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C Giusti

Publications and source records attributed to C Giusti.

At least 37 records · Page 2Linked to original sources
PubMed1998

Microvascular involvement in systemic sclerosis: laser Doppler evaluation of reactivity to acetylcholine and sodium nitroprusside by iontophoresis.

OBJECTIVES: To investigate the skin vasodilatory response to iontophoretically applied acetylcholine (Ach), an endothelium dependent vasodilator, and to sodium nitroprusside (SNP), an endothelium independent vasodilator, in patients with systemic sclerosis (SSc). METHODS: Eleven SSc patients were preliminarily studied (10 females, mean age 40.5; mean disease duration 6.5 years), and 16 age and sex matched control subjects. By means of laser Doppler flowmetry skin blood flow was evaluated at third finger, at baseline, and after postischaemic hyperaemia test and during iontophoretically transcutaneous application of 1% solution of Ach and SNP. RESULTS: No significant differences in basal skin blood flow were detected between SSc patients and controls. Cutaneous vasodilatory response to ischaemia, Ach, and SNP was significantly less pronounced in SSc patients compared with controls (p < 0.001). Moreover, among SSc patients a lower (p < 0.05) vasodilatory response to Ach compared with ischaemia and SNP was recorded. CONCLUSIONS: These data confirm a reduction of skin digital vasodilatory reserve in SSc patients and suggest a defect of both endothelial dependent arteriolar relaxation and wall compliance in the pathogenesis of this dysfunction.

Acetylcholine↗
PubMed1998

Heart involvement in systemic sclerosis: an ultrasonic tissue characterisation study.

BACKGROUND: Clinicoepidemiological findings indicate that symptomatic heart involvement in patients with systemic sclerosis (SSc) predicts a very poor prognosis. At necropsy studies, SSc heart involvement without significant coronary lesions is characterised by patchy myocyte necrosis and contraction band necrosis with collagen replacement leading to myocardial fibrosis. There is a discrepancy between the frequency of clinically evident myocardial disease (25%) and autoptical myocardial fibrosis (81%). OBJECTIVE: The aim of this study was to detect preclinical myocardial alterations in SSc patients by ultrasonic videodensitometric analysis. METHODS: Thirty five SSc patients (three male, aged 48.6 (11) SD years, range 22-65) with normal ventricular function and 25 age and sex matched healthy controls were studied. All patients had a negative maximal exercise stress; in all cases arterial hypertension, renal involvement, and diabetes were excluded. Echocardiographic images were digitised by a real time videodigitiser (Tomtec Imaging Systems). Quantitative texture analysis was performed on data from the septum and the posterior wall, obtaining mean gray level histogram (MGL) at both end-diastole (d) and end-systole (s). The cyclic variation index (CVI), was calculated according to the formula ((MGLd-MGLs)/MGLd) x 100. Left ventricular mass (LVM), body surface corrected, was calculated according to Penn convention. RESULTS: Comparable systolic and diastolic blood pressure, LVM, diastolic and systolic function were recorded in both SSc patients and controls. In contrast, in SSc patients the CVI, which is the expression of the intrinsic myocardial structural function, was significantly lower than in controls (septum: -18 (28)% v 35 (10)%, p < 0.0001; and posterior wall: -13 (32)% v 50 (20)%, p < 0.0001). Changes in cyclic echo amplitude, probably related to myocardial fibrosis, were detected in the large majority of SSc patients (88%). CONCLUSIONS: Ultrasonic videodensitometric analysis represents a non-invasive, feasible method that can detect early myocardial changes in SSc patients, which could be related to both fibrosis and microcirculatory abnormalities. Their potential evolution towards ventricular dysfunction and their link with cardiac sudden death, because of severe conduction system or rhythm disturbances, should be further investigated.

Adult↗
PubMed1998

[Ultrasonic tissue characterization analysis in type 1 diabetes: a very early index of diabetic cardiomyopathy?].

