PubMed Health⌕ Search

Biomedical subjects

R Pini

Publications and source records attributed to R Pini.

At least 19 recordsLinked to original sources
PubMed2002

Features of excessive alcohol drinking in older adults distinctively captured by behavioral and biological screening instruments. An epidemiological study.

The entire > or =65-year-old population living in a small Italian town, where alcohol use is almost ubiquitous, was assessed with a frequency-quantity questionnaire for alcohol intake and with two screening instruments for alcohol problems, the CAGE questionnaire and the MCV-gammaGT test. Aim of the study was to assess whether these instruments identify different subsets of subjects with alcohol problems. Of the 649 participants, 19.1% were at-risk drinkers (average intake > 40 g/day in men and > 20 g/day in women). Both the screening instruments were positive in only a minority of participants. Of the 377 drinkers, 53 gave > or =1 affirmative response to the CAGE questionnaire, whereas 24 had a positive MCV-gammaGT test. The concordance between positive CAGE questionnaire and MCV-gammaGT test was limited to seven subjects (kappa = 0.10), and these tests identified subjects who differed for several health and psychosocial characteristics. Participants aged > or =75 years drank less, but had similar prevalence of CAGE and MCV-gammaGT positive markers as compared to younger participants. In conclusion, excessive drinking is common in the elderly. Screening tests based on behavioral and biological markers identify two different sets of subjects with possible alcohol problems. This might indicate the opportunity to use these instruments in conjunction.

Activities of Daily Living↗
PubMed2001

Cardiac and vascular remodeling in older adults with borderline isolated systolic hypertension: the ICARe Dicomano Study.

Although borderline isolated systolic hypertension (ISH), defined as a blood pressure of 140 to 159/<90 mm Hg, is a proven cardiovascular risk factor, the major clinical trials on treatment of ISH have used a cutoff of 160 mm Hg. Moreover, no data exist on the cardiovascular modifications associated with borderline ISH. Therefore, we compared subjects with borderline ISH to subjects with diastolic hypertension (diastolic blood pressure > or =90 mm Hg) or ISH. Community-dwelling residents (age > or =65 years) of a small town in Italy (Dicomano) underwent extensive clinical examination, echocardiography, carotid ultrasonography, and applanation tonometry. Only untreated subjects were included in this analysis: 95 with diastolic hypertension, 87 with borderline ISH, and 43 with ISH. Despite lower systolic and mean pressures in borderline ISH, left ventricular mass was similar to that in diastolic hypertension. In univariate and multivariate analysis, pulse pressure but not systolic pressure was related to left ventricular mass. Borderline ISH subjects had a tendency to greater carotid cross-sectional area and stiffness index than did diastolic hypertensive subjects despite lower mean carotid pressure, whereas the number of atherosclerotic plaques was similar in the 2 groups. Pulse pressure but not systolic pressure was independently related to carotid remodeling. In our community-based, older population, individuals with borderline ISH had a similar prevalence of left ventricular hypertrophy and carotid atherosclerosis as that of subjects with diastolic hypertension, despite lower systolic and mean pressures. Among blood pressure values, pulse pressure was the single or strongest independent predictor of cardiovascular remodeling.

Aged↗
PubMed2001

Accuracy of equations for predicting stature from knee height, and assessment of statural loss in an older Italian population.

We determined the applicability of deriving the stature from knee height in an older Italian population, and, in the same population, we assessed longitudinally the change in stature over a 6-year interval. The standing stature and knee height in a supine position were measured in the entire home-dwelling older (65 + years) population of a small Italian town (N = 606). Stature measured in 1989 and in 1995 was used to assess longitudinal changes in 258 subjects of the same population. Stature derived from knee height was greater than measured stature in this population and in the two sexes. This difference disappeared when subjects with evident kyphosis were excluded. From 1989 to 1995, stature decreased by 1.7+/-3.0 cm, with women showing a larger decrement than men. Stature estimated from knee height is more accurate than measured stature in subjects with kyphosis. In accordance with previous studies, stature decreases with aging, and such height loss is greater in women than in men.

Aged↗
PubMed2001

Relation of blood pressure variability to carotid atherosclerosis and carotid artery and left ventricular hypertrophy.

