Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The norepinephrine (NE) concentration of cardiac ventricles was determined by radioenzymatic assay in normotensive Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and stroke-prone rats (SPR) at 3-6, 14-19, and over 31 weeks of age. There was no difference between strains prior to hypertension, but a progressive decrease in cardiac NE concentration occurred in SHR and particularly in SPR relative to WKY after hypertension was established. This decrease was not due to cardiac hypertrophy. The cardiac neuronal NE storage capacity in rats over 31 weeks of age was analyzed by determining the maximum concentration of NE obtained in a cardiac microsomal fraction, after saturation in vivo with exogenous NE. The results indicated that, after a long period of hypertension, there was a reduction in cardiac NE storage capacity resulting from a loss either of sympathetic nerve endings or of storage vesicles. Moreover, in addition to this reduction in the total size of the cardiac NE store, there was an independent reduction in the degree of filling of this store in both SHR and SPR. This could reflect an increased turnover of cardiac NE in chronically hypertensive SHR and SPR.
 ...
PMID:Changes in cardiac norepinephrine in spontaneously hypertensive and stroke-prone rats. 9 73

We investigated the role of arginine-vasopressin (AVP) in maintaining the blood pressure of spontaneously hypertensive (SH) rats (stroke-prone strain) with established hypertension (22--28 weeks of age). In comparison with normotensive Wistar Kyoto (WKY) rats, plasma AVP concentrations of SH rats with benign hypertension (BH) were elevated twofold and in rats with severe or malignant hypertension (S-MH), fourfold. The height of the blood pressure was quantitatively related to plasma AVP in both BH and S-MH rats, the overall correlation coefficient being 0.66 (p less than 0.001). The intravenous injection of a specific AVP antiserum into conscious and unrestrained rats lowered blood pressure in 4 BH rats by 48 +/- 14 mm Hg and in 4 S-MH rats by 78 +/- 10 mm Hg and had only a marginal effect in 4 normotensive WKY rats. Infusion of saralasin did not lower blood pressure in WKY and BH rats and reduced blood pressure in only 2 of 7 S-MH rats tetsted (by 15 and 20 mm Hg). During AVP infusion the blood pressure of SH rats increased more (p less than 0.001) and heart rate fell much less (p less than 0.001) than in WKY rats. It is concluded that in SH rats with established hypertension, plasma AVP plays an important role in the maintenance of high blood pressure, while the renin-angiotensin system plays a minor or no role.
 ...
PMID:Studies on the role of vasopressin in blood pressure control of spontaneously hypertensive rats with established hypertension (SHR, stroke-prone strain). 9 26

The use of vasodilators represents a new approach in the treatment of heart failure. These drugs have the property of causing vasodilatation of either arterial or venous predominance or balanced between these two vascular beds. Arterio-dilators (phentolamine, hydralazine) increase stroke volume and cardiac output by decreasing ventricular afterload. Veno-dilators (nitroglycerine) have little effect on cardiac output but decrease ventricular filling pressure, thereby relieving pulmonary venous hypertension. Mixed vasodilators (Sodium nitroprussideate, trimetaphan) combine these two groups of properties in various degrees. The majority of these drugs can only be administered intravenously, with careful haemodynamic surveillance.
 ...
PMID:[The treatment of congestive heart failure by using vasodilators. I. Physiological basis. Different vasodilators (author's transl)]. 9 22

Cardiovascular accidents are the commonest cause of death in patients on intermittent haemodialysis. Our study concerns 158 adult patients in terminal renal failure who were treated by periodic dialysis; it was carried out at Necker Hospital between January 1967 and December 1970. Between these dates, 35 patients died, 17 of the deaths being due to unequivocal or probable cardiovascular complications. The diagnosis of cerebrovascular accident was made in 13 cases. The mean age of the patients who died was 38 years. Fatal cerebrovascular accidents occurred especially during the first 12 to 24 months of treatment. The incidence of fatal vascular accidents is greatest in patients who were hypertensive at the beginning of periodic dialysis, and who remained so after six months of dialysis. Our study has therefore shown that hypertension in patients on chronic haemodialysis is a major vascular risk factors; other risk factors, especially metabolic ones, may also play a part.
 ...
PMID:[Arterial hypertension and mortality due to cardiovascular complications in patients on chronic hemodialysis]. 10 Nov 77

