Targeting the dominant mechanism of coronary microvascular dysfunction with intracoronary physiology tests

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Mejia-Renteria, H.; Hoeven, N. van der; Hoef, T.P. van de; Heemelaar, J.; Ryan, N.; Lerman, A.; Royen, N. van; Escaned, J.

2017-01-01

The coronary microcirculation plays a key role in modulating blood supply to the myocardium. Several factors like myocardial oxygen demands, endothelial and neurogenic conditions determine its function. Although there is available evidence supporting microvascular dysfunction as an important cause

Elevated plasma plasminogen activator inhibitor type-1 is an independent predictor of coronary microvascular dysfunction in hypertension

International Nuclear Information System (INIS)

Naya, Masanao; Tsukamoto, Takahiro; Inubushi, Masayuki; Morita, Koichi; Katoh, Chietsugu; Furumoto, Tomoo; Fujii, Satoshi; Tsutsui, Hiroyuki; Tamaki, Nagara

2007-01-01

Elevated plasma plasminogen activator inhibitor-1 (PAI-1) is related to cardiovascular events, but its role in subclinical coronary microvascular dysfunction remains unknown. Thus, in the present study it was investigated whether elevated plasma PAI-1 activity is associated with coronary microvascular dysfunction in hypertensive patients. Thirty patients with untreated essential hypertension and 10 age-matched healthy controls were studied prospectively. Myocardial blood flow (MBF) was measured by using 15 O-water positron emission tomography. Clinical variables associated with atherosclerosis (low-density lipoprotein-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, homeostasis model assessment (HOMA-IR), and PAI-1 activity) were assessed to determine their involvement in coronary microvascular dysfunction. Adenosine triphosphate (ATP)-induced hyperemic MBF and coronary flow reserve (CFR) were significantly lower in hypertensive patients than in healthy controls (ATP-induced MBF: 2.77±0.82 vs 3.49±0.71 ml·g -1 ·min -1 ; p<0.02 and CFR: 2.95±1.06 vs 4.25±0.69; p<0.001). By univariate analysis, CFR was positively correlated with HDL-cholesterol (r=0.46, p<0.02), and inversely with HOMA-IR (r=-0.39, p<0.05) and PAI-1 activity (r=-0.61, p<0.001). By multivariate analysis, elevated PAI-1 activity remained a significant independent determinant of diminished CFR. Elevated plasma PAI-1 activity was independently associated with coronary microvascular dysfunction, which suggests that plasma PAI-1 activity is an important clue linking hypofibrinolysis to the development of atherosclerosis. (author)

Microvascular Recruitment in Insulin Resistance

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Sjøberg, Kim Anker

the resonating sound from the microbubbles in the systemic circulation were recorded for determination of microvascular recruitment in designated muscle segments. Results showed that microvascular recruitment increased with insulin stimulation by ~30% in rats and ~40% in humans (study I). Furthermore......, it was observed that muscle contractions increased muscle perfusion rapidly by 3-4 fold and by 1-2 fold compared to basal and insulin, respectively, in both rat and human skeletal muscle (study I). The real-time contrast-enhanced ultrasound method was applied to investigate the vaso-active effect of the incretin...... hormone glucagon-like-peptide-1 (GLP-1) in the microcirculation. Glucagon-like-peptide-1 analogs are drugs used for treatments of insulin resistance and type 2 diabetes but the vascular effects of GLP-1 in vivo are elusive. Here it was shown that GLP-1 rapidly increased the microvascular recruitment...

Impact of microvascular obstruction on the assessment of coronary flow reserve, index of microcirculatory resistance, and fractional flow reserve after ST-segment elevation myocardial infarction.

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Cuculi, Florim; De Maria, Giovanni Luigi; Meier, Pascal; Dall'Armellina, Erica; de Caterina, Alberto R; Channon, Keith M; Prendergast, Bernard D; Choudhury, Robin P; Choudhury, Robin C; Forfar, John C; Kharbanda, Rajesh K; Banning, Adrian P

2014-11-04

Invasive assessment of coronary physiology (IACP) offers important prognostic insights in ST-segment elevation myocardial infarction (STEMI) but the dynamics of coronary recovery are poorly understood. This study sought to examine the evolution of coronary flow reserve (CFR), index of microcirculatory resistance (IMR), ratio of distal coronary pressure (Pd) to mean aortic pressure (Pa), and fractional flow reserve (FFR) in patients undergoing primary percutaneous coronary intervention (PPCI). 82 patients with STEMI underwent IACP at PPCI. Repeat IACP was performed in 61 patients (74%) at day 1 and in 46 patients (56%) at 6 months. Contrast-enhanced cardiac magnetic resonance imaging (CMR) was performed in 45 patients (55%) at day 1 and in 41 patients (50%) at 6 months. Changes in IACP were compared between patients with and without microvascular obstruction (MVO) on CMR. MVO was present in 21 of 45 patients (47%). Patients with MVO had lower CFR at PPCI and day 1 (p < 0.05) and a trend toward higher IMR values (p = 0.07). At 6 months, CFR and IMR were not significantly different between the groups. Baseline flow and Pd/Pa remained stable over time but FFR reduced significantly between PPCI and 6 months (p = 0.008); this reduction was mainly observed in patients with MVO (p = 0.006) but not in those without MVO (p = 0.21). In PPCI-treated patients with STEMI, coronary microcirculation begins to recover within 24 h and recovery progresses further by 6 months. FFR significantly reduces from baseline to 6 months. The presence of MVO indicates a highly dysfunctional microcirculation. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Thyroid hormone promotes remodeling of coronary resistance vessels.