The relationship of blood pressure (BP) variability to cardiovascular target-organ damage is controversial. Studies examining BP variability and left ventricular (LV) hypertrophy have been contradictory, and only limited data on the relation of BP variability to carotid atherosclerosis and carotid artery hypertrophy exist. BP variability was assessed as the standard deviation and coefficient of variation of awake and asleep pressures in 511 normotensive or untreated hypertensive subjects who underwent ambulatory BP monitoring and cardiac and carotid ultrasonography. Although the presence of focal carotid plaque was associated with an increase in ambulatory pressures and pressure variability, the differences in variability were eliminated by adjustment for age and absolute pressures. Similarly, LV mass was significantly related to BP variability, but the significance of this finding was eliminated after adjustment for important covariates. In multivariate analyses, age was the primary determinant of carotid artery cross-sectional area, with a weak but independent contribution from awake systolic and diastolic BP variability in addition to absolute pressure. BP variability was not independently related to either carotid or LV relative wall thickness, both measures of concentric remodeling. In the present study, awake BP variability was weakly but independently associated with carotid artery cross-sectional area, a measure of arterial hypertrophy. However, neither systolic nor diastolic BP variability was independently associated with carotid atherosclerotic plaque or LV mass.

Adolescent↗
PubMed2000

A randomized trial comparing the introduction of ritonavir or indinavir in 1251 nucleoside-experienced patients with advanced HIV infection.

ISS-IP1, a multicenter, randomized, 48-week open trial, was designed to compare the introduction of ritonavir or indinavir in patients with previous nucleoside experience and CD4+ cell counts below 50/mm3. Concomitant antiretroviral treatment with nucleoside analogs was allowed. Primary efficacy measures were survival and time to a new AIDS-defining event or death, analyzed through the whole period of observation by the intention-to-treat approach. Primary toxicity measures were time to treatment discontinuation and adverse events, grade at least 3/serious, analyzed by an on-treatment approach. Evaluation-of efficacy also included CD4+ cell and RNA response. The trial enrolled 1251 patients in 5 months. At baseline, mean CD4+ cell count was about 20 cells/mm3 and mean HIV RNA copy number was 4.9 log10/ml in both groups. Overall, 402 patients in the ritonavir group and 250 patients in the indinavir group permanently discontinued the assigned treatment (relative risk, 1.96; 95% CI, 1.68-2.30; p = 0.0001), with most of this difference dependent on a higher number of discontinuation for adverse events in the ritonavir group. After a mean follow-up of 307 days (ritonavir, 304; indinavir, 309), 124 deaths (ritonavir, 61; indinavir, 63; relative risk, 0.96; 95% CI, 0.67-1.36; p = 0.80) and 330 new AIDS-defining events (ritonavir, 170; indinavir, 160; relative risk, 1.05; 95% CI, 0.85-1.31; p = 0.60) were observed. CD4+ cell counts increased in both groups in patients still receiving treatment, with about 100 cells gained by week 24 and 150 cells gained by week 48. Body weight also increased over time in both groups. Analysis of RNA response showed a decrease of 1.5 log10 or higher in both treatment groups. Overall, 400 patients in the ritonavir group and 338 patients in the indinavir group developed at least one grade 3/serious new adverse event during follow-up (relative risk, 1.48; 95% CI, 1.28-1.72; p = 0.0001). Favorable CD4+ cell and RNA responses at 24 and 48 weeks were observed in both groups of patients remaining on treatment. Indinavir showed slightly better effects in sustaining RNA, CD4+ cell, and body weight responses. Ritonavir and indinavir results were comparable in terms of clinical outcome (survival and AIDS-defining events).

Adult↗
PubMed2000

Impact of arterial stiffening on left ventricular structure.

