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Biomedical subjects

M L Muiesan

Publications and source records attributed to M L Muiesan.

At least 91 records · Page 5Linked to original sources
PubMed1991

Reversal of cardiovascular structural changes during long-term antihypertensive therapy.

Several prospective epidemiological and clinical studies have indicated that regression of cardiovascular alterations, preferably at an early stage, is a desirable goal in the treatment of hypertension. The results of a large number of studies have indicated that many antihypertensive drugs can produce a significant regression of cardiovascular structural changes in hypertensive patients. However, it has not been established whether a complete 'normalisation' may occur. Further studies are needed to identify factors that modulate regression of cardiac and vascular smooth muscle hypertrophy. Most important, it remains to be clarified whether regression of cardiovascular structural changes significantly improves prognosis per se independently from blood pressure reduction.

Antihypertensive Agents↗
PubMed1990

[Increase by ANP and ADH of the duration of activation and deactivation of the cardiopulmonary baroreceptor reflex: modification in the presence of left ventricular hypertrophy].

The involvement of cardiopulmonary and arterial sinoaortic receptors in the control of antidiuretic hormone (ADH) and atrial natriuretic peptide (ANP) release is still controversial in humans. Moreover, it is not clear if this control may be impaired in hypertensive patients with left ventricular hypertrophy (LVH). We studied 17 male subjects, age 18-58 (6 normotensives and 9 mild hypertensives, 5 without and 4 with LVH). Each subject underwent selective loading and unloading of cardiopulmonary receptors, in a randomized sequence, by application of a positive (LBPP) or negative (LENP) pressure to the lower body (steps: +10, +20, +40, -10, -40 mmHg, each for about 30 min), through a plexyglass-constructed tubular apparatus with a rubber adhesion round the patients' waist. Blood samples were taken at the end of every step for measurement of ADH, ANP, PRA, immunoreactive renin, aldosterone, noradrenaline and adrenaline. Cuff arterial pressure was measured every 5 min, while heart rate was evaluated by continuous ECG recording. Hypertensive subjects underwent right atrial pressure measurement by an iv catheter and forearm blood flow evaluation at rest and during the different steps (venous occlusion plethysmography). During LBNP, ADH plasma levels increased progressively, but the increase became statistically significant only at the step of -40 mmHg. ANP increased significantly during LBPP. Taking into account only hypertensive patients, a consistent reduction in the changes of ADH and ANP plasma levels, respectively during LBNP and LBPP in patients with LVH in respect to those without LVH was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Regression of structural alterations in hypertension.

Morbidity and mortality are higher in hypertensive patients who have already developed cardiovascular complications. Several prospective epidemiological and clinical studies have indicated that regression of cardiovascular alterations, preferably when still at an initial stage, is a desirable goal in the treatment of hypertension. Clinical assessment of cardiac hypertrophy may be precisely obtained with echocardiography. Structural vascular changes may be evaluated indirectly in man by measuring minimal vascular resistance from maximal blood flow and arterial pressure. The results of a large number of studies have indicated that in hypertensive patients a significant regression of cardiovascular structural changes may be obtained with several antihypertensive drugs, but they have not yet established whether a complete "normalization" may be really obtained. Further studies are needed to identify factors that modulate regression of cardiac and vascular smooth muscle hypertrophy. Most important, it still remains to be clarified whether regression of cardiovascular structural changes in hypertensives significantly improves prognosis per se independently from blood pressure reduction.

Antihypertensive Agents↗
PubMed1989

Short-term effect of captopril and nifedipine on micro-albuminuria induced by exercise in hypertensive diabetic patients.

Physical exercise can induce micro-albuminuria, a urinary albumin excretion rate of 20-200 micrograms/min, in diabetics without micro-albuminuria at rest (stage II of diabetic nephropathy). The aim of the present study was to evaluate the acute effects of captopril, an angiotensin converting enzyme (ACE) inhibitor, and nifedipine, a calcium channel blocker, on exercise-induced micro-albuminuria in hypertensive diabetics with stage II nephropathy. Eleven hypertensive World Health Organisation (WHO) stages I-II non-obese diabetics (five insulin-dependent diabetics, six non-insulin dependent diabetics) underwent five submaximal cycloergometric tests, the first two in basal conditions, the other three after 24-h administration of captopril (25 mg twice a day), placebo (1 tablet twice a day) or nifedipine AR (20 mg twice a day) according to a randomized double-blind design. Our results demonstrate that despite a lower reduction in exercise blood pressure, captopril is more effective than nifedipine in blunting diabetic exercise-induced micro-albuminuria.

