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Biomedical subjects

V Di Bello

Publications and source records attributed to V Di Bello.

At least 55 records · Page 3Linked to original sources
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↗
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

Microalbuminuria and erythrocyte sodium-hydrogen exchange in essential hypertension.

Microalbuminuria (urinary albumin excretion between 20 and 200 micrograms/min) and abnormalities of red blood cell sodium-hydrogen exchange coexist in essential hypertensive patients. To evaluate how the two phenomena relate, we recruited 10 untreated microalbuminuric male essential hypertensive patients without diabetes to be compared with an equal number of matched essential hypertensive patients excreting albumin in normal amounts as well as 10 healthy control subjects. Sodium-hydrogen exchange values were increased to a comparable extent in microalbuminuric and normoalbuminuric hypertensive patients. Systolic and mean blood pressures were higher in microalbuminuric patients. Fasting insulin was greater and high-density lipoprotein cholesterol lower in patients than control subjects. Urinary albumin excretion correlated positively with both mean blood pressure and left ventricular mass values in the absence of a relationship with circulating lipid and insulin levels. In contrast with microalbuminuria, sodium-hydrogen exchange covaried only with high-density lipoprotein cholesterol and insulin levels. Thus, microalbuminuria and an abnormal sodium-hydrogen exchange are unrelated phenomena in essential hypertensive patients. Microalbuminuria appears to be a hemodynamically driven biological variable, while an accelerated sodium-hydrogen exchange seems primarily conditioned by the metabolic abnormalities of hypertension, possibly in the context of an insulin-resistant syndrome.

Aged↗
PubMed1995

Relationship between carotid wall thickness and forearm blood flow reserve in hypertension.

BACKGROUND: The development of a reduced forearm blood flow reserve and an increased carotid intima media thickness is a well known consequence of the structural adaptation of arterioles and large arteries in response to hypertension. It is unknown, however, how those two processes relate to each other in the individual hypertensive patient. METHODS: Minimal forearm vascular resistances (Rmin, the ratio of mean blood pressure to postischemic plethysmographic peak forearm blood flow), common carotid intima media thickness (IMT, high-resolution ultrasonography), blood pressure (indirect method), left ventricular mass, posterior wall and septum thickness (by echocardiography) and lipids were measured in 15 men with mild-to-moderate essential hypertension without evidence of atherosclerotic involvement of the carotid arteries, and in 14 normotensive controls with a similar age range. RESULTS: Rmin and IMT were greater in hypertensives, and a statistically significant positive correlation existed between the two variables. Both Rmin and IMT correlated with left ventricular structure indices and blood pressure. Age showed a positive correlation with IMT, while lipids were unrelated to either parameter. CONCLUSIONS: The micro- and macrovascular segments of the hypertensive circulation readapt in parallel in response to elevated blood pressure, possibly through the commensurate development of medial hypertrophy.

Arterioles↗
PubMed1994

Forearm blood flow reserve and cardiac and renal indexes of pressure load in normotensive and hypertensive individuals.

In response to hypertension, arterioles remodel their structure, the heart develops myocardial hypertrophy, and the kidney reduces creatinine clearance and increases albuminuria. To better understand the interrelations among the target organs involved in hypertension, we evaluated minimal forearm vascular resistances--a hemodynamic index of arteriolar structure derived from mean blood pressure and maximal postischemic forearm blood flow--the echocardiographic indexes of cardiac structure, and urinary albumin excretion and creatinine clearance in 29 male mild to moderate non-macroalbuminuric essential hypertensive patients on no drugs and 11 age- and sex-matched normotensive control subjects. Minimal forearm resistances were elevated in hypertensive patients and correlated with left ventricular mass, wall thickness, and mean arterial pressure. Patients with abnormal minimal forearm resistances (2 SD above normal) were characterized by higher pressure, greater wall thickness, lower creatinine clearance, and higher albumin excretion, suggesting that maximal forearm flow capacity does relate to the hemodynamic load exerted on both the kidney and heart. However, the correlation with cardiac structure and mean arterial pressure explained only part of the variability of minimal forearm resistances. Furthermore, no correlation among these parameters was found when hypertensive patients were evaluated separately from normotensive subjects, possibly because of heterogeneous factors active on arteriolar structure and unrelated to the pressor load. Overall, the data suggest that the development of abnormal minimal forearm resistances in the course of the hypertensive process is related to the pressor load, but its details need further understanding.

Adult↗
PubMed1993

Left ventricular performance and ultrasonic myocardial quantitative reflectivity in endurance senior athletes: an echocardiographic study.

