Results obtained by the investigators in ground-based experiments and in two parabolic flight series of tests aboard the NASA KC-135 aircraft with a hydraulic simulator of the human systemic circulation have confirmed that a simple lack of hydrostatic pressure within an artificial ventricle causes a decrease in stroke volume of ...

OBJECTIVE: For almost 50 years it has been known that hemolysed blood can increase blood pressure. Although preclinical studies suggest that this pressor response is due to an interaction of hemoglobin with endothelium-derived vasoactive substances, its mechanism in humans is unknown. We investigated the involvement of endothelin-1 in the blood ...

To examine the clinical implications of post-stroke hypertension, defined as the rise in blood pressure on admission after the onset of ischemic stroke as compared with the blood pressure before stroke, and to assess the relationship between the value of post-stroke hypertension and neurologic recovery, we retrospectively studied 28 patients ...

BACKGROUND AND PURPOSE: The relevance of elevated blood pressure in acute ischemic stroke and its most appropriate management are unresolved. We aimed to evaluate the rate of functional recovery with relation to early blood pressure management in patients with ischemic stroke. METHODS: Four hundred eighty-one consecutive ischemic stroke patients were ...

Transesophageal echocardiography is often the diagnostic modality used for evaluation of cardiovascular sources of cerebral emboli. While invasive, TEE has proven to be a safe diagnostic method. However, TEE may have hemodynamic consequences within the procedure that are potentially hazardous to the specific population of acute ischemic stroke patients. As ...

We performed a subgroup analysis of the first European Stroke Prevention Study including 1,306 patients recruited in a single center, Kuopio, Finland, to investigate whether or not antiplatelet therapy is effective in the secondary prevention of stroke in hypertensive patients with transient ischemic attack (TIA) or stroke. The patients were ...

Although the blood vessels are exposed to high pressures in hypertension, the main complications of hypertension (stroke and myocardial infarction) are paradoxically thrombotic rather than haemorrhagic. In keeping with Virchow's triad, patients with hypertension do demonstrate abnormalities of vessel wall (endothelial dysfunction or damage), blood constituents (abnormal levels of haemostatic ...

Heat stroke, which is also known as "sun stroke," is a medical emergency, and fatalities can occur unless it is diagnosed early and treated efficiently. Heat stroke may manifest quite suddenly, giving little time to differentiate it from extreme physical exhaustion in collapsed subjects. It is also known to lead ...

Inappropriate management of high blood pressure in acute stroke can adversely affect outcome. We examined blood pressure evaluation and antihypertensive therapy during the first week post-stroke in 40 patients at a district general hospital with no stroke unit. In the first 24 hours, median frequency of blood pressure recording was ...

BACKGROUND AND PURPOSE: Susceptibility to cerebral infarction was compared in stroke-prone spontaneously hypertensive (SHRSP), normotensive Wistar-Kyoto (WKY) rats, and F1 hybrids derived from a SHRSP/WKY cross. METHODS: The proximal left middle cerebral artery (MCA) was occluded under anesthesia and infarct volume assessed 24 hours later by magnetic resonance imaging and ...

Alterations in electrical conductivity between smooth muscle cells (SMCs) can alter the spread and effectiveness of electromechanical SMC contraction. We attempted to determine whether alterations in pressure-dependent constriction (PDC) occurring in relation to stroke development within the middle cerebral arteries (MCAs) of Wistar-Kyoto stroke-prone hypertensive rats (SHRsp) were associated with ...

Antihypertensive treatment achieves its greatest benefit in the primary prevention of stroke. Primary prevention studies show 38% fewer strokes when systolic/diastolic values are reduced by 10-12/5-6 mmHg. Secondary stroke prevention has been less investigated, but restrokes seems to be reduced with antihypertensive treatment. Secondary prevention achieves 25-30% less strokes, if ...

