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Biomedical subjects

A Strano

Publications and source records attributed to A Strano.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Silent myocardial ischemia: prevalence, prognostic significance, diagnosis].

Silent myocardial ischemia (SMI) has been demonstrated in 2 to 5% of subjects in totally asymptomatic population, in 30% of patients with history of previous myocardial infarction and in 60 to 100% of patients with stable or unstable angina pectoris. In these patients, 60 to 80% of transient episodes of ischemia are silent and SMI is induced by daily activities and so can be registered during continuous ECG monitoring. The finding of SMI during an exercise testing or during ambulatory monitoring has an unfavourable prognostic significance both in apparently asymptomatic subjects and in patients suffering from stable or unstable angina pectoris or survivors to a myocardial infarction. Stress testing and Holter monitoring are the most used non invasive tests to detect SMI. The sensitivity and specificity of ergometer test can be improved by 201-Tl myocardial scintigraphy. Moreover, the ergometer test can be used as a provocative test to induce changes in regional wall kinesis and so these alterations can be evaluated by using echocardiogram and radioisotopic or contrast ventriculography. The echocardiogram allows to evaluate the presence of kinesis changes induced by stress test or by pharmacological stimulation with dipyridamole or dobutamine. SMI can be also detected through the study of metabolic alterations during cardiac catheterism.

Angina Pectoris↗
PubMed1993

[The physiopathology of critical ischemia of the lower limbs].

Peripheral obstructive arterial disease (POAD) of the lower limbs is the third main complication of atherosclerosis, after coronary artery disease and cerebrovascular disease. In 15-20% of cases POAD have an unfavourable evolution toward critical leg ischemia (CLI). This clinical condition is characterized by the onset of rest pain and/or trophic cutaneous lesions until gangrene appears. In some cases amputation is needed. The pathophysiological, clinical and therapeutic aspects of CLI were recently discussed in two Consensus Conferences held in Berlin in 1989 and in Rudesheim in 1991, with the elaboration of a final draft published on circulation. CLI appears when peripheral perfusion critically decreases due to macro and microcirculatory alterations. Atherosclerotic plaque is the primum movens, but often there are more plaques in sequence along the ilio-femoro-popliteal axis. The pathophysiological and clinical consequences are more severe if the stenosis is haemodynamically important, after a rapid progression of plaque growth or when thrombotic complications develop. The reduction in distal perfusion induces troubles in the microcirculation and an embalancement between the microvascular defense system (MDS) and the microvascular flow regulating system (MFRS) with endothelial dysfunction, platelet and leucocytes activation, worsening of blood viscosity due to the increase in fibrinogen levels and to the red cells deformability changes, activation of coagulation and impairment of fibrinolysis. So, a vicious circle appears with further worsening of distal perfusion and onset of trophic lesions. A further worsening of CLI can derive from local recurrent infections particularly frequent in diabetic patients.

Critical Illness↗
PubMed1993

Cholesterol and fibrinogen as predictive factors of progressive carotid atherosclerosis.

In order to detect the presence of determining factors as predictors of progressive carotid atherosclerosis, the incidence of total serum cholesterol and fibrinogen elevation was evaluated in patients affected by coronary artery disease (CAD). 61 subjects with CAD (mean age 62 years) and significative lesions (> 50%) underwent periodic Echo-Doppler (Duplex scanning) of the supra aortic branches. Total serum cholesterol, HDL, LDL and fibrinogen were monitored, as well. A 24 month follow-up period was performed. Indicative of the progression of carotid atherosclerosis has been considered the presence of a stenosis degree over 20% than the initial one. In 14 of the 61 subjects who entered the study, there was evidence of progressive carotid atherosclerosis. The same patients showed higher levels of LDL cholesterol (130 +/- 36.3 vs 96.5 +/- 33.2) and Fibrinogen (398.3 +/- 59.4 vs 328 +/- 36.8) and lower levels of HDL cholesterol (27.2 +/- 4.2 vs 34.4 +/- 10.1). Our results confirm the importance of cholesterol and fibrinogen as determining risk factors, especially in patients with multiple vascular disease (coronary and carotid).