Young elite athletes often show left ventricular hypertrophy, but normal values of quantitatively evaluated myocardial wall reflectivity. The aim of this study is to assess the acoustic pattern of ventricular wall reflectivity, as well as of systolic and diastolic function, in older endurance runners with increased left ventricular mass. For this purpose, 12 elite, senior isotonic athletes in full training and 11 normal, age-matched controls with sedentary life styles were studied. The following parameters were measured with a commercially available 2D echo-Doppler machine: end-diastolic diameter, diastolic septum thickness, left ventricular mass index, ejection fraction (by Teicholtz rule); peak E, peak A, E/A ratio, acceleration and deceleration time of mitral inflow velocity and isovolumic relaxation time. On-line radio frequency analysis was also performed to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and the posterior wall. The integrated values of the radiofrequency signals were normalized for the pericardial interface and expressed in percent (% 2D-IB). In spite of the greater left ventricular mass in athletes versus normal controls (319 +/- 81 vs 225 +/- 63 g.m-2, P < 0.0005), there were no significant intergroup differences as regards end-diastolic diameter (50.7 +/- 5.1 vs 48.1 +/- 5.2 mm, P = ns), ejection fraction (75.5 +/- 9.3 vs 71.8 +/- 9.1%, P = ns), and 2D-IB of septum (22.2 +/- 6.9 vs 22.4 +/- 7.0, P = ns) and posterior wall (12.5 +/- 5.6 vs 13.1 +/- 2.8, P = ns).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Microalbuminuria is a marker of left ventricular hypertrophy but not hyperinsulinemia in nondiabetic atherosclerotic patients.

Microalbuminuria predicts cardiovascular events in diabetic and nondiabetic patients. For a better understanding of the physiopathological importance of microalbuminuria in atherosclerotic disease, we evaluated the relation between urinary albumin excretion and arterial blood pressure, left ventricular mass, insulin, and lipid levels. The studies were conducted in patients with atherosclerotic peripheral vascular disease. Urinary albumin excretion (studied by nephelometry; an average of triplicate collections from 8 PM to 8 AM), causal blood pressure, echocardiographic left ventricular mass index and wall thickness, plasma immunoreactive insulin and C-peptide (both basally and after a 75-g oral glucose load), blood lipids, and fibrinogen were studied in eight normal subjects and 20 nonobese, nondiabetic male patients with angiographically documented atherosclerotic peripheral vascular disease and preserved renal function, 12 of whom were either hypertensive or on antihypertensive treatment. Eight patients were microalbuminuric (urinary albumin > 20 micrograms/min) and 12 were not. Ankle-arm index and calf and foot transcutaneous oxygen tension were reduced in comparison with normal control subjects but superimposable between the two patient groups to indicate a comparable clinical progression of the vascular disease. In the microalbuminuric subjects, left ventricular mass index was greater, interventricular septum was thicker, and cardiac hypertrophy was more frequent than in nonmicroalbuminuric patients. The prevalence of hypertension tended to be greater and systolic blood pressure values were higher in the presence of microalbuminuria. Overall, a highly significant relation existed between urinary albumin excretion and left ventricular mass. Systolic blood pressure was greater and a history of arterial hypertension was more frequent among microalbuminurics, whereas diastolic blood pressure values showed a statistically significant correlation with both variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

Suitability of Doppler echocardiography for the assessment of right heart hemodynamics after De Vega tricuspid annuloplasty.

Cardiac Doppler Echocardiography is a suitable method for to evaluating right heart hemodynamics. However, the surgical correction of tricuspid valve annuloplasty changes valve geometry and might possibly lead to a technical obstacle to this estimation. The accuracy of Doppler echocardiography in the assessment of tricuspid regurgitation and systolic pulmonary pressure in patients who had undergone De Vega annuloplasty was evaluated in this study. Ten patients (9 females and 1 male), mean age 55.7 +/- 7.8 years, who had a previous De Vega annuloplasty for the treatment of tricuspid regurgitation due to a severe mitral stenosis, underwent a Doppler echocardiography study and, within two hours, right heart catheterization for a direct comparison of parameters calculated by different methods. Right ventricular-atrial maximal pressure gradient was found to be 32.6 +/- 11.07 mmHg by Doppler and 31.4 +/- 11.07 mmHg by catheterization. Pulmonary systolic pressure was 42.6 +/- 9.1 mmHg at Doppler and 39.1 +/- 11.3 mmHg at catheterization, with a highly significant correlation between the 2 techniques (r = 0.98%, p < 0.01). With semiquantitative Doppler evaluation 10 patients showed tricuspid insufficiency, which was mild in 8 and medium in 2. At catheterization all patients were found to have mild tricuspid insufficiency. Cardiac Doppler seems a reliable method in the evaluation of tricuspid regurgitation and of pulmonary systolic pressure even in patients who underwent De Vega annuloplasty.

