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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comparison was made of the mortality rates for various surgical operations, by age groups and by time periods. The age groups were: under 60, 60-69, 70-79, and 80 or over. The three time periods were: 1951-1955, 1956-1967, and 1967-1977. Only slight improvement was noted in these mortality rates despite the fact that during the 1951-1977 period many improvements were made in anesthesia, surgical techniques, antibiotic therapy, intensive-care units, and presumably the better understanding of disease. Further improvements will depend almost exclusively upon studying the basic problems of old age, chiefly atherosclerosis with its effects on the heart, blood vessels, brain, respiratory system and urinary tract. Unless this is done, there is no prospect of great improvement in operative results, and no basis for believing that the operative risk in the aged is the same as in the young. Unless the physiologic reserves of the aged can be improved, the surgical mortality rates likely will remain static.
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PMID:Comparison of mortality rates for various surgical operations according to age groups, 1951-1977. 46 43

Of 65 patients with neurological disorders examined with rapid serial angiography of the carotid artery, 24 had normal cerebral arteries, 17 atherosclerosis, 11 arterial ectasia and 13 both kinds of vascular changes. These patients were examined for hemispherical rCBF determination on the same occasion, using the 133Xenon clearance method. Primarily, the patients were examined without general anaesthesia, and they did not have acute illness, trauma, or angiographic evidence of a focal intracranial lesion. In addition, other parameters such as arterial size, ventricular size, cerebral circulation time, age, and sex were determined. All these data were studied statistically in a series of multiple regression analyses with a computer. No significant differences in rCBF could be found between cases with ectasia, atherosclerosis and without any kind of vascular changes. However, the mean value of rCBF in patients with atherosclerosis and in patients with intracranial ectasia was below the normal mean value, although it did not differ significantly from this value. Nor was any influence on the rCBF found in patients with marked stenosis of the internal carotid artery and those with slight stenosis.
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PMID:The influence of atherosclerosis and ectasia on cerebral blood flow. 93 71

Angioplasty of the profunda femoris should be the primary approach to revascularization of the limb whenever it is feasible. Claudication distance can be significantly improved in almost all patients and prolonged limb salvage achieved in the majority of patients. In some high risk patients, the entire procedure can be accomplished expeditiously and atraumatically under local anesthesia, using a single groin incision. When the pattern of distribution of atherosclerosis provides the surgeon with the choice of performing either angioplasty of the profunda femoris or femoral popliteal bypass, the former option should be tried initially with resort to the latter if ischemia is not adequately relieved. In many instances when distal bypass is not possible or is unlikely to function effectively, angioplasty of the profunda femoris may provide the only opportunity to relieve ischemic symptoms. Operative blood flow measurements support the thesis that the collateral function of the profunda femoris artery is able to compensate for extensive obstructive disease in both the superficial femoral and popliteal segments.
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PMID:The role of angioplasty of the profunda femoris artery in revascularization of the ischemic limb. 93 26

49 cases of myocardial infarction during pregnancy are reviewed from the literature, considering the frequency, pathogenesis, clinical findings, prognosis, treatment, obstetrical conduct including whether abortion is indicated, and finally 17 cases of pregnancy in women with previous heart attacks are summarized. A myocardial infarction is rare, about .01-.075%, more frequent in late pregnancy or the postpartum, and in older women. This series averaged 32.9 years. 88% were due to atherosclerosis. Other risk factors were usually not reported systematically. 56% of the incidents were the 1st heart attack; 44% were preceded by angina; 68% were anterior. Pregnancy affects the EKG and white blood count, but serum enzymes are the same as in nonpregnant women. 29% of these women died, 23 went to term, and 7 gave birth prematurely. 13 labors were spontaneous, 7 required forceps, and 10 were Caesarean births. Fetal loss was 27%. Treatment is the same as that in any heart attack patient, except for lignocaine and use of anticoagulants. Abortion is only necessary in cardiac insufficiency. Delivery should probably involve forceps, epidural anesthesia, and anticoagulatns immediately after delivery, but oxytocin should be avoided. The 17 cases of pregnancy after a heart attack resulted in 1 abortion, 15 term deliveries, 3 new infarctions, and 1 death due to antoher heart attack at term.
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PMID:[Myocardial infarct and pregnancy]. 103 53

