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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This was an echocardiographic study of the cardiovascular effects of prostacyclin (PGI2) infused intravenously to human volunteers at the rate of 20 ng . kg-1 . min-1 for 10 minutes. The following parameters were recorded in the steady state, at one-minute intervals throughout infusion and the ensuing recovery period: systolic, diastolic, and mean blood pressure (SBP, DBP, MBP); heart rate (HR); left ventricle end-diastolic (EDD) and end-systolic diameter (ESD); stroke volume index (SVI); cardiac index (CI); peripheral vascular resistance (PVR); left ventricle fractional shortening (FS) and ejection fraction (EF). We detected a progressive reduction of MBP without any HR modification. MBP reduction was associated with a reduction of PVR and a parallel rise of CI and SVI. There was also an increase of FS and EF reflecting a reduced ESD. We conclude that PGI2 infused in man at the rate stated above causes hypotension reflecting an arterial vasodilating effect; a lack of heart rate reflex response to afterload reduction (probably a nerve-mediated effect of PGI2); and no venous vasodilation, judging from the absence of any change in end-diastolic diameter.
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PMID:Prostacyclin effect on cardiovascular system in man evaluated by echocardiography. 703 23

The subjects included in the present study were 141 hospitalized patients with essential hypertension (EH) and 45 patients with EH complicated with apoplexy and myocardial infarction. Of the former 15 underwent a 24-hour measurement of direct arterial pressure under unrestricted conditions, and 45 were examined for functioning of the carotid sinus reflex. (1) Even among the hospitalized patients with EH, blood pressure (BP) showed large diurnal variations. Falls and spontaneous fluctuations in BP were observed at a time during nocturnal sleep. The lowest BP (the "dale" pressure) observed at that time remained almost unchanged throughout the night (S.D. less than or equal to 6 mmHg) for each patient. Since casual BP varies considerably during a day, other laboratory findings should also be taken into account for evaluation prior to initiating antihypertensive treatment. (2) The 186 patients with EH were classified by multivariate statistical analyses of laboratory findings into 4 clusters (types). Then, a new severity index was made in order to evaluate atherosclerotic and hypertensive changes in each patient. (3) A newly devised carotid sinus stimulator was used to enhance the distensibility of the carotid sinus. A decrease in systolic blood pressure (delta SBP) was observed after stimulation although differences in delta SBP were found between the 4 clusters. There was a positive correlation between delta SBP and the elastic modulus of the common carotid artery (r = 0.55, P less than 0.01). (4) Each cluster was characterized by differences in plasma renin activity and cardiovascular abnormalities. This classification is considered to be useful for the antihypertensive treatment.
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PMID:Variability of arterial blood pressure and classification of essential hypertension by multivariate statistical analysis. 719 66

The purpose of this study was to estimate the influence of systolic (SBP) and diastolic blood pressure (DBP) on stroke risk. The Copenhagen City Heart Study is a prospective survey of 19,698 women and men who were invited to two cardiovascular examinations at 5-year intervals. Blood pressure was measured in participants once at each examination, together with other variables. Initial cases of stroke and transient ischemic attack were recorded from hospital records and death certificates from 1976 through 1988. When entered separately in the Cox regression model, both SBP and DBP had significant effects on stroke risk. In the lower 60% of the blood pressure distribution in the population, the relative risk of stroke was nearly constant, followed by a gradual increase in the upper 40% of blood pressure distribution. However, when SBP and DBP were entered simultaneously in the model, the effect of DBP vanished, while the pattern of the association between SBP and stroke risk remained unchanged. Persons on antihypertensive treatment had higher risk for stroke than non-treated persons with the same blood pressure, relative risk = 1.6 (95% confidence interval (CI) 1.2-2.2). The relative risk for the highest SBP levels, shared by nearly 3% of the population, was 4.0 (95% CI 2.2-7.3). The attributable risk of SBP in the upper 40% of SBP distribution, i.e., above the mean for each age and sex group, was 22%. Our results indicate that: 1) the association between blood pressure and stroke risk was not log-linear, and 2) SBP was a stronger stroke predictor than DBP.
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PMID:Influence of systolic and diastolic blood pressure on stroke risk: a prospective observational study. 750 48

The cardiac hemodynamic effects of bimakalim, a new potassium channel opener, were evaluated in 12 normal volunteers by echocardiography (ECHO)/Doppler in a placebo-controlled, randomized double-blind, cross-over, dose-ranging study. A single oral dose (0.25-1 mg) was given at weekly intervals. Hemodynamic measurements were made at 0, 90, 120, and 240 min after drug intake and ECHO/Doppler was performed at 0 and 90 min. Reproducibility of the ECHO/Doppler study was assessed by comparing predose baseline values of the four different phases of treatment (placebo and 0.25, 0.5, and 1 mg) by analysis of variance (ANOVA), which showed no significant differences for left ventricular ejection fraction (LVEF). Doppler-derived stroke volume (SV), total peripheral resistance (TPR), and peak mitral early to late velocity ratio (PEV/PAV). ANOVA showed significant increases in LVEF (p = 0.0003) and SV (p = 0.03), however, and decreases in TPR (p = 0.002) and PEV/PAV (p = 0.005) after bimakalim treatment. Heart rate (HR) showed a dose-dependent increase, but systolic and diastolic blood pressure (SBP, DBP) did not change with bimakalim. Despite vasodilatory headaches, none of the volunteers discontinued the study. Bimakalim appears to be a potent vasodilating drug that may have an important role in management of patients with compromised LV function.
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PMID:Potent hemodynamic effects of bimakalim, a new potassium channel opener, in humans. 750 24

