冠心病患者窦性心率震荡与心率变异性和室性早搏关系的探讨

目的探讨冠心病患者的窦性心率震荡(HRT)及其与心率变异性(HRV)和室性早搏之间的关系。方法86例冠心病患者行24h动态心电图检查,计算机自动测定HRT的两个参数震荡初始(TO)和震荡斜率(TS)、HRV时域和频域指标及室性早搏数目。结果冠心病患者的HRT减弱,HRV降低,且TO与时域指标SDNN和SDANN及频域指标LF和LF/HF明显相关(p<0.05),TS与时域指标SDNN和RMSSD及频域指标HF和LF/HF及室性早搏数目明显相关(p<0.05)。结论冠心病患者的HRT现象减弱,且HRT与HRV及室性早搏数目明显相关。HRT应当是一种较HRV更好预测高危冠心病患者的无创性检查方法。     

糖尿病患者窦性心率震荡现象的临床研究

目的探讨糖尿病患者窦性心率震荡（HRT）的变化及意义。方法选择伴室性早搏的糖尿病、冠心病和无器质性心脏病患者107例,计算其震荡起始（TO）及震荡斜率（TS）。结果糖尿病组患者与对照组比较,TO值明显升高,TS值下降,差异有显著性（P〈0．05）;与冠心病组比较,TO、TS差异无显著性（P〉0．05）。结论心率震荡可作为糖尿病患者自主神经系统功能的完整性和稳定性及预后的指标之一。     

Effect of electrophysiologic character of ventricular premature beat on heart rate turbulence

Heart rate turbulence (HRT) has been described as a predictor of high-risk patients with cardiac diseases. The purpose of this study is to determine how the degree of prematurity of a ventricular premature beat (VPB%) and retrograde ventriculoatrial (VA) conduction of VPBs affect HRT. We studied 30 patients without organic heart disease. We calculated turbulent slope (TS) and turbulent onset (TO) from VPBs induced by programmed stimulation from the right ventricular apex. TS was inversely and TO was positively correlated to VPB%. Without retrograde VA conduction of VPBs, TS was inversely and TO was positively correlated to VPB%. In VPBs with retrograde VA conduction, there were no significant correlations between TO and TS with VPB%. In conclusion, TS and TO calculated from VPBs with different degrees of prematurity varied widely. Both VPB% and characteristics of retrograde VA conduction may affect HRT.     

Heart Rate Turbulence

Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death.     

Relationship between heart rate turbulence and heart rate, heart rate variability, and number of ventricular premature beats in coronary patients

INTRODUCTION: Heart rate variability (HRV) illustrates regulation of the heart by the autonomic nervous system whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity. The aim of this study was to determine the association between HRT and HRV parameters and the relationship between HRT parameters and heart rate and number of ventricular premature beats (VPBs) used to calculate HRT parameters. METHODS AND RESULTS: In 146 patients (117 males and 29 females; mean age 62 years) with coronary artery disease, a 24-hour ECG Holter monitoring was performed to calculate mean heart rate (RR interval), number of VPBs, time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (TO) and turbulence slope (TS). Univariate and multivariate regression analyses were performed to evaluate the association between tested parameters. Significant correlation between TS and mean RR interval was observed (r = 0.42; p < 0.001), while no association for TO vs. RR interval was found. TS values were significantly higher in patients with less than 10 VPBs/24 hours than in patients with more frequent VPBs. Significant associations between HRT and HRV parameters were found with TS showing stronger correlation with HRV parameters than TO (r value ranging from 0.35 to 0.62 for TS vs. -0.16 to -0.38 for TO). CONCLUSION: HRT parameters correlate strongly with HRV parameters indicating that HRT should be considered as a reflection of both baroreceptors response and overall autonomic tone. Heart rate dependence of turbulence slope indicates the need to adjust this parameter for heart rate.     