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Olga V Savinova

Full Text Available Low thyroid hormone (TH function has been linked to impaired coronary blood flow, reduced density of small arterioles, and heart failure. Nonetheless, little is known about the mechanisms by which THs regulate coronary microvascular remodeling. The current study examined the initial cellular events associated with coronary remodeling induced by triiodothyronine (T3 in hypothyroid rats. Rats with established hypothyroidism, eight weeks after surgical thyroidectomy (TX, were treated with T3 for 36 or 72 hours. The early effects of T3 treatment on coronary microvasculature were examined morphometrically. Gene expression changes in the heart were assessed by quantitative PCR Array. Hypothyroidism resulted in arteriolar atrophy in the left ventricle. T3 treatment rapidly induced small arteriolar muscularization and, within 72 hours, restored arteriolar density to control levels. Total length of the capillary network was not affected by TX or T3 treatment. T3 treatment resulted in the coordinate regulation of Angiopoietin 1 and 2 expression. The response of Angiopoietins was consistent with vessel enlargement. In addition to the well known effects of THs on vasoreactivity, these results suggest that THs may affect function of small resistance arteries by phenotypic remodeling of vascular smooth muscle cells (VSMC.

The minimum coronary artery diameter in which coronary spasm can be identified by synchrotron radiation coronary angiography

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Matsushita, Shonosuke; Hyodo, Kazuyuki; Imazuru, Tomohiro; Tokunaga, Chiho; Sato, Fujio; Enomoto, Yoshiharu; Hiramatsu, Yuji; Sakakibara, Yuzuru

2008-01-01

Background: Coronary vasospasm is defined as a temporary, intense narrowing of the coronary conduit artery. It brings about ischemic chest pain and becomes one of the causes of myocardial infarction. Coronary spasms are divided into two categories. One is the coronary spasm of the conduit artery and the other is the coronary microvascular spasm. Although coronary spasms are diagnosed with the images of coronary angiography, microvascular spasms cannot be diagnosed because of the limitations of conventional angiographic systems. However, synchrotron radiation coronary angiography (SRCA) can identify coronary arteries down to 100 μm in diameter in the beating heart and 50 μm in arrested heart. Aim: The purpose of this study was to confirm whether microvascular spasms could be identified or not using SRCA, and then down that size identification was possible. Methods: The Langendorff perfusion system with isolated rat hearts was employed. Krebs-Henseleit solution (KH solution) was used as a perfusate. 10 mM of 4-aminopyridine (4-AP: a voltage-gated potassium channel blocker; spasm inducer) was added to the KH solution and maintained for 5 min. SRCA was performed at pre-, during and 10 min after cessation of the KH solution with 4-AP. Coronary spasms were defined as a temporal 75% reduction of coronary arterial diameter. Results and conclusion: Multiple sizes of coronary arteries showed coronary spasms. The minimum stenosed coronary artery size was 100 μm. Since coronary microvascular spasms are seen in the arterioles (50-400 μm), coronary microvascular spasms may be diagnosed with the use of synchrotron radiation coronary angiography

Design and Rationale for the Endothelin-1 Receptor Antagonism in the Prevention of Microvascular Injury in Patients with non-ST Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention (ENDORA-PCI) Trial.

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Liou, Kevin; Jepson, Nigel; Buckley, Nicolas; Chen, Vivien; Thomas, Shane; Russell, Elizabeth Anne; Ooi, Sze-Yuan

2016-04-01

Peri-procedural myocardial infarction (PMI) occurs in a small but significant portion of patients undergoing percutaneous intervention (PCI). The underlying mechanisms are complex and may include neurohormonal activation and release of vasoactive substances resulting in disruption of the coronary microcirculation. Endothelin in particular has been found in abundance in atherosclerotic plaques and in systemic circulation following PCI, and may be a potential culprit for PMI through its action on microvascular vasoconstriction, and platelet and neutrophil activation. In this study we aim to characterize the behavior of the coronary microcirculation during a PCI with the index of microvascular resistance (IMR) and the effect of peri-procedural endothelin antagonism. The ENDORA-PCI trial is a randomized, double-blind, placebo-controlled, single-center clinical trial designed to evaluate the efficacy of endothelin antagonism in attenuating the peri-procedural rise in IMR as a surrogate marker for PMI. The patients of interest are those with non-ST elevation acute coronary syndrome (NSTEACS) undergoing PCI, and we aim to recruit 52 patients overall to give the study a power of 80 % at an α level of 5 %. Patients will be randomized in a 1:1 fashion to either Ambrisentan, an endothelin antagonist, or placebo, prior to their PCI. IMR will be measured before and after PCI. The primary endpoint is the difference in peri-procedural changes in patients' IMR between the two groups. The ENDORA-PCI study will investigate whether endothelin antagonism with Ambrisentan attenuates the peri-procedural rise in IMR in patients with NSTEACS undergoing PCI, and thus potentially the risk of PMI.

