Reduced parasympathetic tone in newly diagnosed essential hypertension

AimThe aim of the study was to compare heart rate variability (HRV) of newly diagnosed essential hypertensive subjects with controls.MethodsThe study was conducted on 120 hypertensive subjects and 120 controls.ResultsThe time-domain measures, standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD), and percentage of consecutive RR intervals that differ by more than 50 ms (pNN50) which reflect parasympathetic activity were significantly less in hypertensive subjects. In frequency-domain measures, high frequency [HF (ms²)] and [HF (nu)], which reflects parasympathetic activity, was significantly less in hypertensive subjects while LF (nu) and LF/HF (%), which reflect sympathetic activity, were comparable between the groups.ConclusionThese findings suggest that HRV is reduced in subjects with newly diagnosed essential hypertension and the parasympathetic dysregulation is present in the early stage of essential hypertension.     

Microalbuminuria and oxidative stress in essential hypertension

OBJECTIVE: To assess the relationship between microalbuminuria and oxidative stress in mononuclear peripherals cells in essential hypertension. METHODS: A total of 123 hypertensive patients in absence of antihypertensive treatment were included. A 24-h ambulatory blood pressure (BP) monitoring was performed using a Spacelabs 90207 monitor, and microalbuminuria was measured in 24-h urine collections. Oxidized/reduced glutathione ratio and the content of malondialdehide and damaged base 8-oxo-2'-deoxyguanosine in genomic and mitochondrial DNA were measured in peripheral mononuclear cells. RESULTS: In the 29 (24%) microalbuminuric subjects, the amount of reduced glutathione was significantly lower and the ratio oxidized/reduced glutathione was significantly higher than in the normoalbuminuric subjects. In contrast, the simultaneous measurement of the levels of malondialdehide and 8-oxo-2'-deoxyguanosine from both genomic and mitochondrial DNA oxidation did not achieve statistical significance between the two groups. Subjects with the highest oxidized/reduced glutathione ratio tertile showed the highest urinary albumin excretion (UAE) (P = 0.04 for trend). In a stepwise multiple regression analysis, oxidized/reduced glutathione ratio was the main significant determinant of UAE accounting for the 9% of the variance when 24-h mean BP, age, sex, body mass index, glucose and total cholesterol were included in the model. CONCLUSIONS: Oxidative stress seems to be a determinant of UAE independent of BP levels even in hypertensive subjects.     

Relationship between oxidative stress and essential hypertension.

This study investigated the association of blood pressure with blood oxidative stress-related parameters in normotensive and hypertensive subjects. A cross-sectional design was applied to 31 hypertensive patients and 35 healthy normotensive subjects. All subjects were men between the ages of 35 and 60 years. Exclusion criteria were obesity, dyslipidemia, diabetes mellitus, smoking and current use of any medication. All patients underwent 24-h ambulatory blood pressure monitoring and sampling of blood and urine. Antioxidant enzymes activity, reduced/oxidized glutathione ratio (GSH/GSSG), and lipid peroxidation (malondialdehyde) were determined in erythrocytes. Parameters measured in the plasma of test subjects were plasma antioxidant status, lipid peroxidation (8-isoprostane), plasma vitamin C and E, and the blood pressure modulators renin, aldosterone, endothelin-1 and homocysteine. Daytime systolic and diastolic blood pressures of hypertensives were negatively correlated with plasma antioxidant capacity (r=-0.46, p<0.009 and r=-0.48, p<0.007), plasma vitamin C levels (r=-0.53, p<0.003 and r=-0.44, p<0.02), erythrocyte activity of antioxidant enzymes, and erythrocyte GSH/GSSG ratio, with hypertensives showing higher levels of oxidative stress. Blood pressures showed a positive correlation with both plasma and urine 8-isoprostane. Neither plasma vitamin E nor the assessed blood pressure modulator levels showed significant differences between the groups or correlation with blood pressures. These findings demonstrate a strong association between blood pressure and some oxidative stress-related parameters and suggest a possible role of oxidative stress in the pathophysiology of essential hypertension.     

