Biomedical subjects

J Hradec

Publications and source records attributed to J Hradec.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Old age from the viewpoint of the cardiologist].

The general cardiovascular performance of old people is determined by: a) inherent changes of the cardiovascular system which develop with age; b) delay of degenerative changes in some subjects caused by genetic factors, optimal physical activity and a proper diet; c) acquired diseases, in particular arteriosclerosis and hypertension. As a result of degenerative changes of the vascular wall the systolic pressure rises advancing age, some of the old people develop isolated systolic hypertension. Mild hypertrophy of the left ventricle develops also. The contracting ability of the heart muscle is preserved, the ejection fraction at rest and the cardiac output do not change. However, the diastolic function changes significantly-the elasticity of the left ventricle declines and its filling depends more on the atrial systole. A frequent cause of heart failure in old people is diastolic dysfunction. Pharmacotherapy of old people has some specific features which are discussed in more detail. A recent multicentre clinical investigation SHEP proved unequivocally, that effective treatment of systolic hypertension reduced in old people the risk of cerebrovascular attacks by 33%, of acute myocardial infarction by 27% and of cardiac failure by more than 50%! Based on these results it is clear that systolic hypertension must be treated equally systematically as diastolic hypertension. The approach to old people with cardiovascular disease must be strictly individual. Age alone must not be the reason for refusing access to the complete spectrum of modern diagnostic and therapeutic possibilities.

Aged↗

PubMed1993

Long-term echocardiographic follow-up of acromegalic heart disease.

Heart muscle disease in acromegaly manifests usually as cardiac hypertrophy. Based on a retrospective analysis, it was suggested that cardiac hypertrophy is slowly reversible after normalization of plasma growth hormone levels. The reversibility of acromegalic heart muscle disease during and after treatment of acromegaly was studied prospectively. A cohort of 78 patients was examined echocardiographically in 1981, and 38 survivors of this group were reexamined 10 years later. Patients were classified according to original hormonal activity in 1981, and change in hormonal activity during follow-up into the following 4 groups: group I--hormonally inactive for entire follow-up (n = 10); group II--hormonally active for entire follow-up (n = 11); group III--initially hormonally inactive with later resurgence (n = 6); and group IV--initially hormonally active with later normalization of growth hormone levels (n = 11). No significant echocardiographic changes occurred during follow-up in group I. Left ventricular posterior wall and septal diastolic thickness, and left ventricular mass increased significantly (all p < 0.05) in group II. Left ventricular posterior wall thickness, mass and diastolic volume increased significantly (p < 0.05, < 0.01 and < 0.001, respectively) in group III. On the contrary, there were significant decreases in left ventricular mass, and both diastolic and systolic left ventricular volumes (p < 0.01, < 0.05 and < 0.05, respectively) in group IV. It is concluded that both hypertrophy and dilatation of the left ventricle in acromegaly are slowly reversible after successful treatment. On the contrary, continuing or relapsed hyperproduction of growth hormone causes further deterioration of acromegalic heart disease.

Acromegaly↗

PubMed1993

[Does a hypertensive reaction to dynamic exercise imply an increased risk of developing essential hypertension?].

Early diagnosis of essential hypertension, preferably in the pre-hypertensive stage, is very important for the prognosis of affected subjects. Based on sporadic information in the literature it seems that people who are normotensive at rest but have an exaggerated hypertensive reaction to exercise have a greater risk of developing essential hypertension in future. The authors selected from protocols of ECG exercise tests a group of subjects with normal blood levels at rest but an exaggerated hypertensive reaction to a dynamic exercise. The control group was formed by people with a normal pressure reaction to a exercise the control group was matched as regards age, sex and basic anthropometric parameters. After a mean period of 7.8 years (range 5-10 years) it was revealed that while in the control group hypertension was manifested in 10%, in the group with an exaggerated hypertensive reaction to an exercise it was manifested in 33.3%. The mean original blood pressure readings at rest were significantly higher in people with a normal blood pressure reaction to an exercise and this difference persisted also at the end of the investigation. An exaggerated hypertensive reaction to a dynamic exercise is one of the prognostic factors for the development of essential hypertension and should be a reason for follow-up.

Adult↗

PubMed1993

Detoxication products of the carcinogenic azodye Sudan I (solvent yellow 14) bind to nucleic acids after activation by peroxidase.

