卡维地洛对慢性心力衰竭患者室性心律失常和心率变异性影响

目的 探讨卡维地洛对慢性心力衰竭患者室性心律失常和心率变异性的影响。方法 97例慢性心力衰竭患者按随机分配原则，分为治疗组49例和对照组48例，治疗组在常规治疗的基础上加用卡维地洛，初始剂量2．5mg，每Et两次，每2周增加一次剂量，直至20mg一次或最大耐受量为止。用动态心电图分析治疗前后心率、室性心律失常和心率变异性变化，并用超声心动图测定患者治疗前后的心功能。结果 治疗组用卡维地洛治疗6个月后，心率下降、室性心律失常减少、心率变异性参数改善（P〈0．01）；心功能改善亦非常显著（P〈0．01）。结论 卡维地洛治疗慢性心力衰竭患者，可降低室性心律失常的发生，改善心率变异性和心功能。     

室性心律失常与心率变异性的相关性研究

作者用２４ｈ动态心电图研究６６例冠心病患者室性心律失常和心率变异的相关性。结果发现,高危室早（Ｌｏｗｎ分级≥Ⅲ级）的发生与性别、年龄、冠脉病变程度和心肌梗死与否无明显相关,但高危室早者的ＳＤＮＮ（Ｐ＜０．０１）,ＳＤＡＮＮ（Ｐ＜０．０１）和ＬＦ（Ｐ＜０．０５）低于低危室早者（Ｌｏｗｎ分级≤Ⅱ级）。提示ＳＤＮＮ,ＳＤＡＮＮ和ＬＦ减小是高危室早发生的独立危险因子。     

心率变异性评价吸烟的室性心律失常患者自主神经功能

目的 探讨吸烟对室性心律失常患者自主神经功能的影响。方法 对吸烟组22例、不吸烟组30例、进行心率变异性时域分析。结果 与不吸烟组比较，吸烟组SDNN、rMSSD、PNN50显著降低（P＜0．05）。结论 吸烟可致复杂室性心律失常患者副交感神经张力下降，从而增加其心电不稳定性。     

维持性血液透析患者心率变异性与室性心律失常的研究进展

维持性血液透析患者心脏性猝死发生率高,而室性心律失常是其重要原因之一。研究表明：室性心律失常的发生与自主神经系统功能失衡有关,而心率变异性是公认的检测自主神经功能的无创性指标。近期研究多集中于室性心律失常,以及心率变异性在维持性血液透析过程中的变化及其影响因素,而探讨二者相关性的报道较少。因此开展这方面的研究、寻找早期预警室性心律失常发生的指标并适时调整血液透析治疗方案,对改善维持性血液透析患者的预后具有极其重要的临床意义。     

充血性心力衰竭伴室性心动过速患者心率变异与预后的关系

为探讨充血性心力衰竭（ＣＨＦ）患者自主神经张力变化与室性心律失常的关系，我们对ＣＨＦ患者有或与持续性室性心动过速（ＮＳＶＴ），ＣＨＦ患者与正常组各项心率变异（ＨＲＶ）时域指标进行比较。结果：ＣＨＦ组的ＨＲＶ降低，其ＨＲＶ各项指标与患者的ＬＶＥＦ不存在直线相关，死亡者的ＳＤＲＲ、ＳＤＡＮＮ明显低于存活者（Ｐ＜０．００１）；ＣＨＦ有ＮＳＶＴ者与无ＶＴ者ＨＲＶ差异无显著性（Ｐ＞０．０５）。作者认为ＨＲＶ低表示自主神经张力失衡，容易导致猝死。在预测ＣＨＦ患者预后时，ＨＲＶ优于ＬＶＥＦ和ＮＳＶＴ；ＨＲＶ时域指标ＳＤＲＲ、ＳＤＡＮＮ敏感性优于ＰＮＮ５０。     

高血压病患者心率变异的变化及其与室性心律失常的相关性研究

目的 探讨高血压病(EH)者24h心率变异性(HRV)的变化及其与室性心律失常(VA)的关系.方法 采用动态心电图(DCG)记录96例患者(A组)和40例对照者(B组)的24h心电信号,分析其HRV变化及其与VA的发生情况.结果 EH者HRV各项时城指标和额域指标中的LF、VLF、HF均较B组显著降低,并有随着VA程度的加重而降低的趋势;时域指标中的SDNN、SDANN、ASDNN、PNN50与VA程度呈弱负相关(P<0.05);SDANN为EH者VA的保护因素.结论 EH者HRV明显降低,HRV与EH者VA程度呈弱负相关.SDANN为EH者VA的保护因素.早期对自主神经功能紊乱进行干预治疗,可能有利于减少EH者VA的发生.     