Aging of the vasculature results in arterial stiffening and an increase in systolic and pulse pressures. Although pressure load is a stimulus for left ventricular hypertrophy, the extent to which vascular stiffening per se, independent of blood pressure, influences left ventricular structure is uncertain. Two hundred seventy-six subjects (79 normotensive and 197 otherwise healthy hypertensive individuals) underwent echocardiography to assess left ventricular structure. Arterial stiffness was estimated by the pressure-independent stiffness index, beta, and the pressure-dependent elastic modulus derived from simultaneous carotid ultrasound and applanation tonometry. Systemic arterial compliance (the inverse of stiffness) was estimated by the arterial compliance index. In multivariate analysis, beta was related to age (P<0.001) and smoking history (P<0.01) but not mean pressure, whereas elastic modulus was related to age and mean pressure (both P<0.001). The arterial compliance index was only related to age. Whereas systolic and diastolic pressures and the elastic modulus were positively associated with left ventricular mass (all P<0.001), primarily because of increases in wall thicknesses, beta and the arterial compliance index bore no relation to left ventricular mass. beta was inversely related to chamber diameter and directly related to left ventricular relative wall thickness, the ratio of wall thickness to chamber radius. Younger and older hypertensive subjects had comparable left ventricular mass, despite higher systolic and pulse pressures in the older group, whereas older hypertensives had higher mean relative wall thickness, associated with a significant increase in arterial stiffness (beta, 7.06 versus 5.17; elastic modulus, 595 versus 437 dyne/cm(2) x10(-6)) and reduction in the arterial compliance index (0.87 versus 1.05 mL/mm Hg per square meter) (all P<0.001). Thus, the extent to which arterial stiffness relates to left ventricular hypertrophy is dependent on the method by which arterial stiffness is estimated. Pressure-dependent methods show an association with left ventricular hypertrophy, whereas the pressure-independent stiffness index, beta, and the arterial compliance index are most strongly associated with aging and left ventricular concentric remodeling but not hypertrophy.

Aged↗
PubMed1999

Cardiac and arterial target organ damage in adults with elevated ambulatory and normal office blood pressure.

BACKGROUND: Ambulatory blood pressure may be higher or lower than clinic blood pressure. Attention has focused on "white coat hypertension" (normal ambulatory blood pressure elevated in the clinic). The converse phenomenon of high ambulatory blood pressure but normal office blood pressure-"white coat normotension"-has not been studied. OBJECTIVE: To assess whether white coat normotension (awake ambulatory blood pressure > 134/90 mm Hg and clinic blood pressure < 140/90 mm Hg) is associated with target organ damage. DESIGN: Cross-sectional observational study. SETTING: University hospital hypertension center and participant work sites. PATIENTS: 295 clinically normotensive adults and 64 patients with sustained hypertension (elevated clinic and ambulatory blood pressure). MEASUREMENTS: Target organ abnormalities were measured by echocardiography and arterial ultrasonography in 61 patients with white coat normotension, 234 with sustained normotension (normal clinic and ambulatory blood pressure), and 64 with sustained hypertension. RESULTS: Patients with white coat normotension were older; had higher body mass indices, serum creatinine concentrations, and glucose levels; and a higher prevalence of current smokers. Left ventricular mass index and relative wall thickness were higher by 13 g/m2 (CI, 8 to 18 g/m2) and by 0.03 (CI, 0.01 to 0.04), respectively, in patients with white coat normotension compared with those who had sustained normotension. Patients with white coat normotension and those with sustained hypertension did not differ significantly for left ventricular mass index (4 g/m2 [CI, - 3 to 10 g/m2) or relative wall thickness (0.01 [CI, -0.01 to 0.03]). The prevalence of discrete atherosclerotic plaques was similar in patients with white coat normotension (17 of 61, or 28% [CI, 17% to 39%]) and those with sustained hypertension (17 of 64, or 27% [CI, 16% to 38%]), but the difference lost significance after adjustment for age. CONCLUSIONS: White coat normotension is associated with left ventricular mass and carotid wall thickness similar to those in sustained hypertension. The association of white coat normotension with prognostically important target organ damage may partly explain the ability of high normal left ventricular mass and high normal clinic blood pressure to predict subsequent hypertension and cardiovascular events in patients with clinical normotension.

Adult↗
PubMed1999

Impact of arterial elastance as a measure of vascular load on left ventricular geometry in hypertension.