BACKGROUND: Based on various epidemiological observations, it has been hypothesized that there is a "diabetic cardiomyopathy" strictly related to diabetes per se and probably due to an increase in the collagen content at the myocardial level, to microangiopathy or to complex alteration of myocardial metabolic pattern. Ultrasonic tissue characterization has recently been applied with different methodological approaches in order to identify early structural alterations of the myocardium. METHODS: We used two different methods of myocardial tissue characterization, i.e. integrated backscatter and videodensitometry, to analyze 26 type I diabetics without clinical symptoms, without hypertension or coronary artery disease, which were excluded on the basis of a negative exercise ECG, and in whom conventional echocardiographic parameters were normal. Seventeen healthy age- and sex-matched subjects were evaluated as the control group. RESULTS: Of the common left ventricular functional indexes, only E/A ratio (expression of global diastolic function) was lower in diabetics compared with controls (p < 0.01). The integrated backscatter index (IBI%) at the septum and posterior wall was significantly higher in diabetics as compared to controls, expressing an increased collagen content on a myocardial level. The cyclic variation index (%) of the mean gray level (videodensitometry) was significantly lower in diabetics in comparison with controls, both for the septum (p < 0.0001) and posterior wall (p < 0.002). This probably expresses an altered intrinsic myocardial contractility, due to an increase in myocardial collagen content and/or impairment of micro-circulatory function. CONCLUSION: In agreement with previous studies, we found an altered behavior in myocardial tissue reflectivity in type I diabetics. The real significance of this finding in the "normal" heart is the subject of intense debate. One hypothesis is that these findings could be considered a very early index of a "diabetic cardiomyopathy".

Adult↗
PubMed1997

Erythrocyte Na+/H+ exchange and preclinical abnormalities of the left ventricular diastolic function in normotensive type 1 (insulin-dependent) diabetic patients.

We assessed the relationship between erythrocyte Na+/H+ antiport activity and myocardial anatomical-functional parameters (by Doppler echocardiography) in normotensive IDDM patients, with and without microalbuminuria. We studied 33 normotensive IDDM subjects and 14 matched healthy controls (group 4). Based on urinary albumin excretion rate (UAER), 23 diabetics were normoalbuminuric, 10 microalbuminuric (group 3). Normoalbuminurics were divided up for normal (group 1, n = 13) or high (group 2, n = 10) antiport activity. We evaluated fasting glycaemia and 24-h urine glucose output, HbA1c, plasma lipids, urea, creatinine and electrolyte clearances, UAER, erythrocyte Na+/H+ countertransport, M-Mode and 2D echocardiograms with Doppler analysis. Antiport, which was higher in diabetics than controls, was significantly overactive in groups 2 and 3 vs group 4, independently from UAER. Diabetics showed left ventricular volume, cardiac mass and systolic function within the control range. In left ventricular diastolic filling, while peak E was similar in diabetic and healthy people, the late peak transmitral flow velocity (peak A) was significantly higher in diabetics than controls, and this was also true in groups 2 and 3 vs group 4. Antiport activity was positively related to peak A (p < 0.03). These observations suggest that (a) the Na+/H+ antiport may be overactive in diabetes, apart from microalbuminuria; (b) increased Na+/H+ antiport activity, in normotensive IDDM people, may be associated with preclinical diastolic myocardial dysfunction ("incipient diabetic cardiomyopathy"?).

Adult↗
PubMed1997

Increased myocardial echo density in left ventricular pressure and volume overload in human aortic valvular disease: an ultrasonic tissue characterization study.

Quantitatively assessed ultrasonic backscatter is an index of ultrasonic tissue characterization directly related to morphometrically evaluated collagen in human beings. Our objective was to assess myocardial reflectivity pattern of patients with severe left ventricular hypertrophy caused by either aortic stenosis (AS) or aortic regurgitation (AR). Ten patients with AS, 10 patients with AR, and 10 closely age- and gender-matched healthy controls were studied by two-dimensional Doppler echocardiography. By using an echocardiographic prototype, we performed a radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and the posterior wall (integrated backscatter index: IBI, expressed in percentage). All patients with stenosis or aortic insufficiency showed a normal regional and global resting systolic function (fractional shortening: AS = 36.0 +/- 6.6 versus AR = 40.3 +/- 6.2 versus control = 40.2 +/- 8.7; p = not significant [NS]) Left ventricular mass index (Devereux's formula) was markedly increased in patients with stenosis or aortic insufficiency (AS = 199.3 +/- 18 versus AR = 208.8 +/- 60 versus control = 97.3 +/- 11 g/m2; p < 0.0001). Myocardial echo density was increased in patients with stenosis or aortic insufficiency in comparison with controls, both in the septum (IBI%: AR = 40.7 +/- 7.9 versus AS = 33.4 +/- 4.2 versus control = 23.0 +/- 6.2; p < 0.0001) and in the posterior wall (IBI%: AR = 27.1 +/- 4.3 versus AS = 23.0 +/- 2.6 versus control = 15.0 +/- 4.2; p < 0.0001). No significant correlations were found between septal and posterior wall IBI and their thickness. Abnormally increased myocardial echo density--possibly related to disproportionate collagen deposition--can be detected in patients with pressure or volume overload caused by aortic valve disease and without overt systolic dysfunction.

