Collateral growth and coronary angiogenesis are chronic adaptations to myocardial ischemia. Collateralization helps to restore blood flow and as a result salvages myocardium in severely ischemic myocardial regions. Thus, good collateral development in patients with severe coronary artery disease (CAD) improves ventricular function and prognosis (1-3).. However, coronary collateral development is different among patients even with similar degrees of coronary artery stenosis. Several factors, such as diabetes mellitus (4) and duration of myocardial ischemic symptoms (5) have been reported to effect coronary collateral development. At the cellular level, inflammatory cells, especially monocytes have an important role in collateralization. In a series of experimental studies with animals, it has been shown that monocytes are important elements for development of collateral vessels (6-7). In a recent study, it has been demonstrated that increased circulating monocyte count is related to good ...
The effect of chronic coronary arterial narrowing on the coronary collateral circulation has been studied in rested and exercised dogs. The data indicate that moderate and severe arterial narrowing results in extensive collateral development proportional to the degree of narrowing, further that exercise leads to even greater anastomoses. The results also show that while mild arterial narlowing fails to initiate collateral growth by itself, the addition of exercise promotes an effective collateral circulation. An attempt is made to define the gross factors in the development of collateral vessels and to correlate them with the concept that exercise may play a beneficial role in building collateral vessels in patients with coronary disease.. ...
AbstractBackground:Well-developed coronary collateral circulation usually results in fewer infarct size, improved cardiac function, and fewer mortality. Traditional coronary risk factors (diabetes, hypertension, and smoking) have some effects on coronary collateral circulation. However, the associat
The possibility that variation in the extent of native collateral circulation is an important determinant of variation in ischemic injury when acute arterial occlusion occurs or disease becomes manifest has historically been overlooked or minimized-, with the exception of those who study or treat acute ischemic stroke7-14 (and references therein), some coronary investigators4-6,69 (and references therein), and among vascular surgeons who frequently encounter or perform arterial occlusions.70,71 This presumably extends, in part, from the small diameter typical of native collaterals in most healthy individuals that is beyond the resolution of digital angiography (,0.2 mm), from the misconception that such minute vessels cannot mediate significant flow in the acute setting until remodeling has occurred, and from the inability to experimentally change native collateral extent to test its importance. The latter restriction has begun to yield in recent studies in which collateral extent was found to ...
Since the first description of the coronary collateral circulation in 1958,15 extensive investigations have been performed to elucidate the mechanisms that stimulate coronary collateral growth. Buschmann and colleagues16 were able to show a significant increase in collateral formation after 7 weeks of intermittent external counterpulsation in 23 patients with stable CAD in comparison with an inactive control group. An increase of collateral blood flow was detected by Zbinden in a nonrandomized clinical trial in 40 patients10 following regular physical exercise, performed 3 times a week over 3 months. However, PCI of the diseased vessel was performed before exercise training was initiated, which eliminated any possible ischemic trigger of collateral formation.. The underlying mechanism for increasing collateral blood flow has been the center of considerable debate.17 There are 2 distinct mechanisms that can be activated in the presence of ischemia caused by a flow-limiting lesion in an epicardial ...
Collateral circulation affects the prognosis of patients with acute ischemic stroke (AIS) treated by thrombolysis. The present study performed a systematic assessment of the impact of the collateral circulation status on the outcomes of patients receiving thrombolysis treatment. Relevant full‑text articles from the Cochrane Library, Ovid, Medline, Embase and PubMed databases published from January 1, 2000 to November 1, 2016 were retrieved. The quality of the studies was assessed and data were extracted by 2 independent investigators. The random‑effects model was used to estimate the impact of good vs. poor collateral circulation, as well as baseline characteristics, on the outcome within the series presented as risk ratios. Subgroup analyses explored the potential factors that may interfere with the effects of the collateral circulation status on the outcome. A total of 29 studies comprising 4,053 patients were included in the present meta‑analysis. A good collateral circulation status ...
The assessment of adequate ulnar collateral supply to the hand is mandatory prior to the harvest of the radial artery as a conduit for coronary artery bypass grafting. However, there is currently no one test which is widely used in all centres. We report a new and objective method of assessing ulnar collateral supply to the hand prior to harvest of the radial artery. This technique involves assessing the presence of a hyperaemic flow response to occlusion of the radial artery using an intraoperative transit time flowmeter. We found this technique to be objective and reliable, and would advocate its use in patients with a positive Allens test ...
It is well known that the protective capacity of the collateral circulation falls short in many individuals with ischemic disease of the heart, brain, and lower extremities. In the past 15 years, opportunities created by molecular and genetic tools, together with disappointing outcomes in many angiogenic trials, have led to a significant increase in the number of studies that focus on: understanding the basic biology of the collateral circulation; identifying the mechanisms that limit the collateral circulations capacity in many individuals; devising methods to measure collateral extent, which has been found to vary widely among individuals; and developing treatments to increase collateral blood flow in obstructive disease. Unfortunately, accompanying this increase in reports has been a proliferation of vague terms used to describe the disposition and behavior of this unique circulation, as well as the increasing misuse of well-ensconced ones by new (and old) students of collateral circulation. ...
Besides severity of coronary obstruction [37, 38], numerous factors that could possibly attenuate the development and biological function of coronary collaterals have been reported such as old age [39], traditional risk factors for coronary artery disease [40-44], hyperlipoprotein (a) [45], hyperuricemia [46] and elevated serum levels of CRP [47], TNF-a [48], N-terminal pro-brain natriuretic peptide [38] and mimecan [49], and high neutrophil/lymphocyte ratio [50]. In contrast, higher plasma levels of MCP-1 [51] or apelin [52] were associated with better coronary collateral development. The presence and extent of spontaneously visible coronary collaterals was also affected by plasma chemokine concentrations, as higher collateralization was associated with increased concentration of the angiogenic ligand and decreased concentrations of angiostatic ligands, and interferon-c [53]. It is known that diabetes mellitus aggressively induces atherosclerosis and may be more susceptible to myocardial ...
METHODS AND RESULTS We studied the effect of VEGF on collateral blood flow in dogs subjected to gradual occlusion of the left circumflex coronary artery (LCx). Beginning 10 days after placement of an LCx-constricting device, VEGF 45 micrograms (n = 9) or saline (n = 12) was administered daily via an indwelling catheter in the distal LCx, at a point just beyond the occlusion. Treatment was maintained for 28 days. Collateral blood flow was determined with microspheres 7 days before treatment, immediately before treatment (day 0), and 7, 14, 21, and 28 days into the treatment period. Collateral blood flow was quantified during chromonar-induced maximal vasodilation and expressed as a collateral zone/normal zone (CZ/NZ) ratio. Treatment with VEGF was associated with a 40% increase in collateral blood flow (final CZ/NZ blood flow ratios of 0.49 +/- 0.06 and 0.35 +/- 0.02 in the VEGF-treated and control groups, respectively, P = .0037) as well as an 89% increase in the numerical density of ...