OBJECTIVE: Effective arterial elastance (Ea), integrating the pulsatile component of left ventricular (LV) afterload, is an estimate of aortic input impedance. We evaluated relationships of Ea with left ventricular anatomy and function in essential hypertension. DESIGN: A cross-sectional analysis in 81 normotensive and 174 untreated hypertensive individuals enrolled in a referral hypertension centre. METHODS: Using echocardiography we determined left ventricular mass index (LVMI), relative wall thickness (RWT), stroke volume (SV), endocardial (FSe) and midwall (FSm) fractional shortening and total peripheral resistance (TPR). Carotid pressure waveforms were obtained by arterial tonometry, and end-systolic pressure (Pes) was measured at the dicrotic notch. Ea index (EaI) was calculated as Pes/(SV index); LV elastance (Ees) was estimated as Pes/LV end-systolic volume, and ventriculo-arterial coupling was evaluated by the Ea/Ees ratio. RESULTS: EaI was higher in hypertensives than in normotensives (3.02 +/- 0.63 versus 2.40 +/- 0.52 mmHg/l per m2; P< 0.0001). Using the 95% upper confidence limit in normotensives, hypertensives were divided in two groups with normal or elevated EaI. The 38 hypertensives with elevated EaI had higher RWT (0.41 +/- 0.06 versus 0.37 +/- 0.05), lower LVMI (87.5 +/- 18.5 versus 96.8 +/- 19.3 g/m2), higher TPR (2247 +/- 408 versus 1658 +/- 371 dynes/cm s(-5)) and lower FSe and FSm (35 +/- 5 versus 39 +/- 5 and 16 +/- 2 versus 18 +/- 2%; all P< 0.05) than patients with normal EaI. Ea/Ees ratio was increased and cardiac output was reduced in hypertensives with elevated EaI. CONCLUSIONS: High values of EaI identify a minority of hypertensive patients characterized by elevated TPR, left ventricular concentric remodelling, depressed left ventricular systolic function and impaired ventriculo-arterial coupling.

Adult↗
PubMed1999

Undertreatment of hypertension in community-dwelling older adults: a drug-utilization study in Dicomano, Italy.

OBJECTIVE: To define: (1) the prevalence of and (2) factors associated with undertreatment of hypertension in older persons; and (3) the prevalence of specific drug regimens and reasons for their selection. PARTICIPANTS: Cross-sectional survey of persons aged > or =65 years living in Dicomano, Italy. MAIN OUTCOME MEASURES: Prevalence of untreated and uncontrolled hypertension, both defined on the basis of two blood pressure (BP) cut-off points (> or =140/90 and > or =160/90 mm Hg) and of the presence of pharmacological treatment Predictors of undertreatment were analysed for the higher BP cut-off only. RESULTS: Five hundred of 692 (72.3%) and 380/692 (54.9%) participants met the 140/90 and the 160/90 mm Hg BP criterion, respectively. Of the latter, 162 (42.6%) were untreated, 119 (31.3%) had uncontrolled and 99 (26.1%) controlled hypertension. Women [odds ratio (OR), 0.4; 95% confidence interval (CI), 0.2-0.7], participants with coronary artery disease (CAD) (OR, 0.2; 95% CI, 0.1-0.6), stroke (OR, 0.3; 95% CI, 0.1-0.7), and preserved cognitive status (Mini Mental State Examination score >21: 0.3; 95% CI, 0.2-0.7) were more frequently treated. Uncontrolled hypertension was less likely in women (OR, 0.5; 95% CI, 0.3-1.0) and CAD patients (OR, 0.3; 95% CI, 0.1-0.7). Angiotensin converting enzyme (ACE)-inhibitors (55%), calcium (Ca)-antagonists (31%) and diuretics (20%) were the drugs most commonly prescribed. ACE-inhibitors were preferred, and diuretics rarely used, in diabetic subjects. Ca-antagonists were used mostly in CAD participants. CONCLUSIONS: Hypertension is undertreated in the majority of noninstitutionalized older adults, especially in men with impaired cognition and no vascular disease. Drug regimens are mostly based on ACE-inhibitors and Ca-antagonists, as a result of associated clinical conditions, requiring individualized treatment.

Adrenergic beta-Antagonists↗
PubMed1999

Heart failure in community-dwelling older persons: aims, design and adherence rate of the ICARe Dicomano project: an epidemiologic study. Insufficienza Cardiaca negli Anziani Residenti a Dicomano.

