PubMed Health⌕ Search

Biomedical subjects

G Grassi

Publications and source records attributed to G Grassi.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Interaction between congestive heart failure and diabetes mellitus: critical review of the literature].

It is known from the Framingham Heart Study that there is a relationship between congestive heart failure and diabetes mellitus. Diabetes can cause myocyte hypertrophy, interstitial fibrosis, impaired myocardial blood flow, increased turnover of free fatty acids, leading to the development of cardiomyopathy. On the other hand, heart failure increases catecholamine plasma levels and it may cause insulin resistance, leading to the development of diabetes. We report and discuss data from the literature: ACE-inhibitors do not alter glucose metabolism, non selective beta-blockers increase insulin resistance, while beta-blockers with vasodilating properties do not seem to alter insulin sensitivity, and high doses of diuretics seem to have a negative effect on glycemic parameters. Since diabetes has a high prevalence among patients with heart failure, it is clinically relevant to monitor glycemic parameters in such patients and also to evaluate changes in the therapy.

Adrenergic beta-Antagonists↗
PubMed2000

Angiographic presentation of coronary artery spasm in heart transplant recipients.

We describe the angiographic characteristics of coronary artery spasm observed in 12 out of 247 (4.9%) patients who underwent 808 coronary angiographies after heart transplantation. Coronary artery spasm was diagnosed when localized and reversible narrowing of the coronary lumen was identified. After coronary artery spasm identification all patients were followed-up clinically for a mean period of 5.1 years. Coronary artery spasm was documented 1-3 years after heart transplant. Coronary artery spasm affected 1 main coronary artery in 10 patients and 2 in 2 patients; in 3 patients 1 or more secondary branches were also affected. The right coronary artery was affected by coronary artery spasm in 8 patients and the anterior descending coronary artery in 6 patients. In 6 patients coronary artery spasm was mechanically induced by the catheter tip. The degree of luminal narrowing due to coronary artery spasm ranged from mild to almost complete occlusion. Coronary artery spasm appeared as a single tubular smooth and concentric stenosis in 8 patients, was discrete in 2 patients and multiple on the same vessel in 2 patients. In 1 patient coronary artery spasm was erroneously interpreted as an organic lesion and percutaneous transluminal coronary angioplasty was planned. During follow-up 3 patients out of 4 who had shown multiple coronary artery spasm died and 2 patients developed critical organic stenosis. In conclusion coronary artery spasm after heart transplant is less rare than commonly believed. Although it usually has a peculiar appearance, it can be misinterpreted as an organic lesion. Multiple coronary artery spasm appears to carry a poor prognosis.

Adult↗
PubMed2000

Sympathoexcitatory responses to the acute blood pressure fall induced by central or peripheral antihypertensive drugs.

This study was designed to evaluate the effects of an acute blood pressure reduction brought about by a peripheral vasodilator agent (prazosin) or by a drug combining central and peripheral modes of action (urapidil), on three markers of adrenergic tone such as muscle sympathetic nerve traffic (MSNA), venous plasma norepinephrine (NE), and heart rate (HR). In 12 untreated essential hypertensives (age, 50.7 +/- 1.9 years; mean +/- SEM), we evaluated in two experimental sessions, according to a double-blind crossover design, the effects of acute oral administration of 2 mg prazosin or 30 mg urapidil on beat-to-beat finger blood pressure (Finapres), HR (electrocardiogram), NE (high-performance liquid chromatography), and MSNA (microneurography at a peroneal nerve). In each session measurements were performed in the no-drug control state and repeated throughout a 3-h period after drug administration. For similar blood pressure reductions, the two drugs caused similar increases in NE and MSNA (peak effects: NE = +1.1 +/- 0.2 vs 0.9 +/- 0.2 nmol/L and MSNA = +10.9 +/- 1.8 vs +10.1 +/- 1.6 bursts/min for prazosin and urapidil respectively, P = ns between drugs), whereas HR increased more markedly after prazosin administration (+6.1 +/- 1.1 vs +2.4 +/- 0.8 beats/min, P < 0.05). These data provide evidence that acute blood pressure reductions induced by antihypertensive drugs with central or peripheral modes of action activate the sympathetic nervous system to a similar extent. Thus adrenergic activation is not peculiar to vasodilators but rather generalized to any drug-induced acute blood pressure fall, presumably because of the lack of a baroreflex resetting, which occurs during chronic but not during acute antihypertensive treatment.

