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Biomedical subjects

A Barsotti

Publications and source records attributed to A Barsotti.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Characteristics and clinical course of degenerative aortic stenosis in the elderly].

Degenerative aortic stenosis represents the most common form of aortic stenosis. The aim of this study was to evaluate the relationship between symptoms, valvular disease severity and prognosis. We studied the evolution of valvular aortic stenosis in 65 patients (39 males and 26 females, mean age 77.78 +/- 6.2 years) for a period of 7 years. All patients were submitted to accurate anamnestic examination, ECG, color Doppler echocardiography. Sixteen patients (26%) underwent cardiac catheterization. Associated diseases were: hypertension (45%), diabetes (40%), dyslipidemia (29%), chronic obstructive lung disease (6%). In 64% patients, the diagnosis of aortic stenosis was made after symptoms onset, and in 36% was occasional. Mean age at symptoms onset was 70 +/- 17 years: dispnoea was present in 81%, chest pain in 32%, and syncope in 8%. At the beginning of the follow-up, echocardiography showed, aortic stenosis to be mild in 21.73%, moderate in 60.8% and severe in 17.4%. At the end of the follow-up, mild stenosis was present in 9.5%, moderate in 38.7%, and severe in 51.8%. At entry, 56.6% had pure aortic stenosis, 34.78% had steno-insufficiency and 8.7 had an associated mitral valve insufficiency. At the end of the follow-up pure aortic stenosis was present in 17%, steno-insufficiency in 40%, and associated mitral valve insufficiency in 4.3%. Surgery was performed in 21% of the patients (77% valve replacement and 23% valve replacement and aortocoronary bypass). The mortality, at the end of the follow-up, was 31%. Causes of death were: heart failure (61%), arrhythmias (23%), and surgical complications (16%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Progression of subclinical atherosclerosis in 6 years. Ultrasound evaluation of the average, combined femoral and carotid bifurcation intima-media thickness.

The intima-media complex thickness (IMT) was evaluated in 472 asymptomatic subjects in a 6-year follow-up study. Four age groups were included (40-45, 46-50, 51-55 and 56-60) with the aim of obtaining a random equal number of men and women sample. The baseline IMT ranged from 0.42 to 2.12 mm (mean 0.63 mm, SD 0.14 mm). In 4.66% subjects completing the 6-year follow-up, the IMT decreased by more than 0.1 mm and in 18% there was no significant IMT change (> 0.1 mm). In the remaining individuals (77.33%) the IMT increased by at least 0.1 mm. The IMT increase in the 56-60 age group was significantly higher than in the remaining age groups (p < 0.02). A significantly higher percentage of smokers was also observed in the 56-60 age group (p < 0.05). However, the IMT increase in the smoker subgroups was not significantly different from the mean IMT increase observed in the whole group or from the IMT increase observed in the non-smoker group. Blood pressure variations were not associated with change of IMT over six years. The main difference between the four groups was an average weight 5.7% higher in the oldest age group at the end of the study (4.44% higher at inclusion). In conclusion the increase in IMT appeared to be greater in older subjects and the effect of smoking did not apparently affect IMT increase. The method of IMT measurements is able to demonstrate the age-related evolution of intima-media in a population.

Adult↗
PubMed1994

[Anatomical and functional characteristics of the myocardial interstitial space].

The extracellular matrix plays an important role in biological processes, for example cellular adhesion, proliferation, migration and differentiation. Many of the cell-cell and cell-matrix interactions are mediated by extracellular matrix components and by their respective membrane receptors. Important pathophysiological processes occur through these interactions of which ontogenesis tissue differentiation and reconstruction, many inflammatory and immunological events and metastatic processes and invasion. The myocardium is made of muscular, vascular and connective components that exist in a state of equilibrium based on their relative proportions, integral structures, and on their physical and chemical characteristics. The Authors have described molecular events that lead to the organization of the cardiac tissue in physiological conditions and to its reorganization in pathological situation. Furthermore they have evaluated the role of fibronectin, a glycoprotein of the extracellular matrix in the initial phase of cardiac ischemia.