Influence of coronary artery stenosis severity and coronary collateralization on extent of chronic myocardial scar: insights from quantitative coronary angiography and delayed-enhancement MRI.. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Looking for Collateral circulation coronary artery? Find out information about Collateral circulation coronary artery. The circulation established for an organ or a part of an organ through the intercommunication of blood vessels when the original direct blood supply is... Explanation of Collateral circulation coronary artery
Coronary heart disease (CHD) is a major health concern for Americans and people worldwide. Arteriogenesis, an adaptive remodeling process in which pre-existing collateral arterioles remodel to form large diameter conductance arteries, has received recent attention for its therapeutic potential in treating CHD, but the mechanisms regulating the process remain incompletely understood. In particular, little is known about how collateral flow, and the resulting effect of shear stress acting along the collateral vessel wall, regulates coronary collateralization. This Thesis combines a series of experimental systems to define the responses evoked in endothelial cells exposed to hemodynamic waveforms characteristic of coronary collateral vessels and the subsequent paracrine effects on smooth muscle cells. Initially, a lumped parameter model of the human coronary collateral circulation was used to simulate normal (NCC) and adaptive remodeling (ACC) coronary collateral shear stress waveforms. These ...
Further analysis of the IMS-III cohort of patients show that collateral status influence outcomes and those with intermediate collaterals seem to benefit the most from endovascular therapy. With the ESCAPE trial, collateral status was used as an inclusion criteria (patients with poor collaterals being excluded from the trial) and outcomes improved significantly in the endovascular group vs the IV tPA group. MR-CLEAN which was a study that did not use collateral status as an inclusion criteria did not have as significant overall good outcomes as the other published endovascular trials. Possibly because they included patients with poor collaterals, who dont benefit from either endovascular or IV tPA treatments as the infarct grows too rapidly for recanalization to have an effect. Had IMS-III recruited patients based on collateral status as in ESCAPE, we may have had a positive trial three years earlier. As we continue to understand the pathophysiological reasons for the success of the recent ...
Coronary artery disease (CAD) is the leading cause of death in industrialized countries. Current therapies for restoration of coronary flow are percutaneous coronary intervention (PCI) or surgical revascularization. However, inherent to them are procedure-related risks and the fact that CAD progression is not prevented. Additionally, up to one fourth of all CAD patients are not amenable to standard revascularization therapies. Thus, there is a need for alternative therapies. Coronary collaterals as natural bypasses are anastomoses without an intervening capillary bed between portions of the same coronary artery or between different coronary arteries. The coronary collateral circulation is prevalent in humans and in CAD the amount of collateral flow is directly related to infarct size, all-cause- and cardiac mortality. Thus, the goal is to promote collateral function in the sense of prophylactic myocardial salvage.. Coronary (collateral) blood flow occurs almost entirely during diastole. Fluid ...
Coronary collateral circulation plays an important role to protect myocardium from ischemia, preserve myocardial contractility and reduce cardiovascular events. Chronic kidney disease (CKD) is associated with poor coronary collateral development and
Previous clinical studies showed that the coronary wedge pressure is increased in the presence of collateral vessels, presumably as a consequence of a reduced collateral vascular resistance, resulting in a reduction of signs of ischemia during brief coronary occlusion ([3, 4, 6]). Our current understanding of the collateral circulation is limited, partly due to the lack of methods capable of expressing the development of the collateral vascular bed in terms of flow and resistance. The dynamic behavior of collateral vessels as seen angiographically before and during balloon coronary occlusion can be examined by blood flow velocity analysis in the contralateral donor coronary artery ([6, 7]). These studies demonstrated that a balloon coronary occlusion results in a transient 10% to 70% increase in coronary blood flow velocity in the contralateral artery when collateral vessels are present, although this phenomenon is marked in the absence of collateral vessels. Blood flow velocity changes in the ...
The importance of the coronary collateral circulation has become increasingly clear over the past 20 years.3-5 The coronary collateral circulation is a complex network of interconnecting vessels, most of which are ,200 μm in diameter. Highly variable from patient to patient, this network develops from the recruitment of existing blood vessels as well as the creation of new vessels. The main stimulants for collateral growth are duration and severity of ischaemia, shear stress on the arterial wall, and inflammation.5 In acute myocardial infarction the presence of collateral circulation decreases infarct size, improves left ventricular function, decreases the likelihood of an aneurysm forming, and improves survival. 3 4 While collateral circulation may provide adequate coronary perfusion at … ...
Conventional methods for qualitatively assessing human coronary collaterals include postmortem coronary angiography (5), patients history of a walking-through angina pectoris (30), nuclear cardiology techniques (31), recording of IC and surface ECG (19)and coronary wedge pressure (32)during PTCA and angiographic grading during vessel patency or occlusion (9). Positron emission tomography has been demonstrated to provide quantitative data of collateral flow to a vascular region of interest (31). However, this can be achieved only in the presence of a naturally occurring coronary artery occlusion of the ipsilateral vessel. The PTCA model for collateral assessment can be used in every patient with a stenotic lesion to be dilated. The presence of ECG ST-segment changes as a sign of myocardial ischemia is regarded to be quite sensitive in studies on collaterals (30). An ECG obtained during PTCA from an IC guidewire with its tip distal to the occluded stenosis can be used even more effectively. For ...
BACKGROUND AND PURPOSE: Current knowledge of the collateral circulation remains sparse, and a noninvasive method to better characterize the role of collaterals is desirable. The aim of our study was to investigate the presence and distal flow of collaterals by using a new MR perfusion territory imaging, vessel-encoded arterial spin-labeling (VE-ASL). MATERIALS AND METHODS: Fifty-six patients with internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis were identified by sonography, VE-ASL was performed to assess the presence and function of collateral flow. The perfusion information was combined with VE maps into high signal-intensity-to-noise-ratio 3-colored maps of the left carotid, right carotid, and posterior circulation territories. The presence of the anterior and posterior collateral flow was demonstrated by the color of the standard anterior cerebral artery/MCA flow territory. The distal function of collateral flow was categorized as adequate (cerebral blood flow [CBF] >= ...
RESULTS: A total 269 patients were participated in the study population (55 in CIN(+) group, 214 in CIN(-) group). The blood creatinine levels were significantly higher in the CIN(+) group on the 48-72 hours following the coronary angiography. In the studied population, 70 out of 269 patients had a good CCC according the Rentrop classification (64 patients [30%] in the CIN(-) group, six patients [16%] in the CIN(+) group). The frequency of the well-developed coronary collaterals were significantly higher in the CIN(-) group ( ...
Background: We hypothesized that cerebral perfusion deficits are more severe in acute stroke patients with poor collaterals and that the severity would increase over time if reperfusion does not occur.. Methods: This is a substudy of DEFUSE 2. Collaterals were assessed on conventional angiography and dichotomized as poor vs. good flow. DWI and PWI were performed before and within 12 hrs after endovascular therapy; PWI lesion volumes were determined using a Tmax,6sec threshold. The hypoperfusion ratio (HR) was calculated by determining the proportion of the PWI lesion that had severe Tmax delay (,10sec). Acute lesion growth was defined as the difference between the baseline and follow-up DWI volume.. Part 1: In patients with an ICA or M1 occlusion we compared the HR to the collateral score. An ROC curve assessed whether the HR predicts the collateral score.. Part 2: Among patients who did not experience early reperfusion, the difference between the baseline and follow-up HR was assessed and ...
The extent of collateral circulation in 46 patients who had intracoronary thrombolysis within six hours of the onset of acute myocardial infarction was evaluated. Patients who had had a previous myocardial infarction (4 cases) or who had spontaneously recanalized infarct related coronary arteries (5 cases) were excluded from the analysis. Collateral development was graded during coronary cineangiography according to the extent of opacification of the collateral and epicardial arteries distal to the site of occlusion (collateral index 0 to 3). Angina was considered to be present before myocardial infarction if it had occurred more than one week before acute myocardial infarction. Collateral channels were visible in only two of 19 patients without angina before infarction and nine of the 18 patients with angina before infarction. The prevalence of angina and the collateral index were not significantly influenced by the extent of coronary vessel disease. It is concluded that myocardial ischaemia is ...