Reproducibility of blood pressure variability, white-coat effect and dipping pattern in untreated, uncomplicated and newly diagnosed essential hypertension

OBJECTIVE: To investigate the reproducibility of blood pressure (BP) variability, white-coat effect (WCE) and nocturnal dipping pattern in untreated patients with uncomplicated essential hypertension using 24-hour ambulatory BP monitoring (ABPM). METHODS: Seventy-five newly diagnosed, untreated essential hypertensive subjects (54 men, 21 women 47.6 +/- 9.3 years) were recruited for the study based on conventional measured BP from a total of 180 patients referred for ABPM. Of these, 65 patients underwent repeated ABPM after 4 weeks observation without treatment. Reproducibility of BP, nocturnal dipping pattern, WCE and BP variability were assessed using different methods. RESULTS: The average 24-hour BP (140.8 +/- 11.9/91.8 +/- 6.4 vs. 140.5 +/- 14.5/90.7 +/- 7.6 mmHg, ns) or PP (49.6 +/- 10.8 vs. 49.8 +/- 9.8 mmHg, ns) did not change, nor did daytime BP or PP. The WCE diminished significantly during the observation period (reduction in SBP WCE delta8.2 +/- 12.5 mmHg, p < 0.0001, in DBP WCE, delta3.3 +/- 9.2 mmHg, p = 0.008 and in PP WCE delta4.8 +/- 11.2 mmHg, p = 0.002). Variability in SBP, DBP and PP decreased consistently and significantly during the observation period. The nocturnal dipping pattern was unchanged in 82% of the patients. In 12% non-dipping pattern was converted to dipping pattern after repeated measurement. CONCLUSION: Average ABPs are highly reproducible in patients with uncomplicated essential hypertension of limited duration. Similarly, nocturnal dipping pattern reproduced satisfactorily. These measures have important clinical applicability. The white-coat effect as well as variability are greatly attenuated during repeated measurements, and these measures may thus be of less utility in clinical practice.     

Telmisartan decreases atrial electromechanical delay in patients with newly diagnosed essential hypertension

BackgroundAtrial electromechanical delay (EMD) parameters predict the development of atrial fibrillation. We investigated the effect of telmisartan treatment on atrial EMD parameters in patients with newly diagnosed essential hypertension.MethodsThirty-six patients with essential hypertension were treated with telmisartan (80 mg/day) for 6 months. Baseline electrocardiographic P-wave measurements and echocardiographic atrial EMD parameters were compared with the 6-month follow-up.ResultsPmax and Pd were significantly decreased (108.4 ± 6.1 vs 93.9 ± 6.2 milliseconds, 33.4 ± 8.6 vs 19.5 ± 7.0 milliseconds, respectively, P = .0001 for each) after 6-month telmisartan therapy. The atrial EMD parameters were decreased from baseline (mitral EMD, 68.9 ± 4.9 vs 53.8 ± 4.9 milliseconds; septum EMD, 51.6 ± 7.1 vs 42.6 ± 7. milliseconds1; tricuspid EMD, 48 ± 6.9 vs 39 ± 6.9 milliseconds; interatrial EMD, 20.9 ± 5.5 vs 14.8 ± 5.7 milliseconds; P = .0001 for each parameter). The reduction of interatrial EMD was correlated with the reduction in systolic BP nighttime and the increase in mitral E wave velocity/mitral A wave velocity ratio.ConclusionTelmisartan decreased the atrial EMD parameters in patients with newly diagnosed essential hypertension.     

Nitric oxide metabolites and oxidative stress in mild essential hypertension

Many papers have showed non univocal data about oxidative stress status and nitric oxide metabolites in essential hypertension. Considering this preamble we examined the total antioxidant status (TAS), the lipid peroxidation (LP), expressed as thiobarbituric acid-reactive substances (TBARS), the stable end products of nitric oxide (NOx) and LP/NOx ratio in 25 subjects with untreated mild essential hypertension. The obtained data show a significant increase in TBARS (p < 0.001) and NOx (p < 0.001) in hypertensives and no variation in TAS and in TBARS/NOx ratio. None of these parameters was statistically related to the metabolic parameters or to the blood pressure values. The high level of lipid peroxidation observed in this group of hypertensives suggests the timely and specific employment of antihypertensive and antioxidant agents while the NOx increase seems to confirm the inflammatory status accompanying this clinical condition.     