A seven-year follow-up in 1973 of a prospective cardiovascular study of 1820 initially, healthy, middle-aged Chinese men of 40-59 years of age identified 1745 (95.9%) known survivors, 49 (2.7%) interim deaths, and 26 (1.4) who could not be traced. Of the survivors, 1462 (83.8%) were re-examined, 292 (16.7%) had another treadmill test of maximal exercise, and 283 (16.2%) failed to return for re-examination. On the basis of interim surveillance of hospital admissions, questionnaires and re-examination, a greater incidence of noncardiovascular events (338 or 18.6%) than evidence of cardiovascular disease (220 or 12.1%) was found while the majority (1021 or 56.1%) remained healthy. Total mortality was 0.29 for men under 50 and 0.76 per 100 person-years for men of 50 or more years of age. Only nine, or 18.4% of the deaths were due to cardiovascular causes, and unexpectedly for this population sample, only three were attributed to stroke. When cardiovascular morbidity was related to presence of ST depression after maximal exercise, to hypertension at rest by WHO criteria, to both findings, or to absence of either on initial intake examination, incidence increased from 2.3% for NEITHER group, to 5.7% for ST group, to 11.9% for HT group, and to 25.0% for BOTH groups. Re-examination revealed more evidence of cardiovascular disease than did surveillance of hospital admissions. Additional to effects of aging and mild adiposity, longitudinal changes in blood pressure and ST depression, increasing in the NEITHER group, but less frequent in the other groups, showed some evidence of regression toward the mean, as well as emerging disease and the confounding effects of uncontrolled treatment of hypertension in many. The potential for prediction of subsequent cardiovascular morbidity or mortality appeared stronger for hypertension than for postexertional ST depression, although the two were additive in this population, which is more prone to hypertension and stroke but now is developing clinical manifestations of coronary heart disease more frequently.
 ...
PMID:Seven-year follow-up of cardiovascular study and maximal exercise of Chinese men. 12 87

Abdominal aortic aneurysmectomy is being performed with progressively lower operative mortality and morbidity. Three hundred thirty seven patients have had elective aneurysm repair since 1954. Factors affecting mortality and morbidity in the last 108 cases are analyzed. Seventy-four per cent of patients had pre-existing disease, either cardiac, pulmonary, renal, cerebrovascular, diabetes mellitus, or hypertension. Six patients died following operation, a mortality rate of 5.5%. One died of pulmonary and 5 of cardiac causes. No patient died of renal failure or required dialysis. A signficant feature of management is the regimen of fluid therapy using dextrose in lactated Ringer's solution during and after operation to minimize hypotensive and renal complications. No patient developed a wound infection, graft infection, wound dehiscence, stroke, or intestinal ischemia. Serious postoperative complications were largely cardiac or pulmonary. Despite recent liberalization of indications for operation, comparative figures show continued reduction in operative mortality from 17% during 1954-1961, or 7.4% during 1962-1967, to 5.5% in the 1968-1974 era. This declining mortality is related to earlier diagnosis using non-invasive methods (sonogram), simplified operative techniques, improvement in fluid management, innovations in cardiopulmonary therapy, and recognition and proper handling of unusual manifestations of aortic aneurysms.
 ...
PMID:Surgical management of abdominal aortic aneurysms: factors influencing mortality and morbidity--a 20-year experience. 12 60

Factors which are known to be associated with cerebral atherosclerosis were evaluated in Nigerian Africans. Of 465 autopsied adult Nigerians, 62 (13%) had cerebral atherosclerosis. The frequency and severity of atherosclerosis among Nigerians with hypertension, particularly male subjects, were higher than in normotensives. Although there was a similar frequency of hypertension among autopsied Nigerian and Minnesota Caucasian populations, the severity and extent of atherosclerosis were greater in the Minnesota Caucasian populations, the severity and extent of atherosclerosis were greater in the Minnesota population. The relatively short duration of hypertension in the Nigerian before death might be an important factor which did not permit progressive development of cerebral atherosclerosis. Other factors which predisposed the Nigerian to increased frequency and severity of atherosclerosis included increased heart weight and diabetes mellitus. The relatively low frequency of cerebrovascular disease in the Nigerian may be explained on the basis of a low degree of cerebral atherosclerosis and relatively short duration of hypertension.
Stroke
PMID:Cerebral atherosclerosis and its relationship to selected diseases in Nigerians: a pathological study. 12 75

