放射性核素电子计算机断层摄影测量左室心肌质量与儿童青少…

高血压合并左心室肥厚早已被人熟知。近年来研究发现左室心肌质量的增加伴随着血压明显增高达９０百分位或以上在儿童时期即已出现。一般认为左室心肌质量的增加是高血压或血压偏高的驻在最近几年才有少数作者发现左室心肌质量的增加出现在儿童发生血压增高之前。血压正常儿童或青少年之父母有血压者，其左室心肌质量均高于无高血压家族史者。本研究者在观察血压增坑与高血压家庭史左室心质量之间遥关系时，结果发现在高血压高危儿童     

父母高血压史对子女高血压患病率及血压水平的影响

目的探讨高血压家族史对人群血压的影响.方法利用1991年全国血压抽样调查的940323人的资料,分析父母高血压史与血压水平和高血压患病率的关系,并分析不同民族人群的遗传背景与血压水平的关系.利用多因素Logistic回归调整年龄、体重指数、吸烟饮酒状况及文化程度后,探讨高血压家族史与高血压患病之间的关系.结果高血压家族史阳性率均为19.3% .有高血压家族史者比无家族史者的血压水平和高血压患病率明显升高(P<0.01),而父母双亲均有高血压者的血压水平和高血压患病率又比父母一方有高血压者明显升高(P<0.01),父母双亲均有高血压史者的高血压患病率为无家族史者的2倍.父亲有高血压者与母亲有高血压者的血压均值及高血压患病率没有显著差异.多因素Logistic回归显示,有高血压家族史者患高血压病的危险是无高血压家族史者的1.79倍.结论遗传因素在中国人群的高血压发病中起重要作用.     

父母高血压史对子女高血压患病率及血压水平的影响

目的：探讨高血压家族史对人群血压的影响。方法：利用1991年全国血压抽样调查的940323人的资料，分析父母高血压史与血压水平和高血压患病率的关系。并分析不同民族人群的遗传背景与血压水平的关系，利用多因素Logistic回归调整年龄，体重指数，吸烟饮酒状况及文化程度，探讨高血压家族史与高血压患病之间的关系。结果：高血压家族史阳性率均为19．3％，有高血压家族史者比家族史者的血压水平和高血压患病率明显升高（P＜0．01），而父母双亲均有高血压者的血压水平和高血压患病率又比父母一方有高血压者明显升高（P＜0．01），父母双亲均有高血压史者的高血压病率为无家族史者的2倍。父亲有高血压与母亲高血压均值及高血压患病率没有显著差异。多因素Logistic回归显示，有高血压家族史者患高血压病的危险是无高血压家族史者的1．79倍。结论：遗传因素在中国人群的高血压发病中起重要作用。     

冠心病家族史儿童血压水平的研究

目的：了解有冠心病（CHD）家族史儿童的血压水平。方法：对83例有冠心病家族史的儿童测量血压，以83例无CHD家族史的健康儿童作为对照。结果：与健康对照组比较，有CHD家族史的儿童收缩压和舒张压明显增高，高血压检出率明显增高（P＜0．01）。男童与女童血压水平无明显差异（P＞0．05）。有早发CHD家族史（父母于45岁以前患CHD）的儿童与非早发CHD家族史儿童比较，收缩压和舒张压更高，高血压检出率更高（P＜0．01）。结论：有CHD家族史儿童血压水平升高，以有早发CHD家族史儿童为更明显。提示成年后发生CHD的危险性显增高。     

血管紧张素Ⅱ受体拮抗剂逆转高血压左室肥厚的研究进展

左室肥厚 (L VH)代表了从高血压到心衰或死亡过程中的关键环节 ,同时也有充分证据表明 ,L VH是中风、心肌梗死、猝死、心绞痛 ,心衰和肾衰竭的主要危险因素 ,因此 ,逆转 L VHe成为临床研究课题。血管紧张素 (Ang )生成增多是导致高血压性心肌肥厚重要原因 ,Ang 受体拮抗剂应用于高血压治疗是近年来研究重点。1　高血压是左室肥厚的主要因素1.1　高血压是左室后负荷增加血压增高、左室后负荷增加可引起心肌细胞代偿性肥大 ,使 L VH。有文献报道 [1 ] ,血压持续增高 ,尤其是收缩压增高 ,血压昼夜节律消失 ,夜间收缩压、舒张压均增高者…     

