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Biomedical subjects

C Giannattasio

Publications and source records attributed to C Giannattasio.

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

Regression of radial artery wall hypertrophy and improvement of carotid artery compliance after long-term antihypertensive treatment in elderly patients.

OBJECTIVES: The present study was designed to assess whether a diuretic- or an angiotensin-converting enzyme inhibitor-based treatment can reduce arterial wall hypertrophy of a distal muscular medium-sized artery--the radial artery--and the stiffness of a proximal large elastic artery--the common carotid artery. BACKGROUND: Large-artery wall thickness and stiffness are increased during sustained essential hypertension and contribute to the increased risk of complications. Whether antihypertensive treatment can normalize the wall hypertrophy of conducting arteries has not yet been determined. METHODS: Seventy-seven elderly hypertensive patients were randomized to receive 9 months of double-blind treatment with perindopril (2 to 8 mg/day) or the diuretic combination of hydrochlorothiazide (12.5 to 50 mg/day) plus amiloride (1.25 to 5 mg/day) after a 1-month placebo washout period. If systolic blood pressure remained at >160 mm Hg after 5 months, chlorthalidone or atenolol was added, respectively. Arterial variables, including radial artery mass and common carotid artery compliance, were calculated from noninvasive measurements of internal diameter and wall thickness with the use of high resolution echo-tracking systems at baseline and after 5 and 9 months. RESULTS: During treatment, blood pressure and arterial variables changed to the same extent in both groups. After a 9-month treatment, systolic, diastolic and pulse pressures and radial artery wall thickness, mass and thickness/radius ratio decreased significantly (p < 0.01), whereas carotid compliance increased (p < 0.001). The decrease in radial artery thickness/radius ratio after a 9-month treatment was significantly related to the reduction in pulse pressure (p < 0.01), whereas the improvement in carotid compliance was related to the reduction in mean arterial pressure (p < 0.01). In healthy subjects and untreated hypertensive patients, radial artery diameter, wall thickness and thickness/radius ratio and carotid artery compliance did not change significantly during a 9-month observation period. CONCLUSIONS: These results indicate that in elderly hypertensive patients, both angiotensin-converting enzyme inhibitor- and diuretic combination-based treatments can reduce radial artery wall hypertrophy and improve carotid artery compliance.

Aged↗
PubMed1998

Effects of isolated systolic hypertension and essential hypertension on large and middle-sized artery compliance.

BACKGROUND: Systolic hypertension of the elderly is characterized by a reduction in arterial compliance. Whether and to what extent this involves arteries of various structure and size is not well known. OBJECTIVE: To study carotid and radial artery compliance in systolic hypertension of the elderly, compared to essential hypertension and normotension. METHODS: We investigated 28 elderly patients with systolic hypertension (age 68.6 +/- 1.4 years, mean +/- SE; systolic blood pressure > 160 mmHg and diastolic blood pressure < 90 mmHg) plus 17 age-matched patients with essential hypertension and 15 age-matched healthy normotensive subjects. Radial and carotid artery compliance were evaluated using echotracking techniques. In both arteries compliance was assessed statistically and dynamically, i.e. as compliance values throughout the diasto-systolic pressure range. Measurements included intima-media wall thickness of the radial artery. RESULTS: Compared to normotensive subjects, carotid artery compliance was reduced in essential hypertension and more so in systolic hypertension. However, although in both groups radial artery wall thickness was markedly greater than in the normotensive group, radial artery compliance was markedly reduced in systolic hypertension, but unchanged in essential hypertension. CONCLUSIONS: In systolic hypertension of the elderly the reduction of arterial compliance is marked in both muscular and large elastic arteries, while in elderly essential hypertensives changes in arterial compliance are more heterogeneous, i.e. only carotid artery compliance is reduced. The different effects of these two types of hypertension on arterial mechanics are visible throughout the physiological range of blood pressure and probably accounted for by different alterations in vessel wall structure.

Aged↗
PubMed1998

Present and future role of combination treatment in hypertension.

