Relationship between left ventricular mass and serum cholesterol level in the untreated hypertensive

OBJECTIVE: To study the relationship between serum cholesterol level and left ventricular mass for a population of untreated hypertensive patients. DESIGN: A cross-sectional study. PATIENTS: We studied 273 untreated hypertensive patients without associated diseases consecutively referred for evaluation of blood pressure. All patients underwent M-mode echocardiographic assessment of left ventricular mass, office blood pressure measurement and 24 h ambulatory blood pressure monitoring. Fasting plasma glucose and total cholesterol levels were measured on the same day. RESULTS: We found a weak but significant correlation (r = 0.20-0.26, P < 0.01) between serum cholesterol level and left ventricular wall thickness or left ventricular mass irrespective of the mode of indexation used (height, height2.7 and body surface area). In multivariate analysis this relation remained significant after introduction of sex, age, weight, height, blood pressure and blood glucose level. When data for men and women were analysed separately the relationship between left ventricular mass and cholesterol remained significant for men only. CONCLUSION: There is a significant and independent positive relationship between serum cholesterol level and left ventricular mass that could contribute to the prognostic value of left ventricular hypertrophy.     

Relationship between genotype of angiotensin converting enzyme gene and left ventricular hypertrophy in Chinese hypertensives

Incontinentia pigmenti is an uncommon neurocutaneous syndrome characterised by skin lesions, dental and ocular abnormalities and central nervous system involvement. We report the cranial MRI findings in two sisters with this condition. These include hypoplasia of the corpus callosum, enlargement of the lateral ventricles and periventricular white-matter lesions. One girl also had unilateral microphthalmia and rostral agenesis of the corpus callosum, a feature not previously described.     

Relationships between left ventricular mass, left ventricular work and coronary artery size in aortic regurgitation--possible mechanism of myocardial ischemia

To investigate the relationships between coronary artery size, left ventricular (LV) mass, and LV stroke work in aortic regurgitation (AR), these values were measured in 19 patients with severe AR. Twenty normal subjects and 15 patients with mitral regurgitation (MR) were used as control groups. The coronary area index, i.e., the coronary cross-sectional area divided by body surface area (BSA), was larger in the AR group than in the control groups in all measured sites except for the peripheral left anterior descending coronary artery (LAD) and right coronary artery (RCA). However, the coronary area index divided by the LV mass was significantly smaller in AR and MR patients than in normal subjects. Furthermore, the coronary area index divided by LV stroke work was smaller in AR patients than in MR patients and normal subjects. These results suggest that the coronary blood flow associated with the increased LV mass and stroke work caused by regurgitation was insufficient in patients with severe AR, especially in the area of the LAD. Therefore, the occurrence of myocardial ischemia in patients with severe AR may involve inadequate enlargement of the coronary artery which perfuses the LV, in addition to factors such as decreased coronary perfusion pressure, increased coronary artery resistance and decreased coronary flow reserve.     

A cross-sectional study on the relationship between depression and left ventricular hypertrophy

PURPOSE: The relationship between different forms of persistent radiation damage in irradiated cells was investigated in order to identify a common underlying mechanism. MATERIAL AND METHODS: V-79 Chinese hamster cells were irradiated with different doses of X-rays, neutrons and alpha-particles. In the progeny of surviving cells, up to 4 weeks after irradiation, delayed reproductive death, delayed micronuclei, delayed appearance of dicentric chromosomes and delayed apoptosis were investigated in parallel. RESULTS: A similar dose-response relationship was found for all endpoints, with a steep rise at low doses to a plateau at doses > 3 Gy. The target for inducing genomic instability by alpha-particles is larger than the nucleus. All chromosomes are equally involved in delayed breakage reunion events. CONCLUSION: The results indicate that non-lethal radiation damage to an extranuclear target leads to a persistent increase in clastogenic activity in the surviving irradiated cells.     

