomic neuropathy is a common dysfunction in manifest diabetes mellitus and is associated with duration of diabetes and/or an inadequate glycaemic control. Heart rate variability (HRV) reflects autonomic heart function. The aim of the present study was to investigate whether in women with prior gestational diabetes (GD; pre-type 2 diabetes) alterations of cardiac autonomic function can be observed after delivery in relation to insulin sensitivity and glycaemic control. MATERIALS AND METHODS: Forty-eight healthy women with prior GD were consecutively admitted to the study. HRV was analysed by both time, as well as frequency, domain methods using 24-h Holter monitoring. In addition, 20 women with normal glucose tolerance during and after pregnancy were investigated as control subjects. All women underwent a frequently sampled intravenous glucose tolerance test (FSIGT) for measurement of insulin sensitivity. RESULTS: Time domain analysis (standard deviation of normal RR intervals; SDNN) showed a reduced HRV in 25 out of the 48 (52%) women with prior GD. Frequency domain analysis revealed that in these 25 subjects both low and high frequency components of power spectral density (reflecting mainly sympathetic respectively parasympathetic activity) were reduced, indicating that sympathetic as well as parasympathetic functional impairment may be assumed. However, a relative predominance of the sympathetic over parasympathetic cardiac function was observed. The impairment of cardiac autonomic function (reduced SDNN) was correlated with HbA1c values and the 2-h blood glucose concentration (oral glucose tolerance test) but not with insulin sensitivity. CONCLUSION: The present results demonstrate that in 52% of the women examined who had prior GD, an impairment of cardiac sympathetic as well as parasympathetic function was present, which related to glycaemic control, but not to insulin sensitivity. This infers that functional autonomic changes could be an early prognostic indicator in pre-type 2 diabetes.