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Biomedical subjects

L Chiandussi

Publications and source records attributed to L Chiandussi.

104 records · Page 6Linked to original sources
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Heart rate variability and left ventricular diastolic function in patients with borderline hypertension with and without left ventricular hypertrophy.

The relationships between heart rate variability (HRV), left ventricular mass and diastolic function in borderline hypertensive patients (BHT) were evaluated. 24 h Holter electrocardiogram (ECG) and blood pressure (BP) monitoring, M and 2 D echocardiogram and Doppler analysis in 42 BHT with and without left ventricular hypertrophy (LVH) and in 20 normotensive controls were assessed. From 24-h ECG, time domain indexes of HRV were calculated. Standard Deviation of all Cycles (SDNN) and Standard Deviation of the means of heart periods over five-minute intervals (SDANN) were significantly reduced in BHT with LVH but not in BHT without LVH. No significant differences of short-term variability measures were detectable, although a progressive decrease among control subjects and BHT with and without LVH was observed. Diastolic left ventricular compliance evaluated by early to late transmitral flow velocity ratio (E/A ratio) significantly declined from normotensive subjects to BHT with LVH. There was a significant positive correlation between E/A and SDNN and SDANN throughout all studied groups. This indicates that BHT with LVH has a reduced HRV compared to other groups. This impairment is probably related to left ventricular mass and left ventricular filling abnormalities.

Adult↗
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Baroreflex sensitivity in secondary hypertension.

A deranged baroreceptor control of the cardiovascular functions has been reported in essential hypertension. Studies performed in experimental animals and in humans using different approaches have documented an impairment of both baroreflex heart rate modulation (resetting and loss of sensitivity) and baroreceptor control of peripheral vasomotor tone (only resetting). Baroreflex alterations have been reported also in secondary forms of hypertension, but data are controversial. This paper reviews recent works concerning baroreflex function in secondary hypertension. Either structural changes of arterial wall (decrease of vascular distensibility) or functional processes (involving angiotensin II, aldosterone, catecholamines, nitric oxide) have been proposed as potential mechanisms responsible for baroreflex readjustments in secondary hypertension. It remains unclear, and it is difficult to define exactly, if baroreflex changes associated with secondary form of hypertension are primarily due to factors specific for different hypertensive conditions, or merely follow blood pressure elevation.

Adrenal Gland Neoplasms↗
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Antihypertensive drugs and sympathetic nervous system.

Several studies have demonstrated that essential hypertension is accompanied by sympathetic activation, which contributes to blood pressure elevation. Sympathetic activation also has adverse consequences in hypertensive patients beyond initiating blood pressure elevation. There is evidence that neural vasoconstriction has metabolic effects in skeletal muscle, impairing glucose delivery to muscles. In the liver, retarding of post prandial clearance of lipids contributes to hyperlipidemia. Cardiac sympathetic activation is a probable cause of sudden death in hearth failure. A trophic effect of sympathetic activation on cardiovascular growth is also likely, contributing to the development of left ventricular hypertrophy. Consequently, one of the major aims of antihypertensive therapy should be to attenuate sympathetic tone. It is possible that, among the antihypertensive drugs available, those inhibiting the sympathetic nervous system might best reduce cardiovascular risk.

Adrenergic alpha-Antagonists↗
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Dopaminergic regulation of aldosterone secretion: assessment in different subtypes of primary aldosteronism and in essential hypertension.

The inhibitory effect of dopamine on aldosterone secretion was investigated in patients with different types of primary aldosteronism, six with idiopathic hyperaldosteronism (IHA) and four with dexamethasone-suppressible hyperaldosteronism (DSH), and in 10 patients with essential hypertension. The effects of 10 mg metoclopramide given intravenously, 10 mg bromocriptine given orally and 100 micrograms adrenocorticotrophic hormone given intravenously on plasma aldosterone and renin activities were investigated in all patients. Metoclopramide induced a rise in plasma aldosterone activity only in patients with IHA and not in those with DSH and essential hypertension. After bromocriptine plasma aldosterone concentrations decreased in patients with IHA only, and after adrenocorticotrophic hormone plasma aldosterone concentrations increased in patients with DSH only. Plasma renin activity was unaffected in all cases. These results provide evidence of increased endogenous dopaminergic inhibition of aldosterone secretion in IHA and of a blunted aldosterone response in both DSH and essential hypertension.

Adrenocorticotropic Hormone↗
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Autonomic nervous function in de novo parkinsonian patients in basal condition and after acute levodopa administration.

