老年高血压左室肥大QT离散度改变及与心率变异关系

目的　探讨老年高血压左室肥大QT离散度的改变 ,及与心率变异的关系。　 方法　对 85例老年高血压患者进行动态血压、心脏超声、QT离散度及心率变异的分析 ,并对左室肥大指数与QT离散度、血压与心率变异作相关分析。　 结果　高血压伴左室肥大者QT离散度增加 [QTcd :(5 0 98± 18 79)ms ,QTacd :(5 1 2 1± 13 42 )ms ,QTsD :(15 47± 7 0 8)ms ,QTaSD :(15 48± 4 6 5 )ms] ;左室肌重与非左室肥大相比 ,心率变异无明显差别 (P >0 0 5 ) ;左室肥大指数 (LVMI)与QT离散度 (QTcd、QTacd、QTsD、QTaSD)呈正相关 ,血压 (SBP、DBP)与心率变异 (MSSD、HF、LF、TF)呈负相关。　 结论 　高血压左室肥大者心肌局部复极化不一致 ,高血压患者心率变异下降 ,但与左室结构改变关系不大     

瑞芬太尼对中老年人心率及心率变异性的影响

目的: 观察瑞芬太尼对不同年龄组患者心率及心率变异性的影响,以及阿托品对心率的保护作用。方法: 选择行择期手术的全麻患者,先按年龄分组:中年(M,40～59岁)和老年(O,≥60岁),每一组又随机分为单纯应用瑞芬太尼(R)组和阿托品(A)预处理,共分为4个组（每组20例）:中年单纯瑞芬太尼组（RM）、老年单纯瑞芬太尼组（RO）、中年阿托品预处理组（ARM）和老年阿托品预处理组（ARO）。RM组和RO组静脉恒速泵入瑞芬太尼2 μg/kg,泵速为1 μg/(kg·min)。其余两组患者给药方式相同,只是在静脉应用瑞芬太尼之前30 min肌肉注射阿托品0.5 mg。记录用药前（T0）、用药后1 min(T1)、2 min(T2)、3 min(T3)、5 min(T5)、7 min(T7)等各时间点的心率(HR)、低高频比值(LF/HF)。结果: RM组和RO组患者的HR、LF/HF值在T1~T7各时间点,与T0相比均降低(P<0.05);而ARM组患者给药后的各时间点的HR、LF/HF值与T0相比较,未出现有统计学意义的变化;ARO组的HR和LF/HF值在给药后也出现有统计学意义的下降（P<0.05）,但与RO组相比,下降的幅度较小。结论: 静脉泵入瑞芬太尼时,中老年患者心率及心率变异性明显降低,而阿托品可以拮抗瑞芬太尼减慢心率的作用,因此瑞芬太尼应用于中老年患者时,提倡预先应用阿托品以预防心动过缓。     

Blood pressure and heart rate variability in elderly hypertensive patients

In elderly hypertensive patients (HP) blood pressure (BP) and heart rate (HR) control and variability seem to be affected by a reduced baroreceptor sensitivity, or autonomic dysfunction, and concomitant cardiovascular diseases. Therefore, the aim of present study was to investigate the circadian profiles and variability of BP and HR, by means of a 24-hour ambulatory BP monitoring, in a group of 22 elderly HP compared with those of a group of 24 middle aged patients with essential hypertension. Many differences in BP and HR profile and variability were observed in elderly HP when compared to those of middle aged HP, such as significantly lower diurnal diastolic BP values, lower nocturnal BP fall, lower diurnal HR but with a greater diurnal variability. Conversely, in middle aged HP a significantly greater diurnal systolic BP variability was observed, and a significant correlation was found between hourly diastolic BP and hourly HR values, while in elderly HP this correlation was not detectable. The changes in BP and HR profile and variability observed in elderly HP may play a role as risk factors for cardiovascular complications and indicate a dysfunction of autonomic and nonautonomic factors in BP control.     

