Biomedical subjects

A Linhart

Publications and source records attributed to A Linhart.

46 records · Page 3Linked to original sources

PubMed2000

Lack of association of angiotensin-converting enzyme and angiotensinogen genes polymorphisms with left ventricular structure in young normotensive men.

Left ventricular (LV) hypertrophy is a strong predictive factor for cardiovascular morbidity and mortality. LV structure and function are influenced by many variables, including genetic background. The potential role of gene polymorphisms of different components of the renin angiotensin system remains controversial. The aim of this study was to determine the influence of deletion/insertion (D/I) polymorphism of the angiotensin-converting enzyme (ACE) gene and M235-->T polymorphism of the angiotensinogen (AG) gene on left ventricular morphology and function in young normotensive men. The study included 110 normotensive healthy males (mean age 24 +/- 4 years, age range 18 to 34 years) who were assessed by echocardiography for LV structure and function. In all subjects ACE D/I polymorphism was evaluated using a polymerase chain reaction (PCR) method. M235-->T polymorphism assessment was available in 98 individuals. Significant differences between groups according to ACE I/D or AG M235-->T polymorphisms were not found for parameters of LV morphology or for parameters of systolic and diastolic function. When subjects with DD or ID genotypes were grouped, their LV mass index was higher than that in subjects with II genotypes (86 +/- 14 vs 79 +/- 15, r = 0.033, p = 0.05). There were no significant differences among other variables. In a population of young normotensive men where the influence of confounding variables such as age, gender and associated pathological conditions is minimized, the gene polymorphisms of ACE I/D and AG M235-->T are not important determinants of LV structure and function.

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PubMed1998

[Home blood pressure monitoring].

Home blood pressure measurement is a simple, precise and highly reproducible method. Its application is possible in a large majority of patients. The method is valid if performed with devices validated according to international criteria and if an appropriate methodology is applied. It is advantegeously used for diagnostic of high blood pressure, particularly white coat hypertension. It allows for an exact appreciation of treatment efficacy and a long term follow-up of blood pressure control. In a majority of patients it improves their compliance to drug treatment. Its precision allows to decrease the number of patients needed in clinical trials. The main obstacle of larger use of home blood pressure monitoring is the need to give a detailed instructions to patients and generally a laborious evaluation of results. The latter could be simplified by using devices transferring measured results directly to physician's computer. However the cost of such instruments remains high. Finally the lack of financial reimbursement of physicians using home blood pressure measurement limits further its larger use.

Blood Pressure Monitors↗

PubMed1998

Vascular and cardiac remodeling in world class professional cyclists.

BACKGROUND: Numerous studies have demonstrated that left ventricular (LV) hypertrophy is often associated with conditioning. METHODS AND RESULTS: The aim of the study was to evaluate cardiac and carotid artery changes induced by professional cycling. We collected M-mode left ventricle and B-mode right common carotid artery data from 149 male professional cyclists before the 1995 "Tour de France" race and 52 male control subjects. LV mass indexed to body surface area in cyclists was double that in control subjects, with no overlap of 95% confidence intervals (cyclists 100.9 to 187 g/m2 and control subjects 51.8 to 96.3 g/m2). Both mean arterial diameter and mean arterial diastolic intima-media thickness (IMT) were 13% higher in cyclists than in control subjects, with overlap of 95% confidence intervals (for arterial IMT 0.45 to 0.65 mm in cyclists and 0.38 to 0.60 mm in control subjects). CONCLUSIONS: Our results suggest that intense cycling has an effect on the cardiovascular system, more pronounced on the left ventricle and less pronounced on large arteries. Nevertheless, athletic training should be considered as a potential determinant of carotid modification.

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PubMed1998

Utility of electrocardiogram for predicting increased left ventricular mass in asymptomatic men at risk for cardiovascular disease.

The objective of this study was to test the value of electrocardiogram for predicting left ventricular mass (LVM), assessed echographically in 136 asymptomatic men with at least one major cardiovascular risk factor. We measured the Sokolow-Lyon and Cornell voltages, as well as the ratio of Cornell voltage to QRS voltage in lead II. The prevalence of left ventricular hypertrophy (LVH), defined as LVM of > or = 125 g/m2, was 6%, whereas that of increased LVM, defined as LVM of > or = 99 g/m2, the 90th upper percentile of a control group, was 29%. Receiver operating characteristics curves showed that for predicting LVH at 80% specificity, the Cornell/QRS(II) voltage ratio had a sensitivity of 75%, whereas those of the Cornell and Sokolow-Lyon voltages were 50% and 12.5%, respectively. For predicting increased LVM at 80% specificity, the Cornell/QRS(II) voltage ratio had a sensitivity of 56%, whereas the sensitivities of the Cornell and Sokolow-Lyon voltages were 36% and 22%, respectively. We conclude that, in constrast with the Sokolow-Lyon voltage, the new dimensionless Cornell/QRS(II) voltage shows a sensitivity at a high specificity value at least as acceptable as that of the Cornell voltage for predicting borderline-high LVM in a population with a low prevalence of LVH.