Correlation of Heart Rate Turbulence with Sympathovagal Balance in Patients with Acute Myocardial Infarction

To examine the relationship among heart rate turbulence parameters, arterial baroreflex sensitivity, and cardiac sympathetic nerve activity, 15 patients with acute myocardial infarction, presenting with sinus rhythm and ≧3 ventricular premature beats/24hr were studied at least 2 weeks after acute myocardial infarction. Turbulence onset (TO) and turbulence slope (TS) were averaged from 3 respective ventricular premature beats. Early heart-to-mediastinum ratio (H/M), delayed H/M, and washout rate were calculated from iodine-123-metaiodobenzylguanidine (¹²³I MIBG) scintigraphy. Arterial baroreflex sensitivity was calculated by phenyrephrine method. Arterial baroreflex sensitivity correlated significantly with TO (r = ? 0.75, p < .01) and TS (r = 0.53, p < .05). TO had no correlations with early H/M, delayed H/M, and washout rate. There were no significant correlations between TS and early H/M. However, TS had significant correlation with delayed H/M(r = 0.74, p < .01) and washout rate (r = ? 0.71, p < .01). Thus, heart rate turbulence of TO and TS parameters depend on sympathovagal balance.     

Impact of Preceding Ventricular Premature Beats on Heart Rate Turbulence

Background: Heart rate turbulence (HRT) has recently been introduced as a noninvasive tool for studying autonomic dysfunction. It presented short time fluctuation of sinus cycle length following single ventricular premature contraction (VPC). However, HRT parameters may be influenced by different factors. This study aimed to evaluate the possible influence of VPC frequency on HRT. Methods: 24‐h Holter recording was performed in patients with VPCs initially detected by 12‐lead electrocardiography (ECG) in the outpatient department. The numbers of VPCs in 2‐ and 5‐minute durations preceding each VPC tachogram were calculated. The HRT parameters and the numbers of the VPCs preceding VPC tachograms were analyzed. Results: There were 23,122 available VPC tachograms from 107 healthy subjects included in the study. The turbulence onset (TO) value increased and the turbulence slope (TS) value decreased as VPC's frequency increased. The TO values rapidly increased when the number of VPCs was >15 beats in the 2‐minute and >35 beats in the 5‐minute durations. There was also a prominent decrease in TS values when the VPCs reached 14 and 30 beats in the 2‐ and 5‐minute durations, respectively. Conclusion: Physiologic baroreflex may be attenuated under intensive stimulation, which is evidenced by blunted HRT parameters by frequent VPCs. Physiologic response to VPC's frequency may be related to baroreflex fatigue and is demonstrated as a sigmoid curve.     

Heart Rate Turbulence for Prediction of Heart Transplantation and Mortality in Chronic Heart Failure

Background: Previous studies have shown conflicting results about the value of heart rate turbulence (HRT) for risk stratification of patients (pts) with chronic heart failure (CHF). We prospectively evaluated the relation between HRT and progression toward end‐stage heart failure or all‐cause mortality in patients with CHF. Methods: HRT was assessed from 24‐hour Holter recordings in 110 pts with CHF (54 in NYHA class II, 56 in class III–IV; left ventricular ejection fraction (LVEF) 30%± 10%) on optimal pharmacotherapy and quantified as turbulence onset (TO,%), turbulence slope (TS, ms/RR interval), and turbulence timing (beginning of RR sequence for calculation of TS, TT). TO ≥ 0%, TS ≤ 2.5 ms/RR, and TT >10 were considered abnormal. End point was development of end‐stage CHF requiring heart transplantation (OHT) or all‐cause mortality. Results: During a follow‐up of 5.8 ± 1.3 years, 24 pts died and 10 required OHT. TO, TS, TT, and both (TO and TS) were abnormal in 35%, 50%, 30%, and 25% of all patients, respectively. Patients with at least one relatively preserved HRT parameter (TO, TS, or TT) (n = 98) had 5‐year event‐free rate of 83% compared to 33% of those in whom all three parameters were abnormal (n = 12). In multivariate Cox regression analysis, the most powerful predictor of end point events was heart rate variability (SDNN < 70 ms, hazard ratio (HR) 9.41, P < 0.001), followed by LVEF ≤ 35% (HR 6.23), TT ≥ 10 (HR 3.14), and TO ≥ 0 (HR 2.54, P < 0.05). Conclusion : In patients with CHF on optimal pharmacotherapy, HRT can help to predict those at risk for progression toward OHT or death of all causes. Ann Noninvasive Electrocardiol 2010;15(3):230–237     