充血性心力衰竭心率变异性改变及其与心室重塑的关系

目的:检测充血性心力衰竭患者心率变异性(HRV)改变,探讨其与心室重塑的关系。方法:采用Holter检查系统检测了36例CHF患者HRV指标24h正常R-R间期标准差(SDNN)、24h内每5min平均正常R-R间期的标准差(SDANN)24h内每5min的正常R-R间期标准差的平均值(SDNNI),相邻正常R-R间期差值的均方根(rMSSD),相邻正常R-R间期差值≥50ms心搏数占总R-R间期数的百分数(PNN50)及超声心动图指标左心室舒张末期内径(LVEDD),收缩末期内径(LVESD),左心室后壁舒张末期厚度(LVPWT),心室间隔舒张末期厚度(IVST),左心室射血分数(LVEF),左心室舒张早期及舒张晚期充盈速度比值(E/A)及左心室重量指数(LVMI),并以20例健康体检者为对照。结果:CHF患者HRV各时域指标均下降,与对照组相比有显著差异(P<0.05～<0.01)。多元回归分析显示SDNN,SDNNI与LVEDD,LVPWT呈负相关(r=-0.337～-0.362,P<0.05);rMSSD,PNN50与LVEDD,LVESD呈负相关(r=-0.142～-0.433,P<0.05);rMSSD、PNN50与LVEF呈正相关(r=0.387～0.464,P<0.05～<0.001)。结论:CHF患者HRV下降,并与心室重塑有关。     

原发性高血压患者伴心肌缺血时心率变异性与室性心律失常之间的关系

目的 探讨原发性高血压(EH)患者伴心肌缺血(MI)时心率变异性(HRV)与室性心律失常之间的关系。方法 对90例EH患者，根据动态心电图上有无MI，分为MI组(40例)和无MI组(50例)，并与20例健康体检者(对照组，20例)进行对照，观察HRV的时域指标和室性心律失常。结果 EH患者中HRV时域指标SDNN、SDANN、SDNNindex、rMSSD和PNN50，除夜间SDNNindex外，其余时间各项指标均明显低于对照组(P＜0．05—0．01)，在EH患者中MI组白天和夜间SDNNindex、白天rMSSD与无MI组无差异，其余指标MI组明显低于无MI组(P＜0．05—0．01)；EH患者中24h室早总数明显于对照组(P＜0．05—0．01)，而EH患者中MI组室早总发生率和Lown Ⅲ级以上室早总发生率明显高于MI组和对照组(P＜0．05—0．01)。结论 EH患者中HRV减低，反映了高血压患者心脏自主神经调节功能失衡，尤其在伴有MI的患者中更为明显，这类患者更易出现复杂室性心律失常。     

高血压患者脉压与心率变异性及室性心律失常的关系

目的研究原发性高血压(EH)患者脉压(PP)与心率变异性、室性心律失常的关系。方法选择122例EH患者,其中男性66例,女性56例,平均年龄(55.3±4.2)岁。将所有病例按PP值分成4组,应用24h动态心电图观察室性心律失常和心率变异性各时域指标(SDNN、SDANN、SDANNIndex、RMSSD、PNN50)、频域指标(LFnu、HFnu)。结果PP较大组患者的24h室性早搏发生率及早搏级别显著高于脉压较小组;PP较大组患者上述时域指标及频域指标中高频成分(HFnu)低于脉压较小组,而低频成分(LFnu)高于脉压较小组。结论高血压患者PP增大与严重室性心律失常的发生及自主神经功能受损关系密切。     