Rentrop et al. researched collateral filling of stenotic coronary artery during inflation of the PTA balloon. Contrast dye was injected as soon as the patient developed ST-T changes on ECG or angina, but no later than 90 seconds after inflation of the balloon.
Background: Collateral grade on cerebral angiography has great predictive significance for patient outcome, which is important to determine indication for endovascular therapy in acute ischemic stroke (AIS). Distal hyperintense vessels (DHV) on fluid-attenuated inversion recovery imaging (FLAIR) is a noninvasive and useful imaging marker that reflects leptomeningeal collateral flow. We investigated whether DHV in patients with AIS was associated with collaterals grade on cerebral angiography and clinical outcome after endovascular therapy.. Methods: We retrospectively reviewed patients with AIS who had internal carotid artery or middle cerebral artery occlusion in three comprehensive stroke centers from August 2011 to July 2015. We selected those who underwent FLAIR sequence before endovascular therapy. Presence of DHV was evaluated using a previously-published method. Collateral grades on pre-treatment cerebral angiography were assessed with the American Society of Interventional and ...
Obesity is associated with impaired coronary collateral vessel development. Yilmaz, M.B.; Biyikoglu, S.F.; Akin, Y.; Guray, U.; Kisacik, H.L.; Korkmaz, S. // International Journal of Obesity & Related Metabolic Disorders;Dec2003, Vol. 27 Issue 12, p1541 BACKGROUND:: Chronic myocardial ischaemia due to coronary artery stenosis or occlusion has been shown to increase the growth of coronary collateral circulation. Collateralization leads to increased oxygen delivery to the area at risk and hence may reduce ischaemia, prevent infarction and... ...
Peripheral arterial disease (PAD) is a global problem - over 202 million people worldwide are estimated to have PAD. In the United States alone, PAD results in $21 billion in annual costs and is the leading cause of lower limb amputation. PAD arises when atherosclerotic plaques block arteries in the lower limbs, thereby limiting blood flow to the distal tissue. A promising therapeutic approach to restore distal blood flow is to stimulate the lumenal growth of the patients own pre-existing collateral arteries that bypass the occlusion(s) (i.e. arteriogenesis). Unfortunately, large clinical trials have had limited success to date, highlighting the critical need to better understand the basic mechanisms regulating arteriogenesis.. Arteriogenesis occurs in response to increased blood flow through the collateral arteries that bypass an occluded artery. We have recently demonstrated that arteriogenesis varies along collateral artery pathways due to differences in regional hemodynamics (Heuslein and ...
When a collateral vessel on the heart enlarges, it lets blood flow from an open coronary artery to an adjacent one or further downstream on the same artery. In this way, collateral vessels grow and form a kind of "detour" around a blockage. This collateral circulation provides alternate routes of blood flow to the heart in cases when the heart isnt getting the blood supply it needed ...
We describe patterns of acquired portal collateral circulation in dogs and in a cat using multidetector row computed tomography angiography. Large portosystemic shunts included left splenogonadal shunts in patients with portal hypertension. Small portal collaterals were termed varices; these collaterals had several patterns and were related either to portal vein or cranial vena cava obstruction. Varices were systematized on the basis of the venous drainage pathways and their anatomic location, namely left gastric vein varix, esophageal and paraesophageal varices, gastroesophageal and gastrophrenic varices, gallbladder and choledocal varices, omental varices, duodenal varices, colic varices, and abdominal wall varices. As reported in humans and in experimental dog models, esophageal and paraesophageal varices may result from portal hypertension that generates reversal of flow, which diverts venous blood in a cranial direction through the left gastric vein to the venous plexus of the esophagus. ...
No. Wellens T-waves are always AFTER an episode of pain, and when no ECG was recorded DURING the pain. But we know from reperfusion trials that this is exactly the same kind of T-wave inversion we get after reperfusion. So, extrapolating backward in time, those who have Wellens had upright T-waves with ST elevation at the time of their pain. They had spontaneous reperfusion (which is very common in STEMI) and when the were pain free with open artery (or good collateral circulation), then the ECG was recorded and showed T-wave inversion. In Wellens study, all 180 patients had EITHER an open LAD or good collateral circulation to the anterior wall.. ReplyDelete ...
RESULTS: Factors associated with good outcome on univariable analysis were younger age, female sex, hypertension, diabetes mellitus, atrial fibrillation, small infarct core (ASPECTS ≥8), vessel recanalization, lower pre-tPA NIHSS scores, and good collaterals according to Tan methodology, ASPECTS methodology, and Miteff methodology. On multivariable logistic regression, only lower NIHSS scores (OR, 1.186 per point; 95% CI, 1.079-1.302; P = .001), recanalization (OR, 5.599; 95% CI, 1.560-20.010; P = .008), and good collaterals by the Miteff method (OR, 3.341; 95% CI, 1.203-5.099; P = .014) were independent predictors of good outcome. Poor collaterals by the Miteff system (OR, 2.592; 95% CI, 1.113-6.038; P = .027), Maas system (OR, 2.580; 95% CI, 1.075-6.187; P = .034), and ASPECTS method ≤5 points (OR, 2.685; 95% CI, 1.156-6.237; P = .022) were independent predictors of extremely poor outcomes. ...
Our ability to link amplified arteriogenesis to a unique hemodynamic stimulus (ie, reversed flow with increase shear stress magnitude) was facilitated by the development of a LSF approach for mouse hindlimb collaterals.18 We developed that approach because, despite the known importance of hemodynamic stimuli in driving collateral development, there was a surprising lack of quantitative data on the hemodynamic changes within these arteries. This is likely because both the small size of the arteries (,100 μm) and the fact that different surgical models elicit arteriogenesis along different collateral pathways.2 Using LSF,18 we determined the occurrence of at least 3 distinct hemodynamic conditions in these collateral vessels: a nonreversed increase in shear stress near the feeding entrance to the collateral loop, an increase in shear stress from low/oscillating flow to sustained high shear stress at the central anastomotic region, and an increase in shear stress but in a reversed direction at the ...
Results and Discussion: Receiver Operating Characteristics demonstrated no improvement using frequency dependant impedance compared to the constant part of the collateral impedance. The functional parameters aCon and cIMP were better than the total blood flow for the characterization of collateral function. The collateral function improved significantly during occlusion time (aCON in one= 0.20+/-0.17, two=0.22+/-0.25, three and more month= 0.28+/-0.18 cm*s-1*mmHg-1). A predominant systolic, diastolic or combined collateral flow profile was not correlated to the collateral function. Considering the anatomic location of Levin 17 patients had one, 15 two and 24 three different collateral pathways. In the majority of cases (63 of 91 patients) a septal pathway was included. In all patients the comparison of the Rentrop grading, the anatomic location classification and the collateral connection grading showed only for the latter an independent and significant relation with the collateral function. In ...
Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial arterial spin labeling (ASL) imaging. Cerebral blood flow and cerebrovascular reactivity were assessed with ASL before and after acetazolamide. Cerebral haemodynamics were normal in asymptomatic ICA stenosis patients, as opposed to patients with ICA occlusion, in whom the haemodynamics in both hemispheres were compromised. Haemodynamic impairment in the affected brain region was always present in
Collateral status has been proposed to be important in defining the course after treatment in acute ischemic stroke.20,21 However, collateral flow varies widely among patients for largely unknown reasons.1-4 Recent studies in mice have provided a potential clue.5-9 Strains with differences in genetic background exhibit wide variation in collateral extent, ≈80% of which depends on a polymorphic region on chromosome 7, Dce1.6,8,9 In this study, we demonstrate that a single gene within this region, Rabep2, is responsible for this variation. However, its contribution varies depending on genetic background. When the BC allele of Rabep2 is on the B6 background, it accounts for 36% and 72% of the differences in collateral number and diameter attributable to Dce1-as determined in the SNP and genetically comparable Del3 mice-and accounts for 64% and 89% of number and diameter when it is deleted as in the Rabep2−/− mice. By comparison, when the B6 allele is present on the BC background (CNG7B6 and ...