遗传因素对高血压患者血压正常子女左心结构及舒张功能的影响

目的:利用超声心动图技术探讨遗传因素对有高血压家族史的血压正常者左室结构及舒张功能的影响。方法:血压正常者100例,其中无高血压家族史者50例(对照组),有高血压家族史者50例(试验组)。分别行M型、二维超声及多普勒组织成像(DTI)检测左心形态及舒张功能,比较两组间的差异。结果:试验组舒张末期室间隔厚度(IVST)及舒张末期左室后壁厚度(LVPWT)、左室质量指数(LVMI)均高于对照组。二尖瓣环舒张早期运动速度e及e与二尖瓣环舒张晚期运动速度a比值(e/a)较对照组减低,差异有显著性(P<0.05)；两组之间主动脉根部内径(AOD)、左心室舒张末期内径(LVIDed)、左房内径(LA)及二尖瓣口舒张早期血流速度峰值E、左房收缩期血流速度峰值A、E／A无显著差异。结论:易患高血压的高危人群其心脏形态及功能的变化可先于血压升高而发生,遗传因素对其发生有一定的影响。     

遗传因素对高血压患者血压正常子女左心结构及舒张功能的影响

目的:利用超声心动图技术探讨遗传因素对有高血压家族史的血压正常者左室结构及舒张功能的影响.方法:血压正常者100例,其中无高血压家族史者50例(对照组),有高血压家族史者50例(试验组).分别行M型、二维超声及多普勒组织成像(DTI)检测左心形态及舒张功能,比较两组间的差异.结果:试验组舒张末期室间隔厚度(IVST)及舒张末期左室后壁厚度(LVPWT)、左室质量指数(LVMI)均高于对照组,二尖瓣环舒张早期运动速度e及e与二尖瓣环舒张晚期运动速度a比值(e /a)较对照组减低,差异有显著性(P《0.05);两组之间主动脉根部内径(AOD)、左心室舒张末期内径(LVIDed)、左房内径(LA)及二尖瓣口舒张早期血流速度峰值E、左房收缩期血流速度峰值A、E/A无显著差异.结论:易患高血压的高危人群其心脏形态及功能的变化可先于血压升高而发生,遗传因素对其发生有一定的影响.     

高血压家族史儿童血压水平的研究

目的：了解有高血压家族史儿童的血压水平。方法：对167例有高血压家族史的儿童测量血压,以175例无高血压家族史的健康儿童作为对照。结果：与对照组比较,有家族史的儿童收缩压和舒张压明显增高,高血压检出率明显增高（2．57％：15．13％,P〈0．01）。有早发高血压家族史的儿童与非早发家族史儿童比较,收缩压和舒张压更高,高血压检出率更高（21．54％：12．94％,P〈0．01）。结论：有高血压家族史儿童血压水平较无高血压家族史儿童高,以有早发高血压家族史儿童更明显,提示成年后发生高血压的危险性显著升高。     

高血压患者血压昼夜节律与左室肥厚及舒张功能的关系

目的观察高血压患者血压昼夜节律与左室肥厚及舒张功能的关系。方法对40名正常血压对照者和60例高血压病患者的血压昼夜节律与超声心动图左室心肌重量指数及舒张功能进行观察。结果发现血压昼夜节律消失的高血压患者左室肥厚检出率(36.6%)显著高于血压昼夜节律正常者(13.6%),血压昼夜节律减退者及倒置者左室重量指数(LVMI)与对照组及高血压昼夜节律存在者差异有统计学意义。左室舒张功能,高血压组中血压昼夜节律消失、减退者与血压昼夜节律正常者比较差异有统计学意义,而高血压组中血压昼夜节律存在者与对照组比较差异无统计学意义。结论血压昼夜节律对左室肥厚(LVH)发生、发展及舒张功能有重要影响,高血压治疗不仅应控制血压,而且应重视恢复正常的血压昼夜节律。     