A phenomenon of heart-rate turbulence,its evaluation,and prognostic value

Identification of high-risk cardiac patients is crucial for stratification strategies and preventionof cardiovascular events, including death. Single ventricular premature beat triggers some oscillations incardiac cycle duration (the shortening followed by the lengthening of the cycle intervals) inhealthy subjects and low-risk patients with ischaemic heart disease and/or heart failure. This phenomenonis called heart-rate turbulence (HRT). It was shown in retrospective and prospective studies thatthe absence of HRT is associated with increased risk of subsequent mortality in cardiac patients. HRT can bequantified by two variables: turbulence onset (TO), describing an early acceleration phase, andturbulence slope (TS), describing a late deceleration phase of heart rate after ventricularpremature beat. Both TO and TS are independent one from another and from other conventional risk predictors.The combination of TO and TS seems to be the strongest Holter-based risk predictor and has some addictivepredictive value to left ventricular ejection fraction, heart rate variability, and the averaged diurnal heartrate and baroreflex sensitivity. In addition, HRT has a predictive value in patients treated withbeta-blockers and amiodarone. Moreover, it is thought that HRT is mediated by baroreflex and therefore can beused as a non-invasive measure of its sensitivity and autonomic nervous system function. Blunted HRT can beobserved in diabetic patients with autonomic dysfunction and in patients with atropine-blocked vagal nerveactivity. Moreover, it seems that a diurnal variation of HRT exists because it is better expressed duringsleep. However, the use of HRT is limited to patients with dominant sinus rhythm and the presence of singleventricular beat. Nevertheless, the assessment of HRT is an inexpensive and simple method and can be performedwith a routine ambulatory 24-hour ECG recording.     

Heart rate turbulence after ventricular and atrial premature beats in subjects without structural heart disease

INTRODUCTION: Studies assessing heart rate (HR) behavior after premature beats have focused on HR responses to ventricular premature beats (VBPs), but there is less information of HR behavior after atrial premature beats (APBs). METHODS AND RESULTS: HR turbulence after VPBs and APBs was first measured in response to ambient APBs and VPBs occurring during 24-hour ambulatory ECG recordings in 29 subjects without structural heart disease, and in response to programmed atrial (AE) and ventricular extrastimuli (VE) in 6 subjects undergoing electrophysiologic (EP) examination. Turbulence onset (TO) was more negative (-2.3 +/- 3.2% vs -0.9 +/- 2.8%, P < 0.01) and turbulence slope (TS) was steeper (11 +/- 11 vs 5.1 +/- 4.1 msec/R-R interval, P < 0.05) after VPBs than APBs. Compared to VPBs, the acceleration of HR after APBs was delayed by one beat, and APBs were associated with a short R-R interval preceding the APB, resulting in a blunted TO. Studies of patients undergoing an EP test confirmed the one-beat delay of HR acceleration and the blunted TO after programmed AE compared to VE (P < 0.05). TO and TS after VPBs were related to baroreflex sensitivity. TO also was related to 24-hour standard deviation of N-N intervals (SDNN). However, the TO or TS following APBs was not related to either SDNN or baroreflex sensitivity. CONCLUSION: HR behavior is different in response to APBs and VBPs among subjects without structural heart disease. Different definitions and calculation formulas should be used in the analysis of HR turbulence after APBs and VPBs.     