Inflammation-induced microvascular insulin resistance is an early event in diet-induced obesity

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Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W.; Barrett, Eugene J.; Cao, Wenhong

2015-01-01

Endothelial dysfunction and vascular insulin resistance usually coexist and chronic inflammation engenders both. In the present study, we investigate the temporal relationship between vascular insulin resistance and metabolic insulin resistance. We assessed insulin responses in all arterial segments, including aorta, distal saphenous artery and the microvasculature, as well as the metabolic insulin responses in muscle in rats fed on a high-fat diet (HFD) for various durations ranging from 3 days to 4 weeks with or without sodium salicylate treatment. Compared with controls, HFD feeding significantly blunted insulin-mediated Akt (protein kinase B) and eNOS [endothelial nitric oxide (NO) synthase] phosphorylation in aorta in 1 week, blunted vasodilatory response in small resistance vessel in 4 weeks and microvascular recruitment in as early as 3 days. Insulin-stimulated whole body glucose disposal did not begin to progressively decrease until after 1 week. Salicylate treatment fully inhibited vascular inflammation, prevented microvascular insulin resistance and significantly improved muscle metabolic responses to insulin. We conclude that microvascular insulin resistance is an early event in diet-induced obesity and insulin resistance and inflammation plays an essential role in this process. Our data suggest microvascular insulin resistance contributes to the development of metabolic insulin resistance in muscle and muscle microvasculature is a potential therapeutic target in the prevention and treatment of diabetes and its related complications. PMID:26265791

Local heart irradiation of ApoE−/− mice induces microvascular and endocardial damage and accelerates coronary atherosclerosis

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Gabriels, Karen; Hoving, Saske; Seemann, Ingar; Visser, Nils L.; Gijbels, Marion J.; Pol, Jeffrey F.; Daemen, Mat J.; Stewart, Fiona A.; Heeneman, Sylvia

2012-01-01

Background and purpose: Radiotherapy of thoracic and chest-wall tumors increases the long-term risk of radiation-induced heart disease, like a myocardial infarct. Cancer patients commonly have additional risk factors for cardiovascular disease, such as hypercholesterolemia. The goal of this study is to define the interaction of irradiation with such cardiovascular risk factors in radiation-induced damage to the heart and coronary arteries. Material and methods: Hypercholesterolemic and atherosclerosis-prone ApoE −/− mice received local heart irradiation with a single dose of 0, 2, 8 or 16 Gy. Histopathological changes, microvascular damage and functional alterations were assessed after 20 and 40 weeks. Results: Inflammatory cells were significantly increased in the left ventricular myocardium at 20 and 40 weeks after 8 and 16 Gy. Microvascular density decreased at both follow-up time-points after 8 and 16 Gy. Remaining vessels had decreased alkaline phosphatase activity (2–16 Gy) and increased von Willebrand Factor expression (16 Gy), indicative of endothelial cell damage. The endocardium was extensively damaged after 16 Gy, with foam cell accumulations at 20 weeks, and fibrosis and protein leakage at 40 weeks. Despite an accelerated coronary atherosclerotic lesion development at 20 weeks after 16 Gy, gated SPECT and ultrasound measurements showed only minor changes in functional cardiac parameters at 20 weeks. Conclusions: The combination of hypercholesterolemia and local cardiac irradiation induced an inflammatory response, microvascular and endocardial damage, and accelerated the development of coronary atherosclerosis. Despite these pronounced effects, cardiac function of ApoE −/− mice was maintained.

The role of coronary microvascular dysfunction in the genesis of cardiovascular diseases

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Parodi, O.; Sambuceti, G.

1996-01-01

Using PET, myocardial perfusion abnormalities secondary to microvascular disorders have beeen investigated in arterial hypertension (AH), dilated and hypertrophic cardiomyopathy (CM), as well as in ischemic heart disease (CAD). In AH, regional perfusion at rest is within the normal range, while the coronary reserve and flow response to increase in metabolic demand are blunted. Both dilated and hypertrophic CM demonstrate abnormal vasodilaing capability, wich as bee schown to be presented in the subclinical form of dilated DM; the reduction of coronary reserve is not related to the presence and extent of the hemodynamic impairment in dilated CM, and involved also nonhypertropied myocardium in asymmetric hypertropic CM. These finding indicate a primary involvement of coronary microcirculation in non advanced forms of dilated and hypertrophic CM. Finally, in patients with CAD, myocardia teritories supplied by angiographically normal coronary arteries schow abnormal coronary reserve and flow during pacing, tachycardia, indicating that, even in absence of epicardial coronary artery obstruction, microcirculation is impaired in subject with coronary atherosclerosis. this abnormally can smooth perfusion differences, between control andd jeopardized regions. Although the agreement with the angiographic documantation of coronary artery disease has been frequently considered to characterize the diagnostic reliability of these techiques, the evaluation of myocardial perfusion provides an independent tool for the functional assessment of patient with heart disease. The possibility of obtain measurement of regional myocardial blood flow, provided by positron emission thermography, helps to identify the mechanisms affecting flow regulation in the myocardium. This tool thus provides a new rationale for the application of perfusion imaging, to obtain a more precise characterization of these patients, beyond the agreement with the morphological angiographic picture

Microvascular function in pre-eclampsia is influenced by insulin resistance and an imbalance of angiogenic mediators.