BACKGROUND: The prevalence of heart failure (HF) increases with age, and HF is a major cause of disability and mortality in older persons. Detection of HF in epidemiological studies has relied on criteria validated only in young and middle-age adults, and, therefore, may prove inadequate in older subjects, because they do not take into account the pathophysiologic and clinical peculiarities of HF in old age. Thus, the true prevalence of HF in the older general population remains uncertain and has probably been underestimated in previous studies. Moreover, the mechanism and the extent by which HF hinders physical functioning in older people has not been fully elucidated. OBJECTIVES: This paper describes the design of the ICARe study, carried out in an older home-dwelling population to collect data about: (1) the sensitivity and specificity of diagnostic criteria used previously in epidemiological studies of HF; (2) the prevalence of the different pathophysiologic forms of HF; and (3) the impact of HF on overall health status, and on physical functioning, in the absence or presence of chronic comorbidity. DESIGN AND SETTING: This was a cross-sectional survey. Eligible were all community-dwelling persons aged 65 years or older recorded in the Registry Office of Dicomano, a small town nearby Florence (Italy). All the domains of multidimensional geriatric assessment were explored through different phases of the study (home interview, laboratory testing, geriatric visit) that comprised an extensive cardiopulmonary instrumental assessment including: color Doppler echocardiography, echotomography of the carotid arteries used in an original method to determine arterial compliance, and bell spirometry. Presence of major chronic conditions was ascertained by predefined, standard algorithms that were based largely on clinical examination. RESULTS: There were 864 older persons eligible for the ICARe study. Even with a substantial decline from home interview (91.2%) to the cardiopulmonary study (71.1%), the adherence rate remained high throughout the study, and the population examined was fairly representative of the original eligible population. Thus, we believe that the data collected in this study offer a unique opportunity to assess the validity of the diagnostic clinical criteria for HF in the general older population, to identify the pathophysiology underlying the syndrome, and to investigate the relationship between HF, comorbidity, and disability.

Activities of Daily Living↗
PubMed1999

Carotid intimal-medial thickness and stiffness are not affected by hypercholesterolemia in uncomplicated essential hypertension.

The combined effects of hypertension and hypercholesterolemia on carotid anatomy and stiffness were studied in 62 normotensives, 141 uncomplicated essential hypertensives with a total cholesterol level <240 mg/dL, and 60 essential hypertensives with a total cholesterol level >/=240 mg/dL. Carotid ultrasonography was performed to evaluate intimal-medial thickness (IMT), relative wall thickness, and the presence of plaque. Carotid pressure waveforms were recorded by applanation tonometry to measure carotid stiffness (beta) and pressure wave reflection (ie, augmentation index). After adjusting for age, body mass index, and smoking habit by analysis of covariance, no significant differences were found between normocholesterolemic hypertensives and hypercholesterolemic hypertensives in terms of IMT (0.79+/-0.19 versus 0.81+/-0.19 mm), relative wall thickness (0.27+/-0.07 versus 0.28+/-0.07), carotid stiffness (6.1+/-3.2 versus 5.6+/-2.7), augmentation index (18. 7+/-12.9% versus 17.3+/-12.8%), and prevalence of plaque (30.8% versus 30.7%). In the whole population, carotid IMT was significantly related to age (r=0.43), systolic (r=0.35) and diastolic (r=0.35) blood pressures, body surface area (r=0.22), and cholesterol levels (r=0.22) (all P<0.05). Carotid stiffness was significantly related to age, blood pressure, body mass index, and body surface area but not to cholesterol levels. In multivariate analyses, age, body surface area, and systolic blood pressure, but not cholesterol, smoking habit, or sex, were independent correlates of IMT (multiple R=0.54, P<0.0001), whereas carotid stiffness was independently associated with age, body surface area, and sex (R=0. 38, P<0.0001). In conclusion, hypertension is a potent stimulus of vascular hypertrophy. The superimposition of hypercholesterolemia does not substantially augment these changes or further increase arterial stiffness in uncomplicated hypertensive subjects.

Adult↗
PubMed1999

Assessment of arterial compliance by carotid midwall strain-stress relation in normotensive adults.

Examining left ventricular midwall as opposed to endocardial mechanics enhances understanding of left ventricular function in individuals with abnormal cardiac geometry. Accordingly, we used carotid ultrasound and applanation tonometry of arterial pressure to derive carotid midwall strain and its relation to carotid peak-systolic and end-diastolic stresses in 82 apparently normal, employed subjects (56 men, 26 women; median age, 47 years; 70% white; 21% overweight) with no evidence of coronary or valvular heart disease. Regression equations relating carotid luminal and midwall strain to the increment in carotid stress during systole (Deltacarotid stress) were used to predict strain for the observed Deltastress. Observed/predicted carotid luminal or midwall strain was calculated as a measure of carotid luminal or midwall strain for imposed stress, termed stress-corrected strain. Midwall carotid strain was similar in women and men but was negatively related to older age (r=-0.35, P=0.001) and higher body mass index (r=-0.31, P=0.005) and brachial and carotid blood pressure (r=-0.30 to -0.45, all P<0.01). The pulsatile change in arterial load, measured by Deltacarotid stress, was positively related to midwall strain (r=0. 44, P<0.001) more closely than was carotid luminal strain. Regression analyses revealed that carotid midwall strain was positively related to Deltastress, with additional negative relations to age and carotid diastolic diameter (all P<0.001). Stress-corrected carotid midwall strain was strongly and negatively correlated with midwall elastic modulus and Young's modulus (both r=-0.77, P<0.001), followed by elastic modulus (r=-0.74, P<0.001), midwall Young's modulus (r=-0.73, P<0.001), midwall stiffness index (r=-0.70, P<0.001), and stiffness index (r=-0.66, P<0.001). Thus, in normal adults, carotid midwall strain is unrelated to gender, is positively related to pulsatile carotid load as measured by Deltacarotid stress, and is negatively related to age, overweight, and standard measures of arterial stiffness.