Effects of four intravenous (i.v.) doses (0.25, 0.5, 1, and 2 micrograms/kg) of the alpha 2-adrenoceptor agonist clonidine (CLO) were studied in 7 normotensive male volunteers in a placebo-controlled double-blind randomized design to evaluate the role of alpha 2-adrenoceptors in spontaneous short-term cardiovascular fluctuations. Heart rate (HR), systolic and diastolic blood pressure (SBP, DBP; Finapres device), stroke volume (SV) and total peripheral resistance (TPR) were monitored for 1 h after infusion of CLO while the subjects rested in a semirecumbent position. For HR, SBP, and DBP, power spectra and variation coefficients were calculated for consecutive time segments of 2.5 min. Power density was assessed for three frequency bands: low (LFB, 0.02-0.06 Hz), mid (MFB, 0.07-0.14 Hz), and high (HFB, 0.15-0.40 Hz). Per time-segment, baroreflex sensitivity (BRS) was estimated as the gain (or modulus) in MFB between systolic pressure values and R-R interval times. Decreases in mean levels of SBP and DBP were observed within 15 min after infusion of > or = 0.5 micrograms/kg CLO. HR first showed a slight increase 15 min after infusion of 0.5, 1, and 2 micrograms/kg CLO, but decreased subsequently as in all doses, including placebo. SV and TPR decreased after a dose of 2 micrograms/kg CLO. LFB and MFB power of HR were reduced after 2 micrograms/kg CLO, but only during the first 30 min after infusion; during this period, respiratory depth was also diminished, indicating that these effects may reflect a reduction in sympathetic outflow as well as a reduction in vagal outflow.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardiovascular variability after clonidine challenge: assessment of dose-dependent temporal effects by means of spectral analysis. 769 82

Essential orthostatic hypotony (EOH) seems to present a rarely occurring and not well recognized syndrome. Group of 20 patients (pts) with EOH were treated with midodrine (Gutron, Gu) 5 mg i.v. Non-invasive hemodynamic variables, such as systolic time intervals and their derivates, based on polycardiographic recordings, were analysed. Heart rate and blood pressure measurements during orthostatic test were measured before and after Gu administration. The results of the orthostatic trial were compared to the control group of 20 volunteers. In healthy subjects, up-right position resulted in heart rate (HR) acceleration, diastolic blood pressure (DBP), total peripheral resistance (TPR), double and triple product (DP, TP), contraction coefficient (PEP/LVET) and dicrotic coefficient ('d') elevation, prejection period (PEP), electromechanical delay (QS1) and isovolumic contraction time (ICT) prolongation and lastly stroke volume (SV), cardiac output (CO) and middle rate of left ventricle ejection time (MRLVET) reduction. Patients with EOH showed a reduction of the degree of tilt-induced changes of the parameters. DBP fell down. After Gu these unfavourable changes were corrected to the values nearer the control group levels in three compensatory mechanisms. After Gu application in EOH-pts were seen: 1) favourable translocation of the resting (supine) values, but with the same reactivity to tilt, as before Gu (HR, TPR); 2) positive influences on orthostatic reaction, but inversely without any changes of resting values (PEPI, ICT, PEP/LVET, DP, DBP) and finally 3) favourable translocation of resting values together with inversed orthostatic reaction (SBP, QS2,TP). We stated clinical valuable efficacy of Gu. Gu influenced mainly the initial state of circulatory hemodynamics in resting and also in a lower degree in orthostatic reaction.
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PMID:Gutron treatment of patients suffering from essential orthostatic hypotony. Part One--Hemodynamic non-invasive investigation. 769 Mar 84

Five young, healthy male students performed two different psychophysical tests each lasting 1 min. The first test (A) consisted of mental arithmetic with digiting of results on a keyboard; the second test (G) consisted of playing an electronic game based on hand-eye coordination. Before and during each test, subjects remained seated with their thoraxes connected to an impedance cardiography monitor which gave, non invasively, beat-by-beat values of heart rate (HR), cardiac output (CO), stroke volume (SV) and left ventricle ejection time (VET). Systolic (SBP) and diastolic (DBP) arterial blood pressures were measured by means of a sphygmomanometer and total peripheral vascular resistance (TPR) and mean systolic ejection rate (MSER) were calculated. During test A, CO (A = +30%, G = +14%), HR (A = +26%, G = +2%) and SBP (A = +16%, G = +10%) increased more than during test G, while SV (A = +3%, G = +12%) and MSER (A = +11%, G = +14%) increased less and TPR (A = -13%, G = -7%) and VET (A = -7%, G = -2%) decreased more than in G. It was concluded that the analysis of a more complete cardiovascular profile may enhance distinctions among the behavioural stressors that induced different combinations in cognitive and sensory-motor responses.
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PMID:Differences in cardiovascular profiles induced by mental arithmetic and by hand-eye task. 770 30