Adult↗
PubMed2000

The role of angiotensin II receptor antagonists in hypertension management: focus on candesartan cilexetil.

The prevention and treatment of hypertension both from the viewpoint of individual patient care and in terms of population health presents a considerable challenge to the medical profession. To assist in meeting this challenge, various bodies have produced guidelines for the management of hypertension during the past 30 years. The aim of this article is to review the recommendations of the most recent of these - the 1999 WHO-ISH guidelines - as well as previous similar documents, including the earlier 1993 WHO-ISH guidelines and the US Joint National Committee on prevention, detection, evaluation

Adult↗
PubMed2000

Sympathetic and reflex alterations in systo-diastolic and systolic hypertension of the elderly.

BACKGROUND: Previous studies have shown that young and middle-aged essential hypertensives are characterized by a sympathetic activation coupled with an impaired baroreflex-heart rate control. The present study aimed to determine whether these neuroadrenergic and reflex alterations also characterize systo-diastolic and systolic hypertension of the elderly. SUBJECTS AND METHODS: In 20 untreated elderly essential hypertensive subjects [10 with a systo-diastolic and 10 with an isolated systolic hypertension, aged 67.2 +/- 1.5 years and 66.9 +/- 1.7 years (mean +/- SEM)], we measured beat-to-beat arterial blood pressure (finger photoplethysmographic device), heart rate (electrocardiogram) and efferent postganglionic muscle sympathetic nerve activity (microneurography) at rest and during baroreceptor stimulation and deactivation induced by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Data were compared with those obtained in 11 age-matched normotensive control subjects. RESULTS: Compared to the elderly normotensive group, muscle sympathetic nerve activity was increased to a similar degree in the group of systo-diastolic and systolic hypertension (50.8 +/- 4.2 versus 75.2 +/- 5.2 and 70.4 +/- 5.1 bursts per 100 heart beats, respectively, P< 0.01 for both). In the control group, the stepwise increase in arterial pressure induced by phenylephrine caused progressive bradycardia and sympathoinhibition, while the stepwise decrease in arterial pressure had opposite effects. While baroreceptor-heart rate control was markedly impaired (average reduction 41.6%), in both systo-diastolic and systolic hypertensive patients, baroreceptor modulation of sympathetic nerve traffic was similar to that seen in normotensive individuals. CONCLUSIONS: These data demonstrate that sympathetic activation is not only a feature of young and middle-aged, but also of elderly hypertensives, regardless of whether both systolic and diastolic or only systolic blood pressure is increased. They also show that hypertension of the elderly is not accompanied by an impaired baroreceptor modulation of sympathetic nerve traffic.

Adult↗
PubMed2000

Mechanisms and clinical implications of blood pressure variability.

Several studies have unequivocally shown that the target-organ damage associated with the hypertensive condition is more closely related to 24 h average blood pressure values than to clinic blood pressure. Blood pressure, however, is highly variable over the daytime and night-time period, and of major interest is whether average 24 h blood pressure values, as well as 24 h blood pressure variability, correlate with, and are possibly responsible for, the hypertension-related alterations of the target-organ structure and function. This paper will address this issue by discussing the main features of blood pressure variability in hypertension. It will also examine the mechanisms involved in this phenomenon, with particular emphasis on the pathogenetic role of sympathetic neural factors. The clinical relevance of blood pressure variability in promoting target-organ damage, as well as its therapeutic implications, will finally be highlighted.

Animals↗
PubMed2000

Adrenergic and reflex abnormalities in obesity-related hypertension.

