Search results for "Vascular resistance"
showing 10 items of 130 documents
Comparison of the sympathetic skin response and continuous wave Doppler sonography of the radial artery.
1999
The value of neurophysiological tests of the autonomic nerve system is limited. One of the clinically most commonly applied test is the skin sudomotor response, frequently referred to as 'sympathetic skin response' (SSR). However, the SSR is a more qualitative than quantitative evaluation technique. Continuous wave (cw) Doppler sonography of the radial artery may be an alternative quantitative approach. We studied 41 age matched volunteers (23 female, 18 male; 16-82 years (mean age 53 years)). The stimulus was a loud and unexpected acoustic signal, alternatively a cough. SSR evaluation included the latency of onset, the duration and the amplitude of the response. Doppler evaluation also inc…
Hypertension and peripheral arterial hemodynamics.
1995
Sixty uncomplicated hypertensive patients (30 stable and 30 borderline) were studied, by strain gauge plethysmography, in comparison with 25 normotensive subjects, in order to evaluate the arterial hemodynamics of the lower limbs in essential hypertension and to verify the different pattern in borderline and in stable hypertensives. Resting blood flow, even if slightly decreased in hypertensive groups, did not show significant differences in its mean values; peak flow, instead, was reduced proportionally to the severity of hypertension in all the hypertensive patients, but only in the stable hypertensives was it statistically significant. Minimal vascular resistance showed a similar behavi…
Pulmonary balloon angioplasty of chronic thromboembolic pulmonary hypertension (CTEPH) in surgically inaccessible cases.
2003
Abstract The clinical course of patients suffering from chronic thromboembolic pulmonary hypertension (CTEPH) depends on the distribution pattern of the thromboembolic material. In patients with thromboembolic findings in the central pulmonary segments pulmonary thrombendarterectomy (PTE) has excellent results and acceptable operative risk. This paper presents two surgically inaccessible cases that were successfully treated with balloon pulmonary angioplasty. Balloon angioplasty improved parenchymal perfusion, increased cardiac index (Delta CI +19.2 % [Case 1], and +15.4 % [2]), reduced pulmonary vascular resistance during follow-up (Delta PVRI -25.0 % [1] and -15.9 % [2]), and is discussed…
Intra-renal hemodynamics and carotid intima-media thickness in the metabolic syndrome.
2009
Aims: Metabolic syndrome (MetS) is associated with increased cardiovascular risk. We hypothesize that early vascular changes are already present at the time of diagnosis of MetS. The relationship of different measures of early vascular impairment with body fat distribution and the natural progression of MetS was examined in newly diagnosed subjects non-pharmacologically treated. Methods: 246 consecutively enrolled subjects were categorized according to the presence of MetS and type 2 diabetes (T2D). Intra-renal Doppler flow was used to ascertain resistive (RI) and pulsatility (PI) indices as markers of vascular resistance. Carotid intima-media thick- ness (IMT), cutis-rectis (CR) and rectis…
Regression of structural vascular changes in hypertensives after captopril treatment.
1992
In order to investigate whether hypertension-related structural vascular changes may be influenced by antihypertensive treatment, 10 patients were studied suffering from essential arterial hypertension, five males and five females, aged between 34 and 61 years (mean age: 46.9 +/- 8.13 years). All patients received a placebo for 1 week and then captopril, 75 mg b.i.d. for 3 months. After placebo and captopril treatments, the following parameters were evaluated: SBP, DBP, mean blood pressure (MBP), by the formula 1/3 (SBP + 2 x DBP) and basal and minimal vascular resistances, respectively obtained by the ratios MBP/rest flow and MBP/peak flow. Blood flows have been obtained by strain gauge pl…
Beta-adrenergic blocking activity and haemodynamic effects in man of K� 1313, a new beta-adrenergic antagonist
1971
The beta-adrenergic blocking activity and haemodynamic effects of o-[2-hydroxy-3-(isopropylamino)-propoxy]-benzonitril (Ko 1313) have been studied in 22 patients. Antagonism of isoproterenol-induced tachycardia was used as a measure of the beta-adrenergic blocking activity. Ko 1313 1.0 mg had its maximum beta-adrenoceptor blocking effect 5–30 min after intravenous injection. Ko 1313 10.0 mg produced maximum betablockade 1–4 h after oral administration. 1.0 mg Ko 1313 injected intravenously had approximately the same beta-adrenergic blocking effect as 1.0 mg propranolol also given intravenously. After intravenous administration Ko 1313 was 3–4 times as potent as the same dose given orally. A…
Influence of early life risk factors and lifestyle on systemic vascular resistance in later adulthood : the cardiovascular risk in young Finns study
2021
Purpose: There are limited data available concerning the effects of lifetime risk factors and lifestyle on systemic hemodynamics, especially on systemic vascular resistance. The purpose of the study was to evaluate how lifetime cardiovascular risk factors (body mass index (BMI), high-density lipoprotein, low-density lipoprotein, triglycerides, systolic blood pressure, blood glucose) and lifestyle factors (vegetable consumption, fruit consumption, smoking and physical activity) predict systemic vascular resistance index (SVRI) and cardiac index (CI) assessed in adulthood. Materials and Methods: Our study cohort comprised 1635 subjects of the Cardiovascular Risk in Young Finns Study followed …
Bilateral photoplethysmography studies of the leg arterial stenosis.
2005
A newly developed portable multi-channel photoplethysmography (PPG) device has been used for comparative studies of 20 healthy control subjects and 45 patients with diagnosed arterial stenosis in a leg. The peripheral blood pulsations were detected simultaneously at four body sites-the same fingers and toes of both arms and legs. The PPG pulses recorded at the periphery of the stenotic leg, if compared with those of the healthy leg, were much weaker, with delayed arrival as a consequence of increased pulse wave transit time (PWTT) due to higher vascular resistance. The specific PWTT delays for the occluded legs were in the range of 20-80 ms, while in the case of healthy subjects the leg PPG…
Reference values of fetal aortic flow velocity waveforms and associated intra-observer reliability in normal pregnancies
2001
Objectives It was the aim of the present study to calculate new Doppler reference ranges for blood flow velocities (Vmax, Vmean, Vmin) and resistance indices (PI, RI) for the fetal descending aorta by automatic waveform analysis. Design Cross-sectional prospective study. Subjects Nine hundred and twenty-six low-risk pregnancies at 18–41 weeks' gestation. Methods Aortic blood flow velocities were derived with pulsed-wave color Doppler. Measurements were carried out at the level of the diaphragm. Reference ranges for the individual measuring parameters were constructed based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square pri…
Relationship Between Carotid Atherosclerosis and Pulse Pressure with Renal Hemodynamics in Hypertensive Patients.
2015
BACKGROUND Structural atherosclerotic damage, arterial stiffness, pulse pressure (PP), and renal hemodynamics may interact and influence each other. Renal resistance index (RRI) appears as a good indicator of systemic vascular changes. The aim of our study was to assess the independent relationships of carotid intima-media thickness (cIMT), aortic pulse wave velocity (aPWV), and peripheral PP with RRI in hypertensives with various degrees of renal function. METHODS We enrolled 463 hypertensive patients (30-70 years) with normal renal function (group 0; n = 280) and with chronic kidney disease (groups I-V; n = 183). All subjects underwent ultrasonographic examination of intrarenal and caroti…