Relationship between arterial stiffness and myocardial damage in patients with newly diagnosed essential hypertension

BackgroundArterial stiffness increases in hypertensive individuals. Arterial stiffness is associated with impairment of systolic and diastolic myocardial function in hypertension (HT). However, the relationship between arterial stiffness and serum heart-type fatty acid-binding protein (H-FABP) levels, a sensitive marker of myocardial damage, has not been previously examined in patients with HT. We investigate the relationship between serum H-FABP levels and arterial stiffness in patients with newly diagnosed HT.MethodsWe studied 46 (48.5 +/- 10.6, years) never-treated patients with HT and age-matched control group of 40 (47 +/- 8.6, years) normotensive individuals. H-FABP levels were determined in all subjects. We evaluated arterial stiffness and wave reflections of study population, using applanation tonometry (Sphygmocor). Carotid-femoral pulse wave velocity (PWV) was measured as indices of elastic-type, aortic stiffness. The heart rate-corrected augmentation index (AIx@75) was estimated as a marker of wave reflections.ResultsCarotid-femoral PWV (10.5 +/- 2.2 vs. 8.7 +/- 1.6, m/s, P = 0.0001) and AIx@75 (22.7 +/- 9.5 vs. 15 +/- 11, %, P = 0.001) were significantly higher in patients with HT than control group. H-FABP levels were increased in hypertensive patients compared with control group (21.1 +/- 14.8 vs. 12.9 +/- 8.5, ng/ml, P = 0.002). In multiple linear regression analysis, we found that the body mass index (beta = 0.42, P = 0.0001) and carotid-femoral PWV (beta = 0.23, P = 0.03) were significant determinants of H-FABP levels.ConclusionArterial stiffness is associated with serum H-FABP levels, a sensitive marker of myocardial damage, in patients with newly diagnosed HT.American Journal of Hypertension (2008). doi 10.1038/ajh.2008.235American Journal of Hypertension (2008); 21, 9, 989-993. doi 10.1038/ajh.2008.235.     

Relation between P-wave dispersion and left ventricular geometric patterns in newly diagnosed essential hypertension

Aim

P-wave durations and P-wave dispersion (PD) are considered to reflect the heterogeneous conduction in atria. The aim of this study was to investigate PD and P-wave duration in different left ventricle geometric patterns of hypertensive patients.

Methods

One hundred forty-nine consecutive patients with newly diagnosed essential hypertension and 29 healthy control groups were included in the study. The maximum and minimum P-wave duration (P_max and P_min, respectively) and PD were measured from the 12-lead surface electrocardiogram. Echocardiographic examination was also performed in all subjects. Four different geometric patterns were identified in hypertensive patients according to left ventricular mass index (LVMI) and relative wall thickness.

Results

P-wave dispersion was longer in concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH) groups when compared with the control group (P = .009, P < .001, P < .001, respectively). P-wave dispersion of normal left ventricle (NLV) geometric pattern was not different from that of the control group. Patients with NLV geometric pattern had shorter PD than patients who had CH and EH (NLV vs CH, P < .001; NLV vs EH, P = .025). P-wave dispersion of the NLV group was not different from that of the CR group. Patients with CR had also shorter PD than patients who had CH (P = .002). In bivariate analysis, there was a significant correlation between PD with left ventricle geometry, body surface area, LVMI, and relative wall thickness. In multiple linear regression analysis, PD was independently correlated only with LVMI (β = .425, P < .001).

Conclusions

P-wave dispersion is independently associated with LVMI rather than left ventricle geometry and relative wall thickness in hypertensive patients. Thus, it is increased particularly in patients with CH and EH.     

原发性高血压患者心率变异性分析

为评价心率变异指数(HRVI)对原发性高血压患者预后判断的意义,测定32例原发性高血压患者的HRVI,并与29例正常人对比分析。结果显示:原发性高血压患者事件组比非事件组的HRVI减低明显(P<0.05);原发性高血压患者事件组与非事件组的HRVI均显著低于正常对照组(P<0.001,P<0.01);原发性高血压患者最大心率与最小心率的差值缩小。提示HRVI减低对原发性高血压患者的预后判断可能有重要价值。     

老年高血压患者心率变异与靶器官损害的相关性研究

目的探讨老年高血压患者心率变异（HRV）与靶器官损害的关系。方法选取老年高血压患者210例,其中单纯高血压组4l例,高血压伴左室肥厚（LVH）患者65例、伴肾功损害者53例、伴颈动脉IMT增厚患者51例;选择健康者50名作为对照组,进行心率变异性时域分析。对人选者做以下检查：心电图、超声心动图、24h动态心电图、颈动脉内膜-中层厚度（IMT）、血肌酐。结果老年高血压患者HRV各项指标低于对照组（P〈0．05）;高血压伴LVH组HRV与单纯高血压组比较,差异有统计学意义（P〈0．01）.高血压伴肾功损害及IMT增厚者HRV与单纯高血压组比较,差异有统计学意岁。’P〈0．05）。结论老年高血压靶器官损害患者的HRV减低,即自主神经对心脏的调节能力减弱;可通过自主神经功能受损程度来评估靶器官受损的程度和判断预后。     