Carotid Artery Diseases↗
PubMed1993

The incidence of asymptomatic extracoronary atherosclerosis in patients with coronary atherosclerosis.

Atherosclerosis is a systemic vascular disease that can produce pathologies in any organ. The aim of this study was to evaluate the incidence of asymptomatic peripheral atherosclerosis (PA) in patients symptomatic for angina and myocardial infarction affected by coronary atherosclerosis (CAD). 315 patients (268 male and 47 female) aged between 36 and 69 years, asymptomatic for claudicatio and cerebral ischaemic disease, underwent selective coronary angiography to detect coronary stenosis > or = 50% and Echo-Color-Doppler examination of the epiaortic trunks and upper and lower limb arteries to detect peripheral stenosis > or = 30%. In the total population the incidence of PA in patients with CAD was 23% but in patients with trivascular CAD it was 32%. These data suggest that in patients with trivascular CAD it is necessary to investigate peripheral circulation as, also in asymptomatic patients, polydistrictual atherosclerosis was frequent.

Adult↗
PubMed1993

Hypertension and other risk factors in peripheral arterial disease.

Aim of this study has been to evaluate the prevalence of arterial hypertension and other risk factors in patients suffering with PAD in two clinical samples (1.: 102 patients with PAD, 69 M, 33 F, studied in our angiology laboratory, matched for sex and age with 102 healthy volunteers; 2.: 184 hospitalized patients, 80 M, 104 F, mean age 57.2 +/- 10.8, with PAD) and in two epidemiological studies (1.: Trabia Study, 835 subjects; and 2.: Casteldaccia Study, 723 subjects). All patients performed a full clinical and laboratory examination, including the determination of the ankle/arm pressure ratio (Winsor index, positive for PAD when lower than 0.95). In the first clinical study we observed a significantly (p < 0.01) greater prevalence of arterial hypertension (51.9 vs 9.8%), hypercholesterolemia (48.2 vs 21.6%), hypertriglyceridemia (53.7 vs 26.1%), smoking habit (64.3 vs 44.2%), and hyperglycemia (26 vs 7.9%) in PAD patients than in controls. In the second clinical study, considering separately the patients under and over 65 years, all risk factors resulted more prevalent in younger people than in the aged, except diabetes and hypertension.

Adult↗
PubMed1992

Regression of structural vascular changes in hypertensives after captopril treatment.

In order to investigate whether hypertension-related structural vascular changes may be influenced by antihypertensive treatment, 10 patients were studied suffering from essential arterial hypertension, five males and five females, aged between 34 and 61 years (mean age: 46.9 +/- 8.13 years). All patients received a placebo for 1 week and then captopril, 75 mg b.i.d. for 3 months. After placebo and captopril treatments, the following parameters were evaluated: SBP, DBP, mean blood pressure (MBP), by the formula 1/3 (SBP + 2 x DBP) and basal and minimal vascular resistances, respectively obtained by the ratios MBP/rest flow and MBP/peak flow. Blood flows have been obtained by strain gauge plethysmography. A significant decrease in systolic (P less than 0.025), diastolic (P less than 0.01) and mean blood pressure (P less than 0.01), basal vascular resistances (52 +/- 19 vs 28 +/- 12 A.U., P less than 0.01) and minimal vascular resistances (6.3 +/- 2.2 vs 3.9 +/- 2.8 A.U., P less than 0.025) has been observed after captopril treatment in comparison to placebo, whereas rest (2.9 +/- 0.7 vs 4.1 +/- 0.9 ml.min-1.100 g-1, P less than 0.01) and peak blood flows (21.3 +/- 5.8 vs 29.7 +/- 9.4 ml.min-1.100 g-1) significantly increased. These data seem to indicate that antihypertensive treatment with the angiotensin-converting enzyme inhibitor, captopril, is not only efficacious in inducing a significant blood pressure decrease, consequent to the reduction of basal vascular resistance (due to the vasodilating effects of the drug), but is also able to reduce minimal vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Cardiovascular structural changes in hypertension: possible regression during long-term antihypertensive treatment.