Previous studies have shown that essential hypertension and obesity are both characterized by sympathetic activation coupled with a baroreflex impairment. The present study was aimed at determining the effects of the concomitant presence of the 2 above-mentioned conditions on sympathetic activity as well as on baroreflex cardiovascular control. In 14 normotensive lean subjects (aged 33. 5+/-2.2 years, body mass index 22.8+/-0.7 kg/m(2) [mean+/-SEM]), 16 normotensive obese subjects (body mass index 37.2+/-1.3 kg/m(2)), 13 lean hypertensive subjects (body mass index 24.0+/-0.8 kg/m(2)), and 16 obese hypertensive subjects (body mass index 37.5+/-1.3 kg/m(2)), all age-matched, we measured beat-to-beat arterial blood pressure (by Finapres device), heart rate (HR, by ECG), and postganglionic muscle sympathetic nerve activity (MSNA, by microneurography) at rest and during baroreceptor stimulation and deactivation induced by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Blood pressure values were higher in lean hypertensive and obese hypertensive subjects than in normotensive lean and obese subjects. MSNA was significantly (P:<0.01) greater in obese normotensive subjects (49.1+/-3.0 bursts per 100 heart beats) and in lean hypertensive subjects (44.5+/-3.3 bursts per 100 heart beats) than in lean normotensive control subjects (32.2+/-2.5 bursts per 100 heart beats); a further increase was detectable in individuals with the concomitant presence of obesity and hypertension (62.1+/-3. 4 bursts per 100 heart beats). Furthermore, whereas in lean hypertensive subjects, only baroreflex control of HR was impaired, in obese normotensive subjects, both HR and MSNA baroreflex changes were attenuated, with a further attenuation being observed in obese hypertensive patients. Thus, the association between obesity and hypertension triggers a sympathetic activation and an impairment in baroreflex cardiovascular control that are greater in magnitude than those found in either of the above-mentioned abnormal conditions alone.

Adrenergic Fibers↗
PubMed2000

The repeatability of choku-tsuki and oi-tsuki in traditional Shotokan karate: a morphological three-dimensional analysis.

The aim of the study was to quantify the repeatability of the displacement of selected body landmarks while performing two different basic karate attacks. Seven karateka (three men, four women) with different levels of training and knowledge of karate were filmed with an optoelectronic computerized instrument (sampling rate 100 Hz) that allows the three-dimensional reconstruction of the movements of selected body landmarks. Thirteen landmarks (head, hips, upper and lower limbs) were analyzed while performing 10 repetitions each of choku-tsuki (straight punch) and oi-tsuki (lunge punch). For each karateka and punch, the average time of execution was calculated, and the standard deviations of each of the three spatial coordinates x, y, z were computed for each landmark. A total standard deviation of the single karateka and punch was also calculated. For all karateka, the execution of oi-tsuki took longer than the execution of choku-tsuki. For both punches and almost all landmarks, the largest repeatability (smallest standard deviation) was found in the vertical direction, while the smallest was found in the anteroposterior direction (direction of movement). In all karateka, oi-tsuki had a total standard deviation about 3 to 6 times larger than that measured during the performance of choku-tsuki. On average, women had a larger repeatability than men. The method employed in the current study allowed the quantitative analysis of the repeatability of two basic attacks in Shotokan karate by using a landmark based approach. The method could offer valuable help to karateka during training indicating which parts of the body do not repeat a selected movement with sufficient accuracy, thus assisting in the achievement of the most correct body form.

Adult↗
PubMed1999

Comparison of angiotensin II receptor blockers: impact of missed doses of candesartan cilexetil and losartan in systemic hypertension.

