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Biomedical subjects

G Muiesan

Publications and source records attributed to G Muiesan.

At least 91 records · Page 5Linked to original sources
PubMed1980

Influence of the sympathetic nervous system on aortic compliance.

1. Aortic compliance and plasma catecholamine levels were determined in 26 essential hypertensive patients: 14 < 45 years (group 1) and 12 > 45 years (group 2). 2. Aortic rigidity, the reciprocal of aortic compliance, was calculated by the ratio of pulse pressure to stroke volume. Pulse pressure was derived by arterial pressure measured in the ascending aorta. Stroke volume was obtained by dye dilution. 3. A significant correlation (r = 0.60) was found between aortic rigidity and plasma noradrenaline in group 2. In this group both aortic rigidity and plasma noradrenaline levels were consistently higher than in group 1. 4. In 15 patients (seven of group 1 and eight of group 2) aortic rigidity was again measured after acute phentolamine (five patients) and labetalol (ten patients) administration. 5. Aortic rigidity was reduced significantly after both alpha-adrenoreceptor blockade alone and combined alpha- and beta-adrenoreceptor blockade. A highly significant correlation was found between aortic rigidity reduction and pretreatment noradrenaline levels (r = 0.77). 6. Aortic compliance is influenced, at least in part, by sympathetic nervous system activity. Drugs which block the peripheral effects of catecholamines may improve aortic compliance and consequently the control of systolic hypertension in selected cases.

Adult↗
PubMed1980

[A comparative evaluation of metoprolol and methyldopa in hypertension therapy (author's transl)].

The antihypertensive effect and the tolerability of the cardioselective beta-blocking drug metoprolol, in comparison to methyldopa, were assessed in 119 hypertensive patients (73 WHO stage 1 and 46 WHO stage 2). After 2 weeks of placebo wash-out, the patients were randomly allocated to treatment with either of the two drugs: metoprolol up to 200 mg bid, and methyldopa up to 500 mg bid, for 6 weeks. Periodical clinical, biochemical, haematological, radiological and electrocardiographical measurements were performed. In respect to pre-treatment values, heart rate, both in lying and standing position, was significantly reduced (P less than 0.01) only in the metoprolol group, while systolic and diastolic blood pressures were significantly reduced (P less than 0.01) with both drugs in both positions. Asymptotic regression analysis showed that velocity of blood pressure reduction was comparable with both drugs. In the lying position, the diastolic blood pressure reduction obtained with metoprolol was significantly greater (P less than 0.05) in respect to that obtained with methyldopa. In general, side effects were few and of mild severity: mainly bradycardia in the metoprolol group and dizziness and fatigue in the methyldopa group. After the formal end of the double-blind trial, 36 patients, 14 in the metoprolol group and 22 in the methyldopa group, were treated in open conditions with metoprolol alone; after an average period of 6.5 weeks, diastolic blood pressure was significantly reduced (P less than 0.05) only in the group previously treated with methyldopa. In conclusion, metoprolol is a well tolerated and effective antihypertensive agent, which may be safely used in patients with mild to moderate hypertension.

Adult↗
PubMed1980

Antihypertensive activity of a fixed combination of oxprenolol and chlorthalidone in mild to moderate arterial hypertension.

In a multicentre double-blind study, 92 out-patients with mild to moderate hypertension who had a resting blood pressure greater than or equal to 160/100 mmHg after a two-weeks' placebo wash-out were treated for 6 weeks with a fixed combination of oxprenolol 80 mg + chlorthalidone 10 mg per tablet or chlorthalidone alone (1 tablet = 10 mg). Five patients were drop-outs, 19 out of 44 patients on fixed combination and 7 out of 43 on chlorthalidone were given only 1 tablet b.i.d. throughout the study; the remaining doubled the corresponding dosage after the first 2 weeks. Resting and standing systolic and diastolic blood pressure decreased on both treatments, the reductions being significantly more marked on fixed combination in comparison to chlorthalidone alone (p < 0.01 and p < 0.05). The systolic blood pressure decrease was significantly greater on fixed combination from the first week of treatment (p < 0.05). Normalization of diastolic blood pressure was reached more frequently on fixed combination (73%) than on chlorthalidone (49%) (p < 0.05). Side-effects were recorded in 14 out of 44 patients treated with fixed combination and in 14 out of 43 treated with chlorthalidone. The advantages of treating patients with mild to moderate hypertension with a fixed combination of beta-blocker and diuretics are discussed.