The relationship between coffee consumption and serum cholesterol under consideration of smoking history

To provide insight into the stream of Medicare payments over time, a sixteen-year longitudinal study examines three age cohorts of beneficiaries, looking separately at beneficiaries who died during the study period and those who survived. The common wisdom that a small minority of the population accounts for a large majority of health care expenditures is tempered when health care use is examined over an extended period of time. By putting high average costs in the final years of life in the context of a cohort's total lifetime experience, the study shows a leveling of spending over time, resulting in a lower concentration of health care resources on a small fraction of the population.     

Determinants of left ventricular mass in early hypertension

Four modified cyclic hexapeptides, tenuecyclamides A-D (1-4), were isolated along with the known antibiotic, borophycin (5), from the methanol extract of Nostoc spongiaeforme var. tenue (TAU strain IL-184-6). The planar structure of tenuecyclamides A-D (1-4) was determined by homonuclear and inverse-heteronuclear 2D-NMR techniques as well as by high-resolution mass spectrometry measurements. The absolute configuration of the asymmetric centers was studied by Marfey's method for HPLC. The stereochemistry of the asymmetric centers in tenuecyclamides A and B (1 and 2) could not be fully determined, while that of tenuecyclamides C and D (3 and 4) was unambiguously determined.     

Single-drug therapy and reduction of left ventricular mass in hypertension

Echocardiography has provided most of what is understood today about the relationships between human hypertension, cardiac anatomic and functional responses. It has proven its value in determining the effects of antihypertensive therapy on cardiac structure and function. A growing body of research supports initial concerns that not all drugs effective for blood pressure reduction are effective for reduction of left ventricular mass and regression of LVH. It has been of interest that agents initially believed to be ineffective for left ventricular mass reduction (principally diuretics and beta blockers) on the basis of pathophysiological theory and inadequate clinical trials, may in fact be quite effective for LVH regression, as well as improved cardiac outcomes. Hence, supposed inefficacy of these agents for this purpose should no longer be used as a reason to disregard long-standing recommendations of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension supporting the use of diuretics and beta blockers for the initial pharmacotherapy of hypertension.     

Increased left ventricular mass in salt-sensitive hypertensive patients

Clinical, biochemical and echocardiographic characteristics were evaluated from 50 essential hypertensive patients classified asccording to their salt-sensitivity status. Salt-sensitive hypertension was diagnosed by means of ambulatory blood pressure monitoring (ABPM) in 22 (44%) patients showing a significant increase in mean BP (P < 0.05) from a 7-day period of low salt (20 mmol NaCl/day) intake, to a 7-day period of high salt (260 mmol NaCl/day) intake. The remaining 28 (56%) patients were considered as having salt-resistant hypertension. Compared with salt-resistant patients, salt-sensitive ones showed an increased left ventricular mass index (P = 0.0118), septal (P = 0.0021) and posterior wall thickness (P = 0.0026), without differences in the internal diastolic diameter. Decreased values of HDL-cholesterol (P = 0.0475) and increased total cholesterol/HDL-cholesterol ratio (P = 0.0098) were also observed in the salt-sensitive, compared with the salt-resistant hypertensive patients. Age, gender, body mass index, systolic and diastolic BP, fasting plasma glucose, creatinine and uric acid did not differ between salt-sensitive and salt-resistant patients. We conclude that, at the same level of BP, salt-sensitive patients exhibit an increased prevalence of left ventricular hypertrophy and a worse lipid profile. These two aspects may confer to salt-sensitive patients an increased risk in terms of cardiovascular morbidity and mortality.     