Twenty-four-hour heart rate and blood pressure are additive markers of left ventricular mass in hypertensive subjects

BACKGROUND: We investigated whether mean heart rate (HR(24)) and blood pressure (BP) parameters during 24-h ambulatory BP monitoring (ABP) are independent or additive markers of left ventricular (LV) mass in subjects with newly diagnosed, untreated hypertension. METHODS: A total of 250 patients (40% women, 60% men; mean age 59.6 +/- 11 years) with essential hypertension who were attending the outpatient Hypertension Unit were studied. All patients underwent 24-h ABP and HR monitoring as well as echocardiography for assessment of left ventricular (LV) dimensions and function. RESULTS: A decreasing HR24 or increasing ABP parameters (ie, systolic, diastolic, mean BP, and pulse pressure) were associated with increasing LV mass (P < .001) and wall thickness (P < .01). In multivariate analysis, after adjusting for age, gender, body surface area, body mass index, hematocrit, glucose, cholesterol, smoking, and each of the measured ABP parameters separately, decreasing HR24 was independently related to increasing LV mass in addition to ABP and body size parameters (P < .001). The addition of HR24 in different multivariate models for prediction of LV mass significantly increased the adjusted model r2 (range of r2 change: 0.039 to 0.064, P for change <.05). Decreasing HR24 or HR during daytime (6 am to 10 pm) was associated with a higher likelihood of LV hypertrophy in addition to ABP parameters (adjusted odds ratio 0.92 (CI 0.87 to 0.98), per 1 beat/min greater HR24 P = .002 and 0.93 (CI: 0.87 to 0.98), per 1 beat/min greater HR in the daytime P = .017). CONCLUSION: The 24-h HR and BP during ABP are independent and additive markers of increased LV mass in untreated hypertensive individuals.     

老老年高血压患者左心室肥厚与心律失常及心率变异性的关系研究

目的 探讨老老年高血压患者左心室肥厚(LVH)与心律失常及心率变异性(HRV)的关系.方法 纳入2012年10月至2014年7月于中国中医科学院广安门医院心内科住院的303例老老年高血压患者,根据是否合并左心室肥厚分为2组,检测24 h动态心电图心率变异性时域分析及超声心动图,观察两组间相关指标的差异.结果 老老年高血压合并LVH组较不合并LVH组房性、室性心律失常检出率增高,差异具有统计学意义(P＜0.05),两组PNN50、RMSSD、SDNN、SDANN的P值分别为0.573、0.198、0.110、0.812,未见统计学差异.结论 老老年高血压合并LVH患者心律失常的发生率明显增高,而老老年高血压合并LVH和不合并LVH患者心率变异性无明显差异.     

Increased heart rate and reduced heart-rate variability are associated with subclinical inflammation in middle-aged and elderly subjects with no apparent heart disease.

AIM: Elevation of inflammation markers, high heart rate, and reduced heart-rate variability are all strong markers of mortality in a broad spectrum of patients. The association between these markers has not been clarified thoroughly. We investigated the associations between markers of inflammation, heart rate, and heart-rate variability. METHODS AND RESULTS: Six hundred and forty-three healthy men and women between 55 and 75 years of age and with no prior history of cardiovascular disease or stroke were included in the study. The baseline study included a physical examination, fasting laboratory tests, and 24-h ambulatory ECG monitoring. We selected the time-domain components of heart-rate variability for further analyses. C-reactive protein concentration and white blood cell count were selected as markers of inflammation. After identifying parameters related to measures of heart-rate variability, we used regression analyses to evaluate independent associations. Heart-rate variability, as measured by the standard deviation of the time between normal-to-normal complexes or the standard deviation of the average of normal-to-normal intervals for each 5-min period, was negatively associated with smoking, C-reactive protein, white blood cell count, blood sugar and triglyceride concentration, female gender, and diabetes. In contrast, physical activity was strongly associated with higher heart-rate variability. In multivariate regression analyses, increased heart-rate and reduced heart-rate variability were significantly and independently related to white blood cell count or C-reactive protein concentration. CONCLUSION: Increased heart rate and reduced heart-rate variability are associated with subclinical inflammation in healthy middle-aged and elderly subjects. The increased mortality that has been reported in these settings may thus have a common aetiology. An autonomic imbalance in favour of the sympathetic system may interact with inflammatory processes to play a more important role in the process of atherosclerosis than previously thought.     