Effects of atherosclerosis on the mean value and daily variation of arterial pressure were studied in 12 Watanabe-heritable hyperlipidemic (WHHL) rabbits aged 12 to 35 months and 25 normal Japanese white rabbits aged 6 to 30 months. A pressure catheter was inserted through the left subclavian artery under pentobarbital anesthesia. A few days after the catheterization, the mean arterial pressure (MAP) of the rabbits, which were active and in a good state of appetite, was recorded by an analogue-to-digital converter every second for about 6 hrs and stored in a computer. The mean (M) and standard deviation (SD) in the WHHL rabbit, calculated from each successive MAP record, ranged widely from 85.8 to 131.4 mmHg and 5.6 to 12.6 mmHg, respectively. There was no significant correlation between M and SD in the WHHL rabbit. M and variance (V) of MAP in the WHHL rabbit were significantly higher than those in the normal rabbit. M did not show any significant change with increasing ages, whereas SD increased significantly with aging in the WHHL rabbit. Concentrations of serum total cholesterol and triglyceride in the WHHL rabbit were 475 and 328 mg/dl, which were about nine and seven times as high as those in the normal rabbit, respectively. Macroscopic and histopathological examinations of the aorta revealed development and spread of sclerotic lesions with aging in the WHHL rabbit. We can conclude that development of atherosclerosis with aging in the WHHL rabbit causes malfunction of the baroreceptors, which contributes to hypertension and lability of arterial pressure.
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PMID:Effects of atherosclerosis on mean and daily variation of arterial pressure in conscious WHHL rabbits. 139 Nov 77

Arterial platelet adhesion is an initiating event in the thrombo-embolic complications of atherosclerosis and may also accelerate the development rate of atherosclerotic lesions. Psychosocial stress has been shown to accelerate atherogenesis in animals, an effect probably mediated via beta-adrenoceptor activation. In view of the postulated roles of platelets and beta-adrenoceptor activation in atherosclerosis development, we decided to test whether beta blockade affects arterial platelet accumulation. We studied the accumulation of radioactivity from 111In-labelled platelets on the wall of the thoracic aorta of rabbits as a measure of platelet accumulation. During the exposure to the labelled platelets, the animals were also exposed to 3 hours of chloralose anesthesia. This is a reproducible model of experimental sympathetic activation, including beta-adrenoceptor activation, which we used to amplify possible effects of beta-blockade on platelet-vessel wall interaction. The effectiveness of the anesthesia in increasing sympathetic activity was verified by significant rises in mean arterial blood pressure (from 77 to 88 mmHg), heart rate (190 to 290 bpm), and plasma levels of norepinephrine (1.0 to 3.3 nM) and epinephrine (0.13 to 0.83 nM). In chloralose anesthetized rabbits, approximately 30 x 10(-9)% of the injected 111In accumulated in each square millimeter of intima at unbranched thoracic aorta. Platelet accumulation was significantly higher at arterial branching points, 70% higher at intercostal artery bifurcations, and 150% higher at coronary artery bifurcations than in unbranched aortic intima. Pretreatment with metoprolol in a dose resulting in "therapeutic" plasma levels significantly reduced platelet accumulation by 48% in unbranched aorta, 65% at intercostal, and 53% at coronary artery bifurcations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibition of platelet accumulation by beta 1-adrenoceptor blockade in the thoracic aorta of rabbits subjected to experimental sympathetic activation. 145 95

Normal New Zealand and Watanabe heritable hyperlipidemic (WHHL) rabbits, about 24 months old, were prepared, under anaesthesia, for recording blood pressure and hindlimb blood flow. Changes in hindlimb vascular resistance were measured after local intra-arterial bolus injection of increasing doses of acetylcholine, bradykinin, serotonin, sodium nitroprusside and phenylephrine. In WHHL rabbits basal hindlimb blood flow was reduced (from 22.6 +/- 3.0 to 12.5 +/- 1.8 ml/min; P less than 0.05) and hindlimb vascular resistance was increased (from 4.6 +/- 0.5 to 8.2 +/- 1.5 mmHg/ml per min; P less than 0.05). No difference was observed in response to acetylcholine, serotonin, sodium nitroprusside and phenylephrine. The only marked alteration found in WHHL rabbits was a clear deficit to bradykinin stimulation. Morphological analysis, using scanning and transmission electron microscopy, indicated a clear damage of the femoral artery, like the presence of atherosclerotic plaques, and an abnormal distribution of patent microvessels in the WHHL muscles of the leg. Peripheral circulation in WHHL rabbits shows some peculiar features, like increased basal vascular resistance and a selective impairment of bradykinin responses. Together with these abnormalities, it seems that responses to various other dilating or contracting agents are normal, suggesting that in this interesting animal model of atherosclerosis the alterations are more specific than in other models.
Atherosclerosis 1992 Mar
PMID:Functional responses of hindlimb circulation in aged normal and WHHL rabbits. 159 96