Blood Pressure↗
PubMed1992

Normal ultrasonic myocardial reflectivity in athletes with increased left ventricular mass. A tissue characterization study.

BACKGROUND: Ultrasonic integrated backscatter of myocardial walls is directly related to the morphometrically evaluated collagen content. The integrated backscatter is also increased in hypertrophic cardiomyopathy, probably because of fiber disarray. The purpose of this study was to investigate myocardial tissue reflectivity in subjects with physiological hypertrophy caused by intense physical training and to assess the relation between the acoustic properties of myocardial tissue and left ventricular wall thickness assessed by conventional two-dimensional echocardiography. METHODS AND RESULTS: Twenty-four young male athletes (14 professional cyclists and 10 weight lifters, all in full agonistic activity) were studied together with 10 normal age-matched controls with sedentary life. By means of a commercially available two-dimensional echocardiograph, standard measurements were obtained according to the recommendations of the American Society of Echocardiography. With a prototype implemented in our Institute, an on-line radiofrequency analysis of ultrasound signals was also performed to obtain quantitative operator-independent measurements of the integrated backscatter of the myocardial walls. The integrated values of the radiofrequency signal were normalized for the pericardial interface and expressed in percent integrated backscatter (%IB). Compared with control subjects, athletes showed greater thickness values of septum (controls, 9 +/- 1; cyclists, 14 +/- 2; weight lifters, 15 +/- 1 mm, mean +/- SD; p less than 0.01) and posterior wall (9 +/- 1, 12 +/- 2, and 12 +/- 1 mm, respectively; p less than 0.01) but similar values of %IB for both septum (23 +/- 4%, 21 +/- 7%, and 23 +/- 8%, p = NS) and posterior wall (10 +/- 2%, 9 +/- 2%, and 11 +/- 2%, p = NS). In athletes, no correlation was found between septal and posterior wall thickness and the corresponding regional myocardial reflectivity (r = 0.23, p = NS and r = 0.01, p = NS, respectively). Furthermore, we compared the quantitative ultrasonic data between two subsets of 10 athletes and 10 patients with hypertrophic cardiomyopathy and similar degrees of septal thickness (16 +/- 1 versus 17 +/- 1 mm, respectively, p = NS). Septal and posterior wall %IB results were significantly higher in patients with hypertrophic cardiomyopathy (53 +/- 13% and 36 +/- 9%, respectively) than in athletes (21 +/- 7% and 10 +/- 3%, respectively; p less than 0.01 for both). CONCLUSIONS: We conclude that 1) endurance athletes show a normal pattern of quantitatively assessed ultrasonic backscatter despite of a marked left ventricular hypertrophy and 2) athletes and patients with hypertrophic cardiomyopathy and similar degrees of myocardial wall thickness can be differentiated on the basis of quantitative analysis of backscattered signal.

Adult↗
PubMed1991

Twenty-four-hour activity of felodipine extended release in chronic stable angina pectoris.

To investigate the antiischemic efficacy and duration of action of the dihydropyridine calcium antagonist felodipine, 15 patients with stable exertional angina were enrolled in a double-blind, crossover study comparing 2 doses (5 and 10 mg) of felodipine extended release (ER) and placebo given once daily for 1 week. Bicycle exercise tests were repeated at the end of each treatment period 4 and 24 hours after dosing. Four hours after dosing with both felodipine doses, only 5 patients discontinued the exercise test because of greater than 2 mm of ST-segment depression, whereas 10 continued until exhaustion (p less than 0.01 vs placebo). Compared with placebo, total exercise time was increased by 19% (p less than 0.001), with no difference between doses. After 24 hours, exercise duration was prolonged up to physical exhaustion in 6 patients taking felodipine 10 mg (p less than 0.05 vs both placebo and felodipine 5 mg); moreover, 11 patients taking 10 mg and 5 taking 5 mg increased time to 1 mm of ST depression greater than or equal to 15% compared with exercise time during the placebo test. Mean time to 1 mm of ST depression at 24 hours was increased by 8% with 5 mg and by 18% with 10 mg (p less than 0.001 vs placebo; p less than 0.01 between doses). Total exercise time at 24 hours was increased with both doses (p less than 0.001), with greater efficacy with the 10-mg dose (p less than 0.05 vs 5 mg).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Echocardiographic parameters and systolic times in arterial hypertension in the elderly].