Both in clinical practice and in drug trials, combination treatment of hypertension plays a fundamental role. This article reviews the features that make combined therapy with two drugs valuable, i.e., additive antihypertensive efficacy, different mechanisms of action, and reciprocal side-effect minimization. Also examined are the advantages and disadvantages of a fixed combination, emphasizing that a major advantage is simplification of the treatment schedule. This is clinically relevant because complexity of treatment negatively affects patient compliance, which in hypertensive patients is poor, leading to poor long-term blood pressure control in the hypertensive fraction of the population.

Drug Therapy, Combination↗
PubMed1998

Effects of prolonged immobilization of the limb on radial artery mechanical properties.

Physical training is associated with an increase in arterial distensibility. Whether the effect of training on this variable is evident also for ordinary levels of exercise or no exercise is unknown, however. We have addressed this issue by investigating the effect on radial artery distensibility of prolonged monolateral immobilization of the ipsilateral limb versus the following resumption of normal mobility. We studied 7 normotensive subjects (age, 25.4+/-3.0 years; systolic/diastolic blood pressure, 119+/-9/68+/-6 mm Hg, mean+/-SE) in whom 1 limb had been immobilized for 30 days in plaster because of a fracture of the elbow. At both the day after plaster removal and after 45 days of rehabilitation, radial artery distensibility was evaluated by an echo-tracking device (NIUS-02), which allows arterial diameter to be measured noninvasively and continuously over all pressures from diastole to systole (finger monitoring), with the distensibility values being continuously derived from the Langewouters formula. In both instances, the contralateral arm was used as control. Immediately after removal of the plaster, radial artery distensibility was markedly less in the previously immobilized and fractured limb compared with the contralateral limb (0.4+/-0.1 versus 0.8+/-0.1, 1/mm Hg 10(-3), P<0.05). After rehabilitation, the distensibility of the radial artery was markedly increased in the previously fractured limb (0.65+/-0.1 1/mm Hg 10(-3), P<0.05), whereas no change was seen in the contralateral limb. Thus, complete interruption of physical activity is associated with a marked reduction of arterial distensibility, indicating that even an ordinary level of activity plays a major role in modulation of arterial mechanical properties.

Adolescent↗
PubMed1998

Early and late sympathetic activation in hypertension.

In several experimental animal models of hypertension, sympathetic factors have been shown to be involved in the development and/or maintenance of high blood pressure. Although the information available on this issue in man is more scarce, recent evidence clearly indicates the participation of adrenergic mechanisms in the early and late phases of the hypertensive process. In addition, several cardiovascular risk factors frequently associated with hypertension, such as obesity, insulin-resistance, cigarette smoking, and the atherogenic process, are also characterized by alterations in sympathetic cardiovascular drive. This contributes to a further activation of the sympathetic nervous system thus favoring the development of the end organ damage (e.g. cardiac and vascular hypertrophy) associated with the hypertensive state.

Animals↗
PubMed1997

Evidence of functional and structural cardiac abnormalities in cirrhotic patients with and without ascites.

Cirrhosis is associated with cardiovascular abnormalities. Scanty information is available as to whether these include left ventricle diastolic dysfunction and wall thickness increase. To this aim in 27 cirrhotic patients with tense ascites, 17 cirrhotic patients with previous episodes of ascites (not actual), and 11 controls we investigated by echocardiography and echocolor Doppler left ventricle diastolic function (E wave, A wave, E/A ratio, deceleration time of E wave), systolic function (ejection fraction), and wall thickness (left ventricle posterior wall thickness + interventricular septum thickness) along with neurohumoral variables. All measurements (supine position) were repeated after total paracentesis (10.7 +/- 0.6 L of ascites) in ascitic patients. Both in patients with and without ascites E/A ratio was reduced as compared with controls (0.93 +/- 0.07 and 0.97 +/- 0.06 vs. 1.18 +/- 0.08, P < .05) while left ventricle wall thickness was increased (18.6 +/- 0.6 and 20.1 +/- 0.8 vs. 17.2 +/- 0.7, P < .05 and P < .01, respectively), irrespective of the postviral or alcoholic cause of liver disease. In all cirrhotics both right and left atrial and right ventricle diameters were significantly greater. Ejection fraction was slightly but significantly (P < .01) reduced in ascitic patients. Paracentesis induced a reduction of the highly increased basal plasma renin activity, aldosterone, norepinephrine (P < .01), and epinephrine (P < .05) and improved diastolic function (E/A, P < .05). Systolic function was unaffected. Thus, irrespective of ascites and cause, advanced cirrhosis is associated with left ventricle diastolic dysfunction and wall thickness increase. We can speculate that neurohumoral overactivity, known to stimulate cardiac tissue growth, may challenge the heart, promoting fibrosis and exerting a further hindrance to ventricular relaxation in patients with cirrhosis experiencing episodes of ascites.