100例高血压病人昼夜分段时间心率变异性分析

目的:研究高血压病人昼夜分段时间的心率变异规律。方法:用24小时动态心电图监测分析系统分别测定100例高血压病人及100例正常人24小时心率变异性(SDNN)及每6小时的心率变异指数,并与之对照。结果:正常人HRV下午3时至9时最小,夜间3时至上午9时最大;高血压病人昼夜变化规律与此相同,但无论24小时的还是各分段时间的HRV均小于正常人(P<0.01)。结论:高血压病人昼夜及各段时间的迷走神经功能受损而交感神经张力升高。     

原发性高血压心率变异性测定的意义

目的：探讨原发性高血压患不同时期心率变异性的改变。方法：记录原发性高血压病人46例,对照组23例的24小时动态心电图,进行心率变异性的时域分析。结果：（1）原发性高血压组时域分析的各项参数指标除PNN50外,SDNN、SDANN、SDANNindex,rMSSD显减低（P＜0．01）;（2）随高血压病程进展（1、2、3级）SDNN、SDANN、SDANNindex逐渐降低,各项之间均存在极显的差异。结论：原发性高血压患的HRV显减低,且随病程进展,变化愈显,提示HRV分析对高血压患有分层及预后的价值。     

原发性高血压的心率变异性分析

目的通过观察原发性高血压患心率变异性（ＨＲＶ）以及高血压患血压昼夜节律正常与异常患ＨＲＶ的变化,了解高血压患心率变异性改变及血压昼夜节律异常与自主神经功能紊乱之间的关系。方法对１００例原发性高血压患进行２４小时动态血压监测,用时域分析法对心率变异性各项指标进行了检测,并与１００例血压正常组进行对照。结果原发性高血压组与血压正常对照组相比,代表心率总变异程度的ＳＤＮＮ、ＳＤＡＮＮＩ和ＳＤＮ     

Candesartan reduces oxidative stress and inflammation in patients with essential hypertension.

The present study was designed to test the hypothesis that blockade of angiotensin II type-1 receptors reduces oxidative stress and inflammation in patients with essential hypertension. The study population comprised 132 hypertensive patients, some receiving and others not receiving medical treatment. At enrollment their systolic and/or diastolic blood pressures were > or = 140 and/or > or = 90 mmHg, respectively. The serum concentration of C-reactive protein, and the urine concentrations of 8-epi-prostaglandin F2alpha and 8-hydroxydeoxyguanosine were measured at baseline and after 12 weeks of treatment either with an angiotensin II type-1 receptor blocker, candesartan (8 mg daily) (age 64 +/- 12 years; male/female 28/39; n = 67), or other antihypertensive agents that do not block the renin-angiotensin system (age 65 +/- 10 years, male/female 25/40, n = 65). Candesartan reduced the levels of C-reactive protein (from 0.07 +/- 0.04 [median value +/- median absolute deviation] to 0.06 +/- 0.03 mg/dl, p < 0.0001), 8-epi-prostaglandin F2alpha (from 210 +/- 92 to 148 +/- 59 pg/mg creatinine, p < 0.0001), and 8-hydroxydeoxyguanosine (from 5.7 +/- 1.9 to 4.0 +/- 1.3 ng/mg creatinine, p < 0.0001), while the levels of these markers were not altered after the treatment with other antihypertensive agents. Blood pressure decreased by a similar amount in both groups, and the reductions in the levels of the markers did not correlate with that of blood pressure. These results suggest that candesartan reduces oxidative stress and inflammation in hypertensive patients independently of its effects on blood pressure. This may provide useful information for determining therapeutic strategies to minimize tissue injury by inflammation and oxidative stress in hypertensive patients.     

老年高血压病并发冠心病心率变异性分析

目的 :探讨老年高血压病并发冠心病患者的自主神经活动特点。方法 :　对 5 9例原发性高血压 （EH）、5 4例冠心病 （CHD）和 38例 EH并发 CHD患者与 34例健康老年人的心率变异性 （HRV）进行对比研究。结果 :EH组和CHD组与对照组除 EH组的 R- R间期标准差的平均数 （SDNNIndex）外 ,其余参数差异均有显著性 （P<0 .0 5 ） ;EH并发 CHD组与对照组比较 ,参数差异均有非常显著意义 （P<0 .0 1） ;但不同疾病组间比较 ,差异均无显著性 （P>0 .0 5 ）。结论 :高血压病和冠心病患者的自主神经功能受损 ,当高血压病并发冠心病时这种受损更加明显。其迷走神经张力降低 ,交感神经紧张性相对增高是导致老年患者心率变异性降低的主要原因。     