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Ghosh, Anshuman; Freestone, Nicholas S; Anim-Nyame, Nicholas; Arrigoni, Francesca I F

2017-04-01

In preeclampsia, maternal microvascular function is disrupted and angiogenesis is dysfunctional. Insulin resistance that occurs in some pregnancies also pathologically affects microvascular function. We wished to examine the relationship of angiogenic mediators and insulin resistance on microvascular health in pregnancy. We performed a nested, case-control study of 16 women who developed preeclampsia with 17 normal pregnant controls. We hypothesized that the impaired microvascular blood flow in preeclamptic women associated with an increased ratio of the antiangiogenic factors; (s-endoglin [sEng] and soluble fms-like tyrosine kinase-1 [sFlt-1]) and proangiogenic molecule (placental growth factor [PlGF]) could be influenced by insulin resistance. Serum samples taken after 28 weeks of gestation were measured for the angiogenic factors, insulin, and glucose alongside the inflammatory marker; tumor necrosis factor-α and endothelial activation, namely; soluble vascular cell adhesion molecule 1, intercellular adhesion molecule-1, and e-selectin. Maternal microvascular blood flow, measured by strain gauge plethysmography, correlated with ratios of pro- and antiangiogenic mediators independently of preeclampsia. Decreased microvascular function measured in preeclampsia strongly correlated with both the antiangiogenic factor (sFlt-1 + sEng): PlGF ratio and high levels of insulin resistance, and combining insulin resistance with antiangiogenic factor ratios further strengthened this relationship. In pregnancy, microvascular blood flow is strongly associated with perturbations in pro- and antiangiogenic mediators. In preeclampsia, the relationship of maternal microvascular dysfunction with antiangiogenic mediators is strengthened when combined with insulin resistance. © 2017 Kingston University. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Syndrome of diminished vasodilator reserve of the coronary microcirculation (microvascular angina or syndrome X): Diagnosis by combined atrial pacing and thallium 201 imaging--a case report

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Magarian, G.J.; Palac, R.; Reinhart, S.

1990-01-01

Patients with angina-like chest pain without evidence of epicardial coronary artery disease or coronary arterial vasospasm are becoming increasingly recognized. These are often related to noncardiac causes including esophageal, musculoskeletal, and hyperventilatory or panic states. However, recently a subgroup of such patients are being recognized as having true myocardial ischemia and chest pain on the basis of diminished coronary microvascular vasodilatory reserve (microvascular ischemia or Syndrome X). The authors describe such a patient who was found to have replication of anginal pain associated with a reversible ischemic defect on thallium 201 imaging during atrial pacing, suggesting ischemia in this myocardial segment. Resolution of angina and ST segment electrocardiographic changes of ischemia occurred with cessation of pacing. We believe this is the first report of a patient with this form of myocardial ischemia diagnosed by this method and should be considered in patients with anginal chest pain after significant coronary artery disease and coronary vasospasm have been excluded

Globular adiponectin ameliorates metabolic insulin resistance via AMPK-mediated restoration of microvascular insulin responses

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Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W; Barrett, Eugene J; Cao, Wenhong; Liu, Zhenqi

2015-01-01

Abstract Hypoadiponectinaemia is closely associated with endothelial dysfunction and insulin resistance, and microvasculature plays a critical role in the regulation of insulin action in muscle. Here we tested whether adiponectin replenishment could improve metabolic insulin sensitivity in male rats fed a high-fat diet (HFD) via the modulation of microvascular insulin responses. Male Sprague–Dawley rats were fed either a HFD or low-fat diet (LFD) for 4 weeks. Small resistance artery myograph changes in tension, muscle microvascular recruitment and metabolic response to insulin were determined. Compared with rats fed a LFD, HFD feeding abolished the vasodilatory actions of globular adiponectin (gAd) and insulin on pre-constricted distal saphenous arteries. Pretreatment with gAd improved insulin responses in arterioles isolated from HFD rats, which was blocked by AMP-activated protein kinase (AMPK) inhibition. Similarly, HFD abolished microvascular responses to either gAd or insulin and decreased insulin-stimulated glucose disposal by ∼60%. However, supplementing gAd fully rescued insulin’s microvascular action and significantly improved the metabolic responses to insulin in HFD male rats and these actions were abolished by inhibition of either AMPK or nitric oxide production. We conclude that HFD induces vascular adiponectin and insulin resistance but gAd administration can restore vascular insulin responses and improve insulin’s metabolic action via an AMPK- and nitric oxide-dependent mechanism in male rats. Key points Adiponectin is an adipokine with anti-inflammatory and anti-diabetic properties. Hypoadiponectinaemia is closely associated with endothelial dysfunction and insulin resistance in obesity and diabetes. Insulin resistance is present in muscle microvasculature and this may contribute to decreased insulin delivery to, and action in, muscle. In this study we examined whether adiponectin ameliorates metabolic insulin resistance by affecting muscle

Stable coronary syndromes: pathophysiology, diagnostic advances and therapeutic need

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Corcoran, David

2018-01-01

The diagnostic management of patients with angina pectoris typically centres on the detection of obstructive epicardial CAD, which aligns with evidence-based treatment options that include medical therapy and myocardial revascularisation. This clinical paradigm fails to account for the considerable proportion (approximately one-third) of patients with angina in whom obstructive CAD is excluded. This common scenario presents a diagnostic conundrum whereby angina occurs but there is no obstructive CAD (ischaemia and no obstructive coronary artery disease—INOCA). We review new insights into the pathophysiology of angina whereby myocardial ischaemia results from a deficient supply of oxygenated blood to the myocardium, due to various combinations of focal or diffuse epicardial disease (macrovascular), microvascular dysfunction or both. Macrovascular disease may be due to the presence of obstructive CAD secondary to atherosclerosis, or may be dynamic due to a functional disorder (eg, coronary artery spasm, myocardial bridging). Pathophysiology of coronary microvascular disease may involve anatomical abnormalities resulting in increased coronary resistance, or functional abnormalities resulting in abnormal vasomotor tone. We consider novel clinical diagnostic techniques enabling new insights into the causes of angina and appraise the need for improved therapeutic options for patients with INOCA. We conclude that the taxonomy of stable CAD could improve to better reflect the heterogeneous pathophysiology of the coronary circulation. We propose the term ‘stable coronary syndromes’ (SCS), which aligns with the well-established terminology for ‘acute coronary syndromes’. SCS subtends a clinically relevant classification that more fully encompasses the different diseases of the epicardial and microvascular coronary circulation. PMID:29030424

[Advances in animal model and traditional Chinese medicine prevention in coronary microvascular dysfunction].