健康入、糖尿病及高血压患者24小时动态血压比较

155例研究对象，分为正常组，糖尿病组高血压组（轻中度）。采用TM-2421动态血压监测仪监测记录24小时ABP。结果：（1）三组ABP均呈勺型变化，糖尿病和高血压组SBP水平显著高于正常组（P〈0．01．P〈0．05）。高血压组DBP水平显著高于正常组和糖尿病组（P〈0．01，或P〈0．05）。余弦法证实三组ABP变化的显著昼夜节律性，糖尿病和高血压组的夜间血压（SBP、DBP）下降率明显低于正常组（P〈0．01，或P〈0．05）。（2）ABP参数：糖尿病和高血压组ABP均值和负荷明显高于正常组（P〈0．01，或P〈0．05）；ABP变异性三组之间无显著性差异；高血压组ABP曲线下面积显著性高于正常组（P〈0．01），与糖尿病组无显著性差别。结论：高血压和临床正常血压的糖尿病患者均出现ABP部分参数与正常对照组的显著性差异。提示：糖尿病患者在临床明确诊断高血压前已发生血压调节的明显改变。     

Determinants of cardiac involvement in children and adolescents with essential hypertension

Left ventricular hypertrophy is often found in association with systemic hypertension and may be an independent risk factor for cardiovascular disease morbidity and mortality. Few studies have investigated the determinants of left ventricular mass (LVM) in young patients with essential hypertension. Therefore, we studied 104 children and adolescents with blood pressure persistently greater than the 90th percentile for age and sex and with no known cause of blood pressure elevation. LVM was determined by echocardiography and was indexed by height to account for body size. The mean LVM index was 90.2 +/- 26.0 g/m. Using the gender-specific 95th percentile from normal children, 40 subjects (38.5%) had left ventricular hypertrophy. Using multiple regression analysis, the significant independent direct correlates of LVM index were male sex, body mass index, dietary sodium intake, age at diagnosis, and systolic blood pressure at maximum exercise. The significant independent inverse correlate of LVM index was resting heart rate (p less than 0.05). These variables accounted for a substantial portion of the LVM index variance in this population (multiple R2 = 0.56, p less than 0.001). The results indicate that left ventricular hypertrophy is prevalent in children and adolescents with essential hypertension. The direct association of LVM index with body mass index and dietary sodium intake suggests weight reduction and dietary salt restriction might be useful to prevent or treat the development of left ventricular hypertrophy in pediatric patients with essential hypertension.     

Enhanced forearm blood flow during mental stress in children of hypertensive parents

This study compared changes in forearm blood flow, forearm vascular resistance, blood pressure, and heart rate elicited by mental stress (mental arithmetic) in 12 adolescents with a hypertensive parent and 13 age-matched adolescents with normotensive parents. The two groups did not differ in resting forearm blood flow, forearm vascular resistance, heart rate, or blood pressure. During mental stress, children with a family history of hypertension had a significantly greater increase in forearm blood flow than did children of normotensive parents (+37.5 +/- 8.0 vs +12.8 +/- 7.5%; p less than 0.05) and a trend toward reduced forearm vascular resistance (p = 0.08). Mental stress significantly increased systolic blood pressure (p less than 0.0001), diastolic blood pressure (p less than 0.001), and heart rate (p less than 0.03) in both groups. The blood pressure and heart rate responses to stress were not significantly different between groups. There was no evidence of a prolonged response or a different pattern of recovery in children with a family history of hypertension. This study indicates that regional blood flow responses underlying similar blood pressure increases during mental stress may be different in adolescents with and without a family history of hypertension.     