The C-hydroxyderivatives of the carcinogenic dye Sudan I, 1-phenylazo-2,6-dihydroxynaphthalene and 1-(4-hydroxyphenylazo)-2-hydroxynaphthalene, which are considered to be detoxication products of this dye bind to DNA or tRNA after oxidation into active metabolites by peroxidase and H2O2 in vitro. The 32P-postlabeling analysis of DNA modified by active metabolites of both Sudan I derivatives provides evidence that the covalent binding to DNA is the principal type of DNA modification. Since the urinary bladder is rich in peroxidases, the participation of these enzymes in activation of detoxicating products of Sudan I may be involved in the initiation of Sudan I-carcinogenesis in this organ.

Animals↗

PubMed1993

[Long-term study of glucose tolerance in individuals with a suspected diagnosis of diabetes].

The authors evaluated the results of the long-term monitoring of the glucose tolerance in 90 subjects, 40 men and 50 women, who were referred to a diabetological clinic as suspect diabetics. The mean age during the initial examination was 55.7 years (mean 55.7 +/- 12.5), a diabetic family--history was recorded in 60% of the patients, obesity in 61%. The monitoring proceeded on average for 8.5 years (mean 8.5 +/- 6.8). During the baseline examination diabetes was detected only in three subjects (3.3%), in 41 (45.6%) impaired glucose tolerance was revealed which in the course of 18 years developed in 28 into diabetes. In 32 examined subjects (35.6%) the oral glucose tolerance test (oGTT) was repeatedly normal, however, 9 subjects developed in the course of 23 years diabetes, although the stage of impaired glucose tolerance was not recorded. oGGT in 11 patients (12.2%) was variable in the course of the follow-up, normal glucose tolerance alternated with impaired glucose tolerance. In three subjects (3.3%) repeated examinations are consistent with renal glycosuria. From the results ensues that subjects suspect of diabetes with a marked family-history of diabetes and who are moreover obese it is important to ensure monitoring on a long-term basis as positivity during the initial examination is low (3.3%), while during long-term follow up the prevalence of diabetes is 54%. In patients with an impaired glucose tolerance there is a high risk of the development of diabetes, although the stage of impaired glucose tolerance is not always detected.

Adult↗

PubMed1993

Repolarization pattern of body surface potential maps (BSPM) in coronary artery disease.

The aim of our study was to assess if repolarization BSPM were able to evaluate the site, size and severity of chronic ischaemic damages and if BSPM were in any way related to the regional attenuation of myocardial contractility or to the site of coronary artery occlusion. The BSPM were obtained from 69 patients suffering from coronary artery disease confirmed by coronarography, with at least 75% occlusion of at least one coronary artery. According to the site of single occlusion, or a combination of the sites of multiple occlusions, the patients were divided into 6 subgroups. According to the region of attenuated kinetics the same group of 69 patients was also divided into other 6 subgroups. As in the polarity distribution there was only a limited accordance in BSPM with coronarographic and echocardiographic findings, in the localization of extreme values there were very important specific changes in patients with normal kinetics as determined by both contrast ventriculography and two-dimensional echocardiography. The repolarization maps can distinguish patients with coronary artery disease and normal echocardiography from healthy persons with a sensitivity of 85% and a specificity of 65% in the case of the isoareal map from the ST segment (RIAM) and 90% and 85%, respectively, in the case of the isointegral map from the whole ST-T segments (RIIM).

Adult↗

PubMed1993

[Stress echocardiography in the selection of patients for coronarography].

Exercise echocardiography has in recent years become the best non-invasive method for detection of IHD. The authors made an investigation with the objective to test the feasibility of exercise echocardiography, under our technically imperfect but generally available conditions, for the selection of patients for coronarography. In 44 consecutive patients (30 men, 14 women, mean age 50 years) the authors used before planned coronarography exercise echocardiography and 24-hour monitoring of ECG according to Holter with evaluation of ST segments. The results of all three non-invasive methods were compared with the coronarographic findings. The criterium of positivity of coronarographies was 75% stenosis. Such a stenosis is an unequivocal indication for cardiosurgery or percutaneous angioplasty. On comparison of results of non-invasive examination methods with coronarographic findings the best indicators as regards reliability were obtained with exercise echocardiography. Its sensitivity was 71%, specificity 69%, positive predictive value 77% and negative predictive value 61%. The sensitivity of exercise echocardiography increased, depending on the number of affected arteries (50, 71 and 100%). On isolated evaluation of findings in individual main coronary arteries the sensitivity was highest in the area supplied from the ramus interventricularis anterior (67%), the specificity was 77%. For the ramus circumflexus the sensitivity was 50% and the specificity 96%. For the right coronary artery the sensitivity was 25% and the specificity 96%. The sensitivity of exercise ECG (44%) was even lower than Holter sensitivity (57%). The specificity, on the other hand, was lower in Holter (47%) than in exercise ECG (61%). Electrocardiographic methods were not, contrary to echocardiography, usable for evaluation fo the extent of damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Incidence and changes in mitral regurgitation in balloon valvotomy of the mitral valve. A color Doppler study].