Chlorthalidone↗
PubMed1979

Acute and chronic effects of nifedipine on plasma renin activity and plasma adrenaline and noradrenaline in controls and hypertensive patients.

1. Nifedipine, a calcium antagonist drug, was given sublingually (10 mg) to seven normal subjects and 19 patients with essential hypertension. In addition, 12 of the hypertensive subjects then received nifedipine (10 mg thrice daily) for 3 weeks. 2. Sublingual administration of nifedipine in hypertensive patients induced a prompt and sustained reduction of blood pressure, without a significant increase of heart rate; in normotensive subjects blood pressure did not change, and heart rate was significantly increased. After chronic treatment, blood pressure remained reduced and heart rate did not rise. 3. Plasma catecholamines and plasma renin activity increased significantly in normotensive subjects after acute administration. 4. After both acute and chronic administration, only plasma noradrenaline was significantly increased in hypertensive patients; in long-term treatment, it was increased in both the lying and standing positions. 5. Nifedipine is an active antihypertensive drug, which may induce some degree of sympathetic activation.

Adult↗
PubMed1979

Catecholamines and haemodynamics in fixed essential hypertension.

1. Arterial plasma catecholamines and haemodynamic status were simultaneously studied in 27 patients with fixed essential hypertension (WHO I-II). 2. Total arterial plasma catecholamines were found to be directly related to mean arterial pressure and to calculated total peripheral resistance, and they were inversely related to stroke index. 3. The degree of total peripheral resistance reduction after alpha-receptor blockade (phentolamine 10 mg intravenously) and the degree of mean arterial pressure reduction after combined alpha- and beta- receptor blockade (labetalol 100 mg intravenously) were directly related to pretreatment plasma catecholamine concentrations. 4. These findings support the view that the sympathetic nervous system, as evaluated by plasma catecholamine concentration, may have an important role in maintaining hypertension in a subgroup of patients, contributing mainly to the degree of peripheral vasoconstriction.

Adult↗
PubMed1979

Risk factors in hypertension and ischaemic heart disease.

Among the identified precursors of cardiovascular disease hypertension acts as a major risk factor. Hyperlipidaemia, hyperglycaemia and cigarette smoking are the other major factors that increase the risk of symptomatic cardiovascular disease (CVD). Other factors influence (obesity, stress, hyperuricaemia, etc.) but are not independent risk factors. More definitive information on the efficacy of multifactorial intervention is needed.

Animals↗
PubMed1979

[Tienilic acid in the treatment of arterial hypertension and congestive cardiac insufficiency].

Tienilic acid (TA) is a common new diuretic agent with a potent uricosuric action. In a double-blind cross-over study its antihypertensive effect was compared to that of hydrochlorothiazide (HCT). 20 patients with essential hypertension were studied: after I weeks of placebo wash-out 10 patients received TA (dose range 250-750 mg/die) and 10 HCT (dose range 50-150 mg/die), for 5 weeks. Systolic and diastolic blood pressures were significantly and equally reduced (p < 0.001) after the first week of treatment in both groups. While serum uric acid concentration increased after HCT, it was significantly reduced (p < 0.001) after TA treatment. Serum potassium was slightly reduced with both treatments. Serum tryglicerides, unchanged after HCT, showed a slight tendency to reduction on TA treatment. Ten patients with congestive heart failure, on full digitalis treatment, were given TA (dose range 250-1000 mg/die): in each patient a prompt diuretic effect was observed, associated to a significant reduction of body weight and to a marked improvement of the clinical signs of heart failure. Therefore, TA is an effective diuretic agent which may be conveniently used in the treatment of arterial hypertension and congestive heart failure, as it induces a diuretic effect comparable to that obtained with HCT, reducing at the same time, serum uric acid levels.

Adult↗
PubMed1978

Antihypertensive activity of alpha-methyldopa on a twice daily regimen in comparison to metoprolol. A multi-centre controlled clinical trial.

1. The antihypertensive effects of alpha-methyldopa and metoprolol have been compared in 110 patients (fifty-one males and fifty-nine females) with previously untreated essential hypertension (sixty-eight WHO stage 1 and forty-two WHO stage 2). 2. After 2 weeks of placebo, the patients were randomly allocated to treatment with either of the two drugs: alpha-methyldopa up to 500 mg b.i.d. and metroprolol up to 200 mg b.i.d. for 6 weeks. Periodical clinical, biochemical, haematological, radiological and electrocardiographical measurements were performed. 3. The average reduction in blood pressure produced by the two drugs was comparable. 4. In general, side-effects were few and tolerable: mainly bradycardia in the metoprolol group and dizziness and drowsiness in the alpha-methyldopa group. 5. The plasma renin activity was significantly reduced in the metoprolol but not in the alpha-methyldopa group.