老老年高血压病患者左心室肥厚与心律失常及心率变异性的关系研究

目的：研究老老年高血压患者左心室肥厚(LVH)与心律失常及心率变异性(HRV)的关系。方法：纳入2012年10月至2014年7月于中国中医科学院广安门医院心内科住院的303例老老年高血压病患者,根据是否合并左心室肥厚分为2组,检测24小时动态心电图心率变异性时域分析及超声心动图,观察2组之间相关指标的差异。结果：老老年高血压合并LVH组较不合并LVH组房性、室性心律失常检出率增高,差异具有统计学意义(P<0.05),二组PNN50、RMSSD、SDNN、SDANN差异无统计学意义。结论：老老年高血压合并LVH心律失常的发生率明显增高,而二者心率变异性无明显差异。     

高血压病患者左室构型异常与心率变异性的关系

目的 :观察高血压病患者左室构型与心率变异性 （HRV）的关系。方法 :使用 Acuson12 8× P1 0 电脑声像仪及2 4小时动态心电图和心率变异记录与分析系统 ,分析了 5 0例高血压病患者的左室构型与 HRV。结果 :向心性重构组、向心性肥厚组、离心性肥厚组的 SDNN,r MSSD和 PNN5 0明显低于正常构型组 ,并有统计学意义 （P<0 .0 1） ;离心性肥厚组的 SDNN比向心性肥厚组明显降低 （P<0 .0 1）。结论 :高血压病患者左室构型异常的程度与 HRV降低的程度相一致 ,随着靶器官受累程度加重 ,HRV降低越明显     

Spectral analysis of heart rate variability in elderly non-dipper hypertensive patients.

To assess by autoregressive model the frequency domain heart rate variability (HRV) during clinostatism and after passive orthostatic load (head-up tilt), 81 hypertensive and normotensive subjects (42 men and 39 women) were subdivided into four groups: 20 adult normotensive subjects (Group 1); 21 elderly normotensive subjects (Group 2); 20 elderly hypertensive subjects with nocturnal blood pressure (BP) falls (Group 3); and 20 elderly hypertensive subjects without nocturnal BP falls (Group 4). They were chosen to assess the influence of aging and arterial hypertension on sympathetic-parasympathetic balance. The age-related decrease observed in nearly all HRV spectral frequency components (normalised units [NUs], high frequency [HF] and low frequency [LF]) was reported in elderly patients in rest conditions. LF indexes resulted in decreases in Group 3 and these data seemed to be emphasised in Group 4. After passive tilt, spectral data were recorded as follows: 25.3+/-1.8 vs 17.8+/-2.2 HF, Group 2 vs Group 1, P<0.001; 72.5+/-0.8 vs 75.6+/-1.8 LF, P< 0.001, Group 2 vs Group 1. Both sympathetic and parasympathetic indexes were lower in Group 3 (44.6+/-1.1 vs 72.5+/-0.8 LF, P< 0.001, Group 3 vs Group 2; 9.9+/-1.8 vs 25.3+/-1.8 HF, P < 0.001, Group 3 vs Group 2) and data became clearer in Group 4 (8.5 2.1 vs 9.9+/-1.8 HF, P< 0.001; 40.4+/-1.5 vs 44.6+/-1.1 LF, Group 4 vs Group 3). The established influence of aging on autonomic nervous system activity appears to be increased by arterial hypertension due to worsening of the sympathetic-parasympathetic response to standardised stimulation. The loss of nocturnal BP declines in arterial hypertension was found to occur in association with a decrease in autonomic nervous system activity.     