美托洛尔对急性心肌梗死心率变异性及 恶性心律失常的影响

目的探讨美托洛尔对急性心肌梗死(AMI)后心率变异性(HRV)及恶性心律失常(MVA)事件的影响。方法将77例分为美托洛尔组(40例)及对照组(37例),美托洛尔组在常规治疗基础上给予美托洛尔6.25～12.5mg,bid,以后根据病情渐加量到25～50mg,bid;对照组仅常规治疗,并分别测定入院后第1天、第7天、0.5年、1年时48h动态心电图,常规进行HRV分析,并同时观察各阶段MVA发生率。结果1周内两组HRV及MVA变化差异无显著性意义,但美托洛尔组MVA事件有减少趋势,0.5年后美托洛尔组HRV显著改善(P＜0.01）,MVA事件发生率显著低于对照组(P＜0.01）。结论美托洛尔能有效改善AMI后患者HRV,降低MVA发生率,但此种改变在长时间治疗后明显。     

Correlation and stability of heart rate and ventricular ectopy variability in patients with congestive heart failure.

The stability of indexes of heart rate variability and their possible association with spontaneous variability of ventricular ectopy was examined in 13 patients with advanced congestive heart failure over 14 consecutive days of 24-hour ambulatory electrocardiographic recording. It was found that time and frequency domain measures of heart rate variability are stable over time and are inversely correlated with spontaneous variability of ventricular ectopy.     

Heart rate variability in heart failure

BACKGROUND: Heart rate variability (HRV) depicts the functional status of the autonomic nervous system and its effects on sinus node. Recently, HRV analysis has been introduced in patients with heart failure (CHF) to identify those who are at risk of cardiac death. AIM: To analyse HRV in patients with CHF with depressed left ventricular ejection fraction (EF) and to relate HRV parameters to EF, NYHA functional class and other clinical parameters. METHODS: The study group consisted of 105 patients with CHF (88 males, 17 females, mean age 54+/-12 years); 77 patients had ischaemic cardiomyopathy, and 28 - dilated cardiomyopathy. All patients were in NYHA class II-IV and had EF <40%. The mean value of echocardiographically assessed EF was 26.9+/-8.3%. The control group consisted of 30 gender- and age-matched healthy subjects. HRV analysis was performed in the time-domain from 24-hour Holter ECG. RESULTS: All HRV variables were significantly lower in patients with CHF than in controls. Patients with NYHA class II had higher values of SDNN and SDANN than those in class III or IV. Patients with sustained or non-sustained ventricular tachycardia (VT) detected during Holter monitoring had lower SDNN and SDANN values than those without VT. Patients with diabetes had significantly lower SDNN and rMSSD values than the patients without diabetes. Similar results were found when patients with or without hypertension were compared. HRV parameters were similar in patients either with ischaemic or dilated cardiomyopathy. Also the values of EF were similar (27.4+/-8.4 vs 25.0+/-8.3%, respectively, NS). In the whole group of patients with CHF the values of SDNN and SDANN significantly correlated with EF (SDNN p<0.001, r=0.42; SDANN p<0.001, r=0.51). This correlation was stronger in the subset of patients with ischaemic cardiomyopathy (SDNN p=0.002. r=0.54; SDANN p=0.002; r=0.53) than in those with dilated cardiomyopathy (SDNN p=0.012, r=0.23; SDANN p=0.008, r=0.42). A significant negative correlation was found between all HRV parameters and NYHA class (SDNN p<0.001, r = -0.33; SDANN p<0.001, r = -0.38; rMSSD p<0.001, r = -0.13). CONCLUSIONS: HRV is depressed in patients with CHF compared with healthy subjects. Among patients with CHF, HRV is further decreased in patients with more advanced NYHA class, lower EF and in those with diabetes, hypertension or VT on Holter monitoring.     