Body weight is more important than family history of hypertension for left ventricular function

Left ventricular function was studied in young men with a positive family history of hypertension for two generations (n = 15). The findings were compared with three control groups: one age-, sex-, and weight-matched group with a negative family history of hypertension (n = 14); one normotensive control group unselected as regards family history of hypertension (n = 27); and one group also unselected regarding family history of hypertension but selected with blood pressure criteria to have mild blood pressure elevation (n = 59). The group with a positive family history of hypertension, in comparison with the normotensive control group, was heavier, had higher blood pressure, increased left ventricular wall thickness, increased left ventricular mass, and signs of changes in diastolic and systolic left ventricular function. There were no differences in these variables between the group with a positive family history and the other two control groups. Data clearly indicated that subjects with a positive family history of hypertension, as well as subjects with mild blood pressure elevation, were heavier than the normotensive control group. It is not possible to judge, with available data, if the changes in left ventricular morphology and function in the two groups with a different family history of hypertension and in the group with mild blood pressure elevation occurred as a physiological response to the increase in afterload or if the neurohormonal and metabolic disturbances leading to the condition of slight overweight also affected left ventricular function.     

Left ventricular structure and function in normotensive adolescents with a genetic predisposition to hypertension

It has been suggested that the heart plays an active role in the pathogenesis of arterial hypertension. If this is true, there must be early cardiac involvement in young normotensive subjects who develop hypertension later in life and differences in cardiac morphology or function may exist between young normotensive subjects with different risks of developing hypertension. M-mode echocardiography was performed in 51 normotensive male adolescents with at least one hypertensive parent (SHT). These subjects were compared with 55 normotensive sons of normotensive parents (SNT) and with 25 adolescents with borderline hypertension (BH). Control groups were matched for sex and age. The following morphologic parameters were significantly greater in the SHT group than in the SNT group: interventricular septum (0.54 +/- 0.08 vs 0.49 +/- 0.09 cm/m2; p less than 0.01) and posterior wall (0.54 +/- 0.11 vs 0.50 +/- 0.08 cm/m2; p less than 0.05) thickness, left ventricular mass (125.0 +/- 29.1 vs 109.2 +/- 25.4 gm/m2; p less than 0.005), and cross-sectional area (9.9 +/- 1.8 vs 8.9 +/- 1.6 cm2/m2; p less than 0.005). No significant differences between SHT and BH subjects were observed. Excursion of left ventricular posterior wall was significantly higher in the BH group. No differences were observed between SHT and SNT subjects. These data show that the same kinds of changes in cardiac morphology are present in normotensive subjects with a family history of hypertension and in subjects with borderline hypertension, suggesting that cardiac involvement may precede elevation of blood pressure.     

Index of left ventricular hypertrophy in adolescents genetically predisposed to the development of arterial hypertension

Experimental studies on strains of normotensive rats genetically prone to hypertension and investigations on humans with borderline hypertension have shown an early involvement of the heart, mainly consisting in a trend to ventricular hypertrophy. To assess whether such alterations may preceed or follow the elevation of blood pressure, subjects who will develop hypertension, but whose blood pressure is currently normal must be studied. For this reason, we studied by means of M-mode echocardiography 51 normotensive males aged 14-19 years with family history for hypertension (at least one hypertensive parent; SHT). Fifty-five normotensive subjects with both normotensive parents (SNT), matched for sex and age, were the controls. Average values of the following parameters were significantly higher in SHT than in SNT subjects: interventricular septum (5.4 +/- 0.8 versus 4.9 +/- 0.9 mm/m2; p less than 0.01) and posterior wall (5.4 +/- 1.1 versus 5.0 +/- 0.8 mm/m2; p less than 0.05) thickness, left ventricular mass (125.0 +/- 29.1 versus 109.2 +/- 25.4 g/m2; p less than 0.005) and cross sectional area (10.0 +/- 1.8 versus 8.9 +/- 1.6 cm2/m2; p less than 0.005). No significant difference between the two groups was observed in the indexes of left ventricular function. The existence of alterations of cardiac morphology in normotensive adolescents with genetic risk of hypertension shows that the cardiac involvement may preceed the development of high blood pressure.     