The Frank-Starling relationship of hearts from adult spontaneously hypertensive rats (SHR, Okamoto 1969), representing the established phase of hypertension, and of young SHR, representing the initial phase of hypertension, was investigated by using the isolated working heart preparation. In the "normal" diastolic pressure range (5 to 10 cm H2O), the left ventricle of both SHR groups displayed significantly reduced stroke volumes compared with hearts of normotensive controls (NCR); the degree of reduction being proportional to the left ventricular hypertrophy. This is suggested to be due to a reduced left ventricular diastolic compliance in SHR, as indicated by direct measurements of ventricular wall thickness and end-diastolic volumes in arrested hearts exposed to different end-diastolic filling pressures. Such a progressive shift of the Frank-Starling relationship to the right with duration of hypertension could, in combination with the gradual development of "structural autoregulation" of the precapillary resistance vessels, constitute dominating factors in shifting the hemodynamic situation in labile hypertension into that characterizing the established, or "fixed", state of hypertension.
 ...
PMID:Consequences of myocardial structural adaptation on left ventricular compliance and the Frank-Starling relationship in spontaneously hypertensive rats. 12 25

Ultrasoundcardiograms (UCG) and radiocardiograms (RCG) were obtained from 50 patients with essential hypertension. They were classified into four groups according to the severity index of Veterans Administration Hospital. These echocardiograms were compared with those obtained from 20 normal individuals. Of the 50 patients with hypertension, ten had abnormal patterns of mitral valve echogram: two had shoulder formation of the A wave (A-A'), three had increased amplitude of the A wave (A greater than E), and five had systolic anterior movement (SAM) of the anterior mitral leaflet toward the ventricular septum. The former two groups were considered to have impairment of left ventricular (LV) function proven by UCG and RCG, however, the SAM group was considered to have hyperfunction with concentric hypertrophy of the left ventricle with thickened ventricular septum simulating that of idiopathic hypertrophic subaortic stenosis (IHSS). This was supported by the fact that SAM increased after inhalation of amyl nitrite and decreased after injection of propranolol. The descent rate of the anterior mitral valve decreased and the thickness of the ventricular septum increased with the severity of hypertension, indicating the LV compliance decreases as the severity of hypertension advances. A significant positive correlation was noted between stroke index (SI) obtained by UCG and RCG. There were no significant differences of LV dimensions and function indices measured by UCG and RCG among the groups classified according to the severity index of hypertension. This suggests that such factors as myocardial ischemia might play an important role in LV function as well as the grade of afterload due to hypertension.
 ...
PMID:Echocardiographic observations in hypertension. 12 50

In almost all of the cases of cardiac hypertrophy due to sustained hypertension, left ventricular capacity is increased in proportion to increased left ventricular weight, even in the absence of manifest cardiac insufficiency. The condition is regarded as the general expression of cardiac response to pressure load, and the concept of "isomorphic hypertrophy" is proposed. Concentric hypertrophy of the current concept is observed only on rare special occasions, and its role in cardiac adaptation to pressure load is obscure. The increase in myocardial mass is sufficient to maintain the work done by a unit myocardial volume at a normal level. However, the calculation on pertinent models demonstrates that hypertrophied hearts of any type expel the normal stroke volume with smaller shortening of muscle fibers under larger stress, which is further elevated with the progress of cardiac contraction. Because the maximum force generated by muscle fibers declines with advancing cardiac contraction, hypertrophied hearts harbor a latent risk of mechanical insufficiency. Even under pressure load, ventricular dilation seems to precede the re-inforcement of ventricular wall in the development of cardiac hypertrophy. A common mechanism may be therefore assumed underlying the development and performance of all types of hypertrophied hearts, regardless of the difference in the character of physical loads.
 ...
PMID:Quantitative analysis of cardiac hypertrophy due to pressure load in reference to the relations of blood pressure, left ventricular weight and left ventricular capacity. 13 18


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>