Aged↗
PubMed1997

Cutaneous vasodilation to acetylcholine in patients with essential hypertension.

Endothelium-dependent vasodilation is reduced in the forearm of patients with essential hypertension. To evaluate whether endothelium-dependent vasodilation is also reduced in the skin microcirculation of patients with essential hypertension, we evaluated the effect of acetylcholine, an endothelium-dependent vasodilator, and sodium nitroprusside, an endothelium-independent vasodilator, on cutaneous and total forearm blood flow in normotensive subjects (n = 8) and matched patients with essential hypertension (n = 9). We infused acetylcholine (0.15, 0.45, 1.5, 4.5, and 15 microg/100 ml forearm tissue/min) and sodium nitroprusside (1, 2, and 4 microg/100 ml forearm tissue/min) into the brachial artery, and we measured cutaneous blood flow (laser Doppler flowmeter) and muscle blood flow (strain-gauge venous plethysmography) modifications. Both the cutaneous and muscle blood flow increases induced by acetylcholine were reduced in patients with essential hypertension as compared with normotensive controls, whereas the skin and muscle vasodilation induced by sodium nitroprusside was similar in the two groups of patients. These data confirm the impairment of endothelium-dependent vasodilation in the muscle vascular bed of patients with essential hypertension and demonstrate the presence of endothelial dysfunction in skin microcirculation.

Acetylcholine↗
PubMed1997

Ultrasonic videodensitometric analysis of two different models of left ventricular hypertrophy. Athlete's heart and hypertension.

Absolute or relative increases in intramyocardial fibrosis accompany hypertrophy development in human hypertension. Myocardial texture analysis of two-dimensional echocardiographic gray-level distribution has been shown to identify alterations attributed to abnormal collagen content in several conditions. Therefore, this echocardiographic tool might help to identify those hypertensive individuals with abnormal interstitial collagen deposition, a condition that may promote and/or aggravate morbidity in this group of people who are at high risk for cardiovascular events. We compared male essential hypertensive subjects who had marked cardiac hypertrophy (left ventricular mass index adjusted for height > 2 SD of mean of control group) (group 1) with normotensive elite veteran athletes who had comparable cardiac hypertrophy (group 2) and sedentary normotensive subjects as controls (group 3). The groups (n = 14 each) were matched for age (+/- 2 years) and sex. We analyzed echocardiographic digitized data quantitatively by means of a calibrated 256 gray level digitization system to calculate midseptal and midposterior end-diastolic and end-systolic mean gray levels and to derive the so-called cyclic variation index, ie, the percent mean gray level variation during the cardiac cycle. Echocardiographic parietal and septal thicknesses and masses were evaluated according to the Penn convention. Left ventricular mass index (adjusted for height) overlapped between groups 1 and 2 (187.1 +/- 17.5 and 181.3 +/- 19.3 g/m, respectively; P = NS), whereas it was obviously smaller in control subjects (93.1 +/- 18.6 g/m; P < .001 for both). According to inclusion criteria, both septal and posterior wall thicknesses were comparable in athletes and hypertensive subjects, and they were higher than in the control group (P < .0001). The hypertensive subjects showed a significantly lower cyclic variation index than the control and athlete groups for both the septum (P < .001) and posterior wall (P < .001); no statistical difference was found between athletes and control subjects for this parameter. In conclusion, abnormalities of two-dimensional echocardiographic gray-level distribution are present in hypertensive hypertrophied individuals but seem unrelated to the degree of echocardiographic hypertrophy as such. An altered collagen network distribution or a decrease in capillary distribution in severe myocardial hypertrophy, secondary to pressure-volume overload in hypertension with other yet unknown mechanisms, could help to explain our findings. Further work is needed to establish the prognostic, clinical, and therapeutic implications of these findings.

