The relationship between blood pressure and left ventricular muscle volume in normal children and adolescents--the Shimane Heart study

Blood pressure (BP) and left ventricular muscle volume (LVMV) were measured in 408 children and adolescents aged 9-15 years. LVMV was determined by M-mode echocardiography. Lean body weight was approximately calculated using body weight, upper arm circumference and triceps skin fold thickness. Lean-BSA was obtained by substituting lean body weight for body weight in the formula for BSA. Subjects were divided into the high and the low BP percentile groups according to their BP percentile values. LVMVI (= LVMV/BSA) and lean-LVMVI (= LVMV/L-BSA) were compared between the two groups. LVMVI and L-LVMVI were larger in the high BP percentile group than in the low one. Regression lines of LVMV to BSA were also compared between the two groups. Regression lines of the high BP percentile group were located in a higher position than those of the low percentile group. These results suggest that LVMV are larger in the high BP percentile group than in the low percentile group even if their BSAs are equal. We concluded that left ventricular hypertrophy has been already initiated in the pre-hypertensive stage of human beings as observed in spontaneously hypertensive rats.     

Quantification of blood pressure tracking of children by tracking index: the Shimane Heart Study

The tracking of systolic blood pressure (SBP) was analyzed in a cohort of children. The study population consisted of 1009 Japanese children in Izumo City, a rural community in the northwest of Honshu. There were 252 subjects in cohort (C)-1, 235 in C-2, 286 in C-3, 131 in C-4 and 105 in C-5. Follow-up periods were from 6 to 9 years of age in C-1, 9 to 12 in C-2, 12 to 15 in C-3, 6 to 12 in C-4 and 9 to 15 in C-5. BP was measured by conventional method. Tracking index (TI) was calculated as follows: TI = (2x + y - z)/N/.24; x, y and z are numbers of subjects who remained at the same quintile, who moved to the next quintile and who moved to a remote quintile, respectively; N = x + y + z; TI becomes 1.0 when SBP changes randomly. SBP tracking was apparent in both sexes of C-1 (TI = 2.4 in boys, 2.5 in girls), in girls of C-2 (TI = 3.5), in both sexes of C-3 (TI = 3.2 in boys, 2.7 in girls) and in girls of C-4 (TI = 4.1) and C-5 (TI = 3.3). TI agreed well with the tracking phenomena visualized by distribution bar graph. We conclude that TI can assess the degree of tracking quantitatively and can be applied to analysis of the tracking phenomena of BP and its related factors.     

Ambulatory blood pressure and left ventricular hypertrophy

The relation between ambulatory blood pressure and left ventricular mass has been studied with three main aims. The first aim was to validate this new technique for measuring blood pressure. Most studies have shown that the left ventricular mass is correlated more closely to the ambulatory blood pressure than it is to the office blood pressure. The second aim was to define the parameters of most interest in ambulatory recordings. Although the mean 24 h blood pressure has emerged as the parameter of most clinical interest, other parameters, such as the blood pressure measured during activity, the difference between daytime and night-time values and the blood pressure measured when the subject arises in the morning, may also be of value. The interest of these parameters awaits confirmation in prospective studies. Random peak pressures and the variability as determined by discontinuous measurements using non-invasive methods appear to be of little value. The third aim was to assess the value of ambulatory monitoring in identifying the role played by mechanical as opposed to genetic, humoural and hormonal factors in the development of left ventricular hypertrophy in the hypertensive patient. Ambulatory blood pressure monitoring might prove of particular value in assessing the true impact of blood pressure reduction by antihypertensive therapy on left ventricular hypertrophy.     

A weight reduction and weight maintenance program with long-lasting improvement in left ventricular mass and blood pressure.