Blood pressure remains poorly controlled in the hypertensive population due in large part to low or unsatisfactory patient compliance. Clinical studies that incorporate an intentionally missed dose have been designed to evaluate the impact of poor patient compliance on the effectiveness of antihypertensive medications. In these studies, ambulatory blood pressure monitoring is continued throughout the dosing interval and beyond in order to determine when systolic and diastolic blood pressure increase into the hypertensive range. In an 8-week, randomized, double-blind, placebo-controlled trial in patients with mild-to-moderate hypertension, the antihypertensive effects of candesartan cilexetil 16 mg were maintained after a missed dose, whereas systolic and diastolic blood pressure increased toward baseline levels after a missed dose of losartan 100 mg. Candesartan cilexetil provided a significantly greater reduction in sitting systolic (p = 0.004) and diastolic blood pressure (p = 0.008) than losartan when measured 48 hours after the last dose. Moreover, the homogeneity of antihypertensive effects was greater after candesartan cilexetil than losartan based on calculation of the smoothness index from ambulatory systolic and diastolic measurements during the first 24-hour period after dosing and during the 12-hour period after the missed dose. These results demonstrate that missing or delaying a dose of candesartan cilexetil has less impact on antihypertensive efficacy than missing or delaying a dose of losartan.

Adult↗
PubMed1999

Baroreflex and non-baroreflex modulation of vagal cardiac control after myocardial infarction.

Vagal control of sinus node exerted by arterial baroreceptors is markedly impaired 48 hours after acute myocardial infarction (AMI), but it recovers 10 days later. However, it is unknown whether this recovery is peculiar to baroreceptor vagal control or reflects normalization of the overall vagal modulation of heart rate. In 21 untreated patients (aged 51+/-3 years, mean +/- SEM) studied 10+/-1 and 21+/-1 days after an AMI and in 13 healthy controls (aged 47+/-2 years), we examined the increases in RR interval (electrocardiogram) induced by carotid baroreceptor stimulation via a neck chamber and by immersion of the face in iced water for 15 seconds (diving reflex). Both 10 and 21 days after AMI, baseline blood pressure and RR interval values were superimposable to those obtained in controls. Ten days after AMI, the bradycardic responses to carotid baroreceptor stimulation were similar to those seen in controls (maximal RR interval lengthenings: 248+/-34 vs 270+/-31 ms, respectively, p = NS) and remained virtually unchanged later. In contrast, the bradycardic response to diving was reduced in patients after AMI compared with controls (maximal RR interval lengthenings: 203+/-43 vs 325+/-52 ms, respectively, p <0.05) and did not improve later. Thus, in AMI recovery of the early impairment of baroreceptor-heart rate control does not reflect normalization of vagal cardiac control, which remains lower than normal values at a time when the baroreflex is restored.

Blood Pressure↗
PubMed1999

Muscle and skin sympathetic nerve traffic during the "white-coat" effect.

BACKGROUND: Sphygmomanometric blood pressure measurements induce an alerting reaction and thus an increase in the patient's blood pressure and heart rate. Whether and to what extent this "white-coat" effect is accompanied by detectable changes in sympathetic nerve traffic has never been investigated. METHODS AND RESULTS: In 10 mild untreated essential hypertensives (age 37.9+/-3. 8 years, mean+/-SEM), we measured arterial blood pressure (by Finapres), heart rate (by ECG), and postganglionic muscle and skin sympathetic nerve activity via microneurography. Measurements were performed with the subject supine during (1) a 15-minute control period, (2) a 10-minute visit by a doctor unfamiliar to the patient who was in charge of measuring his or her blood pressure by sphygmomanometry, and (3) a 15-minute recovery period after the doctor's departure. The entire procedure was performed twice at a 45-minute interval to obtain, in separate periods, muscle or skin sympathetic nerve traffic recordings, whose sequence was randomized. The doctor's visit induced a sudden, marked, and prolonged pressor and tachycardic response, accompanied by a significant increase in skin sympathetic nerve traffic (+38.6+/-6.7%, P<0.01). In contrast, muscle sympathetic nerve traffic was significantly inhibited (-25. 5+/-4.1%, P<0.01). All changes persisted throughout the doctor's visit and, with the exception of skin sympathetic nerve traffic, showed a slow rate of disappearance after the doctor's departure. CONCLUSIONS: Thus, the pressor and tachycardic responses to the alerting reaction that accompanies sphygmomanometric blood pressure measurement is characterized by a behavior of the adrenergic nervous system that causes muscle sympathoinhibition and skin sympathoexcitation.