Arterial hypertension is often complicated by left ventricular hypertrophy (LVH) and by vascular structural changes resulting in decreased proximal and distal compliance. LVH is an adverse prognostic factor because it increases the incidence of sudden death and other morbid events related to ischaemic heart disease, whereas vascular alterations may induce target organ damage and contribute to the maintenance of elevated blood pressure values. Thus, antihypertensive treatment must both reduce blood pressure and halt regression of cardiovascular structural changes. A review of the literature suggests long-term use of calcium antagonists, ACE inhibitors, and beta-blockers may revert LVH. We have found that such long-term drug use not only reduces blood pressure and LVH, but also ventricular arrhythmias that are often related to cardiac hypertrophy; however, diuretics do not have this beneficial effect. As regards vascular disturbances ACE inhibitors partially revert these alterations, whereas beta-blockers do not. Further studies are needed to determine whether there are regional differences in the regression of cardiovascular structural changes or whether different antihypertensive drugs have different effects on these changes.

Animals↗
PubMed1991

[The noninvasive evaluation of the cardiovascular changes in physiological aging].

The physiological aging is frequently associated with structural alterations determining a loss of elasticity both of left ventricular wall (that goes towards hypertrophy), and of great and small arteries and arterioles (that have their compliance reduced). In fact, in our experience, the elderly have, in comparison with younger people, greater values of end diastolic thickness of the septum and of the posterior wall (respectively 10.7 +/- 1.5 vs 9.4 +/- 1 and 10.4 +/- 1.7 vs 9.0 +/- 0.9), of the aortic index, that is inversely related to arterial compliance (0.74 +/- 0.06 vs 0.66 +/- 0.05) as well as of minimal vascular resistances, expression of an impaired maximal vasodilation capacity of the arteriolar bed (4.27 +/- 1.08 vs 3.68 +/- 0.91). At cardiac level the global effect of these changes is a remodelling able to maintain a normal function both at rest and after exercise, i.e., a greater intervention of Frank-Starling mechanisms with increase of the end diastolic volume, in order to counteract the lower chronotropic response to catecholamines. At peripheral level the structural changes in the arterial tree (consequent to an increased collagen content in the intimal and medial components of the vessel walls) lead to an increase in blood pressure with aging: in our study by non-invasive blood pressure monitoring mean 24-hours blood pressure values have been the following ones: 116.4 +/- 3.8/72.1 +/- 7.2 mmHg in 25-35 years aged; 121.8 +/- 9.1/75.9 +/- 5.3 mmHg in 45-55 years aged; and 128.4 +/- 10.1/76.4 +/- 7.8 mmHg in aged more than 60 years. On the other hand, the greater cardiac output during stress, together with the lower arterial vasodilation (consequent also to the impaired function of the baroceptor reflexes) determines an exaggerated systolic blood pressure increase after exercise.

Aging↗
PubMed1991

[Vascular damage in arterial hypertension: its noninvasive assessment].