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Li, Lei; Liu, Jian-Xun; Ren, Jian-Xun; Guo, Hao; Lin, Cheng-Ren

2017-01-01

Coronary microvascular dysfunction (CMD) is a common mechanism for some heart disease like cardiac X syndrome and no-reflow phenomenon after percutaneous coronary intervention(PCI). With the development of medical imageology, CMD has received increased attention. Animal model of CMD is indispensable tool for the research of pathogenesis and treatment evaluation, therefor choose an appropriate animal model is the first issue to carry out CMD research. Experimental and clinical studies have shown unique effectiveness of traditional Chinese medicine(TCM) in CMD therapy. Clarifying of the TCM therapeutic effect mechanisms and seeking an optimal solution of combination of traditional Chinese and western medicine will be the focus of future research. This paper reviewed the establishment and evaluation of CMD animal model, as well as the intervention study of TCM on CMD. The article aims to provide reference for the basic research of CMD and the TCM experimental study on CMD. Copyright© by the Chinese Pharmaceutical Association.

Coronary microvasculopathy in heart transplantation: Consequences and therapeutic implications.

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Vecchiati, Alessandra; Tellatin, Sara; Angelini, Annalisa; Iliceto, Sabino; Tona, Francesco

2014-06-24

Despite the progress made in the prevention and treatment of rejection of the transplanted heart, cardiac allograft vasculopathy (CAV) remains the main cause of death in late survival transplanted patients. CAV consists of a progressive diffuse intimal hyperplasia and the proliferation of vascular smooth muscle cells, ending in wall thickening of epicardial vessels, intramyocardial arteries (50-20 μm), arterioles (20-10 μm), and capillaries (system. The non-immunological factors are older donor age, ischemia-reperfusion time, hyperlipidemia and CMV infections. Diagnostic techniques that are able to assess microvascular function are lacking. Intravascular ultrasound and fractional flow reserve, when performed during coronary angiography, are able to detect epicardial coronary artery disease but are not sensitive enough to assess microvascular changes. Some authors have proposed an index of microcirculatory resistance during maximal hyperemia, which is calculated by dividing pressure by flow (distal pressure multiplied by the hyperemic mean transit time). Non-invasive methods to assess coronary physiology are stress echocardiography, coronary flow reserve by transthoracic Doppler echocardiography, single photon emission computed tomography, and perfusion cardiac magnetic resonance. In this review, we intend to analyze the mechanisms, consequences and therapeutic implications of microvascular dysfunction, including an extended citation of relevant literature data.

Impaired Coronary and Renal Vascular Function in Spontaneously Type 2 Diabetic Leptin-Deficient Mice.

Directory of Open Access Journals (Sweden)

Helena U Westergren

Full Text Available Type 2 diabetes is associated with macro- and microvascular complications in man. Microvascular dysfunction affects both cardiac and renal function and is now recognized as a main driver of cardiovascular mortality and morbidity. However, progression of microvascular dysfunction in experimental models is often obscured by macrovascular pathology and consequently demanding to study. The obese type 2 diabetic leptin-deficient (ob/ob mouse lacks macrovascular complications, i.e. occlusive atherosclerotic disease, and may therefore be a potential model for microvascular dysfunction. The present study aimed to test the hypothesis that these mice with an insulin resistant phenotype might display microvascular dysfunction in both coronary and renal vascular beds.In this study we used non-invasive Doppler ultrasound imaging to characterize microvascular dysfunction during the progression of diabetes in ob/ob mice. Impaired coronary flow velocity reserve was observed in the ob/ob mice at 16 and 21 weeks of age compared to lean controls. In addition, renal resistivity index as well as pulsatility index was higher in the ob/ob mice at 21 weeks compared to lean controls. Moreover, plasma L-arginine was lower in ob/ob mice, while asymmetric dimethylarginine was unaltered. Furthermore, a decrease in renal vascular density was observed in the ob/ob mice.In parallel to previously described metabolic disturbances, the leptin-deficient ob/ob mice also display cardiac and renal microvascular dysfunction. This model may therefore be suitable for translational, mechanistic and interventional studies to improve the understanding of microvascular complications in type 2 diabetes.

Regulation of Coronary Blood Flow in Health and Ischemic Heart Disease

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Duncker, Dirk J.; Koller, Akos; Merkus, Daphne; Canty, John M.

2018-01-01

The major factors determining myocardial perfusion and oxygen delivery have been elucidated over the past several decades, and this knowledge has been incorporated into the management of patients with ischemic heart disease (IHD). The basic understanding of the fluid mechanical behavior of coronary stenoses has also been translated to the cardiac catheterization laboratory where measurements of coronary pressure distal to a stenosis and coronary flow are routinely obtained. However, the role of perturbations in coronary microvascular structure and function, due to myocardial hypertrophy or coronary microvascular dysfunction, in IHD is becoming increasingly recognized. Future studies should therefore be aimed at further improving our understanding of the integrated coronary microvascular mechanisms that control coronary blood flow, and of the underlying causes and mechanisms of coronary microvascular dysfunction. This knowledge will be essential to further improve the treatment of patients with IHD. PMID:25475073

Obesity is associated with lower coronary microvascular density.