The objective of the work was a detailed examination of the incidence and changes of mitral regurgitation (MR) in conjunction with percutaneous transluminal valvotomy of the mitral valve (VMCH). Using coloured Doppler mapping, the authors examined a total of 40 patients before and in the course of one week after VMCH. They assessed the number of regurgitation jets the site of their development, the timing and haemodynamic impact of MR. Knowing the site of development of MR, the authors were able to assess whether the regurgitation after VMCH persisted, developed de novo or disappeared. The total number of mitral regurgitation increased after VMCH from 38 to 51 (increase by 34%, p < 0.05) with a significant rise of the number of double regurgitation jets (4 before as compared with 12 after VMCH, p < 0.05). Before VMCH the authors recorded a holocystic MR in 53%, after VMCH in 86% of the patients (p < 0.01). While before VMCH almost half the regurgitation jets originated in the central portion of the valve, after VMCH MR originated mainly from the area of commissures (48% regurgitation jets before, 79% after VMCH, p < 0.01). Only in 33% of MR after VMCH persisting regurgitation was involved, almost half (47%) of 38 regurgitation jets present before VMCH, disappeared after valvulotomy. MR displays a considerable variability. This may be one of the reasons why prediction of the development and severity of MR after PTMV is difficult.

Catheterization↗

PubMed1992

Formation and 32P-postlabeling of DNA and tRNA adducts derived from peroxidative activation of carcinogenic azo dye N,N-dimethyl-4-aminoazobenzene.

Peroxidase in the presence of hydrogen peroxide catalyzes in vitro the activation of carcinogenic N,N-dimethyl-4-aminoazobenzene (DAB) to DNA-, tRNA- and homopolydeoxyribonucleotide-bound products. tRNA is the most susceptible to modification by the activated DAB. Binding of DAB products to macromolecules is inhibited by methyl viologen, nitrosobenzene, ascorbate, glutathione, NADH and MgCl2. The mechanism of these inhibitions was studied. The nuclease P1 version of the 32P-postlabeling assay was employed for detection and quantitation of some major DNA or tRNA adducts formed with DAB activated by a peroxidase system. tRNA modified by activated DAB shows a significantly increased acceptance for L-methionine.

Animals↗

PubMed1992

Heart in pituitary diseases.

Of hormones secreted by the pituitary, a direct effect on cardiac metabolism and function is exerted only by growth hormone (GH). Its chronic overproduction in adulthood leads to acromegaly. The main cardiovascular manifestations of acromegaly are hypertension and cardiac hypertrophy. The paper summarizes the results of clinical research into the "acromegalic heart" in an internationally unique group of 78 patients with acromegaly on long-term follow-up. Both clinical findings and experimental data available in the literature indicate that cardiac hypertrophy is due to a direct effect of GH on the myocardium. Hypertension occurs in 50% of patients, has the nature of volume hypertension and exerts only an additive effect on the development of left ventricular hypertrophy. Once GH overproduction has been eliminated, cardiac hypertrophy and hypertension can be reversed to a certain stage, a finding highlighting the necessity of instituting treatment of acromegaly as early and as vigorous as possible.

Acromegaly↗

PubMed1992

Heart in thyroid diseases.

The paper examines the basic pathophysiologic mechanisms playing a role in the development of cardiovascular changes on thyroid hyper- and hypofunction. The haemodynamic changes typically associated with increased and decreased secretion of thyroid hormones are described and compared. Using echocardiography, the haemodynamics changes are documented in 12 patients with hyperthyroidism and 19 patients with myxoedema prior to thyrostatic and substitution therapy. Characteristic findings in florid hyperthyroidism include a significant rise in left ventricular end-diastolic volume as well as increases in stroke volume (SV) and cardiac index (CI). Mean velocity of circumferential fibre shortening (mVCF) is also significantly increased. Left ventricular myocardial weight shows a tendency towards an increase. Hypothyreosis is primarily associated with decreases in SV and CI; mVCF also declines. The paper underlines the importance of causative therapy as the above haemodynamics changes are fully reversible on attaining normal thyroid function.