Aged↗
PubMed1997

Treatment of heart failure with fosinopril: an angiotensin converting enzyme inhibitor with a dual and compensatory route of excretion.

Congestive heart failure (CHF) is one of the most common and clinically important cardiovascular diseases. This pathologic state is characterized not only by well-defined hemodynamic alterations, but also by complex abnormalities involving the sympathetic nervous system, the renin-angiotensin system, and other hormones involved in cardiovascular homeostasis. In addition, there is an abnormality in the homeostatic cardiovascular control exerted by arterial baroreceptors and the viscoelastic properties of medium-size arteries are altered, causing a reduction in arterial compliance. All of these abnormalities can be favorably affected by angiotensin converting enzyme (ACE) inhibitors, which have been shown to improve not only the hemodynamic and neurohumoral profiles of CHF, but also patient survival. CHF is accompanied with a decline or some sort of effect on renal function. An ACE inhibitor with a dual route of excretion, such as fosinopril, may be especially useful in treating patients with CHF.

Aged↗
PubMed1997

Large and medium sized artery abnormalities in untreated and treated hypothyroidism.

BACKGROUND: Hypothyroidism is frequently accompanied by cardiac dysfunction, increased vascular resistance and a greater prevalence of hypertension. Whether this condition is also accompanied by alterations of large artery function and structure is not known, however. PATIENTS AND METHODS: We investigated radial artery compliance and wall thickness as well as carotid artery compliance in 11 normotensive recently diagnosed and never treated hypothyroid patients. Fifteen euthyroid healthy age- and sex-matched subjects served as controls. No subject had evidence of large artery atherosclerotic lesions. Carotid artery diameter was evaluated continuously by a B-M mode device and carotid compliance obtained by the Reneman formula. Radial artery diameter and wall thickness were continuously acquired over the systodiastolic blood pressure range (beat-to-beat finger measurement) by an echo-tracking device, and compliance (Langewouters formula) was expressed as the integral of the area under the compliance/blood pressure curve normalized for pulse pressure. RESULTS: Patients with hypothyroidism showed greater radial wall thickness (+109%, P < 0.01) and compliance (+58%, P < 0.03) than controls. Carotid artery compliance was not different in the two groups. In 10 hypothyroid patients L- tiroxine therapy for 9.0 +/- 2.3 months did not change carotid artery function but markedly reduced radial artery wall thickness (-36%, P < 0.05) and compliance (-20%, P < 0.05). CONCLUSIONS: Hypothyroidism is associated with early arterial structural and functional alterations, which involve more muscular than elastic arteries. These alterations, however, are reversible by hormonal replacement therapy.

Blood Pressure↗
PubMed1997

Effects of cigarette smoking on carotid and radial artery distensibility.