Extracellular Space↗
PubMed1994

[Role of interstitial myocardium in ischemia-reperfusion injury: experimental data and clinical implications].

Myocardial interstitium plays an important role in the regulation of cardiac function compared with myocytes and it is actively involved in ischemia-reperfusion damage and in the acute and chronic remodelling during ischemic heart diseases. Myocardial post-ischemic oedema seems to interfere in this process. Myocardial oedema is able to induce structural alterations, to reduce myocardial function and to activate the renin-angiotensin-aldosterone system. Angiotensin II and aldosterone seem to be the cause of myocardial fibrosis that is detected during ischemic heart disease. Post-ischemic vascular permeability alterations have a similar role. In clinical conditions, ACE-inhibitors have important effects on cardioreparation and are able to improve cardiac function and reduce early and late mortality. The effects of myocardial oedema reduction (i.e. hypertonic reperfusion) on ischemia-reperfusion damage and myocardial fibrosis are still to clarify. A reduction in myocardial fibrosis may improve cardioreparation and prevent congestive heart failure, following ischemic heart disease.

Acute Disease↗
PubMed1994

Subclinical arteriosclerosis screening. The PAP/PEA study. Prevalenza dell'Arteriosclerosi Precoce (Prevalence of Early Arteriosclerosis).

Noninvasive screening of subclinical atherosclerosis is possible with ultrasonic biopsy (UB) performed with high resolution ultrasound scanning. Five UB classes have been identified, each class corresponding to a different incidence of cardiovascular events (CVE) in 4 years and silent coronary ischemia (SCI). In a study including 2230 asymptomatic subjects 3 risk groups were defined. In the low risk group (class I and II; 82.01% of the population sample) the incidence of CVE and SCI was zero. These subjects may be seen again after 3 years. In the moderate risk group (class II and IV; 13.3%) monitoring and early intervention may be needed. In the high risk group (class V; 4.6%) prophylaxis or treatment may be necessary. The screening is effective, simple and may be organised at very low cost--i.e. 30.000 asymptomatic subjects may be scanned at the cost of 100.000 ECU. Each scan, including carotid and femoral bifurcations, may be performed in 15 minutes. In our communities this cost is equivalent to the average cost of a single major stroke or major coronary ischemic event in a working adult aging between 45 and 60. Organization problems and the fragmentation of competences has prevented the evolution of atherosclerosis screening. The problem can be solved organising a network including epidemiologists, angiologists and cardiovascular surgical centres where all phases of atherosclerosis may be studied and detected, progression prevented and complications treated with a global vision of the disease.

Adolescent↗
PubMed1993

Noninvasive ultrasonic biopsy: evaluation of early arteriosclerotic lesions progression in normal asymptomatic, hyperlipidemic, and diabetic subjects.

Noninvasive ultrasonic biopsy (UB) is a method of detecting early arteriosclerotic changes by high-resolution ultrasound scanning of the carotid and femoral bifurcation. Six UB classes (scoring 0 to 10) have been identified in 2000 asymptomatic subjects and 600 vascular patients followed up for four years. The incidence of silent coronary ischemia (tested by effort test) and the occurrence of symptomatic events in four years are increased in advanced classes and with increasing UB score. The rate of progression (ROP) in four years to the next UB class has been defined in normal subjects (1.4% in class I, 3.1% in II, 10.7% in III, 17.9% in IV, and 79.2% in class V). In a group of 305 asymptomatic hyperlipidemic subjects and in a group of 269 diabetics the ROP (in four years) was significantly higher. Therefore ultrasonic biopsy is useful to identify subjects at risk of coronary ischemia and cardiovascular events and to follow up noninvasively the progression of arteriosclerosis.

Adult↗
PubMed1993

[Etiopathogenesis of dilated cardiomyopathies].

