Effect of age on mean heart rate and heart rate variability

Age-related changes in heart rate and in its variability might prove to be a suitable parameter to evaluate the physiological course of advancing age in human beings. We demonstrated higher mean heart rate values and increased heart rate variability in younger adult subjects. A significant direct relationship was demonstrated by linear regression equation between age and the product between mean heart rate and heart rate variability. We conclude that the analysis of these parameters may help assess the aging process of human beings.     

Different methods of heart rate variability analysis reveal different correlations of heart rate variability spectrum with average heart rate

Heart rate variability (HRV) spectrum can be calculated from the R-R or the sequence of instantaneous heart rates (IHRs). Because these signals are reciprocal, their use in the determination of the correlation of HRV with average HR may yield opposite results. AIM: The aim of this study is to reveal how HRV parameters correlate with HR depending on the kind of signal used and whether the normalization procedure or use of corrected signals affect the correlations. METHODS: Electrocardiographic recordings (512 beats) of 55 patients were considered in the analysis. RR and IHRs were calculated. Both signals were divided by their average values yielding the corrected RR and IHR. Heart rate variability spectra were estimated from these 4 kinds of signals. Total power (TP), low frequency (LF) and high frequency (HF) components, LF/HF ratio, and normalized values (ie, nLF, nHF) were calculated. RESULTS: Total power and LF estimated from RR correlated negatively with HR, but those calculated from IHR revealed a trend toward a positive correlation (respective correlation coefficients significantly differed, P < .01). The sign of correlation between HF and HR was the same regardless of the type of signal applied. The application of corrected signals made the results almost identical despite different signal origins (RR or IHR). The correlations of LF/HF, nLF, and nHF with HR were similar in all cases. CONCLUSIONS: The type of signal determines the sign of correlation among TP, LF, and HR. The parameters obtained from corrected signals, normalized quantities, and LF/HF reveal a consistent relationship with HR.     

Losartan improves heart rate variability and heart rate turbulence in heart failure due to ischemic cardiomyopathy

BackgroundHeart rate variability (HRV) and heart rate turbulence are known to be disturbed and associated with excess mortality in heart failure. The aim of this study was to investigate whether losartan, when added on top of β-blocker and angiotensin-converting enzyme inhibitor (ACEI) therapy, could improve these indices in patients with systolic heart failure.Methods and ResultsSeventy-seven patients (mean age 60.4 ± 8.0, 80.5% male) with ischemic cardiomyopathy (mean ejection fraction 34.5 ± 4.4%) and New York Heart Association Class II-III heart failure symptoms, already receiving a β-blocker and an ACEI, were randomly assigned to either open-label losartan (losartan group) or no additional drug (control group) in a 2:1 ratio and the patients were followed for 12 weeks. The HRV and heart rate turbulence indices were calculated from 24-hour Holter recordings both at the beginning and at the end of follow-up. The baseline clinical characteristics, HRV, and heart rate turbulence indices were similar in the 2 groups. At 12 weeks of follow-up, all HRV parameters except pNN50 increased (SDNN: 113.2 ± 34.2 versus 127.8 ± 24.1, P = .001; SDANN: 101.5 ± 31.7 versus 115.2 ± 22.0, P = .001; triangular index: 29.9 ± 11.1 versus 34.2 ± 7.9, P = .008; RMSSD: 29.1 ± 20.2 versus 34.3 ± 23.0, P = .009; NN50: 5015.3 ± 5554.9 versus 6446.7 ± 6101.1, P = .024; NN50: 5.65 ± 6.41 versus 7.24 ± 6.99, P = .089; SDNNi: 45.1 ± 13.3 versus 50.3 ± 14.5, P = .004), turbulence onset decreased (−0. 61 ± 1.70 versus −1.24 ± 1.31, P = .003) and turbulence slope increased (4.107 ± 3.881 versus 5.940 ± 4.281, P = .004) significantly in the losartan group as compared with controls.ConclusionsA 12-week-long losartan therapy significantly improved HRV and heart rate turbulence in patients with Class II-III heart failure and ischemic cardiomyopathy already on β-blockers and ACEI.     

Does resting heart rate measured by the physician reflect the patient’s true resting heart rate? White-coat heart rate

ObjectivesIn cardiology, resting heart rate (HR) and blood pressure (BP) are key elements and are used to adapt treatment. However HR measured in consultation may not reflect true resting HR. We hypothesize that there may be a “white-coat” effect like with BP and that there may be an association between HR variations and BP variations.MethodsThis prospective, monocentric, observational, pilot study (January-April 2016) included 57 consecutive ambulatory patients at Poitiers University Hospital, France (58% male, mean age 64 years). Patients’ resting HR and BP were recorded with the same automated blood pressure sphygmomanometer in consultation by the physician then with self-measurement at home.ResultsIn the overall cohort, we found that HR was significantly higher in consultation (70.5bpm ± 12.6 vs. 68.1bpm ± 10.1, p = 0.034). HR also correlated with diastolic BP (r = 0.45, p = 0.001).Patients were divided into three groups to look for associations with BP: masked HR, (higher HR at home, 38.6%), white-coat HR, (lower HR at home 52.6%) and iso HR, (no change between HR at home and consultation, 8.8%).Although there was no difference between groups in diastolic BP measured in consultation, home diastolic BP was lower in the white-coat HR group (74.3 mmHg ± 9.8 vs. 77.9 mmHg ± 7.5, p = 0.016).ConclusionsOur study brings to light an exciting idea that could have a major therapeutic and maybe prognostic impact in cardiology: resting HR measured by the physician in consultation does not reflect true resting HR. This must be taken into account to adapt treatment.     