Changes in 24 Hour Blood Pressure and in Cardiac and Vascular Structure in Normotensive Subjects with Parental Hypertension

Subjects with family history of hypertension represent a suitable model to investigate the mechanisms responsible for early cardiovascular structural and functional changes occurring in essential hypertension. In our study we have addressed the factors involved in determining the mild elevation in office blood pressure frequently observed in normotensive subjects with hypertensive parents. In 15 normotensive subjects with both parents hypertensive (FH++) and in 15 normotensive subjects with one parent hypertensive (FH+?) we found no evidence of a hyperreactivity to stress as compared to the responses of 15 normotensive subjects with no parental hypertension (FH–). On the contrary FH++ subjects were characterized by a significant although mild increase in their blood pressure values recorded either at rest and in ambulatory conditions over the 24 hours, including night sleep. FH++ and FH+? subjects also showed a greater left ventricular mass thickness and a greater minimal forearm vascular resistence than FH subjects. Thus, the elevation in blood pressure found in the pre-hypertensive stage in subjects with positive family history for hypertension does not reflect a hyperreactivity to the stress associated with physician's visit but indicates an early and persistent blood pressure elevation. This blood pressure elevation is accompanied by early cardiovascular structural changes which may indicate that these subjects are exposed to a higher risk even before developing overt hypertension.     

Prevalence, persistence, and clinical significance of masked hypertension in youth

Masked hypertension, an elevated daytime ambulatory blood pressure in the presence of a normal office blood pressure, confers an increased cardiovascular risk to adults. We investigated the prevalence, persistence, and clinical significance of masked hypertension in children and adolescents. We enrolled 592 youths (6 to 18 years old). Youths with masked hypertension (n=34) and a random sample of the normotensive participants (n=200) were followed-up. In a nested case-control study, we compared echocardiographic left ventricular mass among cases with persistent masked hypertension and normotensive controls. At baseline, mean age was 10.2 years; 535 youths were normotensive on office and daytime ambulatory blood pressure measurement (90.4%), and 45 had masked hypertension (7.6%). Compared with normotensive controls, participants with masked hypertension had a higher ambulatory pulse rate, were more obese, and were 2.5-times more likely to have a parental history of hypertension. Among 34 patients with masked hypertension (median follow-up 37 months), 18 became normotensive, 13 had persistent masked hypertension, and 3 had sustained hypertension. Patients with persistent masked hypertension (n=17) or who progressed from masked to sustained hypertension (n=3) had a higher left ventricular mass index (34.9 versus 29.6 g/m2.7; P=0.023) and a higher percentage with left ventricular mass index above the 95th percentile (30% versus 0%; P=0.014) than normotensive controls. In children and adolescents, masked hypertension is a precursor of sustained hypertension and left ventricular hypertrophy. This condition warrants follow-up and, once it becomes persistent, is an indication for blood pressure-lowering treatment.     

Sex, cardiac hypertrophy and diurnal blood pressure variations in essential hypertension.