This study was carried out on 43 patients affected by dilated cardiomyopathy to investigate some of the etiopathological hypotheses on this illness. The Authors investigated: the persistence of virus genoma (coxsackie, HBV) on endomyocardial biopsies; the pattern of the II class major histocompatibility complex (MHC) were in the blood lymphocytes; the microvascular aspect of coronary circulation in the endomyocardial biopsies. Finally, in a separated group of 19 patients, the microvascular circulation was studied on skin biopsies and correlated with diabetic, valvular and normal subject. The results showed a 14% positivity for the presence of the virus genoma and a significant predominate of DR5 in the II class MHC of patients with a worse ventricular function. Capillary vessels of the coronary microcirculation were dilated in the 48% of the patients, especially in more compromised subjects. Viral myocarditis seem to play a role in the etiopathogenesis of dilated cardiomyopathies (DCM) and the pattern of MHC could influence the progression of the illness. The microcirculation is probably a pathophysiological aspect. No etiological hypothesis seems to predominate.

Adult↗
PubMed1993

[Prevention of reinfarction: a global strategy].

Reinfarction occurs in approximately 10-20% of patients with acute myocardial infarction with an year incidence of about 3% for males and 9% for females. The reinfarction induces a worsen prognosis by producing arrhythmias and a new ventricular "remodelling" with an increase in sudden death and cardiogenic shock. The new event may occur, early or later, in regions either adjacent to or remote from the initial myocardial infarction. Among all the patients admitted to our coronary care unit (1181) during the last 6 years, the overall reinfarction rate was 11.4%; among these, 46% were in the same side (SSMI), while 54% in the distant side (DSMI). The SSMI occurred more often during early months after infarction, while the DSMI occurred significantly later. Cigarettes smoking has been shown to be a common and often the only risk factor in patients with early reinfarction; while arterial hypertension, mostly associated with diabetes and hypercholesterolemia, was found the most important risk factor in later reinfarctions. SSMI was strongly related to one coronary vessel disease or to a double vessel disease (especially with interventricular artery and right coronary artery); while DSMI occurred in presence of triple coronary vessel disease involving secondary branches. The later SSMI is related to serious impairment of left ventricular function in 30% of patients, with cardiogenic shock and death evolution in 25%. The clinical trials for prevention of reinfarction showed that the correction of risk factors and the use of anticoagulation and/or antiaggregation therapy, beta-blockers or Ca(++)-antagonist drugs, must be chosen in relation to the myocardial damage related to previous infarct. In all the patients follow-up during the acute, subacute and chronic phases, must be performed by clinical and instrumental controls able to evidence the developing new cardiovascular events in order to decision making.

Decision Trees↗
PubMed1993

[From myocardial hypertrophy to heart failure: role of the interstitium].

In the progression from myocardial hypertrophy to heart failure, abnormalities in the interstitial space of the heart seem to play a critical role. The formation of an extracellular oedema and the alterations in coronary subendocardial perfusion are associated with the development of interstitial fibrosis. Cardiac experimental studies documented the presence of augmented interstitial fluid volume and pressure and a subsequent remodelling of the fibrillar network of the extracellular space of the myocardium during the phases of the cardiovascular response to a sudden overload. Variations of the Starling's forces balance caused by enhanced endothelial permeability or due to an impairment of cardiac lymphatic drainage may contribute to the development of an acute heart failure. During stable hyperfunction, the organization of a chronic oedema should account for interstitial changes in the hypertrophic myocardium. Reactive fibrosis seems to be under hormonal control. The activation of the renin-angiotensin-aldosterone system is responsible for interfascicular and intercellular accumulation of fibrillar collagen within the cardiac interstitium. Perivascular fibrosis in the subendocardium may impair intramyocardial distribution of coronary flow. When an inadequate hypertrophy occurs, because of an elevation in ventricular wall stress, myocardial oxygen consumption rises and this may lead to the exhaustion of coronary blood flow reserve in the subendocardial layers. This underperfusion may be responsible for the development of myocardial ischemia. Coronary hemodynamic changes in the microcirculation as those prompted by interstitial alterations may contribute to the onset of myocyte necrosis and to the formation of restorative fibrosis. The progressive mechanical overload of the spared hypertrophied myocytes could explain the initiation of a positive feedback mechanism which perpetuates endomyocardial perfusion impairment, interstitial oedema and remodelling, finally, causing myocyte deaths and fibrous tissue proliferation. These structural alterations and their pathophysiological counterparts appear to be closely related to the evolution from compensatory hypertrophy to chronic myocardial failure in hypertrophic heart disease.