OBJECTIVE: Cigarette smoking acutely induces a marked increase of blood pressure and heart rate. This is accompanied by a marked reduction of radial artery distensibility. Whether this reflects an alteration of arterial mechanics of large elastic arteries as well is not established, however. DESIGN AND METHODS: In this study we addressed the acute effects of smoking on the stiffness of a peripheral medium-sized muscular artery and a large elastic vessel. We studied seven healthy normotensive smokers (age 28+/-7 years, mean+/-SEM), in the absence of smoking for at least 24 h. Radial artery (NIUS 02) and carotid artery diameter (WTS) were concomitantly acquired beat-to-beat in the 5 min before, during and after smoking of a cigarette containing 1.2 mg of nicotine. Blood pressure and heart rate were concomitantly recorded by a Finapres device. Radial and carotid artery distensibility were calculated according to the Langewouters and Reneman formulae, respectively. Data were collected for consecutive 30 s periods. Statistical comparisons were performed between the three different phases and, within each phase, between 30 s periods. In five subjects the protocol was repeated after 1 week using a stran rather than a cigarette to obtain data under sham smoking. RESULTS: Smoking increased systolic blood pressure by 14%, diastolic blood pressure by 10% and heart rate by 27%. Radial artery diameter was reduced during smoking (-3.7%) and more so after smoking (-14.8%), while carotid artery diameter did not change significantly either during or after smoking. Radial artery distensibility was also significantly reduced only after smoking (-41.3%, P < 0.01), while carotid artery distensibility was significantly reduced both during (-33.3%) and after smoking (-27.2%) (P < 0.01 versus before). No changes in blood pressure, heart rate and arterial wall mechanics were induced by sham smoking. CONCLUSIONS: Acute cigarette smoking reduces distensibility not only in medium-sized but also in large elastic arteries, therefore causing a systemic artery stiffening. The mechanisms of these effects remain to be determined. However, it is likely that adrenergic mechanisms are responsible for the arterial distensibility alterations.

Adult↗
PubMed1997

Differential alterations of common carotid and femoral artery distensibility in 12-week-old spontaneously hypertensive rats.

OBJECTIVE: In essential hypertension, the mechanical properties of the radial artery have been shown to be largely unaltered, whereas more controversial and less reliable data have been obtained for the common carotid artery. We therefore examined the distensibility/pressure relationships of the predominantly elastic common carotid artery and of the predominantly muscle-type femoral artery in 12-week-old normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). METHODS: Eleven 12-week-old SHR and 10 age-matched WKY rats were anesthetized with sodium pentobarbitone. Blood pressure and pulse rate were measured by catheters inserted in the common carotid and in the femoral arteries, while contralateral arterial diameter was continuously recorded via an echo-tracking device. Arterial compliance was derived according to the Langewouters formula, and its values were normalized for the diameter, to obtain distensibility/pressure curves and to calculate the distensibility index. The Peterson elastic modulus was also calculated in order to obtain a pressure-independent estimate of arterial mechanical properties. RESULTS: Femoral artery distensibility/pressure curves and distensibility index were similar in the two groups of rats, the latter being 1.13+/-0.13 mm/mmHg10(-3) in SHR and 1.28+/-0.15 mm/mmHg10(-3) in WKY rats (means+/-SEM; NS). In contrast, in SHR, common carotid artery mechanical properties were clearly impaired, as shown by a marked reduction in distensibility index (2.55+/-0.16 mm/mmHg10(-3) in SHR versus 3.4+/-0.3 mm/mmHg10(-3) in WKY rats; P< 0.05), and by a significant increase in the Peterson elastic modulus. CONCLUSIONS: In the SHR model, high blood pressure alters the mechanics of large arteries even in the relatively early stage of the disease; however, the alterations are not homogeneous inasmuch elastic-type vessels are affected to a much greater extent than muscle-type vessels.

Animals↗
PubMed1997

Combined effects of hypertension and hypercholesterolemia on radial artery function.