Arterial hypertension is a definite risk factor for the atherosclerotic disease and thus has a primary role in the genesis of cardiovascular diseases, but it acts also though a direct structural damage of great and small arteries and arterioles. Up to date, clinical research and technological advancements have made possible the development of instruments and methods for the evaluation of the vascular damage. Ultrasonographic methods are now the better non invasive tools for the study of arterial diseases, allowing a definition power comparable to angiography, and giving useful data on characters and composition of plaques, also minimal, at the level of the arterial district of lower limbs, epiaortic, renal, and abdominal vessels. These methods allow the study of the vascular lesion under the hemodynamic (CW or pulsed Doppler with spectral signal analysis) and the morphological profile (high resolution echotomography) or both echo-Doppler duplex scanning or color flow imaging). Arterial compliance of great vessels can be studied through the Doppler evaluation of pulsed wave velocity along the arterial tree. Other useful parameters are the aortic distensibility (ratio between % change in arterial volume and blood pressure), the elastic module, the index of arterial rigidity and the aortic index (ratio between pulse pressure and stroke volume). By using this latter parameter we demonstrated a significant decrease of arterial compliance that is proportional to the severity of blood pressure values. Small vessels may be studied through strain-gauge plethysmography, that allows to obtain the regional blood flows at the hand and forearm (skin circulation) and the calf (muscular circulation) both in basal conditions and after ischaemic stimulus. From the ratio between mean arterial pressure and post-ischemic blood flow it is possible to obtain minimal vascular resistances, expression of the maximal vasodilatation capacity in the arteriolar bed. With this method we showed that minimal vascular resistances increase proportionally with the increase of blood pressure in borderline hypertensives, in mild, moderate and severe stable arterial hypertension and in hypertension of the aged. The cutaneous microcirculation may be studied also by laser Doppler and capillaroscopy, that show a reduced capillary perfusion in hypertension. Clinically, these diagnostic tools are also extremely useful for studying the effects of antihypertensive treatment on structure and function of arterial vessels, as it seems that some drugs are able to counteract the structural alterations related to hypertension.

Arteriosclerosis↗
PubMed1991

A double-blind, multicenter, placebo-controlled, dose comparison study of orally administered defibrotide: preliminary results in patients with peripheral arterial disease.

Defibrotide is a polydeoxyribonucleotide drug known to modulate the endothelial cell release of t-PA, PAI, and PGI-2 and to improve blood flow and perfusion. A double-blind, multicenter, placebo-controlled, dose comparison study was carried out to test the long-term efficacy and safety of defibrotide in patients with PAD (Leriche stage 2). Informed patients suffering from PAD were enrolled, and after a 15-day washout period were randomly allocated in a double-blind fashion to one of the three following treatments: defibrotide 400 mg (1 cps) b.i.d. for 6 months, defibrotide 400 mg o.d., or placebo. Absolute walking distance (AWD, treadmill) and ankle-arm pressure ratio (Winsor Index, WI) were evaluated at the beginning and after 30, 90, and 180 days after therapy. Two hundred twenty seven patients were recruited and 193 patients were included in the final analysis (800 mg: 67; 400 mg: 60; placebo: 66). All treatments brought about an increase in AWD placebo = +17%; 400 mg = +47%, 800 mg = +52%); however, patients treated with defibrotide exhibited a significantly better AWD at the end of treatment in comparison with placebo (p less than 0.01). AWD was not significantly different in the 400-mg and 800-mg groups. There was a trend indicating a possible improvement of WI after defibrotide, with higher WI in 800-mg patients in comparison with placebo (p less than 0.05). However, this difference was partly due to a decrease in arterial blood pressure elicited by the drug. The tolerability in all groups was optimal. These results indicate that orally administered defibrotide exerts symtomatic benefit in PAD patients and daily doses of 400 or 800 mg seem to be equivalent.

Administration, Oral↗
PubMed1990

Thromboxane biosynthesis and platelet function in type II diabetes mellitus.