OBJECTIVE: To test the hypothesis of a difference between men and women in the left ventricular hypertrophic response to diurnal variations of ambulatory blood pressure in essential hypertension. DESIGN: Non-invasive ambulatory blood pressure monitoring and echocardiography in untreated hypertensive patients and healthy normotensive subjects. SETTING: Community-based ambulatory population in tertiary care centers. PATIENTS: Two hundred and sixty hypertensive patients and sixty-three healthy normotensive subjects. MAIN OUTCOME MEASURE: Patients with average daytime systolic blood pressure (SBP) and diastolic blood pressure (DBP) falling by less than 10% during the night were defined as non-dippers, the others as dippers. RESULTS: In the hypertensive group, dippers and non-dippers did not differ, in either gender, in several covariates possibly affecting left ventricular structure, including daytime ambulatory blood pressure, prevalence of white coat hypertension, age, body mass index, family history and known duration of hypertension, funduscopic changes, diabetes, alcohol consumption and renal function. Left ventricular mass (LVM) did not differ between dippers and non-dippers in hypertensive men whilst in hypertensive women it was significantly lower in dippers than in non-dippers. This sex difference held for all quartiles of the distribution of mean daytime blood pressure. In hypertensive women there was an inverse correlation between LVM and the per cent reduction of SBP and DBP from day to night, but this relationship was absent in hypertensive men. Other indices of left ventricular structure differed between dippers and non-dippers in both genders, as did LVM. CONCLUSIONS: For any level of daytime ambulatory blood pressure, a reduction of SBP and DBP by less than 10% from day to night identifies a subset of hypertensive patients at increased risk of left ventricular hypertrophy only in the female gender. These data suggest that, compared with men, hypertensive women require a longer duration of exposure to high blood pressure levels during the 24 h to develop left ventricular hypertrophy.     

Angiotensin converting enzyme gene insertion/deletion polymorphism,angiotensinogen gene polymorphisms,family history of hypertension,and childhood blood pressure

Earlier epidemiologic studies have yielded inconsistent results on the extent and timing of the blood pressure (BP) increase in offspring of hypertensive parents. We hypothesized that a familial influence on the BP of the offspring exists from birth on, but becomes significant only later in childhood. We studied the influence of familial occurrence of hypertension on the BP of 3596 children aged 6 to 18 years during a 6-year follow-up. In addition, we examined the possible associations of BP variations with polymorphisms of two candidate genes for hypertension, ie, those coding for the angiotensin converting enzyme (ACE) and those coding for angiotensinogen.A positive family history of hypertension was reflected as the occurrence of higher systolic BP values from the age of 9 years and upward among the females and from the age of 12 years and upward among the males. The mean differences in BP varied from 3.2 to 5.8 mm Hg (systolic) and 2.1 to 5.9 mm Hg (diastolic) between the female offspring of normotensive and hypertensive parents and grandparents. The systolic BP values were significantly higher among females with a hypertensive history in two generations in comparison with females from normotensive families. Among the male offspring of hypertensive and normotensive families, the BP differences were inconsistent. The deletion/deletion males had higher systolic BP values than those with other ACE genotypes. In contrast, variation at the angiotensinogen gene locus was not significantly associated with BP.We conclude that parental history of hypertension is a risk factor for high blood pressure among the offspring from the ages of 9 to 12 years and upward, and hypertension within two generations may enhance this effect. Although the common genetic variation of ACE may influence blood pressure in male children and adolescents, our data do not suggest a role for the common variation of the angiotensinogen gene as a BP regulator during childhood.     

Ambulatory Blood Pressure: A Predictor of Left Ventricular Mass and Future Blood Pressure in Subjects Predisposed for Hypertension

Twenty-four-hour ambulatory blood pressure (SpaceLab 5200) and a single laboratory blood pressure were measured in a population-derived sample of normotensive men (mean age 36 years) with (n = 13) or without (n = 16) a positive family history of hypertension. The aim was to determine whether ambulatory monitoring was a better predictor than clinical measurements for echocardiographic derived indices of left ventricular mass and for future blood pressure. At the initial examination ambulatory blood pressure could discriminate between the groups, showing significant differences that were not evident from the clinical blood pressure measurement. After 5 years the blood pressure had increased in the group with a family predisposition for hypertension but only one subject had overt hypertension. The correlation between the average day-time blood pressure and the clinical blood pressure at follow-up was only marginally better than the correlation for the initial clinical blood pressure. In contrast to the clinical blood pressure, both day-time and night-time blood pressure averages were significantly correlated to left ventricular mass at the initial examination. It is concluded that in still normotensive subjects, ambulatory monitoring is a better predictor than clinical measurements for left ventricular mass but not for future blood pressure.