比索洛尔对慢性充血性心力衰竭患者心率震荡的影响

目的观察慢性充血性心力衰竭（CHF）者心率震荡（HRT）现象的特点,以及比索洛尔治疗后HRT的变化。方法测定和比较58例CHF者和41例健康体检者（C组）室性早搏后的震荡初始（TO）和震荡斜率（TS）值;并将CHF者随机分为比索洛尔治疗组（A组）和对照组（B组）。A组在B组常规治疗基础上加用比索洛尔口服,所有CHF者分别于治疗4w后复查24h动态心电图（DCG）。结果 C组TO〈0,而CHF患者TO〉0;CHF患者的TS明显低于健康体检者。CHF患者治疗4周后,HRT均有明显改善：TO下降,TS升高,但A组较B组改善明显,P〈0.05。结论 CHF者中HRT现象明显减弱;比索洛尔能改善其HRT,减少恶性室性心律失常的发生,改善患者的心功能。     

Relationship of abnormal heart rate turbulence and elevated CRP to cardiac mortality in low, intermediate, and high-risk older adults

HRT and CRP for Mortality Risk in Elderly. Introduction: We examined whether heart rate turbulence (HRT) and C‐reactive protein (CRP) add to traditional risk factors for cardiac mortality in older adults at low, intermediate, and high risk. Methods and Results: One thousand two hundred and seventy‐two individuals, age ≥65 years, with 24‐hour Holter recordings were studied. HRT, which quantifies heart rate response to ventricular premature contractions, was categorized as: both turbulence onset (TO) and turbulence slope (TS) normal; TO abnormal; TS abnormal; or both abnormal. Independent risks for cardiac mortality associated with HRT or, for comparison, elevated CRP (>3.0 mg/L), were calculated using Cox regression analysis adjusted for traditional cardiovascular disease risk factors and stratified by the presence of no, isolated subclinical (i.e., intermediate risk) or clinical cardiovascular disease. Having TS + TO abnormal compared to both normal was associated with cardiac mortality in the low‐risk group [HR 7.9, 95% confidence interval (CI) 2.8–22.5, (P < 0.001)]. In the high and intermediate risk groups, abnormal TS and TS + TO ([HR 2.2, 95% CI 1.5–4.0, P = 0.016] and [HR 2.7, 95% CI 1.2–5.9, P = 0.012]), respectively, were also significantly associated with cardiac mortality. In contrast, elevated CRP was associated with increased cardiac mortality risk only in low‐risk individuals [HR 2.5, 95% CI 1.3–5.1, P = 0.009]. Among low risk, the c‐statistic was 0.706 for the base model, 0.725 for the base model with CRP, and 0.767 for the base model with HRT. Conclusions: Abnormal HRT independently adds to risk stratification of low, intermediate and high‐risk individuals, but HRT and CRP appear to both add to stratification of those considered low risk . (J Cardiovasc Electrophysiol, Vol. 22, pp. 122‐127, February 2011)     

β1受体阻断剂比索洛尔对不稳定型心绞痛心率震荡的效应

目的: 观察β1受体阻抗剂比索洛尔对不稳定型心绞痛（UPA）患者心率震荡（HRT）的效应。方法: 有室性早搏的UPA患者33例为比索洛尔治疗组,另25例患者作为安慰剂对照组。分别在开始服用比索洛尔前24 h和每天服用比索洛尔5 mg连续30 d后,以及开始服用安慰剂前24 h和每天服用1片安慰剂30 d后,进行动态心电图检查,分别计算HRT的初始值（TO）、斜率（TS）以及发生恶性室性心律失常(MVA)的患者数。结果: 治疗组口服比索洛尔后与治疗前相比,UPA患者恶性室性心律失常的发生率减少15.1%,TO降低,TS增加;而对照组口服安慰剂前后,上述指标均无明显变化。结论: 比索洛尔能减少UPA患者的发生率,改善HRT。     

Correlation of heart rate turbulence with sympathovagal balance in patients with acute myocardial infarction