It has been suggested that platelet hyperreactivity in patients with diabetes mellitus is associated with increased platelet production of thromboxane. We therefore compared the excretion of a thromboxane metabolite and platelet function in 50 patients with Type II diabetes mellitus who had normal renal function and clinical evidence of macrovascular disease and in 32 healthy controls. The mean (+/- SD) excretion rate of urinary 11-dehydro-thromboxane B2 was significantly higher in the patients than in the controls (5.94 +/- 3.68 vs. 1.50 +/- 0.79 nmol per day; P less than 0.001), irrespective of the type of macrovascular complication. Tight metabolic control achieved with insulin therapy reduced the levels of 11-dehydro-thromboxane B2 by approximately 50 percent. The fractional conversion of exogenous thromboxane B2 (infused at a rate of 4.5, 45.3, or 226.4 fmol per kilogram of body weight per second) to urinary 11-dehydro-thromboxane B2 was assessed in four patients, in whom it averaged 5.4 +/- 0.1 percent; this value did not differ from that measured in healthy subjects. Aspirin in low doses (50 mg per day for seven days) reduced urinary excretion of the metabolite by approximately 80 percent in four patients. The fact that thromboxane biosynthesis recovered over the following 10 days was consistent with a platelet origin of the urinary metabolite.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Alterations of calcium metabolism in spontaneously hypertensive rats.

We have examined the femurs of eight male spontaneously hypertensive rats and eight male Wistar Kyoto rats, aged 24 weeks. The mineral density of the bones was determined at the mid-point of the femurs by dual photon absorptiometry and the calcium content was estimated on bone ash by atomic absorption spectrophotometry. The data show that spontaneously hypertensive rats have lower bone density and calcium content than do age-matched Wistar Kyoto rats.

Absorptiometry, Photon↗
PubMed1990

[Tolerance and effectiveness of transdermal nitroglycerin in angina pectoris. A multicenter study. Adesitrin Italian Study Group].

A multicenter open study was carried out in order to evaluate the tolerability and antianginal efficacy of the nitroglycerin "multilayer transdermal system". Forty eight cardiologic centers enrolled 506 outpatients (123 females and 383 males), mean age: 61 +/- 8 (SD) years, with effort angina (43%), angina at rest (17%) and mixed angina (40%), not well controlled by their previous antianginal therapy (greater than or equal to 2 anginal attacks a weeks). The duration of the treatment with 5 or 10 mg/die was 10 weeks with a control every 2 weeks. At the end of the study, the weekly frequency of anginal attacks was reduced by 88%, and 60% of the patients were free from anginal attacks. In 117 patients, studied by ergometer test, the exercise time increased by 31% (p less than 0.001) and the ST depression decreased by 63% (p less than 0.001). The treatment was interrupted in 9.1% of the patients: in 4.55% for unwanted effects (headache and/or local intolerance) and in 4.55% for other reasons. The same unwanted effects, but of mild or moderate severity, were observed in 18.4% of the patients, most of them during the first 2 weeks of the treatment. In conclusion, the "multilayer system" for delivering transdermal nitroglycerin showed a good clinical and ergometer efficacy and was well tolerated and accepted by the anginal patients in study.

Administration, Cutaneous↗
PubMed1990

Cardiac arrhythmias as correlated with the circadian rhythm of arterial pressure in hypertensive subjects with and without left ventricular hypertrophy.

To evaluate the relationship among supraventricular and ventricular arrhythmias with blood pressure and heart rate (HR) values, we studied 2 groups of 20 hypertensive men with (group I) and without (group II) left ventricular hypertrophy. Ambulatory electrocardiographic tracings were recorded continuously, together with ambulatory arterial pressure. Systolic (SBP) and diastolic (DBP) blood pressure values measured over 24 h showed no difference between the two groups, but we found greater variability in SBP in group I. The incidence of ventricular and supraventricular arrhythmias was significantly higher in patients of group I; moreover, we found a strong correlation between the incidence of ventricular extrasystoles (VPCs) and SBP, DBP, and HR values in group I, whereas in group II the incidence of supraventricular extrasystoles (APCs) was higher during peaks of SBP and HR values. The relationship between APCs and SBP observed in group II may be attributable to the pressure stimulus on a normal atrium, and the significant correlation between VPCs and SBP, DBP, and HR values may be due to episodes of subendocardial ischemia or to the influence of adrenergic stimulation on previously compromised myocardial tissue.

Arrhythmias, Cardiac↗