Albuminuria↗
PubMed1988

Relation between cardiac hypertrophy and forearm vascular structural changes before and during long-term antihypertensive treatment.

In patients with hypertension, structural changes develop in the heart and in the systemic arteries that have a significant role in the maintenance and gradual worsening of the hypertensive disease. Blood pressure, basal and post-ischemic "maximal" forearm blood flow (strain-gauge venous occlusive plethysmography), and echocardiographic left ventricular mass index were measured in 28 hypertensive patients (WHO class I or II, 23 men and five women, aged 26 to 59 years). Minimal vascular resistance (mean arterial pressure/peak blood flow) was taken as an index of vascular structural changes. The same measurements were made in a group of 14 patients before and after long-term antihypertensive treatment: in eight patients after six and 12 months of treatment with captopril (50 mg twice a day, plus 25 mg of hydrochlorothiazide per day if necessary) and in six patients after six months of treatment with nitrendipine (20 mg per day, plus 50 mg of atenolol per day if necessary). A significant but weak direct correlation was found between the degree of left ventricular hypertrophy and mean arterial pressure (r = 0.41) or minimal vascular resistance (r = 0.31). Thus, patients were categorized according to whether they had left ventricular hypertrophy or impaired blood flow; the results suggested that left ventricular hypertrophy may be detected earlier than increased minimal vascular resistance. After six months of treatment, both captopril and nitrendipine significantly reduced left ventricular mass index and minimal vascular resistance. Left ventricular mass index was normalized in 50 percent of the patients, whereas minimal vascular resistance was normalized in one patient only. After 12 months of treatment, left ventricular mass index was normalized in all patients; minimal vascular resistance was on the average further reduced but normalized in only one additional patient. Thus, regression of cardiovascular structure also seems to occur earlier in the heart.

Adult↗
PubMed1988

Beneficial effects of one year's treatment with captopril on left ventricular anatomy and function in hypertensive patients with left ventricular hypertrophy.

This study evaluated by echocardiography (M-mode tracings, two-dimensional-guided) the effects of captopril administration for one year (25 to 50 mg twice a day, alone or in combination with hydrochlorothiazide when necessary) on left ventricular mass index, on systolic function at rest and during stress (hand grip for three minutes and cold pressor test for three minutes), and on diastolic function in 15 patients with essential hypertension (13 men and two women, aged 30 to 67 years) with left ventricular hypertrophy. In addition, supine and standing plasma catecholamine concentrations, plasma renin activity, and plasma aldosterone levels were measured. Examinations were performed during a placebo period and after three, six, and 12 months of captopril treatment. Blood pressure was significantly reduced (p less than 0.001), but heart rate did not change. Left ventricular hypertrophy was progressively reduced during treatment, mainly through reduction of left ventricular wall thickness. After one year, all patients had a normal left ventricular mass index (less than 120 g/m2). Before and during treatment, left ventricular systolic function, at rest and on maximal hand grip and cold pressor testing, evaluated on the basis of fractional shortening as related to end-systolic stress, was within the 95 percent confidence limits (calculated in a group of 25 normal subjects) in all 15 patients with essential hypertension. The percent increase in left ventricular dimensions during the diastolic rapid filling phase was significantly increased by treatment (p less than 0.05), indicating improvement of left ventricular relaxation. As expected, plasma renin activity was increased, plasma aldosterone levels were decreased, and plasma catecholamine concentrations did not change. These results indicate that long-term treatment with captopril has beneficial effects on left ventricular anatomy and function in patients with essential hypertension.

Adult↗
PubMed1988

Long-term antihypertensive treatment may induce normalization of left ventricular mass before complete regression of vascular structural changes: consequences for cardiac function at rest and during stress.

In 14 essential hypertensive patients, aged 26-59 years, blood pressure, left ventricular mass index (LVMI), systolic function (M-mode echo, two-dimensionally guided), post-ischaemic 'maximal' forearm blood flow (strain gauge venous occlusion plethysmography), plasma renin activity, plasma catecholamines and aldosterone were measured before and after 6 and 12 months of treatment (eight patients were given captopril, 100 mg/day, + hydrochlorothiazide 25 mg/day in five patients, and six patients were given nitrendipine, 20 mg/day, + atenolol 50 mg/day in four patients). Minimal vascular resistance (mean blood pressure/peak forearm blood flow) was taken as an index of arterial structural changes. After 6 months of treatment significant reductions in blood pressure (P less than 0.001), LVMI (P less than 0.001) and minimal vascular resistance were observed. After 12 months of treatment blood pressure, LVMI and minimal vascular resistance were further reduced. The LVMI was normalized in nine cases and the minimal vascular resistance in two cases only. Aldosterone and plasma catecholamines did not change, whereas plasma renin activity was increased during captopril only. Before and during treatment the left-ventricular shortening fraction in relation to end-systolic stress in each patient at rest, and at peak of handgrip and cold pressor tests, fell within the 95% confidence limits of correlation obtained in normals. Thus, in essential hypertensives long-term treatment can induce normalization of LVMI before complete regression of arterial structural changes in the forearm. Left ventricular systolic function is preserved after normalization of LVMI, both at rest and during stress.

