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Biomedical subjects

A Westheim

Publications and source records attributed to A Westheim.

At least 37 records · Page 2Linked to original sources
PubMed1994

Left ventricular mass and cardiovascular reactivity in young men.

The relation between left ventricular wall thickness and mass, arterial plasma catecholamines, and blood pressure at rest and during a mental arithmetic challenge and a cold pressor test was examined in 69 healthy men 19 years of age. The subjects were recruited from the 1st (n = 21), 50th (n = 26), and 99th (n = 22) percentiles in mean blood pressure. All underwent echocardiography to determine mean wall thickness and left ventricular mass. Continuous intra-arterial blood pressure, electrocardiogram, and arterial sampling of plasma catecholamines were performed after 30 minutes of supine rest, during a 5-minute mental arithmetic challenge, and during a 1-minute cold pressor test. Stepwise multiple-regression analyses considering mean wall thickness and left ventricular mass as the dependent variables were applied. Intra-arterial systolic blood pressure (r = .54, P < .0001) and arterial plasma epinephrine (r = .31, P = .009) after 30 minutes of supine rest were the only independent explanatory variables of mean wall thickness (multiple R2 = .33, P < .0001). Blood pressure at screening and during mental stress and cold pressor tests were not independent explanatory variables. The present study suggests that resting arterial blood pressure and plasma epinephrine may be of importance for development of left ventricular hypertrophy.

Adult↗
PubMed1993

[Physical activity and the metabolic syndrome].

Hypertension may be accompanied by decreased insulin sensitivity, lipid abnormalities and increased haemostatic risk, all of which, constitute risk factors for coronary artery disease. Modifications of lifestyle, including more physical exercise, are important, and may reduce the coronary risk profile. Physical activity has been shown to lower blood pressure, reduce hypertriglyceridemia, improve insulin sensitivity and increase the fibrinolytic capacity. Hypertensive patients should be encouraged to increase physical activity as an adjuvans to both pharmacological and non-pharmacological treatment of high blood pressure.

Cardiovascular Diseases↗
PubMed1993

Sex differences in essential hypertension.

A group of 41-year-old hypertensive men (n = 35, blood pressure (BP) 149.9 +/- 2.1/98.9 +/- 1.1 mmHg, mean +/- SEM) who had never received treatment for their condition were compared with hypertensive women of the same age (n = 18, BP 155.9 +/- 4.3/98.1 +/- 1.6 mmHg) with comparable body mass index (BMI, 25.9 +/- 0.5 vs. 24.9 +/- 4.5 kg m-2) who, also, had never received treatment. The lipid profile was more atherogenic in the men, with lower HDL cholesterol (1.21 +/- 0.04 vs. 1.38 +/- 0.06 mmol l-1, P = 0.04), higher total cholesterol (6.04 +/- 0.14 vs. 5.54 +/- 0.18 mmol l-1, P = 0.04) and triglycerides (1.80 +/- 0.16 vs. 0.96 +/- 0.10 mmol l-1, P < 0.001). The hypertensive men had higher haemoglobin (P < 0.001) and haematocrit. Plasma catecholamines were inversely related to BMI in the women only (r = -0.52, P < 0.05 for both noradrenaline and adrenaline). Women with BMI above 25 kg m-2 had significantly lower arterial plasma adrenaline and noradrenaline than those with BMI below 25 kg m-2 (28 +/- 5 vs. 78 +/- 16 pg ml-1, P < 0.01 and 101 +/- 17 vs. 206 +/- 33 pg ml-1, P < 0.01 respectively). A negative curvilinear relationship appeared between arterial adrenaline and insulin (r = 0.49, P = 0.05). These results suggest a male propensity for athero-thrombogenic risk factors in otherwise comparable hypertensive subjects. A close relationship between metabolic risk factors within the normal range seems to exist even in hypertensive women. The decreased sympathetic activity at rest in the obese hypertensive women indicates different pathophysiological mechanism for hypertension in lean and obese. Decreased sympathetic activity and thus reduced energy expenditure, promotes a risk for weight gain, and could explain the inverse relationship between insulin and adrenaline.