Does a well developed collateral circulation predispose to restenosis after percutaneous coronary intervention? An intravascular ultrasound study ...
We previously showed that prompt reperfusion and angiographic collateral vessels may impact myocardial salvage and infarct transmural extent among patients with an occluded IRA. In the current investigation, we found that in addition to time to reperfusion and collateral vessels, the angiographic area at risk and the initial TIMI flow grade at the time of PCI are independent predictors of myocardial salvage by multivariate analysis. The novel index of myocardial salvage described here compares favorably with infarct transmurality to predict wall motion recovery after an acute STEMI.. Previous experimental studies have shown that the final infarct size closely correlates with the mass of jeopardized myocardium within the territory of the IRA (9). It is known that reperfusion of an occluded artery results in greater improvement in regional LV function when collateral vessels are present in the acute phase of myocardial infarction (10). However, the adjunctive effect that collateral flow might have ...
CONTRAST-ENHANCED CARDIAC COMPUTED TOMOGRAPHY (CT) is being increasingly used for the investigation of patients with suspected coronary artery disease. Recent technological developments have allowed the reliable diagnosis of both coronary stenosis and occlusion with this modality. In addition to the identification of luminal stenosis, CT has the potential to visualize coronary plaque, collateral circulation, myocardium, and left ventricular function. Although the typical CT appearance of chronic coronary occlusion (extensive calcification and negative remodeling within the artery, potential presence of collateral coronary circulation and, in most cases, impaired left ventricular function associated with thinned myocardium) is well known, characteristics of acute occlusion have not been well described. The distinction between acute and chronic coronary occlusion has particular importance for the management of patients presenting with acute chest pain. In this series of cases, we highlight some ...
In patients with acute ischemic stroke attributable to large-vessel occlusion, selecting a candidate who will benefit most from endovascular revascularization therapy to optimize the practice of endovascular treatment is important for improving clinical outcome.24 In consideration of that point, defining the optimal timeframe for reperfusion based on collateral-flow adequacy is crucial in averting further ischemic injury.25,26 Our study demonstrated that the evaluation of the collateral-flow status before the initiation of intra-arterial treatment could be a key marker to determine a timeframe for reperfusion with a probable favorable clinical outcome.. The effect of the quality of collateral flow on clinical outcome has been examined in previous reports, which show that good collateral flow is associated with favorable outcome.5⇓⇓⇓⇓⇓-11 Also, the ORT in intra-arterial treatment was a main determinant factor in predicting favorable outcome.3,4 Regarding collateral flow and ORT as ...
OBJECTIVES. The aim of this study was to evaluate myocardial blood flow regulation in collateral-dependent myocardium of patients with coronary artery disease. BACKGROUND. Despite great clinical relevance, perfusion correlates of collateral circulation in humans have rarely been estimated by quantitative methods at rest and during stress. METHODS. Nineteen patients with angina and isolated occlusion of the left anterior descending (n = 14) or left circumflex (n = 5) coronary artery were evaluated. Using positron emission tomography and nitrogen-13 ammonia, we obtained flow measurements at baseline, during atrial pacing-induced tachycardia and after intravenous administration of dipyridamole (0.56 mg/kg body weight over 4 min). Flow values in collateral-dependent and remote areas were compared with values in 13 normal subjects. RESULTS. Flow at rest was similar in collateralized and remote myocardium (0.61 +/- 0.11 vs. 0.63 +/- 0.17 ml/min per g, mean +/- 1 SD), and both values were lower than ...
INTRODUCTION Stimulation of coronary collateral vessel growth by therapeutic angiogenesis (TA) offers an alternative treatment option for patients with refractory angina. Several TA modalities, including delivery to the heart of angiogenic growth factors (proteins or genes) and cells have been tested in clinical trials in the past two decades, but so far none of them resulted in significant therapeutic efficacy in large scale studies. This review attempts to identify the main obstacles hindering clinical success and recommends measures to overcome them in the future. AREAS COVERED After stating the medical need and rational for TA, and listing and briefly discussing past and current TA clinical trials, three main areas of obstacles are described: conceptual questions, technical limitations and clinical design uncertainties. Based on scientific and technical advances and lessons learned in past clinical trials, potential solutions to overcome some of these obstacles are proposed. EXPERT OPINION
This invention provides methods of treating a patients lung. One aspect of the invention provides a method of treating a lung including the following steps: inserting a collateral flow blocking agent delivery device into an air passageway of the lung; and delivering a collateral flow blocking agent to reduce airflow between a portion of the lung distal to the delivery device and the exterior of the patient. Another aspect of the invention provides a method of treating a lung including the step of delivering a collateral flow blocking agent to reduce airflow through openings in lung tissue caused by tissue degradation.
A collateralized debt obligation is an investment that is backed by a collection of several different assets. While collateralized...
Definition Myocardial infarction (MI) is defined as death of myocardial tissue. The extent and location of the infarction depend on the degree of ischemic burden, the availability of coronary collateral blood flow, the rapidity of reperfusion, and the location of the afflicted coronary artery.[1] Pathophysiology
Available in: Hardcover. Collateral blood vessels develop by growth of pre or newly formed structures in almost all vascular provinces as a consequence of
We demonstrated that the leptomeningeal collateral anastomoses provided rapid and persistent perfusion to ischemic territories following MCAO. Furthermore, the collateral blood flow continued to increase over 7 d after MCAO with a considerable degree of vascular remodeling as evidenced by the increased diameter of collateral vessels in wild-type mice. In contrast, db/db mice had impaired collateral flow recruitment after MCAO compared with db/+, particularly at proximal MCA where the retrograde flow failed to reach, despite the similarity in baseline flow velocity and vascular anatomy between the two genotypes. The slower flow velocity from ACA to proximal MCA observed in db/db mice following stroke likely contributed to the inadequate retrograde filling of the MCA closest to the site of occlusion, where it was needed most. Consistent with this finding, db/db mice sustained a larger stroke size and poorer neurological outcome 7 d after MCAO. Despite the chronic collateral remodeling in both ...
Principal Investigator:ENDO Masahiro, Project Period (FY):1995 - 1996, Research Category:Grant-in-Aid for Scientific Research (B), Section:一般, Research Field:Thoracic surgery
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accelerated account acquisition actively acts address adenine adhesion allows anatomically angiography animal artery assessed blood branching cascade clearly collateral collaterals compensated confirmed considered controls corkscrew course covered datasets days demonstrating derived detected determined developed development direct displayed distal dual early energetics enhanced equipped established extent extracellularly faster femoral flow formation formed frequencies geometry gradient green growing growth histology important improved in vivo induced inflammatory initial involving issue lack lacking length ligation like matrix metabolic mice micro mouse muscle mutant newly normalized nucleotide occlusion operating part phenotype plays post potent previously processes processing product projection promotes protocol proximal quadriceps quantification quantified quantitative reaching receptors reconstruction recorded recovery reflected regulation reported resolution resonator restoration reveals ...