Age Factors↗
PubMed1999

Assessment of arterial compliance by carotid midwall strain-stress relation in hypertension.

To elucidate the relations between arterial hypertrophy and compliance in hypertension, we studied 205 unmedicated hypertensive patients (129 men and 76 women) and 82 normotensive adults (56 men and 26 women) from an employed population by carotid ultrasound, noninvasive applanation tonometry, and echocardiography. Carotid midwall strain and circumferential stress were calculated at end diastole and peak systole. The relations of luminal and midwall strain to the increment in circumferential stress from end diastole to peak systole (Deltacarotid stress in normal subjects) were used to calculate ratios of observed/predicted carotid luminal and midwall strain. Mean stress-corrected luminal strain (82+/-26%) and midwall strain (78+/-23%) were lower (both P<0.001) in hypertensive patients than in normal adults. Stress-corrected luminal strain identified 14% of hypertensive patients with low arterial compliance, while stress-corrected midwall strain was low in 18% of patients. Patients with subnormal carotid midwall strain were older (61+/-12 versus 54+/-12 years, P<0.01) and had larger carotid diameters (6. 6+/-0.8 versus 5.7+/-0.8 mm, P=0.002) and higher brachial pulse pressures (71+/-25 versus 63+/-17 mm Hg, P<0.05) than other patients. Patients with arterial hypertrophy had lower stress-corrected midwall strain than those without hypertrophy (70+/-24% versus 79+/-23%, P=0.05), whereas no difference was observed in stress-corrected luminal strain (P=0.40). Stress-corrected midwall strain tended to be lower in patients with discrete atherosclerotic plaques than in those without (74+/-20% versus 79+/-24%, P=0.15). Compared with patients with normal left ventricular geometry, those with concentric hypertrophy had larger carotid diameters (6.6+/-0.7 versus 5.8+/-0.9 mm, P<0.05) and lower stress-corrected luminal strain (62+/-11% versus 85+/-25%, P<0.05) and midwall strain (59+/-10% versus 81+/-22%, P<0.05). Therefore, stress-corrected midwall strain identifies patients with reduced arterial compliance, increased arterial wall thickness, and abnormal left ventricular geometry better than conventional measures based on arterial lumen diameters.

Blood Pressure↗
PubMed1998

Differential effects of angiotensin converting enzyme inhibition and diuretic therapy on reductions in ambulatory blood pressure, left ventricular mass, and vascular hypertrophy.

Diuretic-based therapy is less effective in reducing the cardiac complications of hypertension than the risk of stroke and may be less effective in reducing left ventricular (LV) mass than is therapy with angiotensin converting enzyme (ACE) inhibition. In view of the strong association of LV hypertrophy with cardiovascular risk, this study was designed to compare the impact of therapy with a diuretic and ACE inhibition on cardiac and vascular structure. Fifty essential hypertensives (74% male, 88% nonwhite) participated in a double-blind study for 6 months and were randomized to either ramipril or hydrochlorothiazide (HCTZ). Echocardiography, carotid ultrasonography, and ambulatory blood pressure (BP) monitoring were performed at baseline and 3 and 6 months after initiation of therapy. The 22 ramipril patients were comparable to the 28 HCTZ patients at baseline in age, race, and 24-h BP. Although HCTZ resulted in a greater reduction in 24-h BP, only treatment with ramipril resulted in a decrease in LV mass (193 to 179 g, P < .005, v 184 to 182 g, P = NS), attributable to a reduction in wall thicknesses but not in chamber diameter. In multivariate analysis, both change in BP and treatment group were independent predictors of change in LV mass. Importantly, although neither drug reduced carotid artery cross-sectional area, relative wall thickness increased due to a tendency for vessel diameter to decrease and wall thickness to increase, particularly in the diuretic group. Ramipril caused a sustained fall in plasma angiotensin II, whereas HCTZ increased angiotensin II levels. Although diuretic therapy was more effective in lowering ambulatory BP in this predominantly nonwhite population, only therapy with ACE inhibition was associated with regression of LV mass. Vascular geometry was altered consistent with the reduction in distending pressure resulting in vascular remodelling.