Absence of sympathetic overactivity in Afro-Caribbean hypertensive subjects studied by heart rate variability

Black hypertensives present a greater prevalence of left ventricular hypertrophy and an increased mortality compared to white hypertensives. Differences in sympathetic activity might contribute to explain these racial differences in hypertension. Nevertheless, previous laboratory studies did not show any increase of sympathetic activity direct to the heart in black subjects. The aim of the present study was to investigate the cardiac sympatho-vagal balance in black and white hypertensives analysing heart rate variability, during the entire 24 h. We analysed Holter recordings of 52 essential hypertensive patients, who had never received antihypertensive treatment, 26 of whom were black and 26 were white. Consecutive series of 300 beats, with 150 beats overlapped (approximately 600 series/day), were considered for the analysis in time and frequency domain. The mean 24-h value of the power of the low frequency spectral component (0.04-0.15 Hz), expressed in normalised units, ie a marker of sympathetic modulation, was significantly lower in the group of black patients compared to whites (respectively 40.0 +/- 2.1 vs 53.6 +/- 3.6 nu, P < 0.01). Similar results were observed for the LF/HF ratio, an index of the sympatho-vagal balance (respectively 4.11 +/- 0.58 vs 5.98 +/- 0.79; P < 0.05). In a multiple linear regression analysis, considering diastolic blood pressure, left ventricular mass index, race and age as independent variables, only race (P < 0.002) and age (P < 0.01) could independently predict the normalised low frequency power or the LF/HF ratio, as dependent variables. The results of this study suggest some blunting of the cardiac sympathetic neural modulation in black hypertensives compared to white hypertensives, during the entire 24 h.     

高血压病左室肥厚患者心率变异及动态血压分析

观察高血压左室肥厚（ＬＶＨ）患者的心率变异（ＨＲＶ）及血压昼夜节律变化，以期了解三者之间的关系。选择伴有左心室肥厚的高血压病患者２１例，不伴有左心室肥厚的高血压患者２８例，选择年龄与患者可比的健康人２５例作为正常对照组，进行动态心电图及动态血压监测，分析２４ｈＨＲＶ时域指标及血压昼夜节律。结果:高血压伴左室肥厚患者ＨＲＶ各指标均显著低于对照组（Ｐ＜０．０５），也比不伴左室肥厚患者进一步降低。ＰＮＮ５０昼夜节律明显减弱。动态血压结果显示:不伴左室肥厚组与左室肥厚组血压昼夜节律消失者分别占各组总数的１７．９％及４７．６％，组间比较差异显著（Ｐ＜０．０５）。结论:副交感神经调节功能减弱可能与以上变化相关。高血压治疗应注意改善ＨＲＶ，重视恢复血压的昼夜节律     

Effect of n-3 fatty acids on heart rate variability and baroreflex sensitivity in middle-aged subjects

Background

N-3 fatty acids may reduce the risk of sudden death by preventing life-threatening cardiac arrhythmias. Heart rate variability (HRV) and baroreflex sensitivity (BRS) reflect cardiac autonomic regulation; reduced values predict arrhythmic events and mortality. Effects of n-3 fatty acids on these risk indicators of arrhythmia have not been widely studied. We investigated the effect of supplemental intake of n-3 fatty acids on HRV and BRS in apparently healthy subjects aged 50 to 70 years.

Methods

After a run-in period of 4 weeks, 84 subjects were randomized to receive capsules with either 3.5 g of fish oil or placebo oil daily for 12 weeks. Before and after intervention, electrocardiograms and blood pressure were recorded for 10 minutes with standardized respiration of 15 breaths/min. The SD of the duration of all normal RR intervals (SDNN₁₀) and the root mean square successive differences (RMSSD₁₀) were calculated from the 10-minute recordings. We also computed low frequency power (LF) and high frequency power (HF). BRS was computed by integrating the spectral systolic blood pressure to interbeat-interval transfer function in the 0.05- to 0.15-Hz band.