Adult↗
PubMed1988

Left ventricular systolic function in relation to withdrawal of different pharmacological treatments in hypertensives with left ventricular hypertrophy.

We evaluated the left ventricular mass index (LVMI) and the functional response to cold pressor and handgrip tests in 74 untreated essential hypertensive patients and 26 age and sex-matched normals. The same measurements were repeated in 22 essential hypertensives after 6 and 12 months of treatment (captopril or nitrendipine, plus diuretic or beta-blocker in a few cases) and in 21 essential hypertensives after withdrawal of treatment, a reduction in the LVMI and a further increase in blood pressure. Left ventricular systolic function was evaluated by the relationship between left ventricular end-systolic stress and fractional shortening. Highly significant negative correlations, with similar slopes and intercepts, were found between end-systolic stress and fractional shortening under basal conditions, after regression of left ventricular hypertrophy and after withdrawal of treatment, both at rest and at the peak of stress tests. An examination of each point of the relation between end-systolic stress and fractional shortening showed that very few points were beyond the 95% prediction limits of the correlation obtained in normal volunteers. These results indicate that left ventricular systolic function is normal in most untreated essential hypertensives, and is usually well maintained after regression of left ventricular hypertrophy during long-term treatment as well as after withdrawal of treatment, both at rest and during an acutely induced afterload increase.

Adult↗
PubMed1988

Reversal of cardiac hypertrophy by long-term treatment with calcium antagonists in hypertensive patients.

The aim of this study was to assess the effects of chronic antihypertensive treatment with verapamil and nifendipine on left ventricular (LV) anatomy and function, also in relation to adrenergic activity and beta-adrenergic sensitivity. In fact, it is known that, during antihypertensive treatment, changes of LV mass and function may be affected also by the level of adrenosympathetic tone. Blood pressure (BP), heart rate (HR), plasma catecholamines (pCA), beta-adrenergic responsiveness to isoproterenol (dose that increased HR by 25 beats/min = CD25), LV mass as well as systolic function (2D-guided M-mode echo), at rest and during stress (handgrip test [HG], 30% max, for 3 min), were measured on placebo, after 1 and 6 months of monotherapy with verapamil (VER, 240 mg/day, 9 patients) or nifedipine (NIF, 40 mg/day, 10 patients). Both treatments significantly reduced BP (p less than 0.05 at least). HR, pCA, and cardiac output did not change during treatment with VER, whereas they were slightly but significantly increased during treatment with NIF (p less than 0.05 at least). CD25 was significantly increased during treatment with VER (p less than 0.05) but not during treatment with NIF. Both treatments induced a significant reduction of LV mass after 6 months (p less than 0.01 with VER and p less than 0.05 with NIF).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Bacteriological and clinical evaluation of cefotetan in the treatment of severe infections in hospitalized patients.

The authors studied 302 hospitalized patients, 164 males and 138 females aged 15-88 years (average 66 years), with severe infections. Cefotetan was administered to 278 of them at the dose of 1 or 2 g, b.i.d. or a single daily dose i.m. Other patients [24] were treated with a continuous intravenous infusion of cefotetan (3 g daily in 5% dextrose). Of these patients 121 were treated for urinary tract infections (UTI); 114 for respiratory tract infections (RTI); 41 for liver biliary duct infections (BDI); 17 for skin or skin structure infections (SKI); 6 for fever of unknown origin and 3 for sepsis. The following Gram-positive organisms [156] were isolated: Streptococcus pneumoniae, Staphylococcus aureus and Streptococcus group D; and the following Gram-negative organisms [122]: Escherichia coli, Proteus vulgaris, Proteus mirabilis, Serratia spp., Klebsiella spp., Haemophilus influenzae and Pseudomonas aeruginosa. The overall eradication rate for Gram-positive organisms was 74% and for Gram-negative organisms it was 88%. The clinical response was satisfactory in 87.7% of patients (specifically, cefotetan was effective in 90% of UTI, 84.2% of RTI, 97.5% of BDI and 82.3% of SKI). The drug was well tolerated and side-effects (such as skin rash, diarrhoea, purpura and pain at the site of injection) occurred in only 4% of patients treated with cefotetan. In conclusion, cefotetan appears to be safe and highly effective for the treatment of severe infections in hospitalized patients.