Stroke is a severe and prevalent syndrome for which there is a great need for treatment, including agents to block the cascade of brain injury that occurs in the hours after the onset of ischemia. Reactive oxygen species (ROS) have been implicated in this destructive process, but antioxidant enzymes such ...

The aim of this study was to determine whether the prevention of stroke with perindopril treatment in stroke-prone spontaneously hypertensive rats (SHRSP) is associated with the preservation of the myogenic properties of the cerebral arteries. After weaning at 4 weeks of age, male SHRSP were fed a Japanese-style rat diet ...

Intracerebral hemorrhage accounts for about 10% of all strokes. The diagnosis of this stroke subtype has been revolutionized by the use the computed tomography scanner. Therapeutic intervention in the form of medical and surgical management is reviewed. The critical management issues center on identifying the etiology of hemorrhage, controlling blood ...

The stroke-prone spontaneously hypertensive rat (SHRSP) is a genetically determined model of "salt-sensitive" stroke and hypertension whose full phenotypic expression is said to require a diet high in Na+ and low in K+. We tested the hypothesis that dietary Cl- determines the phenotypic expression of the SHRSP. In the SHRSP ...

OBJECTIVE: At present, non-invasive continuous monitoring of finger arterial blood pressure by the volume-clamp technique is considered the best approach to obtain reliable assessments of beat-to-beat blood pressure. However, data on the reproducibility (accuracy and precision) of prolonged recordings and of the hemodynamics derived from wave-form analysis are not available. ...

BACKGROUND AND PURPOSE: Drug treatment of high blood pressure has been shown to reduce the associated cardiovascular risk. Stroke represents the type of event more strongly linked with high blood pressure, responsible for a high rate of death or invalidity, and with the highest proportion of events that can be ...

BACKGROUND AND PURPOSE: Elevated blood pressure (BP) levels are well recognized after acute stroke and are associated with increased BP variability. The underlying mechanisms producing such changes are unclear but may include abnormalities of baroreceptor-mediated control of heart rate and vasomotor tone. Lower body negative pressure (LBNP) can be used ...

BACKGROUND AND PURPOSE: The purpose of this study was to test the hypothesis that the neuroprotective compound CP101,606 will ameliorate the increase in lactate, retard the development of cytotoxic edema, and decrease the infarct volume after ischemic stroke. METHODS: Seventeen adult cats were allocated to control (n = 7) and ...

BACKGROUND AND AIMS: Skeletal muscle ventricles (SMVs) are a potential power source for circulatory assistance. Noninvasive assessment of SMVs is desirable in long-term studies of SMV function. This study evaluated whether tissue velocity imaging (TVI) indices of function correlate with invasive measurements of output and pressure generation and examined the ...

BACKGROUND AND PURPOSE: Lowering of blood pressure can adversely affect ischemic symptoms in acute stroke. The aim of our study was to determine whether induced hypertension in stroke is safe and to examine its effects on neurological deficits in patients presenting with acute cerebral ischemia. METHODS: We retrospectively reviewed all ...

Rats, under urethan anesthesia, were exposed to a high ambient temperature (42 degrees C) to induce heatstroke and to assess the hemodynamic changes associated with heatstroke. Compared with normothermic controls, rats with heatstroke showed higher values of colonic temperature, heart rate, and plasma levels of interleukin (IL)-1 but lower values ...

A proportion of strokes are due to intracranial haemorrhage. Their characteristics and treatment are different from ischaemic stroke-surgery is often necessary and thrombolytic or anticoagulant treatment contraindicated. Most intracerebral haematomas (ICH) are hypertensive in origin. Small haematomas are treated with blood pressure control and rehabilitation. Larger ones often need surgery. ...

Early recognition of heart failure is important because early treatment reduces mortality and hospitalization rates. In screening for this disease, there is a need for a simple, safe, and cost-effective method to obtain cardiovascular variables. Therefore we developed a noninvasive impedance cardiographic method to predict the pulmonary capillary wedge pressure ...