Definition of collateral sulcus in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is collateral sulcus? Meaning of collateral sulcus as a legal term. What does collateral sulcus mean in law?
Definition of Collateral facts evidence in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is Collateral facts evidence? Meaning of Collateral facts evidence as a legal term. What does Collateral facts evidence mean in law?
The authorities are investigating loans based on collateral of metals at a Chinese port, with implications for Western banks and the Chinese credit market.
TY - JOUR. T1 - Early collateral and microvascular adaptations to intestinal artery occlusion in rat. AU - Unthank, Joseph L.. AU - Nixon, J. Craig. AU - Burkhart, Harold M.. AU - Fath, Steven W.. AU - Dalsing, Michael. PY - 1996/9. Y1 - 1996/9. N2 - The technique to repeatedly observe exactly the same vessels in the rat intestine was used to investigate vascular compensation during the 1st wk after abrupt arterial ligation. A collateral-dependent tissue region was created by ligation of three to four sequential intestinal arteries. At the center of the collateral-dependent region, arterial pressure decreased from 96 ± 3.7 to 29 ± 2.5 mmHg, and intestinal blood flow fell ∼80% during maximal dilation initially postligation. One week later, pressure and blood flow at the center had increased 31 and 250%, respectively. Relative to preligation values, the only compensatory adaptation was an enlargement (31 ± 11%) of the collateral arteries located between normal tissue and the center; no ...
Occlusion of radicular arteries-reasons, consequences and anastomotic substitution pathways. Maliszewski, M; Ladzin´ski, P; Aleksandrowicz, R; Majchrzak, H; Bierzyn´ska-Macyszyn, G; Wolan´ska-Karut, J // Spinal Cord;Oct1999, Vol. 37 Issue 10, p710 Aim of study: To investigate the cause of radicular artery occlusion. Method: Fifty specimens of spinal cords were taken at postmortem from individuals in whom no symptoms of spinal cord and spine injuries were present in life. The spinal cord arterial system was filled with colour contrast... ...
Lipomas, lumps and bumps, from the perspective of PetMassage canine massage. This discussion is part of the preparation for the continuing ed workshop I will be facilitating, at the IAAMB/ACWT - NBCAAM Conference this September, in Seattle. In the 4-hour workshop titled, "Canine Myofascial Release: Techniques to Discover and Track Movement," well be wrist-deep in…. Read More ...
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Looking for collateral innervation? Find out information about collateral innervation. The distribution of nerves to a part. The amount of nerve stimulation received by a part. the supply of nerves to organs and tissues, which provides for... Explanation of collateral innervation
The policy objective is to encourage forward planning by both the Bank and SMF members to ensure that borrowing capacity is maintained and that public money is appropriately protected against the risks of a disorderly LIBOR transition. The policy adopts a haircut glide path for all LIBOR linked collateral maturing after end-2021, that will be phased in from 1 October 2020 and result in haircuts being 100% by end 2021, at which point all LIBOR linked collateral will cease to be eligible for use in the SMF. Further, from 1 October 2020, newly issued LIBOR linked collateral will be ineligible for use in the SMF. The Bank considers that this approach should act as an additional incentive both to cease new LIBOR issuance in cash markets and to amend legacy LIBOR linked collateral ...
The devices and methods of placement of such devices disclosed herein are directed to altering gaseous flow within a lung to improve the expiration cycle of, for instance, an individual having Chronic Obstructive Pulmonary Disease. More particularly, these devices produce and maintain collateral openings or channels through the airway wall so that oxygen depleted/carbon dioxide rich air is able to pass directly out of the lung tissue to facilitate both the exchange of oxygen ultimately into the blood and/or to decompress hyper-inflated lungs. The medical kits disclosed herein are also directed to produce and maintain collateral openings through airway walls.
In our study, the success rate of A-PCI was 74.1% and the total PCI success rate was 87.0%. Both are higher than the rates reported in previous studies (1,12,17). Negative remodeling and lesion length ,31.89 mm on coronary CTA, and ostial or bifurcation lesions on CCA were independent predictors of failed A-PCI guided by coronary CTA and CCA. In the absence of these 3 risk factors, the success rate of A-PCI was 98.0%. In contrast, the success rate of A-PCI was especially low (20.0%) if 2 or more risk factors were present. Other signs, such as calcification and tortuous course, were not significantly different between the successful and failed A-PCI groups. R-PCI during the same procedure after failed A-PCI in patients with a satisfactory appearance of the occluded distal segment on coronary CTA and well-developed collaterals (score of 3) on CCA was feasible.. Similar to our results, Rolf et al. (3) reported that performing coronary CTA before PCI of CTO lesions was associated with a higher ...
Diabetes in the United States today is an explosive major public health issue that directly impacts cardiovascular morbidity and mortality. One major reason for...
For full functionality of ResearchGate it is necessary to enable JavaScript. Permanent vena cava-filters can induce various complications during the remainder of the patients life. A case of a year-old woman who became pregnant seven years after the implantation of a Kimray-Greenfield-Filter and gave birth to a healthy child is presented. During pregnancy and after the birth of a healthy child she suffered from two new thrombotic events.. After the delivery, a Journal for vascular diseases Request full-text Article: Treatment of a post-thrombotic spontaneous Palma by selective sclerosis N. Rudofsky Abstract: Typical sequelae of deep vein thrombosis of pelvic and leg veins are not only post-thrombotic changes with a tendency toward oedema, trophic skin changes trophischen Ulkus Beine ICD 10 ulcers, but also the formation of collateral circulation.. After pelvic vein thrombosis these collaterals may occur as subjectively displeasing suprapubic venous convolutions. The authors report on ...
Fig. 2. Differences in collateral growth and tissue recovery in animal models versus humans with arterial occlusive disease. (A) After an acute arterial ligation (shown here in a mouse), there is a strong pressure gradient between the proximal and distal sides of the occlusion (orange line). This redirects the blood flow into adjacent arterioles and causes a strong shear-stress-mediated opening of collateral channels, which restore blood flow into the hypoxic areas. In the hypoxic tissues, ischemic tissue damage (necrosis) occur if the blood flow is not restored within the first hours after the occlusion. Necrosis induces acute inflammation, and recruited inflammatory cells produce angiogenic cytokines such as VEGF. The hypoxia itself activates factors such as HIF that stimulate the production of VEGF among other factors, and angiogenesis. Distal angiogenesis, along with the growth of collaterals, contributes to the tissue recovery by the formation of connections between the collaterals and the ...
In the first part of the study we tested the model on a HC cohort based on medical history and a controversial US CCSVI screening [5, 19-27]. However, a recent meta-analysis clearly shows that the majority of HC are not affected by CCSVI [28]. Finally, also MRI data, more objective and less operator dependent with respect to US, are still controversial because there are confirmatory and not confirmatory studies [25-27, 29].. Our measurements of the inflow are definitively comparable with previously published data [17]. Same result was found for the evaluation of the outflow, because the Q value assessed in J3, J2 and in the VVs are similar to the values previously reported [3, 4, 19].. The novelty of the present study is the application of a complete model which takes into account the haemodynamics of cerebral venous return normalized to the HBinF. Our model, for the first time, also includes J1 and haemodynamic analysis of collaterals.. Furthermore, we confirm that the flow in the IJV increases ...
unless there is bacterial infection, or the infarct has caused necrosis of all the cells in a portion of the brain). Inflammatory cells enter the infarct by the first day, and become plentiful over the next several days. "Big Robbins" lists several observations about infarcts that are worth reviewing. Although they may seem obvious, they are important to remember in clinical medicine. (1) The effects of vascular narrowing or occlusion will probably be worse if the blood already lacks oxygen-carrying capacity (i.e., the patient is anemic) or the heart isnt pumping well (heart failure, shock). (2) Slowly-developing occlusion of an artery (i.e., over months or years) is well-tolerated in organs with collateral circulation, since it allows for development of more and bigger collaterals (3) Remember that different cells tolerate ischemia for different lengths of time. Because of their importance, its worth mentioning DECUBITUS ULCERS here once again. Body weight always prevents blood from flowing ...