Analysis of Variance↗
PubMed1996

Simultaneous dobutamine stress echocardiography and dobutamine scintigraphy (99mTc-MIBI-SPET) for assessment of coronary artery disease.

BACKGROUND: Simultaneous dobutamine stress echocardiography (DSE) and 99Tc-MIBI-SPET (DMS) for the evaluation of the presence and the extent of coronary artery disease (CAD) were assessed for a head to head comparison regarding the diagnostic acuracy of the two rests. METHODS AND RESULTS: Forty-five consecutive patients (33 males and 12 females: 53 +/- 6.8 yr.) underwent exercise electrocardiography and simultaneous dobutamine stress echocardiography and MIBI-SPET imaging. Coronary angiography was performed in all patients (significant coronary stenosis > 50%). On the basis of the results of exercise electrocardiogram the pre-test probability for coronary artery disease (Diamond's algorithm) was low (45.6 +/- 12.7%). The overall specificity, sensitivity and predictive accuracy of Echo-dobutamine stress test for diagnosis of the presence or absence of CAD were: specificity 82%, sensitivity 76%, diagnostic accuracy 80%, positive predictive value 90%, negative predictive value 40%. The overall specificity, sensitivity and predictive accuracy of MIBI-SPET-dobutamine test for diagnosis of the presence or absence of CAD were: specificity 86%, sensitivity 87%, diagnostic accuracy 84%, positive predictive value 97%, negative predictive value 54%. MIBI-SPET-dobutamine test showed a significantly higher sensitivity in comparison with ECHO-dobutamine test (P < 0.05). CONCLUSION: Both noninvasive methods for the detection of CAD showed a good diagnostic accuracy. Nevertheless the SPET model showed a higher sensitivity in comparison with DSE model, essentially in the presence of a lower extent of CAD and during submaximal test.

Cardiotonic Agents↗
PubMed1996

Left ventricular function during exercise in athletes and in sedentary men.

Aim of this study was to evaluate left ventricular function during exercise in 10 male elite runners and in 10 sedentary males. End-diastolic (EDV) and end-systolic volume (ESV), left ventricular ejection fraction (EF), early peak transmitral flow velocity (peak E), time-velocity integral of mitral inflow (m-TVI); mitral cross sectional area (m-CSA); mitral stroke volume (SV), and cardiac output (CO) were measured by echo-Doppler. We simultaneously analyzed: VO2max by spirometric method, mean arterial blood pressure (MAP) by sphygmomanometer, and heart rate (HR) by ECG. The parameters were measured under basal conditions (level 1), at 50% of maximal aerobic capacity (level 2), at peak of exercise (level 3) and during recovery. Ejection fraction in athletes increased significantly at peak of exercise through Frank-Starling mechanism. Stroke volume and cardiac output increased significantly in athletes at peak of exercise. Left ventricular diastolic function was superior in athletes versus controls: in fact, higher peak E in athletes enhanced early diastolic ventricular filling. Therefore, the athletes showed complex cardiovascular adjustments induced by training, which allowed an higher peak working power, a greater cardiac output, and VO2max when compared with an untrained control population.

Adult↗
PubMed1996

Ultrasonic videodensitometric analysis in type 1 diabetic myocardium.