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Duncan J Campbell

Full Text Available BACKGROUND: Obesity is associated with diastolic dysfunction, lower maximal myocardial blood flow, impaired myocardial metabolism and increased risk of heart failure. We examined the association between obesity, left ventricular filling pressure and myocardial structure. METHODS: We performed histological analysis of non-ischemic myocardium from 57 patients (46 men and 11 women undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation or loop diuretic therapy. RESULTS: Non-obese (body mass index, BMI, ≤ 30 kg/m(2, n=33 and obese patients (BMI >30 kg/m(2, n=24 did not differ with respect to myocardial total, interstitial or perivascular fibrosis, arteriolar dimensions, or cardiomyocyte width. Obese patients had lower capillary length density (1145 ± 239, mean ± SD, vs. 1371 ± 333 mm/mm(3, P=0.007 and higher diffusion radius (16.9 ± 1.5 vs. 15.6 ± 2.0 μm, P=0.012, in comparison with non-obese patients. However, the diffusion radius/cardiomyocyte width ratio of obese patients (0.73 ± 0.11 μm/μm was not significantly different from that of non-obese patients (0.71 ± 0.11 μm/μm, suggesting that differences in cardiomyocyte width explained in part the differences in capillary length density and diffusion radius between non-obese and obese patients. Increased BMI was associated with increased pulmonary capillary wedge pressure (PCWP, P<0.0001, and lower capillary length density was associated with both increased BMI (P=0.043 and increased PCWP (P=0.016. CONCLUSIONS: Obesity and its accompanying increase in left ventricular filling pressure were associated with lower coronary microvascular density, which may contribute to the lower maximal myocardial blood flow, impaired myocardial metabolism, diastolic dysfunction and higher risk of heart failure in obese individuals.

A randomised trial comparing the effect of exercise training and weight loss on microvascular function in coronary artery disease

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Olsen, Rasmus Huan; Pedersen, Lene Rørholm; Jürs, Anders

2015-01-01

BACKGROUND: Coronary microvascular function is associated with outcome and is reduced in coronary artery disease (CAD) and obesity. We compared the effect of aerobic interval training (AIT) and weight loss on coronary flow reserve (CFR) and peripheral vascular function in revascularised obese CAD...... patients. METHODS AND RESULTS: Seventy non-diabetic patients (BMI 28-40 kg × m(-2), age 45-75 years) were randomised to 12 weeks' AIT (three weekly sessions lasting 38 min with ≈ 16 min at 85-90% of VO2peak) or low energy diet (LED, 800-1000 kcal/day). Per protocol adherence was defined by training......-attendance ≥ 60% and weight loss ≥ 5%, respectively. CFR was assessed by Doppler echocardiography of the LAD. Peripheral vascular function was assessed by arterial tonometry as reactive hyperaemia index (RHI) and augmentation index. Most participants had impaired CFR with a mean CFR of 2.38 (SD 0.59). Twenty...

Opium addiction as an independent risk factor for coronary microvascular dysfunction: A case-control study of 250 consecutive patients with slow-flow angina.

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Esmaeili Nadimi, Ali; Pour Amiri, Farah; Sheikh Fathollahi, Mahmood; Hassanshahi, Gholamhossien; Ahmadi, Zahra; Sayadi, Ahmad Reza

2016-09-15

Approximately 20% to 30% of patients who undergo coronary angiography for assessment of typical cardiac chest pain display microvascular coronary dysfunction (MCD). This study aimed to determine potential relationships between baseline clinical characteristics and likelihood of MCD diagnosis in a large group of patients with stable angina symptoms, positive exercise test and angiographic ally normal epicardial coronary arteries. This cross-sectional study included 250 Iranian with documented evidence of cardiac ischemia on exercise testing, class I or II indication for coronary angiography, and either: (1) angiographically normal coronary arteries and diagnosis of MCD with slow-flow phenomenon, or (2) normal angiogram and no evidence of MCD. All patients completed a questionnaire designed to capture key data including clinical demographics, past medical history, and social factors. Data was evaluated using single and multivariable logistic regression models to identify potential individual patient factors that might help to predict a diagnosis of MCD. 125 (11.2% of total) patients were subsequently diagnosed with MCD. 125 consecutive control subjects were selected for comparison. The mean age was similar among the two groups (52.38 vs. 53.26%, p=ns), but there was a higher proportion of men in the study group compared to control (42.4 vs. 27.2%, p=0.012). No significant relationships were observed between traditional cardiovascular risk factors (diabetes, hypertension, and dyslipidemia) or body mass index (BMI), and likelihood of MCD diagnosis. However, opium addiction was found to be an independent predictor of MCD on single and multivariable logistic regression model (OR=3.575, 95%CI: 1.418-9.016; p=0.0069). We observed a significant relationship between opium addiction and microvascular angina. This novel finding provides a potential mechanistic insight into the pathogenesis of MCD with slow-flow phenomenon. Copyright © 2016 Elsevier Ireland Ltd. All rights

Improving diagnosis and treatment of women with angina pectoris and microvascular disease

DEFF Research Database (Denmark)

Prescott, Eva; Abildstrøm, Steen Zabell; Aziz, Ahmed

2014-01-01

BACKGROUND: The iPOWER study aims at determining whether routine assessment of coronary microvascular dysfunction (CMD) in women with angina and no obstructive coronary artery disease is feasible and identifies women at risk. METHODS: All women with angina referred to invasive angiographic assess...