Adolescent↗
PubMed1987

Effects of infusing alpha-atrial natriuretic peptide in primary hypertension during converting enzyme inhibition.

The effect of atrial natriuretic peptide (ANP), before and after converting enzyme (CE) inhibition, was investigated in six primary hypertensive patients taking a constant diet. In this placebo-controlled, single-blind, randomized study, the patients received, on three different days, i.v. infusions of (a) placebo, or (b) alpha-human ANP, 150 micrograms over 30 min, or (c) alpha-human ANP after acute CE inhibition by enalapril (EN) 20 mg P.O., 4 h before ANP infusion. ANP infusion increased urinary sodium (p less than 0.001) and volume excretion. Blood pressure (BP), heart rate, stroke volume and shortening fraction (echocardiography), plasma renin activity (PRA), and plasma aldosterone did not change significantly. Urinary norepinephrine and dopamine were significantly increased (p less than 0.05) after ANP infusion. BP was significantly reduced after EN in every patient (p less than 0.05). ANP infusion during CE inhibition induced a more sustained increase of sodium excretion and diuresis with respect to ANP infusion alone (p less than 0.05). PRA was significantly reduced while no further reduction of BP was observed. These data suggest that CE inhibition may increase the natriuretic and diuretic effect of ANP in hypertensive patients.

Adolescent↗
PubMed1987

Left ventricular hypertrophy and ambulatory monitoring of blood pressure.

Left ventricular hypertrophy (LVH) and cuff blood pressure (BP) level are not as closely related as one might suppose. A better correlation was reported between LVH and continuous monitoring of BP. To analyze this relationship we performed continuous intra-arterial ambulatory monitoring (Oxford technique) in 10 patients with essential hypertension (EH) having LVH, and in 10 age-matched EH patients with normal left ventricles (NLV). Average cuff BP did not differ significantly between the two groups. The intra-arterial BP monitoring showed a significantly higher systolic BP in EH patients with LVH for the mean of the 24 hours (p less than .05) and in the 6 PM-6 AM (night) period (p less than .01); whereas the difference was not significant for the mean systolic BP of the 6 AM-6 PM (day) period and for the mean 24-hour diastolic BP. The heart rate was similar between the two groups; however, the variability of BP was not different. The night systolic BP correlated with the thickness of interventricular septum plus left ventricular posterior wall (LVPW) (r = 0.66; p less than .05). These results may have therapeutic implications, although they require confirmations in a larger series of patients.

Adult↗
PubMed1987

Cardiac function as related to adrenergic activity in hypertensive left ventricular hypertrophy.

Studies in experimental animals and in hypertensive patients have shown that changes in cardiac anatomy and function are not just a simple consequence of the increased pressure load. The activity of the sympathetic nervous system is one of the factors that may influence cardiac performance and also, possibly, the cardiac anatomy of hypertensive patients. Animal studies have strongly suggested a possible role of adrenergic factors in the development of left ventricular hypertrophy. In man, plasma catecholamines are usually higher in hypertensive patients with left ventricular hypertrophy, and a correlation between left ventricular mass and plasma noradrenaline has also been observed. The decrease of cardiac performance after acute beta blockade has been found to be directly related to basal plasma noradrenaline concentration. An impaired response to beta-adrenergic stimulation has been reported in hypertensive animals and has been confirmed in hypertensive patients with left ventricular hypertrophy.

Adult↗
PubMed1987

The treatment of angina pectoris with nitroglycerin plasters. A multicenter study involving 6,986 patients.