Results

The different measures of HRV and BRS did not significantly improve with the intake of n-3 fatty acids. SDNN₁₀ decreased by 3.05 ms or 7.7% (95% CI, −8.91-2.82 ms), and BRS decreased by 0.92 ms/mm Hg or 0.1% (95% CI, −2.66-0.81 ms/mm Hg) in the fish oil group compared with the placebo group.

Conclusions

N-3 fatty acids have no effect on HRV from short-term recordings and BRS in apparently healthy subjects.     

Left ventricular regional variations in myosin isoform shift in Dahl salt-sensitive hypertensive rats.

To evaluate the effects of chronic pressure overload on different parts of the left ventricle (LV), we examined a myosin isoform shift from V1 to V3 as a biochemical marker of LV hypertrophy in Dahl salt-sensitive (DS) rats. Six-week-old DS rats were fed an 8% (high salt, HS; n = 24) or a 0.3% (low salt, LS; n = 12) NaCl diet. After 2 or 4 weeks, the hearts were dissected and the LVs were separated into four parts (the base and mid-portion of the interventricular septum (IVS), and the base and mid-portion of the LV free wall) for isomyosin analysis. The myosin isoform shift was analyzed by pyrophosphate gel electrophoresis. Both blood pressure and LV/body weight ratio were clearly increased in the HS group. The myosin isoform shift from V1 to V3, which was measured as a decrease in the percentage of V1 isomyosin, was demonstrated only in the base of LV, with significant predominance in the IVS at 2 weeks and in all four parts at 4 weeks in the HS group. In the LS group, a myosin isoform shift was demonstrated only in the basal portion of the LV at 4 weeks. We concluded that, in rats with salt-induced hypertension, the myosin isoform shift from V1 to V3 starts at the base of the LV, and particularly at the base of the IVS, and then spreads across the entire LV. These results suggest that pressure overload from hypertension may be strongest at the base of the IVS, and that LV hypertrophy may originate at the IVS base.     

Postprandial hypotension in elderly subjects: spectral analysis of heart rate variability and electrogastrograms

Background. In order to clarify the mechanism of postprandial hypotension in the elderly, the influence of gastric motility and autonomic nervous activity on hypotensive reactions after meals was investigated, using electrogastrograms (EGGs) and spectral analysis of heart rate variability. Methods. EGGs, heart rate variability, blood pressure, and blood catecholamine levels before and after a meal were measured in 20 healthy young subjects (mean age, 25.6 ± 5.6 years; young group) and in 20 healthy elderly subjects (mean age, 78.3 ± 5.6 years; elderly group). Results. In the analy-sis of heart rate variability, no significant changes were observed in the low-frequency component (LF power), high-frequency component (HF power), or LF/HF ratio after the meal in the young group. In the other hand, the LF/HF ratio was significantly increased after the meal in the elderly group. In the EGG analysis, the peak power amplitudes after the meal were significantly increased compared with those before the meal in both groups. After the meal, the peak power amplitudes in the young group were significantly greater than those in the elderly group. The baseline blood noradrenaline level (before the meal) was higher in the elderly group than in the younger group, but the level of this catecholamine in the elderly group did not increase significantly after the meal. Conclusions. It is suggested that the down-regulation of catecholamine may be one of the causes of postprandial hypotension in the elderly. The response to secreted catecholamine and the compensatory response to decreased blood flow in the systemic circulation were impaired in the elderly group, which finding may explain the high incidence of postprandial hypotension in the elderly subjects. Received: January 9, 2001 / Accepted: August 10, 2001     

Left ventricular filling studied by echo-Doppler in hypertensive and normotensive subjects