Obesity is a major risk factor for cardiovascular disease and is associated with hypertension and increased left ventricular mass (LVM). Maintenance of reduced weight has been a matter of recent concerns in the treatment of obese subjects. This study was conducted to confirm the effect of the addition of exercise to diet on maintenance of body weight in a weight reduction program. In addition, this study was conducted to estimate whether LVM changes in parallel with a change in body weight during a long-term follow-up after a weight-reduction program. Twenty-two normotensive (NT) obese subjects and 14 mild hypertensive (HT) obese subjects ranging in age from 22 to 51 years participated in a 12-week supervised weight-reduction program involving mild exercise and a mild hypocaloric diet. After this 12-week intervention, they were advised to maintain their modified lifestyle during a 1-year follow-up period. After the 12-week intervention, the mean reductions in body weight (BW) in the NT and HT groups were 4.1 kg (P < .0001) and 5.8 kg (P < .0001), respectively. LVM in the NT and HT groups was significantly reduced from 154 g to 136 g (P < .005) and from 169 g to 152 g (P < .002), respectively. One year after intervention, the mean gains in BW in the NT and HT groups were 2.3 kg (not significant, NS) and 0.4 kg (NS), respectively. The mean gains in LVM in the NT and HT groups were 8 g (NS) and 7 g (NS), respectively. It was also shown that blood pressures in the HT group were significantly decreased after the 12-week intervention and there was no significant change in blood pressure in the HT group 1 year after intervention. In conclusion, reduced body weight was maintained for 1 year after a 12-week supervised weight-reduction program in both normotensive and mild hypertensive obese subjects. Reduced left ventricular mass was maintained for a long period in both normotensive and mild hypertensive obese subjects and lowered blood pressure was maintained in the mild hypertensive obese subjects.     

Correlations between blood pressure, left ventricular hypertrophy, and left ventricular diastolic function in hypertensive patients]

We examined the relationship of hypertension to left ventricular hypertrophy (LVH) and left ventricular diastolic function by ambulatory blood pressure monitoring device and echocardiography. We studied 36 untreated hypertensive non-diabetic patients (16 males and 20 females) whose casual systolic blood pressure (CSBP) and/or diastolic blood pressure (CDBP) were higher than 140 mmHg and 90 mmHg, respectively. All patients were less than 65 years of age without organic heart disease. Resting systolic and diastolic blood pressures (RSBP, RDBP) were measured after lying in a supine position for 30 min by the auscultatory method. Ambulatory blood pressure was measured every 30 or 60 min for 24 hours by Colin ABPM 630, and the mean 24-hour ambulatory systolic and diastolic blood pressures (ASBP, ADBP) and the systolic and diastolic hyperbaric indices (SHI, DHI) were obtained. The left ventricular mass index (LVMI) was obtained as an indicator of LVH by M-mode echocardiography. The ratio of peak velocity of mitral inflow caused by atrial contraction to that of rapid inflow (A/R) was obtained as an indicator of the LV diastolic function by Doppler echocardiography. The coefficients of correlation between BP and the LVMI, and the A/R were determined. There were significant positive correlations between the LVMI and ASBP (r = 0.51, p < 0.005), the SHI (r = 0.49, p < 0.005), CSBP (r = 0.47, p < 0.01) and RSBP (r = 0.41, p < 0.05), however, there were no significant correlations between the LVMI and ADBP, the DHI, CDBP, RDBP and age. There were significant positive correlations between the A/R and ADBP (r = 0.44, p < 0.01), age (r = 0.40, p < 0.02), CSBP (r = 0.38, p < 0.05) and RDBP (r = 0.38, p < 0.05), however, no significant correlations between the A/R and ASBP, the SHI, DHI, RSBP and CDBP. Only a weak correlation was observed in all subjects between the LVMI and A/R, which was slightly improved by use of > 90 mmHg CSBP readings (r = 0.32). It was concluded that LVH is related mainly to continuous systolic hypertension, and that LV diastolic dysfunction is related mainly to continuous diastolic hypertension. Therefore, it was suggested that LVH and LV diastolic dysfunction in hypertensive patients are caused by different mechanisms.     