Model of the coronary circulation based on pressure dependence of coronary resistance and compliance

NARCIS (Netherlands)

Bruinsma, P.; Arts, T.; Dankelman, J.; Spaan, J. A.

1988-01-01

The effect of pressure-dependent changes in vascular volume, resistance and capacitance in the coronary micro-circulation, has been studied by a distributed mathematical model of the coronary micro-vasculature in the left ventricular wall. The model does not include regulation of coronary blood flow

Coronary wave energy: a novel predictor of functional recovery after myocardial infarction.

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De Silva, Kalpa; Foster, Paul; Guilcher, Antoine; Bandara, Asela; Jogiya, Roy; Lockie, Tim; Chowiencyzk, Phil; Nagel, Eike; Marber, Michael; Redwood, Simon; Plein, Sven; Perera, Divaka

2013-04-01

Revascularization after acute coronary syndromes provides prognostic benefit, provided that the subtended myocardium is viable. The microcirculation and contractility of the subtended myocardium affect propagation of coronary flow, which can be characterized by wave intensity analysis. The study objective was to determine in acute coronary syndromes whether early wave intensity analysis-derived microcirculatory (backward) expansion wave energy predicts late viability, defined by functional recovery. Thirty-one patients (58±11 years) were enrolled after non-ST elevation myocardial infarction. Regional left ventricular function and late-gadolinium enhancement were assessed by cardiac magnetic resonance imaging, before and 3 months after revascularization. The backward-traveling (microcirculatory) expansion wave was derived from wave intensity analysis of phasic coronary pressure and velocity in the infarct-related artery, whereas mean values were used to calculate hyperemic microvascular resistance. Twelve-hour troponin T, left ventricular ejection fraction, and percentage late-gadolinium enhancement mass were 1.35±1.21 µg/L, 56±11%, and 8.4±6.0%, respectively. The infarct-related artery backward-traveling (microcirculatory) expansion wave was inversely correlated with late-gadolinium enhancement infarct mass (r=-0.81; Pwave threshold of 2.8 W m(-2) s(-2)×10(5) predicted functional recovery with sensitivity and specificity of 0.91 and 0.82 (AUC 0.88). Hyperemic microvascular resistance correlated with late-gadolinium enhancement mass (r=0.48; P=0.03) but not left ventricular recovery (r=-0.34; P=0.07). The microcirculation-derived backward expansion wave is a new index that correlates with the magnitude and location of infarction, which may allow for the prediction of functional myocardial recovery. Coronary wave intensity analysis may facilitate myocardial viability assessment during cardiac catheterization.

A novel effective method for the assessment of microvascular function in male patients with coronary artery disease: a pilot study using laser speckle contrast imaging

Energy Technology Data Exchange (ETDEWEB)

Borges, J.P. [Laboratório de Atividade Física e Promoção è Saúde, Departamento de Desporto Coletivo, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Lopes, G.O. [Laboratório de Atividade Física e Promoção è Saúde, Departamento de Desporto Coletivo, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Verri, V.; Coelho, M.P.; Nascimento, P.M.C.; Kopiler, D.A. [Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Tibirica, E. [Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Laboratório de Investigação Cardiovascular, Departamento Osório de Almeida, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ (Brazil)

2016-09-01

Evaluation of microvascular endothelial function is essential for investigating the pathophysiology and treatment of cardiovascular and metabolic diseases. Although laser speckle contrast imaging technology is well accepted as a noninvasive methodology for assessing microvascular endothelial function, it has never been used to compare male patients with coronary artery disease with male age-matched healthy controls. Thus, the aim of this study was to determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions of patients with established cardiovascular disease (n=61) and healthy age-matched subjects (n=24). Cutaneous blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with the transdermal iontophoretic delivery of acetylcholine and post-occlusive reactive hyperemia. The maximum increase in skin blood flow induced by acetylcholine was significantly reduced in the cardiovascular disease patients compared with the control subjects (74 vs 116%; P<0.01). With regard to post-occlusive reactive hyperemia-induced vasodilation, the patients also presented reduced responses compared to the controls (0.42±0.15 vs 0.50±0.13 APU/mmHg; P=0.04). In conclusion, laser speckle contrast imaging can identify endothelial and microvascular dysfunctions in male individuals with cardiovascular disease. Thus, this technology appears to be an efficient non-invasive technique for evaluating systemic microvascular and endothelial functions, which could be valuable as a peripheral marker of atherothrombotic diseases in men.

A novel effective method for the assessment of microvascular function in male patients with coronary artery disease: a pilot study using laser speckle contrast imaging

International Nuclear Information System (INIS)

Borges, J.P.; Lopes, G.O.; Verri, V.; Coelho, M.P.; Nascimento, P.M.C.; Kopiler, D.A.; Tibirica, E.