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PubMed1998

Preclinical changes of extracoronary arterial structures as indicators of coronary atherosclerosis in men.

BACKGROUND: Carotid artery structure change was associated with coronary artery stenosis by angiography of subjects who were for the most part symptomatic. OBJECTIVE: To determine whether structural changes at multiple extracoronary sites were associated with noninvasively detected coronary calcium for 94 asymptomatic high-risk men. METHODS AND RESULTS: B-mode ultrasonography allowed us to detect plaque at three sites (carotid, femoral, and abdominal aorta) and to measure intima-medial thickness both in common carotid and in femoral arteries. Ultrafast computed tomography determined the presence and amount of coronary calcification. After adjustment for age, plaques at two or three sites were associated with extensive amounts of coronary calcium [odds ratio 4.94 (95% confidence interval 1.08-23)], but not with the presence of coronary calcium; increase in carotid intima-medial thickness was not associated with presence and extent of coronary calcium; and increase in femoral intima-medial thickness was associated with presence of coronary calcium [odds ratio 1.44 (95% confidence interval 1.03-2)] and extensive coronary calcium [odds ratio 1.50 (95% confidence interval 0.97-2.33)]. Adjustment for cardiovascular risk factors attenuated these associations. CONCLUSIONS: Femoral intima-medial thickness predicted presence of coronary calcium whereas femoral intima-medial thickness and overall multiple plaques predicted extensive coronary calcium. Because coronary calcium is a marker of atherosclerosis and a predictor of coronary events, B-mode ultrasonography could be of clinical value for stratifying coronary risk.

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PubMed1996

Carotid artery and left ventricular structural relationship in asymptomatic men at risk for cardiovascular disease.

To determine whether a relationship between echographically assessed carotid artery and left ventricular (LV) structures existed in asymptomatic men at risk for cardiovascular disease, we evaluated carotid and LV parameters in 69 subjects (23-62 years) without LV hypertrophy. The right common carotid far wall intima-media thickness (IMT) was measured using an automated technique and the cross-sectional intima-media complex area (IMC-CSA) was calculated, assuming a circular profile of carotid wall layers, as (IMC-CSA = pi x IMT x (IMT + D)), D being the lumen diameter. LV mass was evaluated using the M-mode echocardiography. Among study subjects 30% were hypertensive, 67% hypercholesterolemic, 21% current smokers and 52% had a positive smoking history. In the study population LV mass correlated both with IMT (r = 0.54, P < 0.001) and IMC-CSA (r = 0.62, P < 0.001). In multivariate analysis LV mass was associated with IMC-CSA (P < 0.001), body mass index (P < 0.01), lifelong smoking dose (P < 0.01) and systolic blood pressure (P < 0.05), r2 = 0.58, P < 0.001. Therefore, IMC-CSA may be a clinically relevant independent indicator of LV mass even within its normal ranges.

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PubMed1996

Echographic assessment of carotid and femoral arterial structure in men with essential hypertension. Group PCVMETRA.

Extracoronary in vivo structural arterial changes were studied in asymptomatic essential hypertension. Carotid and femoral arteries were examined with B-mode echography for the presence or absence of plaque (the whole vascular segments of each vessel in the both sides) and for automated measurement of the far wall intima-media thickness (the vascular segment of each vessel proximal to the bifurcation in the right side) in 53 never treated hypertensive men and 133 normotensive men similar with regard to age, serum cholesterol levels, and smoking history. In the hypertensive group carotid plaque was more frequent (P < .05) and carotid and femoral intima-media thicknesses were greater (P < .001) than in the normotensive group. In the overall normotensive and hypertensive population intima-media thickness was independently associated with age and systolic pressure in both arteries (P < .001) and with cholesterol in the femoral artery (P < .05) while plaque was associated with systolic pressure (P < .01), and cholesterol (P < .01) in the carotid arteries and with age (P < .01), cholesterol (P < .05), and smoking (P < .001) in the femoral arteries. No significant difference in intima-media thickness in both arteries existed between hypertensive subjects with plaque and those without. Wall thickening and plaque were more frequent in hypertensive patients. Thickening was distributed homogeneously to both arteries, while plaque affected preferentially the femoral bed. The influence of age and pressure was more marked on intima-media thickness than on plaque. The lack of association between wall thickening and plaque suggested that vascular hypertrophy and early atherosis might be two different structural changes.

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PubMed1996

Metabolic, humoral and haemodynamic characteristics of normotensive offspring from hypertensive families.