Adult↗
PubMed1999

Early effects of total paracentesis and albumin infusion on muscle sympathetic nerve activity in cirrhotic patients with tense ascites.

BACKGROUND/AIMS: Cirrhotic patients with ascites are characterized by a marked activation of the sympathetic and the renin-angiotensin-aldosterone system. Total paracentesis is associated with a short-lived suppression of the renin-angiotensin-aldosterone system. Little information exists as to whether this favourable effect is parallelled by sympathoinhibition. METHODS: In 16 Child C cirrhotic patients (age: 57.1+/-6.2 years, mean+/-SEM) with tense ascites we assessed the time course of the effects of total paracentesis followed by intravenous albumin (6-8 g/l of ascites) on beat-to-beat mean arterial pressure (Finapres), heart rate, plasma norepinephrine, epinephrine (high performance liquid chromatography) and muscle sympathetic nerve activity (microneurography, peroneal nerve). Measurements were obtained under baseline conditions, during staged removal of ascitic fluid (250 ml/min) and 24 h later. The patient remained supine throughout the study period. RESULTS: Total paracentesis (10.6+/-1.3 l) induced a decrease in mean arterial pressure (from 95.0+/-2.6 mmHg to 88.2+/-3.2 mmHg, p<0.01), in heart rate (from 82.5+/-3.3 beats/min to 77.1+/-2.8 beats/min, p<0.01) and a reduction in plasma norepinephrine values (from 782+/-133 pg/ml to 624+/-103 pg/ml, p<0.01), which were substantially maintained 24 h later. In eight patients muscle sympathetic nerve activity did not change during paracentesis (from 65+/-7.1 bursts/min to 65+/-7.4 bursts/min, p=NS), but a marked reduction was observed 24 h later (48.4+/-5.6 bursts/min, p<0.01). CONCLUSIONS: These data provide the first evidence that total paracentesis exerts an acute marked sympathoinhibitory effect. Whether this is a long-lasting phenomenon and to what extent plasma expansion with albumin contributes to this effects need to be further addressed.

Adult↗
PubMed1999

Current antihypertensive treatment: can we do better?

Results of various randomized, controlled clinical trials have shown that antihypertensive treatment is accompanied by reductions in morbidity and mortality caused by cardiovascular, cerebrovascular, and renal disease. Treatment confers a protective benefit against stroke, coronary artery disease, and heart failure, as well as against conditions previously considered unrelated to elevated blood pressure (eg, loss of cognitive function and dementia). Overall benefits of antihypertensive treatment are probably even greater than those shown in clinical trials. More rigorous blood pressure control in high-risk and multiple-risk patients provides even greater benefits. Because epidemiologic findings indicate that elevated systolic blood pressure (SBP) may be a greater risk factor for cardiovascular disease than elevated diastolic blood pressure (DBP), more attention should be paid to the control of SBP. Pulse pressure may be a better indicator of target-organ damage than either SBP or DBP, but further evaluation of its prognostic value is required. New monotherapies that can significantly reduce blood pressure, especially SBP, and confer protection on the target organs most affected by chronic hypertension may substantially add to current treatment.

Antihypertensive Agents↗
PubMed1999

Time-resolved fluoroimmunoassay for delta(9)-tetrahydrocannabinol as applied to early discrimination of Cannabis sativa plants.

In the cultivations of Cannabis, it is important to be able to distinguish fiber-type plants from drug-type plants by an easy observation of their phenotype. This study required the screening of many samples for their cannabinoid content. A simple and highly sensitive time-resolved fluoroimmunological method was developed for the determination of Delta(9)-tetrahydrocannabinol in the leaf extracts. The useful range of the calibration curve was between 10 pg and 25 ng of standard. Matrix effects were minimized by a high dilution of samples.

Animals↗