OBJECTIVE: To test the hypothesis that quantitative analysis of two-dimensional echocardiographic gray-level distributions could allow one to detect the early changes in acoustic properties of human diabetes myocardium differentiating it from normal myocardium. METHODS: We evaluated, by two-dimensional echocardiography, 28 asymptomatic type 1 insulin-dependent diabetic patients with normal ventricular function (group A) and 15 age- and sex-matched healthy controls (group B). By selection, all of the diabetics were normotensive and had a negative maximal exercise stress. Echocardiographic images were digitized by using a calibrated digitization system. Quantitative texture analysis was accomplished on data from the septum and posterior wall both at end-diastole and at end-systole. The following parameters were obtained: the mean gray level of the regions of interest, and its absolute SD, skewness, kurtosis, and cyclic variation index. RESULTS: The main result of this study was that the cyclic variation indices of the echo amplitudes of the septum and posterior wall in the diabetic group were significantly lower than those in controls (P < 0.001 and P < 0.002, respectively). Furthermore, the diabetic group had a significantly higher mean gray level of the septum [group A 54.3 +/- 22.5 (mean +/- SD) versus group B 39.7 +/- 9.8, P < 0.03] at end-diastole. The mean gray-level of the posterior wall was similar in the two groups, both at end-diastole and at end-systole. CONCLUSION: Alterations of cyclic echo amplitude (possibly related to collagen deposition) can be detected in asymptomatic diabetic patients with normal resting function. Theoretically, this finding might be considered an early preclinical alteration, potentially related to subsequent development of "diabetic cardiomyopathy'.

Adult↗
PubMed1996

Vitreal alterations in retinitis pigmentosa: biomicroscopic appearance and statistical evaluation.

The authors present a biomicroscopic evaluation of vitreal alterations in a large group of patients affected by primary retinitis pigmentosa (RP). 286 RP patients (571 eyes), 153 (305 eyes) males and 133 (266 eyes) females, have been studied; the mean age of this whole group was 37.26 + or - 14.93 years (age range: 5-77). Vitreal static and dynamic biomicroscopy was performed on fully dilated pupils by means of a Haag-Streit 900 slit-lamp and high-power positive precorneal lenses (+90 and +78 dpt Volk lenses). Most patients showed floating cottonball-like condensations (26.824%) often associated with fibrillary degeneration (15.88%), while non-pigmentary vitreal particulation was detected in 26.609% of cases and the pigmentary type in 12.017%, respectively. Posterior vitreal detachment was detected alone in only 0.43% of cases while 18.24% of examined eyes showed no vitreal alterations. A high statistical correlation between vitreal aspects and pigmentary grading of the fundus oculi (p = 0.0001), as well as duration of the disease (p = 0.0074), was found; at the same time, no statistical correlation with refractive error was demonstrated (p = 0.47).

Adolescent↗
PubMed1996

The effect of cigarette-smoking on cardiovascular risk factors: a study of monozygotic twins discordant for smoking.

The association of cigarette smoking with the development of occlusive vascular disease is firmly established. Unfavourable changes in a series of variables held independent risk factors for the development of vascular lesions (HDL-cholesterol, haematocrit, white blood cell count, fibrinogen and plasminogen activator inhibitor-1 (PAI-1)) are thought to be directly influenced by cigarette smoking. However, the role played by the genotype in the effect of smoking on the above parameters has not been investigated. To control the genotype, we studied the relationship between cigarette smoking and a series of cardiovascular risk factors in 27 monozygotic twin pairs (7 male and 20 female pairs, mean age +/- SD: 47.4 +/- 12.9 yrs) with a life-long discordance for smoking. Smoking twins had a life-long dose of smoking (Brickman index) of 287.3 +/- 241.5. Body mass index, blood pressure, haematocrit, haemoglobin and red blood cell counts, total cholesterol levels and the acute phase reactants alpha 1-acid glycoprotein and C-reactive protein were similar in smokers and non-smokers. Triglyceride was higher by 12.6% (9.5-35%, 95% confidence interval, p = 0.02) and HDL-cholesterol lower by 7.5% (0.2-15%, p = 0.04) in the smoking co-twins, who also had 8.4% (-0.2-17%, p = 0.06) higher white blood cell counts and 4.1% (1.2-7%, p < 0.01) larger mean platelet volume. There was no significant difference in clottable fibrinogen (by two methods) or in the activity of plasminogen activator inhibitor-1 between the two groups, nor was the within-pair difference in these parameters related to the smoking dose. Echo-doppler examination of the carotid arteries of 24 twin pairs showed mostly minor atherosclerotic lesions in 46% and 42% of the smoking and non-smoking co-twins. After adjustment for age, systolic blood pressure and platelet count and volume were the only variables significantly associated to the presence of vascular lesions. Cigarette smoking is associated with an atherogenic lipid profile and with changes in platelets and white cells potentially reflecting endothelial cell damage. When controlling the genotype, fibrinogen and PAI-1 activity levels did not seem directly influenced by cigarette smoking.