Cytokines and heart rate variability in patients with chronic heart failure

INTRODUCTION: Heart rate variability (HRV) analysis is a non-invasive method of assessment of the autonomic nervous system's effects on heart function. In chronic heart failure (CHF), decreased HRV correlates with the progression of the disease. It is also known that in CHF increased levels of proinflammatory cytokines are present. Because these molecules are believed to influence the nervous system at both the central and peripheral levels, their potential role in HRV reduction in the course of CHF has been proposed. AIM: The study was designed to verify potential relations between cytokines and HRV parameters in CHF patients. The concept of the study was driven by the recognition of controversies in this field and the paucity of published reports. METHODS: Forty-four patients with CHF and stable NYHA class I-IV symptoms and 15 healthy controls were enrolled in the study. Time-domain HRV analysis was performed based on of 24-hour Holter ECG monitoring. Plasma concentrations of soluble TNFalpha receptors sTNF-RI and sTNF-RII and interleukin 6 (IL-6) were measured using commercially available ELISA kits (Quantikine, RD Systems). RESULTS: In patients with CHF, HRV indices included in the analysis were significantly decreased, and the levels of cytokines increased in comparison with the control group. In the whole study population, both in the CHF patients and the control group, significant negative correlations were observed between sTNF-RI level and long-term HRV indices such as SDNN (r=-0.44; p=0.0006), SDANN (r=-0.44; p=0.0005) and short-time index SDNNI (r=-0.37; p=0.004). Similar negative correlations were found between sTNF-RII level and SDNN (r=-0.35; p=0.007), SDANN (r=-0.34; p=0.01), and SDNNI (r=-0.31; p=0.02), as well as between IL-6 level and SDNN (r=-0.41; p=0.001), SDANN (r=-0.44; p=0.0005) and SDNNI (r=-0.34; p=0.009). CONCLUSIONS: Significant negative correlations between TNF-alpha soluble receptors sTNF-RI, sTNF-RII and IL-6 levels and time-domain HRV parameters were observed in the study. Because the results of investigations conducted so far do not elucidate the cause-effect relationship, further studies are needed to clarify the mechanisms of HRV depression in CHF and the role of cytokines in this severe clinical condition.     

Cholinergic stimulation with pyridostigmine prevents the impairment in ventricular function during mental stress in coronary artery disease patients

Mental stress causes physiological autonomic adjustments that may trigger myocardial ischemia and ventricular dysfunction in patients with coronary artery disease. Thus, it was hypothetized that cholinergic stimulation may counteract the ventricular dysfunction provoked by mental stress in coronary disease. Six patients with coronary disease underwent a randomized, double-blind, cross-over, and placebo-controlled protocol in which they received placebo or a single dose of pyridostigmine bromide (45 mg p.o.), a reversible cholinesterase inhibitor, and thus, a cholinomimetic agent 2 h before a standard mental stress task (Stroop color-word test), while hemodynamic and echocardiographic variables were continuously monitored. There were no signs of myocardial ischemia on ECG during mental stress under PYR or placebo. Heart rate and blood pressure increased during mental stress (P<0.01) similarly with placebo and PYR (P>0.05). There were no ventricular wall motion abnormalities during mental stress with either placebo or PYR, but mental stress decreased ejection fraction (pre 63+/-2%, stress 57+/-2%; P=0.004) and impaired the indices of diastolic ventricular function. On the other hand, PYR prevented the fall in ejection fraction (pre 62+/-2%, stress 64+/-2%; P=0.13) and in the indices of diastolic function (P>0.05). In conclusion, cholinergic stimulation with pyridostigmine prevented the impairment in myocardial function during mental stress in patients with coronary artery disease.     

曲美他嗪治疗慢性心力衰竭患者心功能及心律失常疗效观察

目的观察曲美他嗪治疗慢性心力衰竭患者心功能及其心律失常的疗效.方法60例慢性心力衰竭患者,随机分为常规治疗组(对照组)及曲美他嗪组(治疗组),观察曲美他嗪治疗前及治疗后6个月,对心功能及心律失常的影响.结果与治疗前相比,两组左室射血分数(LVEF)明显提高,对照组LVEF从33.1±2.4提高至35.9±2.8,治疗组从32.3±1.7升至39.6±3.9,两组P＜0.00l,对照组FS由12.2±3.5至14.3±3.2,治疗组从12.1±3.2升至17.6±3.9,P＜0.05,治疗组与对照组比较,P＜0.002,与对照组相比,治疗组室性心律失常从(1287.1±115.4)次/24 h减至(756.8±119.7)次/24-h减至(213.1±67.9)次/24 h,P＜0.001,室上性心律失常从(129.2±51.8)次/24.h减至(67.5±32.5)次/24 h,P＜0.001,对照组室性心律失常从(1156.8±134.9)次/24 h至(1058.7±121.5)次/24 h至(1056.3±119.6)次/24 h,P＞0.05.结论曲美他嗪能明显改善慢性心力衰竭患者的心功能,并能减少心律失常的发生.     