Hydrogen, Artery, Blood, Cells, Collateral Circulation, Coronary Artery, Endothelial Cells, Gene, Growth, Human, Hydrogen Peroxide, Knowledge, Muscle, Placenta, Smooth Muscle, Arteries, Conditioned Medium, Gene Expression, Monocytes, Muscle Cells
Rule under consideration by CFTC would require Treasuries to be covered by lines of credit when used as collateral for swaps and futures trades.
So the good news is things compare well so far. However, this doesnt represent reality. In reality, you have to set aside a certain amount of your capital as collateral/margin. If you are trying to replicate SHY with futures and not use any leverage, you would fund an account with ~$200k (using this value for round number purposes), put ~$1k in collateral toward the 2-year futures contract, and put the remainder in an instrument that would earn you back the risk-free rate. The futures contract is 100% long the total return of 2-year treasuries and 100% short the risk-free rate (due to cost of carry). However, in this scenario, you would be able to offset ~99.5% of that short position on the risk-free rate by putting the cash not being used as collateral in an ultra-short bond ETF like MINT of JPST. These arent entirely risk-free, but they also earn a little more than the risk-free rate and make up for the fact that you have to have some of your capital sitting idle in margin ...
So the good news is things compare well so far. However, this doesnt represent reality. In reality, you have to set aside a certain amount of your capital as collateral/margin. If you are trying to replicate SHY with futures and not use any leverage, you would fund an account with ~$200k (using this value for round number purposes), put ~$1k in collateral toward the 2-year futures contract, and put the remainder in an instrument that would earn you back the risk-free rate. The futures contract is 100% long the total return of 2-year treasuries and 100% short the risk-free rate (due to cost of carry). However, in this scenario, you would be able to offset ~99.5% of that short position on the risk-free rate by putting the cash not being used as collateral in an ultra-short bond ETF like MINT of JPST. These arent entirely risk-free, but they also earn a little more than the risk-free rate and make up for the fact that you have to have some of your capital sitting idle in margin ...
Exercising often has the effect of lengthening your lifespan and improving your looks. As such, you do not have to wait for aging to catch up with you when you can add a few years to your life. A recent study on effects of exercises on the aging process shows that aging reduces the rates at which our cells age. As much as this occurs at a cellular level, it has a direct impact on the overall aging process. Also, improved blood circulation on the skin leaves you looking years younger.. ...
We discussed the comments from the previous meeting about usage of terms Independent Amount. We discussed whether more granular breakdown definitions i.e. VaR vs Portfolio Margin could be used. Takeaway was to come back with a couple of suggestions on how to represent this one being straight Independent Amount, being a summation of all IA values for the agreement i.e. trade level and agreement level the other being a more flexible and granular definition where it would be possible to specify IA amounts with a type or description. The sum of these values would equate to the equivalent of the Total Upfront Margin in the original ISDA requirements. An draft example is attached based on FpML type syntax ...
Aneurysm surgery: optic nerve often displaced superiorly by aneurysm, vs. falciform ligament (sharp tethering edge). Early opening of optic canal & falciform ligament to free optic nerve --, decrease risk of visual deficit. If clipped, orbit dependent on collateral supply from ECA (maxillary, facial arteries ...
Decreased collateral vessel formation in the diabetic peripheral limbs is characterised by abnormalities of the angiogenic response to ischemia. Hyperglycemia is known to activate protein kinase C (PKC) affecting the expression and activity of growth factors such as VEGF and PDGF. The present study investigates the role of PKCδ in diabetes-induced poor collateral vessel formation and inhibition of angiogenic factors expression and actions. Ischemic adductors muscles of diabetic Prkcd+/+ mice exhibited reduced blood reperfusion, vascular density and number of small vessels as compared to non-diabetic Prkcd+/+ mice. By contrast, diabetic Prkcd-/- mice showed significant increased blood flow, capillary density and number of capillaries. Although expression of various PKC isoforms were unchanged, activation of PKCδ was increased in diabetic Prkcd+/+ mice. VEGF and PDGF mRNA and protein expression were decreased in muscles of diabetic Prkcd+/+ mice and normalized in diabetic Prkcd-/- mice. ...
There is intense controversy as to the mechanisms underlying chronic but reversible left ventricular (LV) ischemic dysfunction. The aim of this study was to investigate the physiology underlying this condition in a canine model of noninfarcted collateral-dependent myocardium. METHODS: Six mongrel dogs were instrumented with ameroid constrictors on the left circumflex and right coronary arteries and a partial occluder on the left anterior descending coronary artery. The animals were followed up for 6 mo. Every 6 wk, measurements of regional wall thickening (M-mode echo), myocardial blood flow ((13)N-ammonia PET), oxygen consumption ((11)C-acetate PET), and glucose uptake ((18)F-FDG PET) were obtained. After 6 mo, myocardial blood flow reserve (during adenosine infusion) and regional contractile reserve (during infusion of a low dose of dobutamine) were also investigated. RESULTS: Following ameroid implantation, regional thickening decreased in the posterior wall (to 34% +/- 13% of baseline; P , ...
Natural adaptation to femoral artery occlusion in animals by collateral artery growth restores only approximately 35% of adenosine-recruitable maximal conductance (C(max)) probably because initially elevated fluid shear stress (FSS) quickly normalize
Looking for online definition of Collateral estoppel in the Medical Dictionary? Collateral estoppel explanation free. What is Collateral estoppel? Meaning of Collateral estoppel medical term. What does Collateral estoppel mean?
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In the setting of CTOs, we have learned not to overtreat distal lesions, particularly small vessels; the distal bed disease, which has been chronically underperfused, tends to be overestimated, and the vessel frequently vasodilates and remodels with restoration of antegrade flow, as previously shown.. Few data have been published to investigate the role of blood flow restoration in the remodeling process (1). Galassi et al. (2) have suggested that the improvement of distal vessel diameter size detected at follow-up after CTO recanalization can theoretically be explained by 3 different mechanisms: 1) impaired endothelium-dependent and/or -independent vasomotion immediately after CTO recanalization (hibernated vascular wall) and/or an intense vasoconstriction that improves at follow-up; 2) positive remodeling; or 3) a combination of both. ...
Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. We report that disruption of the mixed-lineage protein kinase (MLK) - cJun NH2-terminal kinase (JNK) signaling pathway in endothelial cells causes severe blockade of blood flow and failure to recover in the murine femoral artery ligation model of hindlimb ischemia. We show that the MLK-JNK pathway is required for the formation of native collateral arteries that can restore circulation following arterial occlusion. Disruption of the MLK-JNK pathway causes decreased Dll4/Notch signaling, excessive sprouting angiogenesis, and defects in developmental vascular morphogenesis. Our analysis demonstrates that the MLK-JNK signaling pathway is a key regulatory mechanism that protects against ischemia in arterial occlusive disease.