Adult↗
PubMed1993

Regional differences of atrial natriuretic factors in humans.

During sinus coronarius catheterization in humans undergoing diagnostic right-sided cardiac catheterization, levels of atrial natriuretic factor (ANF) measured in sinus coronarius (n = 12) were four times higher than in peripheral arterial blood. Atrial natriuretic factor underwent average extractions of 0.57, 0.40, and 0.28 in the kidneys (n = 14), liver (n = 15), and forearm (n = 15) respectively. However, a close relationship was observed between arterial and peripheral venous concentrations. The substantial clearance of ANF even over the forearm indicates that arterial sampling may be preferred in conditions with altered peripheral vascular resistance, since an uptake of ANF in the peripheral vascular bed is likely to have occurred.

Aged↗
PubMed1993

Cardiovascular reactivity, coronary risk factors, and sympathetic activity in young men.

We have previously demonstrated that awareness of high blood pressure may increase blood pressure, plasma catecholamine levels, and stress responses. In the present study, three groups of 19-year-old men, all unaware of their blood pressure status, were selected from the first (group-1, 62 +/- 2 mm Hg, [mean +/- SEM], n = 15), 50th (group-50, 90 +/- 4 mm Hg, n = 15), and 99th (group-99, 123 +/- 5 mm Hg, n = 14) percentiles in causal mean blood pressure at a screening. They were studied (blinded examiners) with intra-arterial blood pressure recordings and multiple measurements of arterial plasma epinephrine and norepinephrine during a mental arithmetic challenge and cold pressor test. Despite high mean blood pressure at the screening, group-99 did not differ from group-50 either in intra-arterial mean blood pressure after 30 minutes of supine rest (89 +/- 3 versus 86 +/- 2 mm Hg) or in serum lipids and resting plasma epinephrine and norepinephrine. However, in group-99 resting plasma epinephrine showed a positive hyperbolic relation to resting diastolic blood pressure (r = .73, P = .004) and a negative hyperbolic relation to the ratio of high-density lipoprotein cholesterol to total cholesterol (r = -.75, P = .002). None of these correlations were present in the two other groups. Furthermore, the three groups differed in heart rate responses (P < .0005) and systolic (P < .0005) and diastolic (P < .05) blood pressure responses to mental arithmetic challenge, group-99 being hyperreactive compared with the other two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Haemodynamic and neurohumoral effects of cold pressor test in severe heart failure.

The effect of a cold pressor test (CPT) on haemodynamics in relation to general and regional sympathetic activity and arginin vasopressin (AVP), was studied in eleven patients with severe congestive heart failure (CHF). Compared to an age-matched control group (C), resting arterial plasma noradrenaline (NA) (419 +/- 77 vs. 182 +/- 15 pg ml-1), and adrenaline (A) (142 +/- 28 vs 54 +/- 10 pg ml-1) were higher (P less than 0.05) in CHF. AVP showed no significant difference (14 +/- 4 vs. 9 +/- 4 pg ml-1). During CPT systolic and diastolic blood pressure and systemic vascular resistance increased (P less than 0.01), as did NA (delta 114 +/- 39 pg ml-1, P less than 0.01), A (delta 33 +/- 10 pg ml-1, P less than 0.01) and heart rate (delta 10 beats min-1, P less than 0.01). The myocardial v-a difference of NA decreased (P less than 0.05), but was unchanged across the renal vascular bed during CPT. The a-v difference of NA in the hepatic vascular bed, and fractional extraction of A in the coronary sinus, renal and hepatic vascular beds remained unchanged during CPT. AVP did not change significantly and no change in cardiac index or left ventricular filling pressure was observed during CPT. These data suggest that despite an increased activation of the sympathetic nervous system at rest, a further increase in blood pressure and catecholamines took place during CPT. Thus, the effect of a CPT which activates the central sympathetic system seems not to be altered in patients with severe CHF.

Aged↗
PubMed1992

Physical activity and the metabolic cardiovascular syndrome.