In this article, we look at the literature concerning the relationship between blood pressure and cognitive function. If untreated, hypertension leads to stroke or cerebral infarction, and may therefore increase the risk of dementia or cognitive impairment. Patients with hypertension perform less well in some, but not all, cognitive tasks ...

Beraprost sodium is a stable analog of the vasodilator, platelet antiaggregatory eicosanoid, prostacyclin. Experiments were performed to determine whether long-term therapy with beraprost produces vascular protective effects in saline-drinking stroke-prone spontaneously hypertensive rats (SHRSPs). Oral beraprost at 30, 100, or 300 micrograms/kg/day starting at 8.4 weeks of age did not ...

The central neural mechanisms of circadian rhythm are well known in animal models but less so in humans. In this study we looked for correlations between abnormalities of circadian rhythm and the sites of stroke, with the aim of identifying the location regulating the circadian rhythm in humans. We investigated ...

We investigated the utility of home blood pressure measurements for determining the risk of stroke. We also analyzed the relationship between home blood pressure and the incidence of stroke. Home blood pressure and screening blood pressure measurements were obtained from 1,789 residents (aged 40 yr or older) of a rural ...

BACKGROUND: The mechanism by which cardiomyoplasty appears to enhance left ventricular (LV) function is not well understood. We applied the time-varying elastance model to study the effect of cardiomyoplasty on LV function, ventriculovascular coupling, and LV energetics in an acute canine model. METHODS: Right latissimus dorsi cardiomyoplasty was performed in ...

The purpose of the study was to determine the effect of transient changes in intrathoracic pressure on systemic arterial pressure by utilizing hiccups as a tool. Values of systolic and diastolic pressures before, during, and after hiccups were determined in 10 intubated preterm infants. Early-systolic hiccups decreased systolic blood pressure ...

The stroke-prone spontaneously hypertensive rat (SHR-SP) is an experimental model that has been widely used to investigate the potential preventive effects vs stroke and mortality of numerous antihypertensive agents. Among the latter, angiotensin I-converting enzyme inhibitors, angiotensin II AT1-receptor blockers and calcium antagonists have proven to be very effective. The ...

OBJECTIVE: To examine the incidences of hypertension, hypotension, and bradycardia after carotid endarterectomy (CEA) and to identify any hemodynamic variables predictive of postoperative stroke, death, or cardiac complications. METHODS: Retrospective population-based cohort study of 291 consecutive patients undergoing CEA using hospital chart review. Hemodynamic data collected from time of arrival ...

Cerebrovascular disease and high blood pressure both appear to increase the risk of vascular dementia. PROGRESS aims to investigate whether blood pressure lowering with an angiotensin coverting enzyme inhibitor-based regimen will reduce the risk of cognitive impairment in patients with a history of stroke or transient ischaemic attack. A total ...

In clinical stroke cardiovascular abnormalities are frequently neglected although they occur more often than it is generally assumed. However, cardiac arrhythmias, pathological ECG findings, and changes of circadian blood pressure patterns are significantly increased in patients with acute cerebrovascular lesions and are associated with an increased mortality. Several clinical studies ...

Dynamic exercise increases the transcranial Doppler determined mean blood velocity in basal cerebral arteries corresponding to the cortical representation of the active limb(s) and independent of the concomitant rise in the mean arterial pressure. In 12 rowers we evaluated the middle cerebral artery blood velocity response to ergometer rowing when ...

This study attempts to explain the unexpected finding of an inverse population (ecological) relationship between mean systolic blood pressure levels and stroke death rates in 25 years follow-up of the Seven Countries Study, a cross-cultural study of cardiovascular disease. Sixteen cohorts of all men aged 40-59 in seven countries (one ...

To investigate whether the lack of nocturnal decline of blood pressure (nondipper) is a primary cause of stroke or a secondary abnormality due to stoke, we examined the relation between the blood pressure variation and parental history of stroke in 110 hypertensive patients. In nondippers (n = 54), the frequency ...