Many collateral adjectives enter the language because English regularly substitutes attributive use of the noun itself (or of a verbal noun from a related verb) for use of an adjective, so true adjectives are often missing. Adjectives are then borrowed from Greek or Latin for technical and academic usage, where true adjectives are preferred over attributive use of nouns. Because of this, collateral adjectives tend to be more technical or academic in tone than their corresponding nouns. Some collateral adjectives have a related noun which may be a near synonym for the noun in question. For example, one adjective for business is commercial, which also has a cognate noun commerce. Because there is no one-to-one correspondence between adjective and noun in English, and there is no regular derivation that they upset, they are not actually suppletive. Some nouns have both collateral and derived adjectives. For example, for the noun father there is derived fatherly alongside collateral paternal, and ...
Hemorrhage: Trans-Arterial Embolization for Hemorrhage or Vascular Malformations. Veterinary patients occasionally suffer from hypovolemic shock secondary to severe hemorrhage from a number of different causes including neoplasia, coagulopathy, GI ulceration, and trauma. In the majority of cases, standard medical and surgical procedures can be used to stabilize these often severely debilitated animals. Occasionally, standard therapies fail and alternatives are necessary.. For example, severe epistaxis can typically be managed conservatively. However, once intractable, few options remain. Carotid ligation can be performed and although this may temporize bleeding, once collateral blood supply develops bleeding may resume and no further treatment options exist. This is an especially important consideration when the underlying cause of epistaxis persists because the patient remains at risk for bleeding. An alternative to carotid ligation that permits repeated treatments if necessary is ...
TY - JOUR. T1 - MR Perfusion to Determine the Status of Collaterals in Patients with Acute Ischemic Stroke. T2 - A Look Beyond Time Maps. AU - Nael, Kambiz. AU - Doshi, A.. AU - De Leacy, R.. AU - Puig, J.. AU - Castellanos, M.. AU - Bederson, J.. AU - Naidich, T. P.. AU - Mocco, J.. AU - Wintermark, M.. PY - 2018/2/1. Y1 - 2018/2/1. N2 - BACKGROUND AND PURPOSE: Patients with acute stroke with robust collateral flow have better clinical outcomes and may benefit from endovascular treatment throughout an extended time window. Using a multiparametric approach, we aimed to identify MR perfusion parameters that can represent the extent of collaterals, approximating DSA. MATERIALS AND METHODS: Patients with anterior circulation proximal arterial occlusion who had baseline MR perfusion and DSA were evaluated. The volume of arterial tissue delay (ATD) at thresholds of 2- 6 seconds (ATD2- 6seconds) and 6 seconds (ATD6seconds) in addition to corresponding values of normalized CBV and CBF was calculated ...
Arteriogenesis, the adaptive outward growth of pre-existing collateral arteries, is the most efficient endogenous rescue mechanisms in vertebrates against the occlusion of a major artery (biological bypass). Here, collateral growth was induced using the first model for cerebral arteriogenesis, the 3-vessel occlusion (3-VO) rat model. (I) 3-VO resulted in a significant diameter increase within 7 days in the posterior cerebral artery (PCA) and posterior communicating artery (Pcom), classifying the region of interest. Immunhistological staining demonstrated proliferative activation and macrophage invasion, already 24h post 3-VO within the PCA, confirming the arteriogenic phenotype. Furthermore, activation of the PCA endothelium was detected within 3 days post 3-VO by scanning electron microscopy. (II) For analysing the molecular mechanism of cerebral arteriogenesis, collateral tissue from the growing PCA was selectively isolated. Here, 24h post 3-VO 164 genes were detected to be significantly ...
A method of delivering an arteriogenic factor. The factor is delivered in a medically effective manner to structurally enlarge an existing blood vessel. A distal portion of a catheter can be advanced to an existing blood vessel to deliver the arteriogenic factor.
Formats for Collaterals: The formats, as per NSE Clearing, that are required for submission of documents for Trading Members operating in the Capital Market Segment. Know more about Formats for Collaterals Today, visit NSE India.
bachelorsthesis{Gadllah_Hani_2016, title = "Comparative Visualization of the Circle of Willis", author = "Hani Gadllah", year = "2016", abstract = "The human brain is supplied with blood by arteries that form a collateral circulation, the so-called Circle of Willis (CoW). The anatomy of the CoW varies considerably among the population. In fact, depending on the study, just 13% to 72% of the population does have the typical textbook illustration of the CoW. Although divergent configurations are usually not pathological, some incomplete configurations increase the risk of stroke. Furthermore, studies suggest an association between certain neurological diseases and abnormal configurations of the CoW. Thus, for the diagnosis and treatment of diverse neurological diseases the assessment of the patients CoW is an important issue. This thesis addresses the development of a software for a comparative visualization of the CoWs of a population with the CoWs of a second population. For this purpose, an ...
An arterial exam looks at the arteries in the body. Arteries carry blood to cells and organs. An upper extremity arterial evaluation examines blood flow in the arms and a lower extremity arterial evaluation examines arteries in the legs. Normally the inner wall of the arteries is smooth. When the inner lining becomes hard and thick, atherosclerosis ("hardening of the arteries") develops. This can cause an artery to narrow (called a "stenosis") or close off completely (called an "occlusion"). When this happens, blood must go through other blood vessels to get around the blockage causing alternate circulation called "collateral circulation". Atherosclerosis occurs in all arteries to some degree however the arteries of the neck, heart and legs are most commonly affected. Peripheral Arterial Disease (PAD) refers to the blockages in the arms or legs.. An arterial evaluation is done to examine the arteries in the arms or legs to look at the blood flow to locate stenosis or occlusion.. An arterial ...
An arterial exam looks at the arteries in the body. Arteries carry blood to cells and organs. An upper extremity arterial evaluation examines blood flow in the arms and a lower extremity arterial evaluation examines arteries in the legs. Normally the inner wall of the arteries is smooth. When the inner lining becomes hard and thick, atherosclerosis ("hardening of the arteries") develops. This can cause an artery to narrow (called a "stenosis") or close off completely (called an "occlusion"). When this happens, blood must go through other blood vessels to get around the blockage causing alternate circulation called "collateral circulation". Atherosclerosis occurs in all arteries to some degree however the arteries of the neck, heart and legs are most commonly affected. Peripheral Arterial Disease (PAD) refers to the blockages in the arms or legs.. An arterial evaluation is done to examine the arteries in the arms or legs to look at the blood flow to locate stenosis or occlusion.. An arterial ...
There is evidence of lateral STEMI with hyperacute T-waves in V5 and V6 and I and aVL. So this is consistent with circumflex occlusion. However, it is common for circ occlusions to show little on the ECG, at least in the literature. My experience is that there is nearly always evidence of it to an expert reader with a discerning eye. As for V1, RV involvement only happens with RCA ACS: with a proximal occlusion in which the RV does not get collateral circulation from the LAD, there can be RV STEMI with ST elevation in V1. These certainly can cause hypotension. In this case, the hypotension was due to poor LV function from LAD STEMI.. Delete ...
Depends: It depends if the vessel is an artery or a vein, the size of the vessel, collateral circulation, co-existing illnesses etc. Blood clot in a vein can travel to lung and cause lung infarction. Clot in an artery may damage the tissue/organ supplied by that artery. Heart attack is one example of clot in an artery. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex. ...Read more ...