Hyperinsulinemia, lipid abnormalities, and impaired fibrinolytic capacity may accompany hypertension, and comprise the metabolic cardiovascular syndrome. They are all independent risk factors for coronary artery disease. Lifestyle modifications can reduce the coronary artery risk. Physical activity has been shown to improve insulin sensitivity, reduce hypertriglyceridemia, improve fibrinolytic capacity, and reduce the blood pressure. A sedentary lifestyle is associated with increased mortality compared to a physically active lifestyle. Hypertensive patients, who often have other atherothrombogenic risk factors, should be encouraged to undertake physical activity as an adjuvant to other nonpharmacological interventions as well as to pharmacological treatment.

Blood Pressure↗
PubMed1991

[Ambulatory non-invasive 24-hour blood pressure measurement--do we need it?].

The introduction of non-invasive, portable, automatic blood pressure measurement devices enables characterization of the blood pressure profile throughout the day in an ambulatory setting. The article advises against uncritical use. 24-hour ambulatory blood pressure measurements have become a valuable tool in scientific research, however, especially in studies dealing with antihypertensive efficacy. In hypertensive patients with "white coat hypertension", important data cannot be obtained without the use of 24-hour ambulatory blood pressure monitoring or blood pressure measurement at home.

Ambulatory Care↗
PubMed1991

[The effect of doxazosin on blood pressure, lipids, fibrinogen and plasminogen activator inhibitor. A comparative study among smokers and non-smokers with essential hypertension].

Hypertensive cigarette smokers run particularly high risk of coronary heart disease. Doxazosin, which has beneficial effects on haemodynamic factors and lipid metabolism, may be a suitable agent for treating these patients. The effects on blood pressure and metabolic parameters were investigated in a 16-week, open, parallel, comparative study comprising 64 heavy cigarette smokers and 69 non-smokers who received doxazosin after four weeks on placebo. Eight patients (three smokers and five non-smokers) dropped out due to adverse effects. Blood pressure was significantly reduced in both groups, but there was no change in heart rate. Doxazosin induced a decrease in the triglyceride, total cholesterol and LDL-cholesterol levels, and an increase in HDL-cholesterol concentration. Thus, doxazosin has favourable effects on atherogenic factors in smoking hypertensive patients. There was also a significant lowering of plasma fibrinogen levels and plasminogen activator inhibitor (PAI-1) concentration in non-smokers.

Adult↗
PubMed1991

Awareness of high blood pressure increases arterial plasma catecholamines, platelet noradrenaline and adrenergic responses to mental stress.

Thirty-six, 19-year-old men within the 95th percentile of mean blood pressure (110 mmHg) at a routine medical screening were randomized into two groups and requested to return for a follow-up visit in 2 weeks. One group was sent a neutral letter, while the other was sent a letter conveying the information that their blood pressures were elevated. After 15 min sitting in the laboratory, there was a significantly higher heart rate (P less than 0.05) in the informed group. Thirteen informed and 13 uninformed subjects were examined further by intra-arterial blood pressure recording and serial sampling of arterial catecholamines during cold pressor and mental stress tests. The study was undertaken examiner-blind. Informing the subjects of high blood pressure increased both baseline plasma noradrenaline (P less than 0.01) and adrenaline (P less than 0.05) and intraplatelet noradrenaline (P less than 0.05). Blood pressure (P less than 0.05) and heart rate (P less than 0.05) increased significantly more in the informed group when the subjects were told of the cold pressor test. In addition, there were exaggerated adrenaline (P less than 0.05) and diastolic blood pressure (P less than 0.05) responses to mental stress in the informed group. Thus, awareness of high blood pressure in young men may increase sympathetic tone and responses as measured in the laboratory. Conclusions from studies on early pathogenesis of essential hypertension should therefore be drawn with more caution when patients are aware of their high blood pressure.

Adult↗
PubMed1991

Faster and more reliable absorption of adrenaline by aerosol inhalation than by subcutaneous injection.