Hemodynamics↗

PubMed1992

Heart in adrenal diseases.

The paper reviews the hitherto rather scarce literature concerned with cardiac changes in phaeochromocytoma, primary hyperaldosteronism and Cushing syndrome, and presents the authors' own echocardiographic findings in these diseases. In phaeochromocytoma they found a slight thickening of the interventricular septum which, however, did not fulfil the criteria of asymmetric left ventricular hypertrophy. Also other parameters showed higher values attesting to an increased left ventricular mass, however, without exceeding normal limits. Focal disturbances of left ventricular kinetics and the decrease in LV systolic function were non significant. The picture of obstructive hypertrophic cardiomyopathy, frequently mentioned in the literature, was observed only once, giving grounds to the suspicion that it is only a nonspecific manifestation of the hypercontractile state of the myocardium. In primary hyperaldosteronism only slight posterior LV wall thickening and an increase in the LV mass index were found, compared to control group. No significant changes were found in Cushing syndrome besides a tendency to concentric LV hypertrophy. Echocardiographic changes observed in all three affections disappeared after successful surgical or drug treatment.

Adrenal Gland Neoplasms↗

PubMed1992

[Changing views on mitral valve prolapse].

Views regarding mitral valve prolapse, in particular its diagnosis and prognosis, have undergone great changes in recent years. The typical auscultation finding of a meso-systolic click and/or late systolic murmur is very specific for prolapse but it is not very sensitive. The basic diagnostic method of mitral valve prolapse is echocardiography. The non-realistic high prevalence of echocardiographic findings of prolapse in otherwise healthy subjects led recently to the introduction of stricter echocardiographic diagnostic criteria. The term mitral valve prolapse syndrome describes not confirmed association of anatomical valvular prolapse with non-specific symptoms of autonomous dysfunction. An attempt to explain non-specific complaints by an anatomical abnormality of the mitral valve has become very popular but, as increasingly apparent, is purely speculative. Controlled investigations provide evidence that the mitral valve prolapse syndrome does not exist that it is only an incidental coincidence of two conditions very frequently encountered in the population. The prognosis of the great majority of people with a mitral valve prolapse is very favourable. Only about 2-4% of subjects with prolapse are seriously threatened by complications such as infectious endocarditis, thromboembolic episodes, complex arrhythmias and sudden death. This small sub-group with a high risk is formed above all by patients with mitral insufficiency with severe haemodynamic impact. Independent negative prognostic signs are age above 50 years and male sex.

Humans↗

PubMed1991

[Significance of coronarography for therapeutic strategy in patients with ischemic heart disease].

In 100 consecutive patients where planned coronary arteriography was performed, in the majority on account of IHD, the authors analyzed retrospectively information on risk factors of IHD, medicamentous treatment and the reasons for coronarography, findings on the coronary arteries, the size and function of the left ventricle and the final choice of subsequent treatment. A significant finding on the coronary arteries (stenosis of more than 50%) was recorded in 65% of the patients, in 22% of the patients the coronarographic finding was normal, in another 7% only insignificant changes were found (stenosis of less than 50%) and in 6% of the patients on coronarography a spasm of the coronary artery was recorded. A bypass operation was performed in 15% of the patients subjected to coronarography, in another 6% successful PTCA was performed, i.e. a total of 21% patients were revascularized. These results are compared with those of other departments in Czechoslovakia and abroad and the causes of revealed differences are discussed. Finally the authors emphasize the necessity of stratification of IHD patients according to risk and the selection of suitable candidates of coronarography and subsequent possible revascularization of the heart muscle according to accepted criteria for indication.

Adult↗

PubMed1991

The effect of metoprolol on left ventricular systolic and diastolic function in essential hypertension.