Adult↗
PubMed1995

Informed versus randomised consent to clinical trials.

We compared different procedures for seeking consent to participate in a sham randomised clinical trial and assessed whether refusal is affected by awareness of the severity of outlook. 2035 healthy subjects aged between 20 and 80 years, who visited a scientific exhibition, were enrolled in a hypothetical trial of experimental versus standard therapy, and randomly assigned to groups asked for conventional informed consent or prerandomisation consent. There were four study groups: one-sided informed consent for randomisation (subjects who refused would receive standard treatment); two-sided informed consent for randomisation (subjects who refused could choose between standard and experimental treatment); randomised consent to experimental treatment (subjects who refused would receive standard treatment); and randomised consent to standard treatment (subjects who refused would receive experimental treatment). The refusal rates were 16.2%, 19.9%, 12.1%, and 49.2%, respectively. The perceived severity of the simulated disease affected the refusal rate: the worse the outlook, the lower the refusal rate for informed consent or for consent after randomisation to new treatment, and the higher the refusal rate for consent after randomisation to standard treatment. The prerandomisation design seems to be efficient in a one-sided clinical scenario (eg, a trial of a new drug that would not be given outside the trial) because the refusal rate was substantially lower for prerandomisation to the new treatment than for conventional one-sided informed consent. However, in a two-sided clinical scenario (eg, a trial comparing similar treatments) the prerandomisation design is potentially highly inefficient; the refusal rate was much higher for prerandomisation to standard treatment than for conventional two-sided informed consent.

Adult↗
PubMed1995

Increased echodensity of myocardial wall in the diabetic heart: an ultrasound tissue characterization study.

OBJECTIVES: We sought to characterize myocardial echodensity in asymptomatic patients with insulin-dependent diabetes and normal conventional two-dimensional echocardiographic findings to determine whether ultrasound tissue characterization can detect ultrastructural changes in myocardium, such as an increase in collagen content. BACKGROUND: Fibrosis alters the acoustic properties of the heart in animals and humans, and these changes are detectable by cardiac tissue characterization with ultrasound. Early changes detected in the diabetic heart include increased interstitial collagen deposition. METHODS: Using two-dimensional echocardiography, we evaluated 26 asymptomatic patients with insulin-dependent diabetes with normal regional and global rest function, and 17 age- and gender-matched control subjects. By selection, all diabetic patients were normotensive and had negative maximal exercise stress test results to avoid the confounding effects of hypertension and coronary artery disease. Using an echocardiographic instrument implemented at the Institute of Clinical Physiology, we performed an on-line radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated back-scatter signal of the ventricular septum and posterior wall. The integrated values of the radiofrequency signal from the myocardial wall were normalized for those from the pericardial interface and were expressed as percentages (integrated backscatter index). RESULTS: Diabetic patients showed a significant increase in myocardial echodensity both in the septum ([mean +/- SD] 36.6 +/- 8.1 vs. 23.6 +/- 4.4, p < 0.0001) and posterior wall (21.2 +/- 5.3 vs. 18.4 +/- 3.7, p < 0.001). By individual patient analysis, 17 patients exceeded the 95% confidence limits for normal myocardial echocardiographic reflectivity found in normal subjects, and only 3 had a relatively abnormal transmitral Doppler filling pattern (E/A ratio), mainly consisting of an abnormally increased late peak flow velocity (65% vs. 11%, p < 0.001). The increased myocardial intensity was similar in patients with (n = 16) and without (n = 10) noncardiac complications, such as retinopathy or nephropathy (37.5 +/- 7.9% vs. 35.0 +/- 8.3%, p = 0.35). CONCLUSIONS: Abnormally increased myocardial echodensity, possibly related to collagen deposition, can be detected in asymptomatic diabetic patients with normal rest function. Theoretically, this finding might be considered a very early preclinical alteration potentially related to subsequent development of diabetic cardiomyopathy.