To examine the relationship among heart rate turbulence parameters, arterial baroreflex sensitivity, and cardiac sympathetic nerve activity, 15 patients with acute myocardial infarction, presenting with sinus rhythm and > or = 3 ventricular premature beats/24 hr were studied at least 2 weeks after acute myocardial infarction. Turbulence onset (TO) and turbulence slope (TS) were averaged from 3 respective ventricular premature beats. Early heart-to-mediastinum ratio (H/M), delayed H/M, and washout rate were calculated from iodine-123-metaiodobenzylguanidine (123I MIBG) scintigraphy. Arterial baroreflex sensitivity was calculated by phenyrephrine method. Arterial baroreflex sensitivity correlated significantly with TO (r = - 0.75, p < .01) and TS (r = 0.53, p < .05). TO had no correlations with early H/M, delayed H/M, and washout rate. There were no significant correlations between TS and early H/M. However, TS had significant correlation with delayed H/M (r = 0.74, p < .01) and washout rate (r = -0.71, p < .01). Thus, heart rate turbulence of TO and TS parameters depend on sympathovagal balance.     

窦性心率震荡检测方法及影响因素的研究

目的 探讨窦性心率震荡（HRT）的测量方法及影响该指标测量的临床因素。方法 随机选择我院门诊接受24h动态心电图（Holter）检查并记录有室性早搏（VPC）的健康体检者50例，分别计算窦性心率震荡的震荡初始（TO）、震荡斜率（偈）及震荡斜率起始时间（TT），分析各参数与年龄、室早前基础心率等因素之间的相关关系．并比较不同基础心率段各参数之间的差别。结果 先计算每个室早的窦性心率震荡参数，然后求平均值所得的偈、TT值较先平均RR值再计算窦性心率震荡所得的偈、TT值高；窦性心率震荡与年龄、室早前基础心率、代偿间期以及室早数目相关，与联律间期不相关；且不同基础心率段TO、TS指标差异具有显著性（p〈0．05）。结论 计算窦性心率震荡之前就取RR间期平均值然后测量可能提供更好的死亡预测率：应用窦性心率震荡时应同时考虑到年龄、室早前基础心率、代偿间期及室早数目对其的影响.     

Relationship of heart rate turbulence, heart rate variability and the number of ventricular premature beats in patients with mitral valve prolapse and non-significant regurgitation

Cardiac arrhythmia is frequently detected in patients with mitral valve prolapse (MVP) and improper autonomic tone is considered the etiology. Heart rate turbulence (HRT) and heart rate variability (HRV) are methods assessed for autonomic dysfunction. To evaluate whether the number of ventricular premature contractions (VPCs) is influenced by HRT or HRV in patients with MVP. Holter monitoring for the number of VPCs and correlation analysis with HRT and HRV was performed. There were 31% and 3% with abnormal turbulence onset (TO) and turbulence slope (TS) values in totally 68 patients. No significant correlation is found between the number of VPCs and HRT, HRV parameters. In analysis the relationship between HRT and HRV parameters, TS has higher correlation with HRV than TO values, particular in time-domain.     

Short-term variability of heart rate turbulence in chronic heart failure

Background

Heart rate turbulence (HRT) is associated with risk in chronic heart failure (CHF). The objective of this study was to assess the short-term variability of HRT and to compare the diagnostic yield of 7-day (7DH) versus 24-hour (1DH) Holter monitoring for calculating HRT in a CHF population.

Methods and Results

Forty-nine consecutive patients with CHF were studied. At inclusion, 7DH was performed to evaluate the variability of HRT parameters. For categorized analyses, turbulence onset (TO) ≥0% and turbulence slope (TS) ≤2.5 ms/RR were defined as abnormal, and patients were classified into subgroups based on the number of abnormal HRT parameters.The cumulative percentage of patients with calculable HRT increased from 69.4% with 1DH to 93.9% with 7DH. The intraclass correlation coefficients across the 7-day monitoring were 0.81 (95% confidence interval [CI] 0.70–0.89) for TO and 0.90 (95% CI 0.84–0.95) for TS. When comparing 2 randomly selected days, TO and TS values were similar (P > .1) and showed a strong correlation (TO: r = 0.79; TS: r = 0.84: P < .001). Bland-Altman plots showed a mean difference of 0.31% (95% CI −0.07 to 0.70) for TO and 0.44 ms/RR (95% CI −1.37 to 0.48) for TS. In contrast, categorized analyses showed that up to 16% of patients changed their HRT subgroup score from day 1 to day 2 of comparison.