Using ultrasound techniques, parameters of left ventricular systolic and diastolic function were assessed in 23 patients with degree I-II essential hypertension treated with metoprolol. Metoprolol administration was followed by increases in ejection fraction (p less than 0.01) and stroke volume (p less than 0.05), a decrease in heart rate (p less than 0.01) while cardiac output remained unchanged. Left ventricular filling was abnormal in 12 patients (52.2%). After metoprolol, the ratio of early diastolic to late diastolic transmitral velocity (E/A) rose; the increase indirectly correlated both with the baseline value of E/A (r = -0.59, p less than 0.01), and the change in heart rate (t = -0.65, p less than 0.01). Improved left ventricular diastolic filling was significant only in patients showing abnormal baseline diastolic function, and may be due to the decrease in heart rate rather than a direct effect exerted by metoprolol on the myocardium.

Adult↗

PubMed1990

[Pregnancy and labor in women with mitral valve prolapse].

In a prospective study the authors investigated 30 pregnant women (mean age 27 +/- 5.5 years) with prolapse of the mitral valve confirmed on echocardiography, without significant mitral regurgitation, in order to assess whether mitral valve prolapse is a risk factor for the development of complications during gestation and childbirth. As control served a group of 30 healthy pregnant women of corresponding age and number of previous pregnancies, incidence of complications during pregnancy, the type of delivery, sex, length, weight and maturity of the neonates. In women with mitral valve prolapse the authors recorded a significantly higher incidence of subjective complaints such as palpitations associated in 7 of 8 cases with sinus tachycardia 110-140/min. at rest and with vasovagal syncopes. The palpitations were always favourably influenced by beta-blocker therapy or by calcium antagonists. Mitral valve prolapse without haemodynamically significant mitral regurgitation during pregnancy is not a significant risk factor for the development of complications.

Adult↗

PubMed1990

[Disorders of the cardiovascular system in Turner's syndrome].

A group of 22 adults with Turner's syndrome, mean age 29.6 years, was subjected to a careful examination by one-dimensional, two-dimensional, pulsed and coloured Doppler echocardiography. The purpose was to assess the incidence and character of congenital and acquired abnormalities of the cardiovascular system which occur within the framework of this defined genetic syndrome. A quite normal echocardiographic finding was recorded in 13 patients, i. e. in 59.1%. In the remainder a wide spectrum of abnormalities was found such as prolapse of the mitral valve (in 13.6%), bicuspid aortal valve with a medium regurgitation (4.5%), hypoplasia of the coronary cusp of the aortal valve (4.5%), dilatation of the ascending aorta with a residual significant stenosis at the site after operation of coarctation of the thoracic aorta (4.5%), subaortal defect of the interventricular septum (4.5%) and slight left ventricular hypertrophy in patients with arterial hypertension (9.1%). Echocardiographic examination in Turner's syndrome makes early diagnosis of abnormalities of the cardiovascular system possible, incl. quantification of the haemodynamic impact. Some of these pathological changes (bicuspid aortal valve, dilatation of the root of the aorta) are for a long time clinically silent but may be nevertheless associated with serious complications. An echographic diagnosis made in time may be of decisive importance for the prevention of complications.

Adolescent↗

PubMed1990

[The effect of OROS metoprolol in mild and moderately severe essential hypertension].

The authors tested in an open, uncontrolled trial in a group of 23 patients with essential hypertension grade I-II (WHO classification) the effect of Metoprolol OROS. The OROS system is a new form of Metoprolol administration which makes it possible to maintain by a single dose per day a steady plasma concentration, while preserving the cardioselectivity and total 24-hour effectiveness during treatment of hypertension and angina pectoris. After eight weeks of Metoprolol OROS administration, in doses gradually adjusted to the therapeutic action, gradually a significant decrease of the heart rate (HR) occurred, of the systolic blood pressure (BPs) and diastolic blood pressure (BPd) (p less than 0.01 for all values) in a recumbent as well as upright position. A reduction of the BPd in an upright position by greater than or equal to 10 mm Hg was achieved in 85% of the patients, in 73.9% of the patients the BPd in an upright position dropped below 95 mm Hg. Four patients developed side-effects which were mild to medium severe (vertigo, palpitations, fatigue, sensation of tremor, tension in the lower extremities). Two patients discontinued treatment early, the main reason in both being palpitations which were under better conversely, in two patients palpitations which were not adequately controlled by previous metoprolol treatment, disappeared completely during Metoprolol OROS treatment. During the trial no significant changes in the investigated laboratory values incl. total cholesterol were recorded, Metoprolol OROS administered once per day is an effective, safe and well tolerated preparation in treatment of mild to medium severe essential hypertension.

Adult↗