Adult↗
PubMed1976

Evaluation of the effect of timolol alone and in combination with hydrochlorothiazide and amiloride in the treatment of mild to moderate arterial hypertension: a double-blind, controlled study.

1. The effects of timolol alone and in combination with a fixed dose of hydrochlorothiazide and amiloride have been studied in a double-blind, controlled study in fifty-four patients with mild to moderate essential hypertension. 2. After a 4 weeks placebo period patients were randomly assigned to enter groups receiving timolol alone (group A), hydrochlorothiazide + amiloride (group B) or timolol + hydrochlorothiazide + amiloride (group C). Each treatment was carried out for 6 weeks. 3. The use of timolol (10 mg), hydrochlorothiazide (25 mg) and amiloride (2-5 mg) in a combination tablet given twice daily gave better control of blood pressure in patients with mild to moderate essential hypertension than did equivalent dosages of timolol alone or of hydrochlorothiazide and amiloride. 4. Clinical and laboratory side effects were minimal.

Adult↗
PubMed1975

Hypotensive effect of oxprenolol in mild to moderate hypertension: a multicentre controlled study.

In a multicentre, double-blind, between-patient study the hypotensive effect of oxprenolol was investigated in 329 patients with mild to moderate hypertension. A factorial experimental design with three factors was chosen: oxprenolol--none or daily doses of 20, 40, 60 and 80 mg; dihydralazine and hydrochlorothiazide, respectively, none or 30 mg daily. Each treatment was given for 4 weeks after an adequate period of withdrawal from any other possible hypotensive therapy and one week of placebo wash-out. Irresponsive of the association with dihydralazine and/or hydrochlorothiazide, oxprenolol had a hypotensive effect linearly related to dose for standing systolic (P less than 0.05) and diastolic (P less than 0.01) pressure, and for lying diastolic (P less than 0.05) pressure. The additional of dihydralazine enhanced the time-course of the hypotensive effect of oxprenolol, particularly the 80 mg dose level. In general, the combination of oxprenolol with dihydralazine and hydrochlorothiazide caused larger reductions in blood pressure, particularly with oxprenolol 80 mg. In the latter group, the eventual falls in blood pressure were 30.5 and 14.4 mmHg for lying systolic and diastolic, respectively; and 32.1 and 20.0 mmHg for the standing systolic and diastolic pressures. The drug was well tolerated; major side effects (heart failure and bronchospasm) occurred in three patients.

Clinical Trials as Topic↗
PubMed1975

Effect of oxprenolol on catecholamines and plasma renin activity: acute response to frusemide in hypertensive patients.

1. Catecholamine plasma concentrations and urinary excretion were measured together with plasma renin activity in ten patients with essential hypertension and in five normal control subjects before and after a frusemide challenge. 2. The same procedure was repeated in the same subjects 3--4 days later after pretreatment with oxprenolol. 3. Noradrenaline plasma concentrations and urinary excretion increased significantly after frusemide in all cases, returning to normal values at 30 and 60 min. Adrenaline plasma concentrations and urinary excretion were unchanged. 4. Plasma renin activity increased significantly in seven patients with hypertension and normal renin basal values, remaining unchanged in three hypertensive patients with low-renin basal values. 5. Oxprenolol suppressed the response of noradrenaline and plasma renin activity to frusemide in all cases.

Adult↗
PubMed1975

[Exercise test and atrial pacing in angina pectoris: behaviour of adrenosympathetic system (author's transl)].

Arterial plasma noradrenaline and adrenaline concentrations before, during and after an attack of pain, induced first by constant supine exercise and then by multistep atrial pacing, were determined in four patients with coronary occlusion disease and stable angina pectoris. An identical protocol was applied to a patient with atypical precordial pain (anxiety state) and normal coronary arteriograms. When compared, the results led to the following conclusions: 1) during supine exercise arterial plasma catecholamine concentrations, particularly noradrenaline, progressively increase, reaching highest values in temporal coincidence with the onset or the peak of pain, 2) during multistep atrial pacing-induced angina no significant changes of arterial plasma catecholamine concentrations are seen. These data, obtained from the same patients, further emphasize that the application of atrial pacing to the study of pathophysiology of angina pectoris and for evaluating antianginal drugs, especially if interfering with adrenosympathetic system activity, must be considered with caution.

Adrenal Glands↗