There have been few prospective epidemiological studies of asymptomatic hyperglycaemia as a risk factor for cardiovascular disease and all causes mortality in women. Gender-specific all causes, cardiovascular disease (CVD), ischaemic heart disease (IHD) and stroke mortality rates and relative risks for asymptomatic hyperglycaemics (top 5%) have been compared to normoglycaemics (bottom 95%) during a mean follow-up of 11.6 years (range 10-14) among 4696 men and 5714 women aged 45-64 at entry in the west of Scotland. Univariate analysis showed that asymptomatic hyperglycaemia was associated with increased risk of all causes, CVD, IHD and stroke mortality in both genders. The degree of this association was greater in women than in men. Using multiple logistic regression (MLR) analysis to take into account differences in age, systolic (SBP) and diastolic blood pressure (DBP), serum cholesterol, body mass index (BMI), and cigarette smoking, high causal blood glucose level was still a significant risk factor for CVD mortality in both genders. It was also a significant risk factor for all causes, IHD and stroke mortality in women but not in men. This study shows that to a lesser degree asymptomatic hyperglycaemia shows the same gender differentials in risk of mortality as have been demonstrated amongst known diabetics.
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PMID:A prospective population based study of gender differential in mortality from cardiovascular disease and "all causes" in asymptomatic hyperglycaemics. 773 Aug 65

Debate continues on whether left ventricular (LV) systolic function during exercise is abnormal in young subjects with mild hypertension and on whether the abnormal blood pressure (BP) trend observed in hypertensives during prolonged exercise is due to impaired LV function. LV function was measured by means of M-mode echocardiography during prolonged exercise in 13 physically trained, young, mild hypertensives and 12 age-matched, trained normotensives with similar working capacity. Systolic BP/end-systolic volume (SBP/ESV) and end-systolic stress/ESV at rest were greater in the hypertensives (P < 0.0001 and P = 0.034), while LV filling was impaired (P = 0.05). BP changes during the first 20 min of exercise were similar in the two groups, but thereafter the between-group BP difference tended to decline progressively. LV diastolic dimension was similar at rest. During exercise it slightly increased in the normotensives and slightly decreased in the hypertensives (P = 0.032). Exercise ejection fraction (P = 0.018), SBP/ESV (P < 0.0001) and stress/ESV (P = 0.027) were greater in the hypertensives throughout the test. SBP/ESV normalized for LV wall thickness (P < 0.0001) and the changes in SBP/ESV from rest to exercise were also greater in the hypertensives (P = 0.002). Stroke volume increased to a lower extent in the hypertensives, but the between-group difference was not statistically significant. The increase in SBP/ESV from rest to exercise was related to the concentric remodelling of the ventricle in the hypertensives (P < 0.0001) and the subjects grouped together (P < 0.0001), but not in the normotensives. In conclusion, increased LV systolic performance is present early in hypertension not only at rest but also during vigorous exercise. It is partly due to concentric remodelling of the left ventricle and partly to enhanced inotropic state.
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PMID:Above-normal left ventricular systolic performance during exercise in young subjects with mild hypertension. 774 96

Aim of this study was to evaluate the antihypertensive efficacy, tolerability, drug plasma levels and hemodynamic effects after long-term treatment with the slow release (SR) formulation of verapamil (240 mg od). After a wash-out period of two weeks, 96 subjects (39 M, 57 F; mean age: 55 +/- 8.4 years; recruited in 9 centers) with mild to moderate, uncomplicated hypertension received verapamil 240 mg SR od for 24 weeks. The following parameters were considered: systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR), ECG, echocardiogram, routine blood and urine chemistries, drug plasma levels. In addition, hemodynamic parameters were assessed in 30 subjects. A significant decrease in SBP and DBP (p < 0.01) was observed already after 1 week of treatment and was evident during all the study. HR was significantly reduced after 4 weeks (p < 0.01). No changes of ECG and echocardiographic parameters occurred. A significant increase in drug plasma levels was measured after 12 and 24 weeks of treatment (p < 0.05), when compared to the values recorded after 1 week. After 24 weeks drug levels were slightly decreases, even if not significantly, when compared to the values observed at the 12th week. No significant changes of cardiac output (CO), cardiac index (CI), stroke volume (SV) were evident. Total vascular resistances (TVR) decreases significantly (p < 0.001) 80 subjects completed the study. These results confirm the antihypertensive efficacy and tolerability of SR formulation of verapamil and suggest that the effective mechanism by which it reduces blood pressure is the progressive reduction of TVR without a sympathetic reflex stimulation. This hemodynamic effect is achieved by small drug concentrations. In conclusion, SR formulation of verapamil allows a good therapeutic control in hypertensive subjects when it is administered od and, therefore, it can be considered a drug of first choice in the treatment of arterial hypertension.
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PMID:[Plasma levels and noninvasive hemodynamic profile of slow release verapamil (240 mg). A multicenter study]. 776 76


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