1. The aim of the present study was to compare absorption of adrenaline given by aerosol spray inhalation with absorption after subcutaneous injection. 2. Arterial plasma adrenaline was measured in nine healthy volunteers following adrenaline administration by both methods. 3. Following inhalation of 20 puffs of adrenaline aerosol, 0.15 mg/puff, a peak arterial adrenaline concentration after 1 min and a rapid fall to baseline from this peak occurred. 4. When given by subcutaneous injection absorption was slower with a peak arterial adrenaline concentration after 4 min. The fall in arterial adrenaline from this peak level was not statistically significant within 30 min after injection. 5. There was less intersubject variation of arterial adrenaline concentration following inhalation when compared with injection. 6. Heart rate, blood pressure and finger tremor followed the changes in arterial adrenaline concentrations. 7. These results indicate that absorption is more reliable when adrenaline is given by inhalation. The rapid fall in arterial adrenaline following inhalation, suggests that repeated inhalations are necessary when such adrenaline therapy is required.

Absorption↗
PubMed1990

Doxazosin in combination with atenolol in essential hypertension: a double-blind placebo-controlled multicentre trial.

Doxazosin (mean dose 11 mg) given once daily in combination with 100 mg atenolol (n = 44) was compared with placebo and atenolol (n = 43) in a double-blind, multicenter study in patients with mild to moderate essential hypertension. In the atenolol/doxazosin-treated group, standing blood pressure significantly decreased by 17.0/12.3 mm Hg compared to 6.2/6.7 mm Hg in the atenolol/placebo group whereas supine blood pressure decreased by 13.2/9.8 mm Hg and 9.2/6.0 mm Hg, respectively in the two groups. Serum lipids did not change significantly in either group. The majority of side-effects reported were mild and transient. This study confirms that doxazosin may be safely combined with a beta-blocker. Doxazosin proved to be well tolerated and effective in patients with blood pressure refractory to atenolol alone.

Adolescent↗
PubMed1990

Renal haemodynamic and sympathetic responses to head-up tilt in essential hypertension.

Nine mild-to-moderate hypertensive patients (HT), aged 41 +/- 0.6 years (mean +/- SEM) and nine age-matched normotensive control subjects (NT) were tilted to 60 degrees for 10 min. During tilt, both systolic (S) blood pressure (BP) (p less than 0.01) and diastolic (D) BP (p less than 0.05) increased in HT, but not in NT. At supine rest renal blood flow was higher in HT than in NT and increased by 17% in HT during tilt, while a decrease of 13% was observed in NT (p less than 0.05). Renal vascular resistance was unchanged in HT during tilt, while a significant increase (p less than 0.01) was observed in NT. Arterial plasma noradrenaline increased in both groups (p less than 0.05) during tilt, significantly more in HT than in NT (p less than 0.05). No statistically significant difference was observed between the groups in renal catecholamine uptake or release. Our data indicate enhanced general sympathetic and circulatory responses to tilt in subjects with mild-to-moderate essential hypertension. However, the enhanced haemodynamic and sympathetic responses were not shared by hypertensive kidneys and renovascular resistance remained unaffected by tilt.

Adult↗
PubMed1990

Selective alpha 1 inhibition with doxazosin in hypertensive smokers and non-smokers: haemodynamic and metabolic effects.

Hypertensive cigarette smokers have an especially high risk of coronary heart disease. Doxazosin, which has beneficial effects on haemodynamic factors and lipid metabolism, may be suitable for treating these patients. The haemodynamic and metabolic effects of doxazosin were investigated in a 16-week open, parallel, comparative study of 64 heavy cigarette smokers and 69 non-smokers after a 4-week placebo period. Of the 133 patients who entered, six patients (one smoker and five non-smokers) withdrew due to adverse events. Doxazosin significantly reduced blood pressure without reflex tachycardia in both the smokers and the non-smokers. The therapeutic success rates (reduction in sitting diastolic blood pressure to less than or equal to 90 mmHg and greater than or equal to 5 mmHg reduction, or greater than or equal to 10 mmHg reduction from baseline) were similar for the smokers (93.3%) and the non-smokers (92.5%). Doxazosin significantly decreased total cholesterol and low-density lipoprotein (LDL) cholesterol, but increased high-density lipoprotein (HDL) cholesterol and the HDL:total cholesterol ratio in both smokers and non-smokers. Doxazosin corrected the reduction in HDL cholesterol caused by smoking; compared with baseline, doxazosin increased HDL cholesterol by 19% in hypertensive smokers. The beneficial effects of doxazosin on blood pressure and the lipid profile were apparent in the change in the 10-year probability of developing coronary heart disease as calculated by the Framingham equation; the calculated risk of coronary heart disease decreased by 39% in smokers and by 33% in non-smokers. Plasma fibrinogen and plasminogen activator inhibitor, which independently contribute to atherosclerosis, were significantly reduced by doxazosin in the non-smokers but not in the smokers.