The Arteriograph is a diagnostic instrument which is able to measure the severity of arteriosclerosis. This is the condition of arterial blockage caused by inflammation or damage within arteries followed by an over production of a compound known as plaque created by the body to repair the damage. Plaque is made up of cholesterol, minerals such as calcium, specialised red blood cells known as platelets and other clotting factors. The Arteriograph is a simple and painless, non invasive investigation that can diagnose arteriosclerosis at an early stage . Symptoms of arterial blockage include chest pain from blocking heart arteries, or the loss of sensation, numbness, or cramp in the lower limbs as the leg arteries block. These symptoms tend not to occur until a considerable amount of an artery is blocked and other arteries are no longer able to offer effective collateral circulation. Symptoms of cardiovascular disease leading to heart attacks and strokes usually appear only in the last and late ...
Each monthly episode will discuss recent publications in the fields of genomics and precision medicine of cardiovascular disease.
Annual precipitation in the largely agricultural South-Central United States is characterized by a primary wet season in May and June, a mid-summer dry period in July and August, and a second precipit
The Mammalian Phenotype (MP) Ontology is a community effort to provide standard terms for annotating phenotypic data. You can use this browser to view terms, definitions, and term relationships in a hierarchical display. Links to summary annotated phenotype data at MGI are provided in Term Detail reports.
NEW YORK - J.P. Morgan today announced that its Projections & Simulations service is now available globally. Part of the Securities Collateral Management product, Projections & Simulations provides se...
Collateral Damage - StarCraft II - Legacy of the Void: A Short Story By: MATT BURNS A crowd stands outside the safe house on Anselm, the people shifting and jostling and craning their necks for a chance...
March 12, 2001 (HedgeWorld.com) The Bank for International Settlements this week released a report on the use of collateral to manage counterparty risk in terms of creditworthiness and liquidity.
Meanwhile Open Europe looks at a proposal that was reportedly floated a day or so ago by the boss of the Eurozones bailout fund as a (partial) solution to the problem posed by the Finnish insistence that any funds advanced by Finland to Greece be adequately collateralized. The idea was that some or all of the collateral should take the form of yet-to-be nationalized chunks of Greek banks, a plan so evidently absurd that I thought it would be dead before I could post on it. I might have been wrong. Open Europe believes that it may survive long enough to be presented when Eurozone finance ministers meet on September 16. Open Europe notes that the plan "has one slight snag": ...
Major aortopulmonary collateral arteries (or MAPCAs) are arteries that develop to supply blood to the lungs when native pulmonary circulation is underdeveloped. Instead of coming from the pulmonary trunk, supply develops from the aorta and other systemic arteries. Major aortopulmonary collateral arteries (MAPCAs) develop early in embryonic life but regress as the normal pulmonary arteries (vessels that will supply deoxygenated blood to the lungs) develop. In certain heart conditions the pulmonary arteries do not develop. The collaterals continue to grow, and can become the main supply of blood to the lungs. Though it is usually associated with congenital heart diseases with decreased pulmonary blood flow like tetralogy of Fallot or pulmonary atresia it may be seen sometimes in isolation i.e. not associated with any congenital heart disease in that case it is termed as isolated aortopulmonary collateral artery. In these cases it may be one of the cause of congestive cardiac failure in neonates. ...
Background: Diabetes mellitus is common and on the increase globally. The associated accelerated macro-vascular angiopathy impairs blood flow in medium sized arteries including hand collateral arteries among others with consequent risk of hand ischemia after any surgical intervention on the radial artery e.g. as free arterial grafts for coronary artery by-pass graft, arterial-venous fistula creation for dialysis among others. The Modified Allen test evaluates the adequacy of hand arterial collateral circulation by mimicking total occlusion of the radial artery which is frequently used in such procedures. Although proved to be accurate by several previous studies, there is great variability in the arbitrary selected modified Allen test cutoff time used. In addition, no prior study evaluates the accuracy of this test in a diabetic population despite the high predisposition for vascular disease in this group. Objectives: The objectives of the study were; 1. To estimate the optimal sensitivity, ...
1) The extent and severity of visual field loss has been compared in a series of 14 patients with occlusions of the posterior cerebral artery or its branches, all verified angiographically. Atheroma, embolism, and migraine were the commonest types of underlying vascular disease. (2) Occlusion of the main trunk of the artery was associated with severe and permanent field loss usually with some sparing of the central area and, in one case, of some field adjacent to the vertical meridian. It is suggested that this is due to collateral blood flow reaching the margins of the posterior cerebral territory from the adjacent middle cerebral territory via pial anastomoses. (3) Single or multiple occlusions of the main branches of the posterior cerebral artery gave variable amounts of field loss with considerable recovery in some cases. Collateral blood flow from the middle cerebral territory and from other branches of the posterior cerebral artery was demonstrated and the variation may be due to the size ...
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Classically, chronic intestinal angina is caused by a reduction in mesenteric blood flow [1], and the pathophysiology of most cases is atherosclerotic stenosis of the celiac and mesenteric arteries. Arterial dissection, fibromuscular dysplasia, and vasculitis are included as rare etiologies of arterial narrowing, and the median arcuate ligament of the diaphragm can compress the celiac artery and disturb blood flow (median arcuate ligament syndrome) [5, 6]. Intestinal circulation consists of an abundant collateral blood supply, and chronic intestinal ischemia is associated with high-grade stenosis or occlusion of two or more of the three major vessels: the celiac artery, the superior and inferior mesenteric arteries [7, 8]. In our case, the arterial lesions were relatively mild compared with previous reports [9, 10]; thus, we hypothesized that our patients major symptoms were not due to his arterial lesions alone.. Specifically, our patients symptoms depended greatly on his hemodynamic ...
BACKGROUND Upper gastrointestinal haemorrhage is mainly caused by ulcers. Gastric varicosis due to portal hypertension can also be held responsible for upper gastrointestinal bleeding. Portal hypertension causes the development of a collateral circulation from the portal to the caval venous system resulting in development of oesophageal and gastric fundus varices. Those may also be held responsible for upper gastrointestinal haemorrhage. CASE PRESENTATION In this study, we describe the case of a 69-year-old male with recurrent severe upper gastrointestinal bleeding caused by arterial submucosal collaterals due to idiopathic splenic artery thrombosis. The diagnosis was secured using endoscopic duplex ultrasound and angiography. The patient was successfully treated with a laparoscopic splenectomy and complete dissection of the short gastric arteries, resulting in the collapse of the submucosal arteries in the gastric wall. Follow-up gastroscopy was performed on the 12th postoperative week and showed no
The semimembranosus-tibial collateral ligament bursa is a U-shaped structure that wraps around the anterior expansion of the semimembnanosus tendon. It is positioned between the semimembranosus-gastrocnemius (cupcake in the diagram) and middle collateral ligament bursae superiorly and the pes anserinus bursa (Canada goose in the diagram) inferiorly. The semimembranosus-tibial collateral ligament bursa does not communicate the adjacent bursae or with the knee joint ...
TY - JOUR. T1 - Splenic infarction after splenorenal arterial bypass. AU - Valentine, R. James. AU - Rossi, Matthew B.. AU - Myers, Stuart I.. AU - Clagett, G. Patrick. PY - 1993. Y1 - 1993. N2 - Because of the spleens extensive collateral circulation, the risk of splenic infarction after splenorenal arterial bypass (SRB) has been considered negligible. We report four patients in whom splenic infarctions developed after SRB. Splenic infarction developed in one patient at the time of SRB, and symptoms of splenic abscess (fever, abdominal pain, and leukocytosis) that proved to be splenic infarctions at laparotomy developed in three patients 2 to 16 days after the operation. Factors possibly contributing to splenic infarction could be determined for three patients. These included interruption of collateral vessels, intraoperative hypotension and disseminated intravascular coagulation, and distal splenic artery ligation. Normal Doppler flow was detected in the splenic parenchyma during test ...