Diastolic ventricular interaction in chronic heart failure: relation to heart rate variability and neurohumoral status

It is likely that abnormal baroreflex control mechanisms are at least partially responsible for autonomic dysfunction in chronic heart failure. We recently demonstrated that diastolic ventricular interaction is associated with impaired baroreflex control of vascular resistance in heart failure. We reasoned that by constraining left ventricular filling, such interaction would decrease baroreflex activity and, thereby, increase sympathetic and decrease parasympathetic outflow. We hypothesized, therefore, that diastolic ventricular interaction in chronic heart failure patients would be associated with autonomic dysfunction. We used radionuclide ventriculography to measure changes in left and right ventricular end-diastolic volumes during acute volume unloading achieved by -30 mm Hg lower-body negative pressure in 30 patients with chronic heart failure. An increase in left ventricular volume in association with a reduction in right ventricular volume indicates diastolic ventricular interaction (a larger increase indicating a greater degree of interaction). We also measured heart rate variability (n = 23) and resting venous plasma norepinephrine (n = 24), epinephrine (n = 24), and atrial natriuretic peptide (ANP) (n = 14). During lower-body negative pressure, while right ventricular volume decreased in all patients (P < 0.001), left ventricular end-diastolic volume increased (from 152 +/- 25 to 157 +/- 36 ml/m2, P = 0.01). The change in left ventricular volume was positively correlated with resting plasma norepinephrine (P < 0.01) and ANP (P < 0.005), and negatively correlated with the standard deviation of normal to normal R-R intervals (P < 0.005), the root-mean-square of differences between successive normal to normal R-R intervals (P < 0.05), total power (P < 0.01), low-frequency power (P < 0.01), and high-frequency power (P < 0.05). Diastolic ventricular interaction in patients with chronic heart failure is associated with sympathetic nervous system activation evidenced by increased plasma norepinephrine and reduced heart rate variability.     

Heart rate variability enhances the prognostic value of established parameters in patients with congestive heart failure

This prospective study evaluated whether heart rate variability (HRV) assessed from Holter ECG has prognostic value in addition to established parameters in patients with congestive heart failure (CHF). The study included 222 patients with CHF due to dilated or ischemic cardiomyopathy (left ventricular ejection fraction LVEF 21+/-1%; mean+/-SEM). During a mean follow-up of 15+/-1 months, 38 (17%) patients died and 45 (20%) were hospitalized due to worsening of CHF. The HRV parameter SDNN (standard deviation of all intervals between normal beats) was significantly lower in non-surviving or hospitalized than in event-free patients (118+/-6 vs 142+/-5 ms), as were LVEF (18+/-1 vs 23+/-1%), and peak oxygen uptake during exercise (peak VO(2)) (12.8+/-0.5 vs 15.6+/-0.5 ml/min/kg). While each of these parameters was a risk predictor in univariate analysis, multivariate analysis revealed that HRV provides both independent and additional prognostic information with respect to the risk 'cardiac mortality or deterioration of CHF'. It is concluded that the determination of HRV enhances the prognostic power given by the most widely used parameters LVEF and peak VO(2) in the prediction of mortality or deterioration of CHF and thus enables to improve risk stratification.     

阵发性室性心动过速与心率变异性的研究

本文分析５２例冠心病伴阵发性室性心动过速患者的心率变异性（ＨＲＶ），并与６０例单纯冠心病患者（非室速组）比较。提示冠心病患者的心肌缺血，产生心脏自主神经调节功能失调是诱发阵发性室速的基本病理基础，治疗上应考虑到改善心肌缺血和调节心脏自主神经功能。