Pulmonary blood volume: relationship to changes in left ventricular end-diastolic pressure during atrial pacing

Little data exist about the relationship between changes in cardiac end-diastolic pressure and changes in pulmonary blood volume. To assess this relationship, we studied 11 patients with coronary heart disease during atrial pacing in an attempt to produce multiple pressure-volume points. During catheterization, we obtained Millar pressure recordings of end-diastolic pressure along with equilibrium radionuclide angiograms. Cardiac output, ejection fraction, and pulmonary blood volume were obtained by means of recently validated radionuclide techniques. During pacing, substantial changes in pulmonary blood volume occurred only with marked increase in end-diastolic pressure volume (greater than or equal to 15 mm Hg) and rarely exceeded 15% of control pulmonary blood volume. Cardiac output did not change, while ejection fraction declined during pacing. There was a fair correlation between the absolute change in pulmonary activity (or pulmonary blood volume) or the percentage of change in pulmonary activity over the control value with end-diastolic pressure when all the data points were evaluated (n = 74, r greater than 0.70). However, the scatter in the data precluded making accurate estimates of pressure changes from changes in radionuclide volume changes. We conclude that large changes in cardiac filling pressure must occur during atrial pacing, where cardiac output does not change, before visible pulmonary blood volume changes occur. This may limit the extrapolation of presumed pressure changes from known pulmonary blood volume when changes are small.     

Effects of dextran infusion on left ventricular volume and pressure in man

The purpose of this investigation was to quantitate the changes in left ventricular volume and end-diastolic pressure that occur with rapid infusion of 500 ml of low molecular weight dextran, and thus to study left ventricular pressure-volume relationships. Left ventricular pressure and echocardiographic dimensions were recorded before, during, and following dextran infusion in eight patients with normal left ventricular function. With the infusion of dextran, left ventricular end-diastolic pressure rose progressively from 10 ± 3 mmHg (mean ± SD) to 24 ± 5 mmHg, whereas end-diastolic volume increased from 95 ± 23 ml to 118 ± 26 ml (24%). These results serve to emphasize the steepness of the left ventricular pressure-volume relationship at end-diastole in subjects with normal ventricular function when in the supine position.     

Influence of contemporary versus 30-year blood pressure levels on left ventricular mass and geometry: the Framingham Heart Study.

To determine whether long-term blood pressure levels correlate with left ventricular mass, echocardiographic measurements were performed in 152 men and 299 women who were participants in the Framingham Heart Study. All subjects were free of obesity and cardiovascular and pulmonary disease, were not taking antihypertensive medications and had echocardiographic studies that were adequate for estimating left ventricular mass. Thirty-year average systolic blood pressure was correlated with left ventricular mass (corrected for height) (r = 0.27, p less than 0.001 in men; r = 0.31, p less than 0.001 in women). Multivariate linear regression analyses taking into account age and body mass index showed 30-year average systolic blood pressure to be a significant independent predictor of left ventricular mass (p less than 0.01 in men and women). Systolic blood pressure at echocardiography was not independently associated with left ventricular mass when 30-year systolic blood pressure was entered into the multivariate model. The prevalence of left ventricular hypertrophy was associated with 30-year average systolic blood pressure (odds ratio for every 20-mm Hg increase in blood pressure: 3.20, p less than 0.05 in men; 3.27, p less than 0.001 in women). The increase in left ventricular mass associated with 30-year average systolic blood pressure reflected changes in left ventricular wall thickness but not in left ventricular internal dimension. Thirty-year average diastolic blood pressure was also correlated with left ventricular mass but to a lesser degree than was systolic blood pressure (r = 0.18, p less than 0.05 in men; r = 0.18, p less than 0.01 in women).(ABSTRACT TRUNCATED AT 250 WORDS)     