高血压病合并糖尿病患者的心率变异分析

目的：探讨高血压病合并糖尿病患的自主神经活动特点。方法：对46例健康,59例原发性高血压（EH）,27例糖尿病（DM）和14例EH＋DM患的心率变异性（HRV）进行了对比研究。结果：高血压病和糖尿病患的心率变异性均低于正常人,以高血压病＋糖尿病患降低最明显。结论：高血压病、糖尿病患的自主神经活动受损,高血压病＋糖尿病患更加明显,其迷走神经张力降低,交感神经张力相对增高,发生心源性猝死的危险性增加。     

原发性高血压患者的心率变异性与QT离散度的分析

目的观察原发性高血压患者的心率变异性(HRV)及QT离散度(QTd)的变化,以期了解原发性高血压患者左心室受累情况与HRV及QTd之间关系。方法选择伴有左心室肥厚(LVH)的原发性高血压患者42例及不伴有LVH的原发性高血压患者54例,与30例健康人作为对照组进行动态心电图监测,分析24h HRV时域指标及室性心律失常,同时进行QTd分析。结果原发性高血压伴LVH组HRV各指标均显著低于对照组(P<0.05),也低于不伴LVH组(P<0.05)。不伴LVH组中:相邻R-R间期差值>50ms的百分比(PNN50)及24h内连续5min节段正常R-R间期标准差的平均数(SDNNindex)明显低于对照组(P<0.05),原发性高血压伴LVH组复杂室性心律失常(CVA)发生率明显高于原发性高血压不伴LVH组与正常对照组(P<0.01),后两者也有显著性差异(P<0.01)。QTd分析:显示原发性高血压伴LVH组QTd及校正的QTd(QTcd值)明显高于原发性高血压不伴LVH组与正常对照组(P<0.01),后两者无显著性差异(P>0.05)。结论原发性高血压患者的HRV降低程度、QTd增大及CVA发生率与原发性高血压患者左心室受累程度相一致,反映原发性高血压患者心室水平的自主神经调节及心室肌本身的病变状态,对预测室性心律失常及猝死的发生可能有重要的意义。     

原发性高血压患者动态血压昼夜节律变化与心率变异的关系

目的　观察原发性高血压 (EH )患者的血压昼夜节律的变化与心率变异的关系。方法　对 10 3例原发性高血压患者进行 2 4h动态血压检测 ,并用时域分析法对心率变异性 (HRV)各项指标进行检测 ,并与 6 0例正常对照 (NC)组比较。结果　心率总变异程度的SDNN(2 4h正常RR间期标准差 ) ,SDANNI(2 4 0 8h平均RR间期标准差 )明显下降(P <0 0 5 )。按照夜间血压下降百分率将原发性高血压病人分为节律消失组、节律正常组 ,并分别与正常对照组比较 ,发现节律消失组HRV各项指标下降更为显著 ,SDNN、SDAN NI、SDNNI(2 4 0 8h正常RR间期标准差均值 )不但显著低于正常对照组 (P <0 0 5 ) ,也显著低于节律正常组 (P <0 0 5 )。结论　原发性高血压患者中节律消失者的心脏自主神经系统功能损害更为严重 ,HRV对评价高血压病对靶器的损害及预后有重要的临床意义。     

左心室肥厚对原发性高血压患者心率变异性的影响

目的 :分析原发性高血压 (EH)伴左心室肥厚者的心率变异性 (HRV)变化及与左心室肥厚程度的关系。方法 :对 84例 EH患者和 31例正常人行 2 4h动态心电图和心脏超声检查 ,并采空腹血查血 K 、甘油三酯、胆固醇和葡萄糖浓度。结果 :EH无左室肥厚组仅相邻正常 R- R间期差值 >5 0 ms的百分比显著低于对照组 (P <0 .0 1) ,而 EH左室肥厚组的各项 HRV指标均显著低于对照组 ,EH左室肥厚组的 2 4h正常 R- R间期的标准差(SDNN)、5 min平均正常 R- R间期的标准差 (SDANN index)和 5 m in正常 R- R间期标准差的均值 (SDNNindex)又显著低于 EH无左室肥厚组 (P <0 .0 1,<0 .0 1,<0 .0 5 )。 EH患者的 SDNN、SDANN index和 SDNNindex与左室心肌重量指数呈负相关。结论 :EH左室肥厚患者的 HRV降低 ,HRV与左室肥厚的程度呈负相关