Variants of renin-angiotensin system genes and echocardiographic left ventricular mass

AIMS: Variants of renin-angiotensin system genes are shown to be associated with cardiovascular pathology. The association between renin-angiotensin system genes and left ventricular mass was investigated in a population-based case-control study. METHODS AND RESULTS: The association between echocardiographic left ventricular mass and both insertion/deletion polymorphism of the angiotensin-converting enzyme gene and the methionine-threonine variant at position 235 of the angiotensinogen gene was studied in a random cohort of 430 hypertensive and 426 control subjects. No differences in the adjusted left ventricular mass values between the different genotypes were seen among either the hypertensive or the control subjects, whether men or women, or in the subgroups of normotensive or physically active subjects. Gene variation had no statistically significant synergistic effect on left ventricular mass values. In control women, the deletion allele of the angiotensin-converting enzyme gene was associated with an increased risk of left ventricular hypertrophy. However, this finding was based on a small number of women with left ventricular hypertrophy and should be interpreted with caution. CONCLUSION: Variations in renin-angiotensin system genes had no major effect on left ventricular mass in this middle-aged population-based cohort of hypertensives and control subjects.     

The relationship between R amplitude in lead V5 (RV5) and left ventricular mass in the groups of adolescent subjects classified by body composition

How the amplitude of the R wave in lead V5 (RV5) of the ECG represents the left ventricular (LV) mass was investigated in 894 students aged 15 (boys: 545, girls: 349). The influence of body composition [ie, percentage of body fat (%fat)] was taken into consideration. A significant correlation was found between RV5 amplitude and LV mass for both genders. However, the relationship was stronger for boys than for girls. The students were then divided into 3 groups; that is, those at either the top or bottom 10th percentile (low or high-fat range) and the rest of the students (middle-fat range), depending on the % fat calculated by the bioelectrical impedance method. The significant correlation between RV5 and LV mass was found only for the 2 groups of boys whose percentage fat was in the low or middle-fat range. The correlation coefficients were 0.40 and 0.34, respectively. Moreover, in the boys' low-fat range, the RV5 of students whose LV mass was large (> or =90th percentile), was significantly higher (p<0.01) than in the other ranges. Setting a particular cutoff point of RV5 in the low-fat range of boys improved sensitivity as well as specificity (20-30% better among all boys) for detecting large LV mass. These observations suggest that classification of subjects by body composition could be improve the reliability of ECG assessment for left ventricular hypertrophy, although the gender and number of subjects in whom improvement is expected are limited.     

Transfer of cholesterol and lecithin between erythrocytes and serum in vitro

1. In human blood incubated in vitro, the transfer of free cholesterol and lecithin from erythrocytes to serum was not related to glycolytic activity in erythrocytes or esterification of cholesterol in serum. 2. The stability of free cholesterol concentration in serum was dependent on the activity of lecithin:cholesterol acyltransferase (EC 2.3.1.43), and the stability of lecithin concentration in erythrocytes, on glycolytic activity.     

Long-term effects of delapril hydrochloride on procollagen type III amino-terminal peptide, left ventricular mass and left ventricular function in hypertensive patients

The long-term effect of delapril hydrochloride, a non-sulfhydryl angiotensin converting enzyme inhibitor, on serum concentrations of procollagen type III amino-terminal peptide (PIIIP) and left ventricular mass (LVM) and function were investigated in 15 hypertensive patients. Patients were treated with delapril hydrochloride 30 mg/day po for 12 months. Blood samples and an echocardiogram were obtained before treatment and after 6 and 12 months of treatment. Blood pressure, PIIIP, and LVM significantly decreased associated with an increase in left ventricular fractional shortening and mean systolic and diastolic posterior wall velocity at 6 and 12 months of treatment. Positive correlations between PIIIP and LVM (r=0.49, p<0.005) and negative correlations between PIIIP and left ventricular fractional shortening (r=-0.31, p<0.05) were found. Delapril hydrochloride reduced PIIIP and LVM and improved cardiac function in hypertensive patients.     

Determination of total cholesterol in serum by liquid chromatography-isotope dilution mass spectrometry

We have developed a liquid chromatography-isotope dilution mass spectrometry procedure to quantify total cholesterol in serum. A particle-beam interface was used for coupling the liquid chromatograph and the mass spectrometer. After electron impact ionization the ions m/z = 386 and m/z = 389 were used for selective ion monitoring of cholesterol and the internal standard [25,26,27-(13)C]cholesterol. The sample preparation steps required for serum materials are alkaline hydrolysis and an extraction of the cholesterol into the cyclohexane phase. Imprecision for the determination of cholesterol in control materials is typically <1.0%. The deviation from the certified reference values was <0.75% for all control materials tested. A method comparison of the results obtained by this method with those obtained by gas chromatography-isotope dilution mass spectrometry for n = 28 pooled human sera derived from samples analyzed in our routine laboratory did not show differences >2.5%.     