Importance of blood pressure control in left ventricular mass regression

Blood pressure (BP) reduction to 140/90 mm Hg or lower using renin-angiotensin-system blockers reportedly provides the greatest left ventricular (LV) mass regression; β-blockers have less effect. This study examined whether combination antihypertensive therapy would provide greater benefit. With a double-blind, parallel-group design, the effects of 3 different combinations, carvedilol controlled-release (CR)/lisinopril, atenolol/lisinopril, and lisinopril, on left ventricular mass index (LVMI) were assessed by MRI after 12 months. Patients were treated to achieve guideline-recommended BP (<140 mm Hg/<90 mm Hg; diabetes: <130 mm Hg/<80 mm Hg). Sample size was calculated to achieve 90% power to detect a 5 g/m² difference in mean change from baseline in LVMI between the carvedilol CR/lisinopril group and each of the other treatment groups. Of 287 patients randomized, more than 50% were titrated to maximum dosage; 73% reached targeted BP. At month 12 (last observation carried forward ≥ month 9) for 195 evaluable subjects, mean BP was similar in all groups (carvedilol CR/lisinopril: 128.8/77.9; atenolol/lisinopril: 128.7/76.5; lisinopril: 126.3/80.3 mm Hg). Compared with baseline, mean LVMI decreased to a similar extent in all groups (carvedilol CR/lisinopril: –6.3; atenolol/lisinopril: –6.7; lisinopril: –7.9 g/m²). Achievement of targeted BP control is more important than treatment regimen in achieving LV mass reduction.     

Ambulatory blood pressure and left ventricular mass index in hypertensive children

To determine whether ambulatory blood pressure is more predictive of left ventricular hypertrophy than is casual blood pressure in hypertensive children, echocardiography and ambulatory blood pressure data from 37 untreated hypertensive children were analyzed. Left ventricular mass was calculated using the Devereux equation, left ventricular mass index was calculated as left ventricular mass (in grams)/height(2.7) (in meters), and left ventricular hypertrophy was defined as left ventricular mass index >51 g/m(2.7). Average blood pressure, blood pressure load, and blood pressure index (average blood pressure divided by pediatric ambulatory blood pressure 95th percentile) were calculated. Left ventricular mass index was strongly correlated with 24-hour systolic blood pressure index (r=0.43, P=0.008) and was also correlated with 24-hour systolic blood pressure (r=0.34, P=0.037), 24-hour systolic blood pressure load (r=0.38, P=0.020), wake systolic blood pressure load (r=0.37, P=0.025), sleep systolic blood pressure (r=0.33, P=0.048), and sleep systolic blood pressure load (r=0.38, P=0.021). Left ventricular mass index did not correlate with age, weight, clinic blood pressure, or ambulatory diastolic blood pressure. The overall prevalence of left ventricular hypertrophy was 27%. The prevalence of left ventricular hypertrophy was 47% (8 of 17) in patients with both systolic blood pressure load >50% and 24-hour systolic blood pressure index >1.0, compared with 10% (2 of 20) in patients without both criteria (P=0.015). These data suggest ambulatory blood pressure monitoring may be useful for the clinical assessment of hypertensive children by identifying those at high risk for the presence of end organ injury.     

日间血压变异与高血压患者左心室肥厚的相关性

目的:探讨日间血压变异性(blood pressure variability,BPV)与高血压患者左心室肥厚的相关性。方法:入选2013年11月至2014年1月于心内科及神经内科住院的高血压患者183例,连续监测血压6 d,以收缩压(SBP)值的标准差作为日间BPV的评估指标,将患者分为2组:BPV≥8.62 mmHg组、BPV8.62 mmHg组,收集患者的临床资料,进一步探讨日间BPV与左心室肥厚的关系。结果:(1)与日间BPV8.62 mmHg的患者相比,日间BPV≥8.62 mmHg的患者脑卒中患病率、SBP、舒张压、低密度脂蛋白胆固醇水平、尿蛋白阳性率、左心室后壁厚度、左心室质量指数(left ventricular mass index,LVMI)明显增高,低脂饮食的比例、平均睡眠时间较低(P0.05);(2)多元线性回归分析显示,在校正了多个混杂因素后,日间BPV与LVMI呈正相关。结论:日间BPV高的患者临床状况较差,日间BPV高是左心室肥厚的独立危险因素。     