Adult↗
PubMed1995

Evaluation of maximal left ventricular performance in elite bicyclists.

Aim of this work was to study in a group of elite cyclists, undergoing laboratory testing, the trend of the left ventricular systolic and diastolic function, echocardiographically and Doppler derived, simultaneously with the evaluation of ergospirometric parameters during maximal exercise. We studied a group of male subjects, consisting of 10 professional elite bicyclists (mean age: 25.1 +/- 3.2 years) during competitive activity (VO2/kg max: 78.5 +/- 7.7 ml.kg.min-1). The maximal exercise test, conducted with Wind Loaded Simulator for optimisation of ergometric capacity, showed, at the end of exercise, at a speed of 49.2 +/- 2.4 km/h, a VO2max of 5365 +/- 543.4 ml/min, with a calculated Cardiac Output (CO) of 19.3 +/- 3.7 l/min. A linear regression relationship was found between VO2max and CO (r = 0.84; p < 0.0001) as well as between VO2max and maximal reached speed (r = 0.97; p < 0.0001). During the aerobic period a slight but significant increase in End Diastolic Volume (EDV) was observed due to the greater venous return from exercising muscles. At stop, in anaerobic period, the EDV remained substantially constant. Ejection Fraction (EF) also increased during exercise through the Frank-Starling mechanism activation. The slight, but not significant, increase in EF at stop level may be explained by an activation of homeometric control of contractility with a sympathetic modulation on myocardial fibres. The early diastolic mitral flow velocity (Peak E) increased significantly during exercise, in comparison with basal upright values. The left ventricular diastolic compliance observed in athletes permits a good left ventricular filling, particularly in early diastolic phase; this allows an excellent left ventricular systolic performance. Based on echocardiography and pulsed Doppler measurements, calculated cardiac output is underestimated by approximately 20%.

Adult↗
PubMed1995

[The request for consent in clinical research: a randomized study in healthy subjects].

To compare two strategies of consent requirement (classical informed consent and randomised consent according to Zelen), the Clinical Data Elaboration Centre of South Italy, within the special project Clinical Application of Oncological Research of the National Research Council of Italy (CNR-ACRO) invited healthy people visiting the 7th edition of the scientific exhibition "Futuro Remoto" to simulate of being ill and receiving the offer of entering a clinical trial. Within informed consent strategy patients are asked to agree to the randomisation process, while, in the randomised consent, randomised treatment assignment is performed before consent requirement and patients should agree directly to the assigned therapy. Major aims of the study were (a) to compare the strategies in terms of refusal rate to a hypothetical clinical trial, and (b) to estimate whether severity of prognosis affected subjects' decision. 3,217 visiting people participated to the simulation; they were prevalently young, males and with a high level of school education. The study was performed in two different scenarios. In the first one, with one choice option, subject refusing consent could receive standard therapy only; refusal rate was 16% after informed consent and 13.4% after randomised consent (for experimental therapy). In the other scenario, with two choice options, subjects refusing consent could choose the preferred therapy; refusal rate was 20.6% after informed consent, 48.1% after randomised consent (for standard therapy) and 13.4% after randomised consent (for experimental therapy).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Ultrasonic evaluation of early atherosclerotic damage in patients with type 1 diabetes mellitus].

UNLABELLED: The aim of this study was to evaluate the influence of metabolic control on the development of atherosclerotic lesions in type 1 insulin-dependent diabetic patients (IDDM). MATERIALS AND METHODS: Twenty-eight well controlled IDDM patients, without known risk factors or clinical evidence of cardiovascular disease, together with 28 age-matched healthy controls spontaneously underwent high-resolution echographic evaluation of carotid femoral arteries. A global score of atherosclerotic damage as been assigned to the four investigated vessels on the basis of 1-6 scale, which takes into account most important ultrasound atherosclerotic lesion found in every artery. RESULTS: Diabetic and healthy controls differed significantly as regard to medio-intimal carotid thickness (p < 0.001), but were similar as for score of atherosclerotic damage. CONCLUSIONS: Our results suggest that, in spite of a carotid wall medio-intimal thickness more pronounced in IDDM patients, well controlled IDDM is associated with atherosclerotic damage almost identical to that of healthy age-matched controls.

Adolescent↗