Compliance and distensibility of middle-sized conduit arteries are increased in hypertension and reduced in hypercholesterolemia. Despite their frequent association in the same individual, the combined effect of these two conditions on arterial mechanical properties is unknown. We studied four groups of age- and sex-matched subjects: 10 normotensive normocholesterolemic subjects, 10 mild hypertensive normocholesterolemic subjects, 10 mild hypercholesterolemic normotensive subjects, and 10 mild hypertensive and mild hypercholesterolemic subjects. We measured radial artery diameter by an echotracking device and beat-to-beat blood pressure from an ipsilateral finger. Compliance-pressure and distensibility-pressure curves were derived by Langewouters' formula. Between-group comparisons were made by calculating for both compliance and distensibility the integral of the area under the portion of the curve common to the four groups ("isobaric" compliance and distensibility). Blood pressure was similarly elevated in the two hypertensive groups, and serum cholesterol was similarly elevated in the two hypercholesterolemic groups. Compared with values in normotensive normocholesterolemic subjects, isobaric compliance and distensibility were greater in hypertensive normocholesteroclemic (+38% and 47%, respectively) and smaller in normotensive hypercholesterolemic (-6% and -23%) subjects. However, when both hypertension and hypercholesterolemia were present, isobaric compliance and isobaric distensibility were significantly reduced (-26% and -18%, P < .05). Therefore, hypercholesterolemia reverses the effect of hypertension on arterial compliance and causes arterial stiffening, as when present alone.

Adult↗
PubMed1997

Effect of sympathectomy on mechanical properties of common carotid and femoral arteries.

Sympathetic stimulation is accompanied by a reduction of arterial distensibility, but whether and to what extent elastic and muscle-type arterial mechanics is under tonic sympathetic restraint is not known. We addressed this issue by measuring, in the anesthetized rat, the diameters of the common carotid and femoral arteries with an echo-Doppler device (NIUS 01). Blood pressure was measured by a catheter inserted contralaterally and symmetrically to the vessel where the diameter was measured. Arterial distensibility over the systolic-diastolic pressure range was calculated according to the Langewouters formula. Data were collected in 10 intact (vehicle pretreatment) and 9 sympathectomized (6-hydroxydopamine pretreatment) 3-month-old Wistar-Kyoto rats. Compared with the intact animals, sympathectomized rats showed a marked increase in arterial distensibility over the entire systolic-diastolic pressure range. When quantified by the area under the distensibility-pressure curve, the increase was 59% and 62% for the common carotid and femoral arteries, respectively (P<.01 for both). In the femoral but not in the common carotid artery, sympathectomy was accompanied also by an increase in arterial diameter (+18%, P<.05 versus intact). Therefore, in the anesthetized normotensive rat, sympathetic activity exerts a tonic restraint on large-artery distensibility. This restraint is pronounced in elastic vessels and even more pronounced in muscle-type vessels.

Animals↗
PubMed1997

Radial artery compliance and distensibility in hypertension and hypertension-related conditions.

Arterial compliance and distensibility, measured by non-invasive and specific techniques, give us information on the cardiovascular alterations occurring in pathophysiological conditions. Recently, it has been observed that familial hypertension is characterized by a slight but significant increase of 24-hour blood pressure and, despite this, by normal arterial function. On the contrary, long-term hypertension is associated with arteria distensibility changes, that is a slight increase of peripheral muscle artery distensibility in the systo-diastolic hypertension and a marked reduction in the isolated systolic hypertension. This probably comes from the different arterial wall content changes in these two hypertensive conditions. Also familial hypercholesterolemia and non-familial hypercholesterolemia cause a reduction in arterial distensibility. Hypercholesterolemia has also an unfavorable effect because its association with high blood pressure values induces stronger alterations in arterial elastic properties than hypertension alone.

Biomechanical Phenomena↗
PubMed1996

Impaired radial artery compliance in normotensive subjects with familial hypercholesterolemia.