In 40 subjects, 15 mean age 70.7 +/- 5.6 with systolic-diastolic hypertension, 15 mean age 75.5 +/- 6.8 years with systolic hypertension and 10 mean age 73.6 +/- 5.1 normotensive control group we have analyzed with M-mode 2D echocardiography and echophonocardiography the following parameters: diastolic--EDD--and systolic diameter--SD--of left ventricle, diastolic thickness of septum--SSD--and posterior wall--SPPD--of left ventricle, left ventricular ejection fraction--EF--(Theicholtr. formula), radius posterior wall thickness--R/SPPD--, left ventricular mass--LVM--(Devereux' formula), and systolic time intervals (Q-A2, LVET, PEP and PEP/LVET). The differences between groups are: systolic-diastolic hypertensive patients have increased EDD, SPPD and LVM, reduction of EF and increased PEP/LVET ratio in comparison with B and C groups; systolic hypertension doesn't increase EDD; SSD and PEP/LVET increase, while the EF remains within normal limits. In the healthy aged subjects SSD, SPPD and LVM are normal.

Aged↗
PubMed1987

Cardiovascular adjustments induced by training evaluated during semisupine isotonic exercise and recovery period: an echocardiographic study.

Two groups of subjects were examined: trained athletes (group A) and a sedentary control group (group B). The subjects performed submaximal bicycle exercise in the semisupine position to evaluate the differences between the two groups with regard to cardiovascular response during exercise and recovery and to point out all the changes due to training. During the first part of exercise, cardiac output increased contemporary with heart rate and myocardial contractility as shown by the trend of the ejection fraction, higher in group A, under the same level of total vascular peripheral resistances. Later there was an increase of cardiac output for a further increase of heart rate and cardiac inotropism due to the homeometric mechanism. During recovery the heart rate and peripheral vascular resistance reduction led to an increase of venous return which set up the Frank-Starling mechanism via an increase of left ventricular dimensions. These adjustments were more efficient in group A. During exercise and recovery the heart rate-pressure product was constantly lower in group A with a significant difference to group B. Therefore, trained athletes' myocardium is more efficient than that of the sedentary group because it performs an external work load with a lower oxygen consumption.

Adult↗
PubMed1987

Cardiac damage due to nonpenetrating trauma. Report of four cases.

Four examples of cardiac damage secondary to nonpenetrating trauma in road accidents are described. Two patients had interventricular septal defect and other two had tricuspid insufficiency. In all four cases the lesion was not recognized at the time of the accident but became clinically important later. The time interval between trauma and surgery was one month to thirteen years. After surgical treatment, all four patients have continued to be asymptomatic.

Accidents, Traffic↗
PubMed1984

[Correlation between electrocardiographic and echocardiographic findings in chronic aortic insufficiency].

Echocardiographic indices of left ventricular volume and mass and electrocardiographic indices of left ventricular hypertrophy have evaluated in 25 patients with chronic aortic regurgitation and in 10 normal subjects. When the patients with aortic regurgitation were subdivided in three groups with increasing evidence of left ventricular hypertrophy, the echocardiographic measures of left ventricular dimension and mass were also found to be increased, with statistically significant differences between patients and controls and among the three groups of patients as well. A specially constructed cumulative electrocardiographic index of left ventricular hypertrophy (Sokolow and Lyon's index plus Lewis' index plus strain pattern) is correlated with the left ventricular end-diastolic diameter (r = 0.65; P less than 0.001), cross-sectional area (r = 0.65; p less than 0.001) and mass (r = 0.75; p less than 0.001) better than the isolated electrocardiographic indexes.

Adult↗
PubMed1984

[Analysis of variations in cardiac performance induced by tilt and hand-grip in athletes and in untrained subjects].

The aim of the present study is to analyze variations of external cardiac work and of indices of myocardial oxygen consumption induced by upright tilting and hand-grip in volley-ball athletes (group A) in comparison with a group of normal subjects (group N). For this purpose we have used impedance cardiography, a simple, reproducible and non invasive technique, which is very reliable in evaluating both systolic time intervals and hemodynamic parameters such as stroke volume and cardiac output. No significant differences, of external cardiac work, double and triple product were observed between group A and N upon upright tilting. Hand-grip test, on the other hand, can differentiate the myocardial behaviour of trained people from that of the control group. The double product was significantly reduced in group A in comparison with group N (P less than 0.001 and the end of the test, P less than 0.05 after 30", P less than 0.001 after 1' and 3"). The triple product was significantly reduced in group A in comparison with group N at the end of the test (P less than 0.005). External cardiac work was always higher in group A in comparison with group N (P less than 0.02, at the stop P less than 0.05 after 30", P less than 0.01 after 1', P less than 0.0001 after 3'). Therefore in volleyball athletes the myocardium exhibits better mechanical performance than in normal subjects.

Blood Pressure↗