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.     

心率与人类心血管疾病的相关性

心率是新陈代谢的重要标志之一，1997年，Levine等曾综述了心率与寿命的关系。一般而言，体型越小的动物心率就越快，寿命越短。研究表明哺乳动物一生的心率是一个恒定的值。Azbel则强调寿命的长短与存活细胞的基础能量有关。人类的平均心率为70次／min，而预期寿命则为80岁，若将人类的基础心率从70次／min降为60次／min可将寿命从80岁延长至93．3岁。     

心率对心力衰竭患者预后的影响

心力衰竭作为很多心血管疾病的最终恶化趋势,对于其相关的临床诊疗近年来有了很大进步.近年的临床研究也显示,快速心率对于心力衰竭患者的病情发生、发展及预后有着重要的影响,当心率控制在适当范围内可明显改善心功能不全的预后.对心率的严密监控能够有效地指导临床诊疗,并且通过指数差异预测心力衰竭的预后,从而有效地判断治疗效果.心率...     

Alterations of an average heart rate change heart rate variability due to mathematical reasons

In the article, we demonstrate how the mathematical rules may bias the results of heart rate variability analysis. We also propose the way how to get rid of this problem.     

心肌炎患儿心率及心率变异特点分析

目的 研究不同年龄心肌炎患儿的心率及心率变异(HRV)改变的特点和相关性.方法 对120例心肌炎患儿进行24h全程动态心电图检查,分析心率及HRV.结果 不同年龄心肌炎患儿心率范围不同,年龄越小心率越快;24h内连续正常R-R间期的标准差(SDNN);5分钟正常R-R间期标准差的平均值(SDNN index);全程相邻...     

糖尿病患者窦性心率震荡与心率变异性关系的初步探讨

目的 探讨糖尿病患者的窦性心率震荡(HRT)与心率变异性(HRV)的关系.方法 糖尿病患者和健康体检者各50例行24h动态心电图(Holter)检查,计算并比较2组患者心率震荡初始(TO)、震荡斜率(TS)与HRV各指标的相关性.结果 糖尿病组的HRT减弱,HRV降低,且震荡初始与SDNN、SDANN及低频成分具有明显相关性(P＜0.05),震荡斜率与SDNN、RMSSD及高频成分具有明显相关性(P＜0.05).结论 糖尿病患者的HRT现象减弱,且与HRV明显相关.HRT对诊断糖尿病自主神经功能损伤更有价值.     

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.     

优化重组技术在冠心病患者心率过快和心率波动中的诊断价值评估

目的：探讨优化重组技术在冠心病患者心率过快和心率波动中的诊断价值。方法选取196例确诊为冠心病的患者,据心率程度及波动范围分为四组,均行64层螺旋CT检查,以优化重组技术评估各组各支冠脉可评价率。结果四组自动重组后各支血管图像质量比较差异均有统计学意义（ P＜0.01）,A组优于其他三组（ P＜0.01）;再次优化重组后各支血管图像质量比较,左回旋支及右冠状动脉差异有统计学意义（ P＜0.01）;自动重组和再次优化重组后,B、C、D组各支可评价率比较差异均有统计学意义（ P＜0.05或P＜0.01）。结论64层螺旋CT优化重组技术可有效提高影像图像可评价率,但仍存在一定的局限和不足,检查前有效控制心率及心率波动可提高可评价率和诊断率。     

Exercise and heart rate recovery

PURPOSE: This study examines whether heart rate recovery (HRR) improves as a result of exercise training during cardiac rehabilitation (CR). METHODS: A retrospective study was performed that included 100 patients who completed phase II CR and had entry and exit exercise stress tests. HRR was compared for the sample. Improvements in HRR were compared between gender and age groups. Correlation between age and HRR was performed. RESULTS: The total sample improved HRR (P = .020). There was no significant difference in the improvement of HRR based on gender, indicating males and females improve at similar rates (P = .833). Similarly, there was no significant difference in the improvement of HRR based on age, indicating older subjects improve similarly to younger subjects (P = .700). There was no relationship between age and HRR; therefore, as age increases there is no decrease in HRR. CONCLUSION: HRR improves in patients who complete CR.     

Age-predicted maximal heart rate revisited

OBJECTIVES: We sought to determine a generalized equation for predicting maximal heart rate (HRmax) in healthy adults. BACKGROUND: The age-predicted HRmax equation (i.e., 220 - age) is commonly used as a basis for prescribing exercise programs, as a criterion for achieving maximal exertion and as a clinical guide during diagnostic exercise testing. Despite its importance and widespread use, the validity of the HRmax equation has never been established in a sample that included a sufficient number of older adults. METHODS: First, a meta-analytic approach was used to collect group mean HRmax values from 351 studies involving 492 groups and 18,712 subjects. Subsequently, the new equation was cross-validated in a well-controlled, laboratory-based study in which HRmax was measured in 514 healthy subjects. RESULTS: In the meta-analysis, HRmax was strongly related to age (r = -0.90), using the equation of 208 - 0.7 x age. The regression equation obtained in the laboratory-based study (209 - 0.7 x age) was virtually identical to that obtained from the meta-analysis. The regression line was not different between men and women, nor was it influenced by wide variations in habitual physical activity levels. CONCLUSIONS: 1) A regression equation to predict HRmax is 208 - 0.7 x age in healthy adults. 2) HRmax is predicted, to a large extent, by age alone and is independent of gender and habitual physical activity status. Our findings suggest that the currently used equation underestimates HRmax in older adults. This would have the effect of underestimating the true level of physical stress imposed during exercise testing and the appropriate intensity of prescribed exercise programs.