Hypercholesterolemia impairs arteriolar dilatation, but whether the vascular abnormalities accompanying this condition include large artery function is unknown. We addressed this issue in 13 normotensive subjects with familial hypercholesterolemia (serum cholesterol 401.6 +/- 16.9 mg/dl, mean +/- S.E., FHC) and no evidence of atherosclerotic lesions, in whom radial artery (RA) diameter and blood pressure (BP) were measured beat to beat by an echotracking and a Finapres device, respectively. RA compliance (RAC) was derived from the diameter/BP relationship and expressed over the systo-diastolic BP range, both at baseline and after a 12-min brachial artery occlusion. RAC was expressed also as the area under the RAC/BP curve divided for pulse BP. Measurements included maximal forearm blood flow (plethysmography) and minimal forearm vascular resistance (FVR) which were obtained from the values following the 12-min brachial arterial occlusion. Data were collected before and after 6- and 24-month lipid lowering treatment (simvastatin 40 mg/day). Ten age-matched normotensive normocholesterolemic healthy subjects (N) served as controls. Compared to N, baseline RAC was strikingly reduced in FHC (-53.5%, P < 0.01). After ischemia RAC increased significantly and markedly in N (+38.7, P < 0.01), while only a modest and non-significant increase was observed in FHC. Minimal FVR was markedly higher in FHC than in N (3.5 +/- 0.9 vs 1.6 +/- 0.1 units, P < 0.01). In FHC (7 subjects) RAC remained unchanged after 6 months of lipid lowering treatment, but increased markedly (+55.2%, p < 0.05) when treatment was prolonged to 24 months. Lipid lowering treatment also reduced minimal FVR, the effect being significant both after 6 and after 24 months. No changes in RAC and minimal FVR were seen after 6 months in controls. Thus, in subjects with a marked increase in serum cholesterol due to FHC, not only arteriolar dilatation, but also RAC and distensibility are markedly impaired. This impairment can be favourably affected by an effective lipid lowering treatment of long duration.

Anticholesteremic Agents↗
PubMed1996

Benefit and costs of anti-hypertensive treatment.

Hypertension is common throughout the world and represents the single greatest risk factor for increasing cardiovascular mortality, cardiovascular morbidity and overall mortality. Diseases associated with hypertension are not only, in general, of a chronic disabling nature, but, in most instances, require frequent hospitalization, with expensive drug treatment and management. Stroke, coronary heart disease, congestive heart failure and chronic renal insufficiency represent the most commonly encountered corollaries of inadequately treated hypertension. Anti-hypertensive treatment is accompanied by a reduction of hypertension-related cardiovascular risk and a clearcut benefit in terms of reduced incidence of major cardiovascular complications of hypertension and overall mortality. This benefit has frequently been underestimated in many clinical trials. Attempts to improve the cost-benefit ratio have included the use of treatment strategies based upon 24-h control of blood pressure, since it has been demonstrated that hypertension-related end-organ damage correlates more closely with 24-h average blood pressure and with 24-h blood pressure variability than with blood pressure measured in the clinic. It is hoped that new anti-hypertensive agents, which smoothly reduce 24-h blood pressure profile, will further reduce the incidence of hypertension-related end-organ damage.

Antihypertensive Agents↗
PubMed1996

Heart rate-dependence of arterial distensibility in vivo.

OBJECTIVES: Viscous and inertial components contribute to arterial distensibility and compliance in vitro. The purpose of our study was to determine whether this phenomenon is of relevance in vivo, namely, whether arterial compliance is altered by an increase in heart rate. DESIGN: Arterial diameter was assessed by an echo-Doppler device in a common carotid and femoral artery, namely, in a large elastic and a muscle artery. The studies were performed in 12-week-old pentobarbitone-anaesthetized Wistar-Kyoto rats subjected to atrial pacing via a transjugular unipolar catheter at five different randomly sequenced rates (280, 310, 340, 370 and 400 beats/min). After each stage, spontaneous sinus rhythm was allowed to return. Blood pressure was measured via a catheter inserted into the carotid or femoral artery contralateral to the vessels in which the diameter was measured. Arterial compliance and distensibility values were derived according to the Langewouters formula. RESULTS: A progressive increase in heart rate caused by pacing was accompanied by progressive and marked reductions in carotid artery compliance and distensibility. When quantified by the area under the distensibility-pressure or compliance-pressure curve the reduction was in the range 15-43%. Although a tendency to a similar phenomenon was observed in the femoral artery, in the latter vessel the reduction in distensibility and compliance was less marked and statistically insignificant. CONCLUSIONS: In the anaesthetized rat acute increases in heart rate are accompanied by reductions in arterial compliance and distensibility. The effect is greater in elastic than in muscle arteries.

Animals↗