Increased left ventricular muscle mass after long-term altitude training in athletes

STUDY OBJECTIVES: To compare the costs and effectiveness of directly observed therapy (DOT) vs self-administered therapy (SAT) for the treatment of active tuberculosis. DESIGN: Decision analysis. SETTING: We used published rates for failure of therapy, relapse, and acquired multidrug resistance during the initial treatment of drug-susceptible tuberculosis cases using DOT or SAT. We estimated costs of tuberculosis treatment at an urban tuberculosis control program, a municipal hospital, and a hospital specializing in treating drug-resistant tuberculosis. OUTCOME MEASURES: The average cost per patient to cure drug-susceptible tuberculosis, including the cost of treating failures of initial treatment. RESULTS: The direct costs of initial therapy with DOT and SAT were similar ($1,206 vs $1,221 per patient, respectively), although DOT was more expensive when patient time costs were included. When the costs of relapse and failure were included in the model, DOT was less expensive than SAT, whether considering outpatient costs only ($1,405 vs $2,314 per patient treated), outpatient plus inpatient costs ($2,785 vs $10,529 per patient treated), or outpatient, inpatient, and patients' time costs ($3,999 vs $12,167 per patient treated). Threshold analysis demonstrated that DOT was less expensive than SAT through a wide range of cost estimates and clinical event rates. CONCLUSION: Despite its greater initial cost, DOT is a more cost-effective strategy than SAT because it achieves a higher cure rate after initial therapy, and thereby decreases treatment costs associated with failure of therapy and acquired drug resistance. This cost-effectiveness analysis supports the widespread implementation of DOT.     

Which arterial and cardiac parameters best predict left ventricular mass?

BACKGROUND: Many cardiovascular and noncardiovascular parameters are thought to be determinants of left ventricular mass (LVM). Complicated interactions necessitate the simultaneous measurement and consideration of each to determine their individual and collective impact on LVM. We undertook such a comprehensive study. METHODS AND RESULTS: The influence of anthropometry, cardiac size and contractility, arterial structure and function, as well as indices of lifestyle, physical activity, and dietary salt intake on LVM (by two-dimensionally guided M-mode echocardiography) was analyzed in 1315 Chinese subjects who were either normotensive or had untreated hypertension. Effects of many cardiac and arterial factors were assessed. In univariate analysis, almost all measured noncardiovascular, cardiac, and arterial variables were significantly correlated with LVM. In multivariate linear regression analyses, when age, sex, body habitus, fasting serum C-peptide level, dietary salt, physical activity, and lifestyle were accounted for, the optimum multivariate linear regression main effects model had an adjusted model r2 of 0.740, with 98% of the model variance accounted for by the 5 independent determinants of LVM: stroke volume (49.6%), systolic blood pressure (30.7%), contractility (14.7%), body mass index (1.8%), and aortic root diameter (1.6%). Other proposed arterial indices were significant independent determinants of LVM only when blood pressure was removed from the model and, even then, these indices not only resulted in less powerful prediction but also accounted for only a very small percentage of the total variance of LVM. CONCLUSIONS: In a large population, we (1) confirmed that age, body habitus, and some indexes of arterial structure and function are independent determinants of LVM; (2) found aortic diameter to be an independent structural determinant of LVM; (3) demonstrated that the effects of the derived measures of arterial function were small and provided no better predictive power than blood pressure alone; and (4) showed that when the best measures of cardiac and vascular load were included, the single most potent predictor was an index of left ventricular size.     