Conclusions

In this population, 7DH significantly increased the percentage of patients with calculable HRT parameters. The short-term variability of the quantitative HRT values was good, but when patients were categorized into the established HRT subgroups, the concordance was suboptimal.     

自主神经系统对窦性心律震荡的影响

目的通过心室起搏诱发窦性心律震荡(HRT)模型,观察自主神经对HRT指标的影响。并探讨诱发室性早搏的不同联律间期(CI)及代偿间期(CP)与HRT指标之间的关系。方法15例无器质性心脏病患者,在不使用自主神经阻断药物情况下(基础状态),采用右室心尖部V-S2刺激,联律间期以刺激前平均心动周期的60%感知V波,并逐渐2%递减,直至连续发出10个V-S2刺激,每个S2刺激之间至少间隔有20个VV间期;然后静脉注入艾司洛尔(艾司洛尔状态),待药物作用至高峰后重复上述V-S2刺激;静脉注入阿托品(阿托品状态),待其作用至高峰后再次重复上述刺激;随即再次注入艾司洛尔(联合用药状态)后重复发出10个V-S2刺激。测量并分析四种状态下体表心电图及腔内心电图数据。结果基础状态下RR间期是698.91±75.70ms,震荡初始(TO)为-1.65%±2.29%,震荡斜率(TS)为8.16±4.63ms。而在使用不同的自主神经阻滞药物后,TO显著性增加发生在阿托品状态和联合用药状态,而在艾司洛尔状态无显著变化。TS显著性降低发生在阿托品状态和联合用药状态(P均<0.01),而在艾司洛尔状态无显著变化。基础状态诱发的室性早搏,它的CI与HRT指标并没有相关性(所有的P>0.05),而CP则与HRT指标相关。结论自主神经系统对HRT的影响中,迷走神经起着主导作用;基础状态下CI和HRT指标之间不相关,而CP与之相关。     

Mechanisms involved in heart rate turbulence

Proper understanding of the mechanisms involved in heart rate turbulence (HRT) may offer anexplanation of why it is such a potent postinfarction risk stratifier. This article reviews the physiologicalbackground of ventriculophasic sinus arrhythmia—a phenomenon which shares some underlying physiologicalfeatures with HRT including cardiac autonomic regulation. It is now believed that HRT is principally triggeredby a transient loss of vagal efferent activity in response to the missed baroreflex afferent input due toventricular premature beat-induced haemodynamically inefficient ventricular contraction. Studies are summarizedwhich support more or less directly this hypothesis. The physiology of early acceleration and late decelerationof heart rate after a ventricular premature beat is discussed. Qualitatively different but otherwisequantitatively uniform postectopic dynamics of systolic blood pressure after ventricular premature beats isdemonstrated in subjects with normal and abnormal left ventricular function. It is concluded that the slope oflate deceleration of heart rate after ventricular premature beats can serve as a reasonable surrogate forbaroreflex sensitivity.     

右室流出道室性早搏患者的窦性心率震荡变化

目的观察右室流出道室性早搏患者窦性心率震荡（HRT）的变化并探讨其临床意义。方法52例右室流出道室性早搏患者按室早数目分为两组：A组（室早≥1000／24h）和B组（室早〈1000/24h），比较两组间的HRT参数震荡初始（TO）和震荡斜率（TS）。结果右室流出道室性早搏患者HRT异常的发生率为23．08％，且A组患者中异常HRT的发生率明显高于B组；与B组相比，A组患者的TO值明显增大，幅值降低（p均〈0．05）；HRT与室早数目呈明显正相关（p〈0．01），TS与室早数目呈明显负相关（p〈0．01）。结论频发右室流出道室性早搏（室早≥1000／24h）患者的窦性心率震荡现象减弱，且HRT与室性早搏数目明显相关。HRT是一种较好的检测心脏自主神经功能的新技术。