The aims of this study were to assess autonomic nervous function in subjects with recently diagnosed Parkinson's disease (de novo patients) and to evaluate its changes following acute levodopa administration. In 13 patients (8 males, 5 females) and 13 age-matched control subjects, three cardiovascular autonomic function tests (Deep Breathing, Valsalva, Lying to Standing) were performed, the QT interval was calculated on a 12-lead electrocardiogram, and the response of plasma norepinephrine to standing was assessed in basal conditions. The cardiovascular tests and the measurement of the QT interval were repeated in de novo Parkinsonian patients 90 minutes after the administration of levodopa 200 mg per os. The results of the Deep Breathing and Valsalva tests were worse and the QT interval longer in patients than in control subjects (although the differences were not statistically significant). The heart rate increase at 30 seconds after standing up was significantly higher in Parkinsonian patients than in the control group. The response of plasma norepinephrine to standing was similar in both groups. Levodopa administration produced a slight improvement in the Deep Breathing test, a shortening of the QT interval and increased tachycardia on standing. Our data suggest that a mild subclinical impairment of parasympathetic function can be a feature of de novo Parkinsonian patients and that levodopa therapy could have a beneficial effect on this autonomic dysfunction.

Adult↗
PubMedDate not supplied

[Primary dexamethasone-suppressible hyperaldosteronism and hyperprolactinemia].

This report describes a clinical case with rare association: dexamethasone-suppressible hyperaldosteronism (DSH) and hyperprolactinemia. Previous studies reported that endogenous dopaminergic activity would be increased in both primary aldosteronism and in hyperprolactinemic syndromes. By manipulating dopamine tone with metoclopramide, bromocriptine, ACTH and amineptine, the aldosterone and prolactin responsiveness was evaluated. Our results showed a lack of dopamine inhibiting aldosterone secretion, despite dopaminergic tone is known to be increased in hyperprolactinemia. Thus it seems unlikely that dopaminergic control of aldosterone secretion could be account for this type of hyperaldosteronism associated to hyperprolactinemia, where the suggestion is that ACTH represents the principal regulator of aldosterone secretion.

Adrenocorticotropic Hormone↗
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[ACE inhibitors and vagal activity: the effect of captopril and lisinopril on cardiovascular reflexes].

The influence of the ACE-inhibitors captopril and lisinopril on parasympathetic activity in normotensive subjects was evaluated. Three cardiovascular tests which explored chiefly parasympathetic function (deep breathing, lying to standing and Valsalva test) were performed in 10 normotensive volunteers (mean age 26.1 years) in both basal conditions and after four days of treatment with either captopril (25 mg twice a day) or lisinopril (20 mg once a day). Mean blood pressure was not influenced by captopril, whereas it was significantly lowered with lisinopril (from 94.4 +/- 6.8 to 88.7 +/- 5.7 mmHg; p < 0.05). Neither drug interfered with heart rate or with the results of the deep breathing and Valsalva tests. The 30/15 ratio, an index of heart rate variability during the lying to standing test, significantly worsened after assumption of both captopril (from 1.37 +/- 0.18 to 1.21 +/- 0.14; p < 0.05) and lisinopril (from 1.31 +/- 0.17 to 1.20 +/- 0.11; p < 0.05). Although our subjects had a lisinopril-induced drop in blood pressure, their heart rate remained steady. This finding confirms previous studies reporting the lack of reflex tachycardia during ACE-inhibition. The slight effect of ACE-inhibitors on the results of deep breathing and Valsalva tests suggests that such drugs do not directly stimulate vagal activity; the significant decrease of the 30/15 ratio may be due to a functional impairment of the baroreflex mechanism.

Adult↗
PubMedDate not supplied

[Familial Mediterranean fever: a report of 2 cases of Italian origin].

Familial Mediterranean fever is an inherited disease, occurring almost exclusively in Arabs, Jews and Turks. Cases are very rarely described in the USA, USSR, France, and patients are all natives to the Mediterranean area. This paper describes two cases of familial Mediterranean fever in brothers native to Campania, Italy. Both had complained of repeated episodes of fever, with acute abdomen, thoracalgia and arthralgia since the age of about 20. One of them had had pleuritis when he was 6 years old. In the period preceding our first observation, both underwent laparotomy to evaluate abdominal symptoms, with negative results. After ruling out other diseases with similar signs and symptoms, we raised the hypothesis of familial Mediterranean fever, despite the fact that the literature has described very few Italian natives affected by this disease. The diagnostic hypothesis was confirmed by the positivity of the metaraminol provocation test. At the same time we evaluated the presence of amyloidosis by rectal biopsy, with negative results. Treatment with colchicine 1 mg/day per os was established. Dramatic improvement of the symptoms was observed in both patients. The present paper stresses the importance of familial Mediterranean fever, its correct diagnosis in Italy and the fundamental role played by the metaraminol provocation test as a determinant diagnostic tool. It allows establishment of appropriate treatment as soon as possible, so that renal amyloidosis, the most severe complication and major prognostic determinant of familial Mediterranean fever, can be prevented. Inappropriate, useless and potentially harmful surgical diagnostic procedures are also avoided.