A multicenter study was carried out in order to evaluate the efficacy and tolerability of 2 doses of a nitroglycerin transdermal system (TTS-NG 5 mg/24 h and TTS-NG 10 mg/24 h) on a large population of patients affected by angina pectoris. Nine hundred and seventy three cardiologists enrolled a total of 6,986 patients, 4,290 males and 2,696 females, mean age 61.7 years (range 26-95), 3,283 with effort-angina, 2,062 with mixed angina and 1,641 with angina at rest. Patients whose angina was not satisfactorily controlled by their previous therapy, were given TTS-NG 5 for 1 week in the morning, while continuing their antianginal treatment, with the exception of nitrates which were gradually withdrawn. At the end of this period, patients who responded to the treatment continued taking the same dose for a further 6 weeks, while poor responders were given a double dose of the study medication over the same period. Six thousand two hundred and sixty patients (90%) completed the study. TTS-NG 5 proved to be effective in 2,091 patients (33%) with a reduction in weekly anginal attacks after only 1 week of treatment (from 5.8 +/- 2.9 to 2.4 +/- 2.3). This reduction improved in the following 2 weeks (from 2.4 +/- 2.3 to 1.2 +/- 1.6) and subsequently remained virtually unchanged. Four thousand one hundred and sixty-nine patients (67%), whose angina was not sufficiently controlled by TTS-NG 5 (from 5.0 +/- 2.4 to 4.3 +/- 2.8), received double the dose at the end of the first week. TTS-NG 10 brought about a reduction in weekly anginal symptoms during the 2nd and the 3rd week (from 4.3 +/- 2.8 to 2.0 +/- 2.2), with a further decrease during the following 2 weeks (from 2.0 +/- 2.2 to 1.1 +/- 1.7). The reduction in anginal attacks was of the same extent both during the day and the night, thus suggesting that the drug is effective throughout 24 hours. A similar pattern was observed in the reduction of the number of anginal attacks weighted by their severity, the severity of attacks weighted by their number and the number of trinitrine pills taken. Tolerability was good in the majority of cases. In conclusion, this study confirms the efficacy of TTS-NG in the treatment of angina pectoris, thus supporting some recently published data obtained by using more standardized protocols and rigorous evaluation criteria.

Administration, Cutaneous↗
PubMed1986

Adrenergic activity and left ventricular function during treatment of essential hypertension with calcium antagonists.

The effects of 2 calcium antagonist drugs, verapamil and nifedipine, on blood pressure, heart rate (HR), plasma catecholamines, plasma renin activity and some echocardiographic indexes of left ventricular anatomy and function were studied in 67 patients with essential hypertension. The short- and long-term antihypertensive effect of verapamil was not associated with significant changes in HR, plasma catecholamines or plasma renin activity; the decrease in blood pressure after nifedipine was associated with a significant increase in HR and plasma catecholamines (mainly noradrenaline) (p less than or equal to 0.05). These findings were confirmed in a crossover comparison in 12 hospitalized patients treated with verapamil and nifedipine for 8 days each. The dose of isoproterenol that increased HR by 25 beats/min was significantly increased during verapamil treatment (p less than 0.05) and decreased during nifedipine treatment (p less than 0.01). Stroke volume and shortening fraction increased slightly but significantly (p less than 0.05) with 3 months of nifedipine treatment, while no change was detected with verapamil treatment. Left ventricular mass was significantly decreased after effective antihypertensive treatment for 3 months with verapamil or nifedipine (p less than or equal to 0.05).

Adult↗
PubMed1986

Similarities and differences in the antihypertensive effect of two calcium antagonist drugs, verapamil and nifedipine.

The short- and long-term effects of two calcium channel blocking drugs, verapamil and nifedipine, on blood pressure, heart rate, plasma catecholamines, plasma renin activity, plasma volume and cardiac performance (echocardiography) were studied in essential hypertensive patients and in normal subjects. Verapamil, 160 mg orally, reduced blood pressure within 60 minutes in 22 hypertensive patients, but not in 12 normotensive subjects. Nifedipine, 10 mg sublingually, reduced blood pressure within 15 minutes in 19 hypertensive patients, but not in 7 normotensive subjects. Plasma noradrenaline was significantly increased both in normal subjects and in hypertensive patients only after nifedipine was administered. Verapamil (80 mg three times a day) first, and nifedipine (10 mg three times a day) thereafter, or vice versa, were given to 12 hospitalized hypertensive patients on a fixed sodium and potassium intake; the drugs produced similar blood pressure reductions, but heart rate and plasma catecholamines were increased only after nifedipine (p less than 0.05). Neither drug affected plasma volume, aldosterone or plasma renin activity. Long-term ambulatory treatment with verapamil (80 or 160 mg three times a day for 2 to 4 months) or nifedipine (10 mg three times a day for 2 months) produced changes in all variables that were similar to those observed in the hospital (controlled) study. Shortening fraction was significantly increased after nifedipine (p less than 0.05) but no change was observed after verapamil. In conclusion, blood pressure is effectively reduced by both verapamil and nifedipine; an appreciable adrenergic stimulation may be caused by nifedipine, but usually not by verapamil, and fluid retention, renin release or myocardial depression is not observed during verapamil or nifedipine treatment.

Adult↗