Circadian blood pressure changes and left ventricular hypertrophy in essential hypertension

The effects of circadian blood pressure (BP) changes on the echocardiographic parameters of left ventricular (LV) hypertrophy were investigated in 235 consecutive subjects (137 unselected untreated patients with essential hypertension and 98 healthy normotensive subjects) who underwent 24-hour noninvasive ambulatory blood pressure monitoring (ABPM) and cross-sectional and M-mode echocardiography. In the hypertensive group, LV mass index correlated with nighttime (8:00 PM to 6:00 AM) systolic (r = 0.51) and diastolic (r = 0.35) blood pressure more closely than with daytime (6:00 AM to 8:00 PM) systolic (r = 0.38) and diastolic (r = 0.20) BP, or with casual systolic (r = 0.33) and diastolic (r = 0.27) BP. Hypertensive patients were divided into two groups by presence (group 1) and absence (group 2) of a reduction of both systolic and diastolic BP during the night by an average of more than 10% of the daytime pressure. Casual BP, ambulatory daytime systolic and diastolic BP, sex, body surface area, duration of hypertension, prevalence of diabetes, quantity of sleep during monitoring, funduscopic changes, and serum creatinine did not differ between the two groups. LV mass index, after adjustment for the age, the sex, the height, and the daytime BP differences between the two groups (analysis of covariance) was 82.4 g/m2 in the normotensive patient group, 83.5 g/m2 in hypertensive patients of group 1 and 98.3 g/m2 in hypertensive patients of group 2 (normotensive patients vs. group 1, p = NS; group 1 vs. group 2, p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)     

收缩压与高血压左室重构的关联

目的探讨动态血压参数变化与高血压左心室重构之间的关系。方法对105例原发性高血压患者进行超声心动图检查;24小时动态血压监测获取动态血压参数。采用多元回归方法对左心室质量（LVM）与动态血压各参数作逐步回归分析。结果24 h平均收缩血压和白天收缩血压均值与左心室重构有关。结论收缩血压是影响左心室重构的主要危险因素。     

Relationship between left ventricular mass and blood pressure in treated hypertension

This study evaluated prospectively whether there is still a relationship between left ventricular mass and blood pressure once hypertension is treated and determined the relative importance of daytime vs night-time blood pressure, systolic vs diastolic blood pressure and office vs ambulatory blood pressure. A total of 649 patients (305 or 47% female) with essential hypertension, treated with antihypertensive drugs for at least 3 months, underwent office blood pressure measurement and both daytime and night-time ambulatory blood pressure measurement, electrocardiography and echocardiography. Correlations were made between blood pressure values and parameters of left ventricular mass. Electrocardiographic voltage criteria and even more so echocardiographic parameters correlate significantly albeit weakly (r < or = 0.28) with blood pressure in treated hypertension. Correlations are consistently higher when systolic blood pressure is considered. Overall, the best correlations are found between 24-h ambulatory systolic or night-time blood pressure and the Sokolow-Lyon voltage as well as the echocardiographic age and body mass index adjusted left ventricular mass. In conclusion, once hypertension is treated, the relationship between blood pressure and left ventricular mass is low. Nevertheless, in this the largest single centre study of its kind, echocardiographic parameters of left ventricular mass in treated hypertensive subjects correlate better with blood pressure than electrocardiographic parameters. Parameters of hypertrophy are more closely related to systolic blood pressure than to diastolic blood pressure. In accordance with the finding that dippers have a better prognosis than non-dippers, night-time blood pressure consistently correlates better with left ventricular mass than daytime blood pressure.