Abdomen, Acute↗
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Association of the Budd-Chiari syndrome with lupus anticoagulant. Case report and critical review.

The Budd-Chiari syndrome (BCS) was diagnosed in a 30-year-old male hospitalized with hepatomegaly, abdominal collateral vessels and hepatic veins and inferior vena cava thrombosis (IVC) in 1988. The presence of circulating lupus anticoagulant (LAC) was suspected and demonstrated on this occasion in view of an earlier diagnosis of systemic lupus erythematosus (SLE) and recurrent vein thrombosis dating from 1981. There are sporadic reports of an association of BCS with SLE and other autoimmune diseases. The recent literature also describes associations with hypercoagulability due to LAC. These are reviewed together with the personal case to provide the rationale for correct diagnosis and therapy.

Adult↗
PubMedDate not supplied

Autonomic neuropathy and sexual impotence in diabetic patients: analysis of cardiovascular reflexes.

Four cardiovascular tests exploring autonomic nervous function (Deep Breathing, 30:15 ratio, Lying to Standing, Hand Grip) have been performed in 38 diabetic patients with erectile failure (mean age 53.2 years, range 34.5-60.5) and in 35 diabetic subjects without sexual dysfunctions (mean age 52.8 years, range 45-60.5). In our study Deep Breathing test was abnormal in 21 patients with erectile failure (55.3%) and in 9 patients without sexual dysfunction (25.7%) (P less than 0.05). Seven patients with sexual impotence (18.4%) and 2 subjects without sexual dysfunction (5.7%) showed abnormal results of 30:15 ratio test. The Lying to Standing test was not abnormal both in impotent and in non impotent subjects, while the Hand Grip test was abnormal in 7 patients with impotence (18.4%) and in 8 patients without sexual dysfunction (22.9%). Results obtained from Deep Breathing test were significantly lower (P less than 0.01) in impotent (10.25 +/- 6.10 beats/min) than in non impotent patients (14.63 +/- 6.85 beats/min). Lower 30:15 ratios were also found in patients with erectile failure (1.09 +/- 0.10 vs 1.12 +/- 0.09). The tests exploring the sympathetic function did not show any difference between the two groups of patients. The present study confirms the major role of parasympathetic impairment in the pathogenesis of sexual dysfunctions in diabetic men. Cardiovascular tests can be a first-step diagnostic tool in the assessment of diabetic impotence.

Adult↗
PubMedDate not supplied

Acute effects of alpha-1 adrenoceptor antagonist, doxazosin on circulating vasoactive hormones.

The acute effects of doxazosin, a new selective alpha-1 adrenergic blocking agent, on blood pressure, heart rate, and on some circulating vasoactive hormones, such as plasma renin activity, catecholamines, serotonin and endothelin-1 in ten healthy normotensive volunteers and eight moderate-severe essential hypertensives were studied. Two milligrams doxazosin was administered orally in randomised fashion as compared to placebo and the acute effects were evaluated one half to four hours later. Doxazosin did not reduce blood pressure and did not increase heart rate in normotensive subjects as compared to placebo. A significant decrease in blood pressure was found in hypertensives after doxazosin (p < 0.01), without change in heart rate. Simultaneously, doxazosin did not modify plasma renin activity, catecholamines, serotonin and endothelin-1 concentrations both in normotensive and hypertensive subjects when compared with placebo administration. Thus, it appears that doxazosin does not influence local and systemic vasopressor hormones involving in the regulation of blood pressure. In conclusion, the lack of effects on plasma vasoactive factors confirms the selective alpha-1 postsynaptic antagonism of doxazosin and an effective antihypertensive action in the treatment of essential hypertension.

Adrenergic alpha-1 Receptor Antagonists↗
PubMedDate not supplied

[Osteodystrophy in thalassemia major].

Subjects with thalassemia major frequently have bone disorders of debatable pathogenesis. We attempt here to analyze the relationships between siderosis and thalassemic osteodystrophy by assessing calcium-phosphorus balance, hormone-vitamin homeostasis, osteoblastic-osteoclastic activity parameters, and bone mineral density (BMD) in 30 patients with thalassemia major (16 males, 14 females, age range 17-30 years). We found a significant increase in ferritin (p < 0.001) and significant decreases in serum i-PTH, 25OHD3, 1.25(OH)2D3, osteocalcin, estradiol, testosterone and FT4 (p < 0.001) in both sexes. In all patients a net decrease of bone mineral density was documented (p < 0.001). These results were then submitted to linear regression analysis: positive correlations between BMD and FT3, testosterone, estradiol (p < 0.01), were documented, and an inverse correlation between osteocalcin and ferritin was confirmed. Our findings suggest that thalassemic osteodystrophy is the result of several inhibitory influences on osteoblastic activity and bone apposition (related to hormone deficits and siderosis) which are aggravated further by anemia, chronic hypoxia and red marrow expansion.

Adolescent↗