Acute Disease↗
PubMed1993

[The myocardial protective effects of cardiac tissue ACE inhibition in experimental ischemia-reperfusion in isolated rat hearts].

The protective effects of captopril were evaluated in vitro on isolated perfused rat hearts after a global ischemia of 20 min. The hearts were randomly allocated in 2 groups. In the first one (n = 6) captopril was added at a concentration of 270 microM. The second one was utilized as control (n = 6). Aortic flow and minute work respectively decreased on reperfusion by 35% and 49% in captopril group and by 65% and 71% in controls (p < 0.001). No changes occurred in heart rate. Aortic systolic pressure and coronary flow decreased in the 2 groups, but not significantly. Myocardial enzyme release during reperfusion showed significant lower levels of CPK and LDH in the captopril group as compared to controls (p < 0.001 after 41 min). The occurrence of serious ventricular arrhythmias was considerably higher in controls with respect to the captopril group. Irreversible ventricular fibrillation occurred only in control hearts (50%). These data indicate that captopril exerts a protective effect during myocardial ischemia and reperfusion by preventing serious ventricular arrhythmias, reducing enzymatic release and a lower decrease in cardiac performance, without an increase in heart rate.

Animals↗
PubMed1993

Inter/intra-observer variability of carotid and femoral bifurcation intima-media thickness measurements.

Arterial wall thickening may be quantitatively assessed by measuring the intima-media thickness (IMT) with high resolution ultrasound. Previous studies have shown a good inter/intraobserver variability of IMT measurements in the common carotid. In this study we evaluated the inter/intraobserver variability of IMT measurements in 10 randomly selected asymptomatic subjects (age 55.4 +/- 6). Two carotids and two femorals were studied in each subject. IMT for each patient was the average of five IMT measurements at the artery bifurcation. Three observers repeated the scanning and the measurements twice with no knowledge of the previous readings. The between observer coefficient of variation (CV) was 8.45%; the intraobserver CV (mean of carotids and femorals) varied from 4.4 to 5.1% for the three observers who measured IMT three times. The mean absolute difference between the first and the third measurement was 0.0738 mm. In conclusion IMT measurement variability is mostly due to differences between observers. The intraobserver variability is very small. IMT measurements at the carotid and femoral bifurcations have a low variability and are a good expression of atherosclerosis as they consider early lesions at the bifurcation level which may not be observed in the common carotid.

Arteriosclerosis↗
PubMed1992

Fibrinolytic enhancement in diabetic microangiopathy with defibrotide.

Skin microcirculation was evaluated in 117 patients with diabetic microangiopathy over a period of six months. They were divided into two groups. Group 1 (64 patients) was treated with oral defibrotide, a new profibrinolytic drug, in association with diet and oral antidiabetic drugs. Group 2 (53 patients) was treated only with diet and antidiabetic agents. The microcirculation was studied by means of laser-Doppler flowmetry transcutaneous partial pressure of oxygen and carbon dioxide pressure measurements, and evaluation of capillary filtration. After six months, patients in group 1 improved their microcirculatory parameters in association with an improvement in signs and symptoms. Moreover, 30 patients in group 1 and 36 in group 2 were followed up for eighteen months, and the authors observed that the deterioration of the microcirculatory parameters was significantly slowed in diabetics treated with defibrotide. A decrease in plasma fibrinogen during defibrotide treatment was observed in all treated patients in association with an increased fibrinolytic activity. In conclusion, it appears that defibrotide, enhancing fibrinolysis, improved the microcirculation in diabetics, preventing further, progressive deterioration.

Adult↗