Adult↗
PubMed1997

Intraocular measurements of pressure transients induced by excimer laser ablation of the cornea.

BACKGROUND AND OBJECTIVE: The evolution of pressure waves induced by argon-fluoride laser ablation of the cornea in the typical operative conditions of clinical laser keratectomy has been studied experimentally and analyzed. MATERIALS AND METHODS: Freshly enucleated porcine eyes were irradiated at a laser fluence of 180 mJ/cm2 with various spot diameters in the range 1-6.5 mm. Pressure transients were detected by a fast rise time needle hydrophone inserted into the eyeball from the posterior pole and moved along the eye optical axis toward the cornea. RESULTS: Pressure peaks as high as 90 bar and 50 ns pulse duration (FWHM) were measured in the anterior chamber. Observation of the pulse shape evolution during propagation put in evidence the onset of a marked rarefaction phase following the compressional spike, with intense negative peaks (up to -40 bar) located at increasing distances from the corneal surface for increasing spot diameters. CONCLUSIONS: This behavior was explained by means of simplified models describing pressure pulse generation and diffraction effects occurring during its propagation. Implications to clinical procedures, as possible damages due to tissue stretching and cavitation formation, are also discussed.

Animals↗
PubMed1997

Transthoracic three-dimensional echocardiographic reconstruction of left and right ventricles: in vitro validation and comparison with magnetic resonance imaging.

Two-dimensional (2D) echocardiographic and angiographic measurements of ventricular volumes are limited by geometric assumptions concerning cavity shape. We compared in vitro the accuracy of a three-dimensional (3D) echocardiographic system suitable for transthoracic imaging to magnetic resonance imaging (MRI) in the measurement of left and right ventricular volumes. Ventricular cast volumes from 14 excised formalin-fixed sheep hearts filled with an agarose solution were compared with data derived from 3D echocardiography and MRI. Left and right ventricular volumes from 3D echocardiographic reconstructions agreed well with actual volumes without significant underestimation or overestimation. MRI progressively underestimated left ventricular volumes as these increased and systematically underestimated right ventricular volumes. Our echocardiographic system designed for 3D transthoracic imaging combines excellent measurements of left and right ventricular volumes and the computed reconstruction of tomographic slices with the full spatial resolution of the original 2D images. Thus in this in vitro model, 3D echocardiography exhibited greater accuracy than MRI.

Animals↗
PubMed1997

Vessel-wall recovery after diode laser-assisted microvascular anastomosis: clinical and histologic analysis on long-term follow-up.

The authors recently reported an experimental study on diode laser-assisted microvascular anastomosis (LAMA) in the femoral arteries and veins of rats. Good success rates and very promising histologic results obtained in this preliminary phase suggested an extension of the investigation with a larger number of rats and for longer follow-up periods. In the present work, they describe an experimental study with two main goals: 1) improvements of the laser-assisted surgical procedure for reduction in the number of permanent stay sutures, with minimization of bleeding at the end of the intervention, compared with conventional microvascular sutured anastomosis (CMSA); and 2) providing more information on the repair mechanism(s) induced by laser treatment, obtained from clinical and histologic analyses extended up to 3 months of follow-up. In a total of 64 Wistar rats, 46 arterial and 22 venous LAMAs were performed, and 15 arterial and 11 venous CMSAs. The recorded success rates of LAMA in both arteries and veins were fairly high (67/68 at the time of surgery, and 54/55 in the follow-up), and substantially comparable with those of CMSA. Clear evidence of a superior healing process in the LAMAs was provided by histologic examinations. In particular, specific stains and immunohistochemistry analysis indicated that laser irradiation can induce wide proliferation of smooth muscle cells and negligible scar tissue which, together with diminished foreign-body reaction consequent to the reduction of suture material, result in a better restoration of vessel structures.

Anastomosis, Surgical↗