The normal control of coronary blood flow is through alterations in the resistance of the intramyocardial arterioles (R2). Myocardial cellular hypoxia causes increased breakdown of ATP (or decreases synthesis) resulting in increased concentrations of the purine metabolite, adenosine. This potent endogenous, vascular smooth muscle relaxant vasodilates the R2 arterioles increasing coronary blood flow and myocardial O2 delivery. This mechanism autoregulates coronary blood flow according to myocardial O2 needs. Myocardial hypertrophy (from chronic hypertension) or coronary atherosclerosis interfere with this process and result in myocardial ischemia which may cause symptoms (angina), signs (ECG changes, regional muscle dysfunction) or tissue death (myocardial infarction). In addition, coronary atheroma disrupt endothelial function in the large R1 coronary arteries predisposing to vasoconstriction, platelet aggregation and thrombosis. Therapeutic measures for controlling ischemia may include decreasing oxygen demand (especially heart rate) and maintaining supply (R1 vasodilators and anti-thrombotic drugs such as non-steroidal anti-inflammatories). Intravenous, most inhalational and regional anesthesia appear to interfere minimally in the control of both the normal and ischemic coronary circulation. Thus optimizing myocardial oxygen balance (maintaining supply and decreasing demand) during anesthesia protects the ischemic myocardium. High doses of isoflurane, sevoflurane or desflurane are potent R2 coronary vasodilators which may cause redistribution of collateral blood flow away from ischemic regions (coronary steal). However, if tachycardia and hypotension are avoided, such an effect has not been shown experimentally or clinically. Preliminary evidence suggests that halothane may preferentially dilate R1 arteries and/or interfere with platelet aggregation. If these effects are confirmed, then halothane may prove to be the anesthetic of choice in the non-failing ischemic heart.
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PMID:Physiology, pathophysiology and pharmacology of the coronary circulation with particular emphasis on anesthetics. 164 43

Intra-arterial infusions used in treatment of ischemia of lower extremities in patients with obliterating atherosclerosis can cause pronounced vasoconstrictory reactions in distal parts of the extremity with reduced pulse blood filling and oxygenation of tissues. As necessary measures of prophylactics of negative shifts in regional blood circulation the author suggests to be valuable anesthesia and atraumatic character of interventions, use of warm solutions, exclusion of irritating drugs and osmotically active substances. The final efficiency of intra-arterial infusions is dependent on the observation of the above conditions.
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PMID:[An evaluation of the results of intra-arterial injections in treating chronic ischemia of the lower extremities]. 166 30

Clinical and epidemiological investigations provide evidence that psychosocial factors influence the development of coronary heart disease and underlying atherosclerosis, an association that appears to be independent of the effects of other coronary disease risk factors. It has been hypothesized that sympathoadrenal medullary activation mediates behavioral influences on coronary disease, perhaps by potentiation of atherogenesis. This article summarizes four recent studies of the effects of psychosocial stress and sympathetic arousal on atherogenesis in cynomolgus monkeys (Macaca fascicularis) and rabbits. It is reported that socially dominant male monkeys, when fed an atherogenic diet and subjected to periodic social disruption, developed markedly worsened coronary atherosclerosis in comparison with subordinate monkeys; this effect may have been sympathetically mediated, as it was inhibited in similarly aggressive monkeys treated with a beta-adrenergic blocking agent. Studies using chow-fed rabbits demonstrated that exposure to chloralose anesthesia (an agent that provokes profound sympathetic activation) induced endothelial injury (indicated by intracellular accumulation of immunoglobulin G in the aortic endothelium) and abnormal (increased) platelet accumulation. The further observation that these effects were inhibited under beta-adrenoceptor blockade implicates sympathoadrenomedullary arousal in the initiation of atherogenesis. Additionally, sympathetically mediated endothelial damage and increased platelet accumulation occurred preferentially at circumostial sites in the rabbits, a finding consistent with the hypothesis that the hemodynamic concomitants of sympathetic activation contribute to atherogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of sympathoadrenal medullary activation in the initiation and progression of atherosclerosis. 168 7


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