QT dispersion as a marker of left ventricular mass in essential hypertension

Resting L1210 cells were treated with nimustine (ACNU), a bifunctional alkylating anticancer agent, for 2 h in a nutrient-depleted medium. The cells were then transferred to a fresh medium and incubated for a further 48 h. Functions of the cells thus prepared were examined in terms of the dye-exclusion of the membrane, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl] -2H-tetrazolium hydroxide, inner salt, sodium salt (XTT)-reducing ability of the mitochondria, and heat generation due to vital metabolism as the measure of cell viability. The cells treated with ACNU were functioning normally in all the cell functions examined but were completely devoid of proliferating capacity. These results suggest the possibility that ACNU might impair the proliferative capacity of the resting cell population inside a solid tumor without causing such impairment to the cells of normal organs and tissues composed of intrinsically non-proliferative cells.     

Gender differences in the relationship between left ventricular size and ambulatory blood pressure in borderline hypertension. The HARVEST Study

AIM: To assess whether the are gender differences in cardiac adaptation to raised blood pressure levels in young subjects with borderline to mild hypertension. METHODS AND RESULTS: In 499 18-45-year-old stage I hypertensive subjects (377 men and 122 women) with a mean age of 33 +/- 9 years and office blood pressure of 146 +/- 11/ 94 +/- 6 mmHg, ambulatory blood pressure monitoring in duplicate, echocardiography and 24-h urinary catecholamines measurement were performed. RESULTS: The whole group was divided into quartiles of increasing daytime blood pressure and differences in left ventricular echocardiographic data were analysed in the two sexes separately. In men no left ventricular parameter differed across the quartiles, while in women left ventricular mass, posterior wall thickness and interventricular septum thickness showed a clear tendency to increase with increasing levels of systolic blood pressure. In multiple regression analysis, daytime systolic blood pressure explained only a small fraction of the variance in left ventricular parameters in men, while in women daytime systolic blood pressure was a main determinant of left ventricular mass and posterior wall and septal thicknesses. Body weight explained most of the variance in all dimensional parameters in men. In women weight was an important predictor of left ventricular mass and diameter, but was unrelated to left ventricular posterior wall and septal thicknesses. CONCLUSIONS: Daytime systolic blood pressure is the most important predictor of left ventricular mass and geometry in pre-menopausal women with stage I hypertension, while in men left ventricular dimensional indices are chiefly explained by body weight.     

Various ways of calculating echocardiographic left ventricular mass and their relative prognostic values

OBJECTIVE: To compare the calculations of left ventricular mass according to thick-wall [American Society of Echocardiography (ASE) and Penn convention] and thin-wall (Wikstrand formula) models. METHODS: We have reexamined the data from the cross-sectional study on the general population sample of Vobarno and from a prospective longitudinal study of hypertensive patients assessing the prognostic significance of changes in left ventricular mass during a follow-up period of 10 years on average (Brescia population). RESULTS: For the Vobarno and Brescia populations, we found a close relationship between values of left ventricular mass calculated by using a thin-wall ellipsoidal model (Wikstrand formula) and those calculated using a thick-wall model with Penn convention or ASE left ventricle measurements (r = 0.99, for both the Vobarno and Brescia populations). Highest values of Penn left ventricle mass were slightly underestimated by use of the thin-wall formula. The numbers of nonfatal cardiovascular events and the relative risks, evaluated by Cox proportional hazard models for 151 patients seen at follow-up did not differ for patients with persistence of left ventricular hypertrophy (LVH), those with regression of LVH, and those with normal left ventricle mass, both at baseline and at follow-up, when these different ways of measuring left ventricle mass and partition values for LVH were used. CONCLUSIONS: The calculation of left ventricle mass according to the ASE recommendations or to the Penn convention, both of which are based on the assumption that the left ventricle can be represented by a prolate ellipsoid with both the internal and external long axes twice the short axis, produces results similar to those obtained using an alternate formula for the calculation of left ventricle mass, considering wall thickness constant around the ellipsoidal cavity. The cardiovascular risk stratification, in relation both to baseline left ventricular mass and to its change during long-term antihypertensive treatment, does not differ significantly among the results of these three different calculations.