Arterial hypertension is not only a haemodynamic abnormality, but it is associated with several metabolic and humoral changes. Heredity appears to be participating in the pathogenesis of essential hypertension (EH). We studied whether some metabolic, humoral and haemodynamic changes could be detected in genetically predisposed normotensive sons of hypertensive families (SH) compared with normotensive sons of normotensive parents (SN). The study groups consisted of 40 young SN and 40 SH matched for age and body mass index (BMI). Blood samples for laboratory determination were taken under basal conditions and 90 min after a 75 g glucose load. SH already had a higher systolic blood pressure (BP) (120.7 +/- 1.7 mm Hg) and a tendency to a higher diastolic BP than the SN group. In spite of the fact that both basal and stimulated glycemia did not differ significantly between the study groups, significantly higher glucose-stimulated immuno-reactive-insulin (IRI) was found in SH (80.1 +/- 7.06 vs 62.9 +/- 5.76 uU/l). Higher plasma concentration of catecholamines in SH indicate their higher sympathetico-adrenal activity. The groups did not differ significantly in basal and stimulated plasma renin activity (PRA), aldosterone and atrial natriuretic peptide (ANP). There was a tendency for higher levels of endothelin (ET) in the plasma of SH. The glucose load increased as expected, glycemia, IRI and C-peptide, but ANP and ET concentrations were unexpectedly reduced. These abnormalities were associated, in SH, with higher left ventricle (LV) mass index and impaired diastolic filling. Persistence of high LV mass index, even after adjustment for respective systolic BP, suggests the participation of more than haemodynamic stress in the increase of LV mass. Our results suggest that in normotensive genetically predisposed subjects from hypertensive families, some metabolic and humoral abnormalities can already be detected. They might be responsible for the higher BP readings with subsequent manifestations of hypertension and LV morphological and functional abnormalities.

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PubMed1995

Wall thickening of carotid and femoral arteries in male subjects with isolated hypercholesterolemia. PCVMETRA Group. Prevention Cardio-Vasculaire en Medecine du Travail.

This study was performed to determine whether hypercholesterolemic men had increased large artery intima-media thickness (IMT), a potential surrogate measure of atherosclerosis, compared to normocholesterolemic controls. The measurements were performed in the far walls of common carotid and femoral arteries with non-invasive automatic computerized ultrasonic technique in 101 asymptomatic men (28-60 years) of whom 40 were normocholesterolemic (total cholesterol < 5.2 mmol/l, controls), 25 had borderline hypercholesterolemia (5.2 < or = total cholesterol < 6.2 mmol/l, group 1) and 36 had hypercholesterolemia (total cholesterol > or = 6.2 mmol/l, group 2). All the subjects had no other traditional risk factors, except smoking. Carotid and femoral IMT were significantly increased in group 2 (P < 0.01) but not in group 1 compared to controls. When all subjects were pooled for analysis, carotid and femoral IMT were correlated (r = 0.47, P < 0.001) and increased with total cholesterol (r = 0.35, P < 0.001) and LDL cholesterol (r = 0.33, r = 0.34, respectively; P < 0.001). Carotid and femoral IMT increased with age in each group: controls, r = 0.46, P < 0.01 and r = 0.50, P < 0.001, respectively; group 1, r = 0.42, P < 0.05; group 2, r = 0.48, P < 0.01, and r = 0.59, P < 0.001, respectively. At the carotid and femoral sites, the regression slopes between age and IMT were steeper in group 2 than in controls (P < 0.01). Thus, hypercholesterolemia was associated with diffuse large artery wall thickening, whose presence might be useful in the identification of those hypercholesterolemic individuals most prone to developing atheromatous changes, in the decision to treat, and in the monitoring of lipid-lowering treatment.

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PubMed1993

Analysis of ventricular activation in patients with chronic non-Q wave myocardial infarction: comparison with left ventricular asynergy and myocardial perfusion defects.

In this report, we dealt with ventricular activation abnormalities in 30 patients with previous non-Q myocardial infarction (MI) by means of the CARDIAG 128.1 device, which enables analysis of ECGs, VCGs and body surface potential maps. The diagnosis was verified by left ventriculography, echocardiography and perfusion scintigraphy. Twenty-nine healthy subjects served as the control group. Morphological findings confirmed the presence of a significant subgroup with serious left ventricular asynergy. Seven electrocardiological variables, which significantly differed from control values, disclosed that non-Q MI is responsible for localized activation time prolongation, and that inferoposterior scars tend to delay the entire activation of ventricles, and to cause disturbances of the terminal depolarization phase together with a decrease in voltage production during QRS. Lesions of the anterior wall and the apicomesial part of the inferoposterior wall affect the distribution of the Q wave more often than the posterior basal ones. The probability of such abnormalities increases with the degree of asynergy. Some VCG criteria increase the sensitivity of electrocardiological analysis. These parameters will be used for evaluating the diagnostic value of electrocardiological analysis in the chronic non-Q MI. Non-Q myocardial infarctions represent a heterogeneous group of infarctions from both electrophysiological and morphological aspects.

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