Purpose of the study was to evaluate the influence of different clinical and echocardiographic parameters on left ventricular diastolic filling in a group of 66 mild to moderate hypertensive subjects (mean age = 45.9 +/- 13.9 yrs) and in 49 normotensive controls (mean age = 44.2 +/- 15.9 yrs). All subjects underwent an echocardiographic study with pulsed Doppler evaluation of left ventricular filling. In the hypertensives, a noninvasive 24-hour blood pressure monitoring was performed. The ratio of early to atrial peak diastolic filling velocity (VmaxE/VmaxA) and the ratio between the respective velocity flow integral (Earea/Aarea) were significantly lower in the hypertensives compared to the normotensives (p less than 0.001). As within the hypertensives, office systolic blood pressure, average 24-hour mean blood pressure (24MBP), left atrial dimensions, and left ventricular mass index (MAXIND) were related both to age and diastolic filling. To study the relation between these parameters and diastolic filling a partial correlation test was used. The only variable related to diastolic filling, independently of age, was 24MBP (VmaxE/VmaxA vs 24MBP: r = -0.307, p less than 0.05, Earea/Aarea vs 24MBP: r = -0.261, p less than 0.05). Linear multivariate analysis using the method of stepwise regression established that age, 24MBP and heart rate were responsible for 75% of the VmaxE/VmaxA variance in the hypertensive group. To evaluate if the difference between the indexes of diastolic filling in the normotensives and the hypertensives varied according to age, we divided each group into two classes of subjects older and younger than 40 yrs. Under the age of 40 only VmaxE/VmaxA was significantly different in the two groups (p less than 0.05), while in the subjects older than 40 yrs both VmaxE/VmaxA and Earea/Aarea differed to a great level of statistical significance (p less than 0.001). The results of the present study allow the following conclusions: 1) age has the greatest influence on diastolic filling in both hypertensive and normotensive individuals. Diastolic filling is impaired in mild to moderate hypertension, when systolic function is still normal; 2) the worsening of diastolic filling determined by hypertension is more evident in the subjects greater than 40 yrs; 3) the only clinical variable that influences diastolic filling, independently of age, is 24MBP, while office blood pressure, MAXIND and left ventricular ejection fraction do not seem to be related to this clinical entity.     

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。     

QT intervals and heart rate variability in hypertensive patients

Low heart rate variability and increased QT dispersion are risk factors for cardiac mortality in various patient populations. We studied dispersion of QT interval, i.e. an index of inhomogeneity of repolarization, and heart rate variability (HRV) i.e., a measure of cardiac autonomic modulation in 76 essential hypertension cases (45 women, 53.0 +/- 11.1 years, body mass index: 25.1 +/- 1.4 kg/m2) and 70 healthy cases (42 women, 54.0 +/- 10.2 years, body mass index: 25.5 +/- 1.6 kg/m2, p > 0.05). QT-corrected QT intervals and their dispersions were significantly higher in the hypertensive group (p < 0.0001), all showing a direct relation with the level of systolic and diastolic blood pressures, ventricular mass index and high Lown grade ventricular rhythm problems. Time domain measures like standard deviation of RR intervals, standard deviation of the means of all corrected RR intervals calculated at 5 min intervals (p < 0.0001), proportion of adjacent RR intervals differing by > 50 msec (p = 0.005), HRV triangular index (p = 0.007), the square root of the mean squared differences of successive RR intervals (p = 0.011), and the high frequency (HF, 0.16-0.40 Hz, p < 0.0001) part of the frequency domain measure of HRV were all decreased, whereas the low frequency (LF, 0.04-0.15 Hz, p = 0.013) part of the frequency domain measures and LF / HF ratio (p < 0.0001) were increased in hypertensive cases. Time domain and the HF part of frequency domain measures of heart rate variability showed an inverse relation with the increased levels of both systolic and diastolic blood pressures and Lown grading system of ventricular rhythm problems, whereas LF and LF / HF showed direct relations with high levels of systolic and diastolic blood pressures and high Lown grade ventricular rhythm problems. The measures of heart rate variability apart from LF and LF / HF were inversely related with the QT intervals and dispersions, whereas LF / HF was directly related with them. Therefore, we conclude that the levels of both systolic and diastolic blood pressures are related to the generation of ventricular rhythm problems either via increasing left ventricular mass which results in an increase in QT parameter measurements, or by altering heart rate variability measures indicating a disturbance in cardiac autonomic balance in essential hypertension.