We have used an oesophageal Doppler to measure aortic blood flow velocity before, during and after induction of carbon dioxide pneumoperitoneum in 10 consecutive patients, mean age 58 yr, undergoing laparoscopic hernia repair. Derived values for stroke distance, minute distance and systemic vascular resistance showed considerable interpatient variation indicating unpredictable ...

OBJECTIVE: To examine the usefulness of preload indices obtained by transoesophageal echocardiography (TOE) for estimating stroke volume at various levels of cardiac index. DESIGN: Prospective clinical study. SETTING: Intensive care unit with surgical patients. PATIENTS: 16 ventilated patients monitored via Swan-Ganz catheterization and TOE. INTERVENTIONS: Echocardiographic images of left ventricular ...

OBJECTIVE: To examine the risk of stroke in relation to quality of hypertension control in routine general practice across an entire health district. DESIGN: Population based matched case-control study. SETTING: East Lancashire Health District with a participating population of 388,821 aged < or = 80. SUBJECTS: Cases were patients under ...

Stroke-prone spontaneously hypertensive rats (SHRSP) are liable to suffer a stroke between 25 and 40 weeks of age. Left ventricular capillarity was studied in 40-week-old SHRSP to clarify the effects of hypertrophic changes in cardiomyocytes on oxygen transport capacity within the tissue. The innermost region of the left ventricular subendocardium ...

After 48-h ambulatory blood pressure monitoring, the incidence of ischaemic stroke, nephropathy, coronary heart disease and retinopathy was prospectively assessed for 6 years in 297 subjects, including 176 treated patients with an elevated blood pressure mean (MESOR-hypertensives). The relative risk associated with an excessive circadian blood pressure amplitude is 8.2 ...

PURPOSE: A 28-year-old hypertensive professional football player suffered a lacunar stroke. Given the rarity of stroke at this young age, the contributory roles of hypertension and competitive athletics merit consideration. CASE SUMMARY: A 28-year-old defensive lineman, with long-standing, albeit recently well-controlled hypertension, experienced slurred speech and veering to his right ...

BACKGROUND: Both the 21-aminosteroid U74006F, a potent inhibitor of lipid peroxidation, and L644-711, an anion channel blocker that inhibits both neutrophil and astrocyte function, have been previously shown to reduce brain injury in pretreatment paradigms of cerebral ischemia. It was therefore of interest to examine the effect of these agents ...

The release of cytokines during cardiopulmonary bypass (CPB) may contribute to haemodynamic alternations encountered after open heart surgery. Regulatory mechanisms exist and include soluble cytokine receptors. We have measured blood levels of tumour necrosis factor (TNF) and its soluble receptor (TNFsr) during and after open heart surgery in children. Correlation ...

BACKGROUND: Despite concern that hypertension increases the risk for intracranial hemorrhage during thrombolysis for acute myocardial infarction, the exact nature of the risk remains unclear. OBJECTIVE: To assess the effects of previous hypertension and blood pressure at study entry on the outcomes of patients who had acute myocardial infarction and ...

A 67-year-old adult male with borderline hypertension who had extracapsular cataract extraction under general anaesthesia is reported. There were marked fluctuations in his arterial blood pressure following induction of anaesthesia and during the recovery period. He developed a stroke in the immediate postoperative period but was fully recovered after 3 ...

OBJECTIVE: To determine the effect of perindopril treatment and treatment withdrawal in the prevention of stroke in male stroke-prone spontaneously hypertensive rats (SPSHR). DESIGN: After weaning at 4 weeks of age, male SPSHR were given a Japanese-style rat diet which induces stroke in these animals. Beginning at 6 weeks of ...

RELATIONSHIP BETWEEN BLOOD PRESSURE AND STROKE: Data from prospective observational studies indicate that usual levels of blood pressure are directly and continuously related to the risk of initial stroke. A prolonged difference in usual blood pressure levels of just 9/5 mmHg is associated with approximately a one-third difference in stroke ...