Adrenergic alpha-Antagonists↗
PubMed1989

Late sequelae of lung contusion.

Twenty-four patients with severe lung contusion and multiple rib fractures were studied at a mean 4.9 years (range 2-9 years) after injury. All patients had been in good health before the accident. After the accident 15 (63 per cent) patients had respiratory symptoms such as dyspnoea at rest or moderate exercise (4), pain (8), cough or increased expectoration (11) and frequent bronchopulmonary infections (5). Three patients had changed their job because of respiratory disturbance. The average vital capacity, forced expiratory volume in 1 s, maximal voluntary ventilation and CO transfer factor were reduced respectively to 87, 88, 82 and 83 per cent of predicted values (P less than 0.01), while total lung capacity, residual volume and helium mixing time showed no definite changes (P greater than 0.05). Arterial blood gases at rest and at maximum exercise showed slight changes only. Maximal working capacity and ECG, as well as the ventilatory cost of moderate exercise were normal, where as the CO2 recovery time after moderate exercise was slightly increased (P less than 0.05). Overall there was a tendency towards poorer function in patients treated with artificial ventilation. Chest radiographs were normal in 10 patients (42 per cent), and moderate changes were seen in 14 patients. Diaphragmatic movements were essentially normal in all patients. Severe injury to the chest causes frequent respiratory symptoms. However, objective tests were only moderately reduced when compared with normal values. There was no unequivocal association between the subjective symptoms and the pulmonary function.

Adult↗
PubMed1989

Effect of dopamine and dopamine-antagonist infusion on blood platelet count, size and release reaction in hypertensive and normotensive subjects.

To examine the effect of dopamine on in vivo platelet function and a possible platelet contribution to the clearance of dopamine we measured platelet count, platelet size and plasma concentration of the platelet specific protein beta-thromboglobulin (BTG) in groups of 40 year old untreated hypertensive and normotensive men. One hypertensive (n = 10) and one normotensive (n = 10) group received dopamine infusion at doses from 0.5 to 2.0 micrograms/kg/min which increased plasma dopamine 100-fold from baseline. Two other groups of hypertensive (n = 10) and normotensive (n = 11) subjects received 10 mg of the dopamine antagonist metoclopramide intravenously, upon which serum prolactin concentration increased 10-fold. No significant effect on platelet function in any group was observed during these interventions. Platelet phenol-sulphotransferase may contribute to dopamine conjugation. However, the selected platelet parameters correlated only weakly with dopamine kinetics during the infusion. Neither dopamine nor a dopamine antagonist altered the selected platelet parameters, nor did these parameters influence the clearance of dopamine during a short-lasting pharmacological infusion.

Blood Platelets↗
PubMed1988

Decreased serum phosphate in essential hypertension. Related to increased sympathetic tone.

Forty-year old men with untreated mild essential hypertension (n = 35) had decreased serum phosphate (P less than 0.001) concomitant with elevated resting plasma epinephrine (P less than 0.05) and heart rate (P less than 0.001) compared with age-matched, normotensive control men (n = 44). Blood pressure correlated negatively with serum phosphate (P less than 0.001) and positively with plasma epinephrine (P less than 0.01) and heart rate (P less than 0.01). Serum phosphate was significantly lowered during infusion of epinephrine, increasing arterial plasma epinephrine within the lower pathophysiological range corresponding to arousal reactions. Serum concentrations of immunoreactive parathyroid hormone were unchanged. Thus, hypophosphatemia in patients with mild essential hypertension appears to be inversely related to sympathetic adrenal tone and may be caused by increased plasma epinephrine within pathophysiologic arterial concentrations.

Adult↗