2016-01-01

Evaluation of microvascular endothelial function is essential for investigating the pathophysiology and treatment of cardiovascular and metabolic diseases. Although laser speckle contrast imaging technology is well accepted as a noninvasive methodology for assessing microvascular endothelial function, it has never been used to compare male patients with coronary artery disease with male age-matched healthy controls. Thus, the aim of this study was to determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions of patients with established cardiovascular disease (n=61) and healthy age-matched subjects (n=24). Cutaneous blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with the transdermal iontophoretic delivery of acetylcholine and post-occlusive reactive hyperemia. The maximum increase in skin blood flow induced by acetylcholine was significantly reduced in the cardiovascular disease patients compared with the control subjects (74 vs 116%; P<0.01). With regard to post-occlusive reactive hyperemia-induced vasodilation, the patients also presented reduced responses compared to the controls (0.42±0.15 vs 0.50±0.13 APU/mmHg; P=0.04). In conclusion, laser speckle contrast imaging can identify endothelial and microvascular dysfunctions in male individuals with cardiovascular disease. Thus, this technology appears to be an efficient non-invasive technique for evaluating systemic microvascular and endothelial functions, which could be valuable as a peripheral marker of atherothrombotic diseases in men

Estimation of the flow resistances exerted in coronary arteries using a vessel length-based method.

Science.gov (United States)

Lee, Kyung Eun; Kwon, Soon-Sung; Ji, Yoon Cheol; Shin, Eun-Seok; Choi, Jin-Ho; Kim, Sung Joon; Shim, Eun Bo

2016-08-01

Flow resistances exerted in the coronary arteries are the key parameters for the image-based computer simulation of coronary hemodynamics. The resistances depend on the anatomical characteristics of the coronary system. A simple and reliable estimation of the resistances is a compulsory procedure to compute the fractional flow reserve (FFR) of stenosed coronary arteries, an important clinical index of coronary artery disease. The cardiac muscle volume reconstructed from computed tomography (CT) images has been used to assess the resistance of the feeding coronary artery (muscle volume-based method). In this study, we estimate the flow resistances exerted in coronary arteries by using a novel method. Based on a physiological observation that longer coronary arteries have more daughter branches feeding a larger mass of cardiac muscle, the method measures the vessel lengths from coronary angiogram or CT images (vessel length-based method) and predicts the coronary flow resistances. The underlying equations are derived from the physiological relation among flow rate, resistance, and vessel length. To validate the present estimation method, we calculate the coronary flow division over coronary major arteries for 50 patients using the vessel length-based method as well as the muscle volume-based one. These results are compared with the direct measurements in a clinical study. Further proving the usefulness of the present method, we compute the coronary FFR from the images of optical coherence tomography.

Coronary flow reserve in patients with diabetes mellitus and prediabetes.

Science.gov (United States)

Atar, Asli I; Altuner, Tugba Kayhan; Bozbas, Huseyin; Korkmaz, Mehmet E

2012-07-01

Abnormalities of coronary microcirculation have been reported in patients with diabetes mellitus (DM) even in the presence of normal coronary arteries. It is unknown when the microvascular effects on coronary arteries begin to appear in the DM disease course. Coronary flow reserve (CFR), determined by pharmacological stress transthoracic Doppler echocardiography, is a reliable indicator of coronary microvascular function. We sought to determine the coronary microvascular function of prediabetic patients compared to DM patients and normal population. Seventy-four subjects with normal coronary arteries were enrolled. DM and prediabetes were diagnosed according to American Diabetes Association criteria. All subjects had Doppler recordings of the left anterior descending artery with adenosine infusion at a rate of 0.014 mg/kg per minute. The demographical characteristics and laboratory findings of the three groups were similar (DM group: n = 25, mean age 62 ± 7 years, 19 females; prediabetic group: n = 25, mean age 64 ± 12 years, 21 females; control group: n = 24, mean age 63 ± 7 years, 15 females) except fasting glucose levels. CFR values of the three groups were significantly different (DM group: CFR = 1.75 ± 0.50; prediabetic group: CFR = 2.24 ± 0.43; control group: CFR = 2.38 ± 0.32, P < 0.001). CFR values of DM group were lower than those of prediabetic and control groups (DM vs. prediabetic: P < 0.001, DM vs. control: P < 0.001). However, CFR levels of prediabetic group were not different from those of the control group (P = 0.481). DM was an independent factor predictive of CFR < 2 (OR, 22.69; 95% CI, 6.47-79.51; P < 0.001). Coronary microvascular function seems to be normal in the prediabetic state, but dysfunction appears after DM becomes overt. © 2012, Wiley Periodicals, Inc.

Reduced coronary flow and resistance reserve in primary scleroderma myocardial disease

International Nuclear Information System (INIS)

Nitenberg, A.; Foult, J.M.; Kahan, A.; Perennec, J.; Devaux, J.Y.; Menkes, C.J.; Amor, B.

1986-01-01

The maximum coronary vasodilator capacity after intravenous dipyridamole (0.14 mg X kg-1 X min-1 X 4 minutes) was studied in seven patients with primary scleroderma myocardial disease and compared to that of seven control subjects. Hemodynamic data and left ventricular angiographic data were not different in the two groups. The coronary flow reserve was evaluated by the dipyridamole/basal coronary sinus blood flow ratio (D/B CSBF) and the coronary resistance reserve by the dipyridamole/basal coronary resistance ratio (D/B CR). Coronary reserve was greatly impaired in the group with primary scleroderma myocardial disease: D/B CSBF was lower than in the control group (2.54 +/- 1.37 vs 4.01 +/- 0.56, respectively; p less than 0.05) and D/B CR was higher than in the control group (0.47 +/- 0.25 vs 0.23 +/- 0.04, respectively; p less than 0.05). Such a decreased coronary flow and resistance reserve in patients with primary scleroderma myocardial disease was not explained by an alteration of left ventricular function. It may be an important contributing factor in the pathogenesis of primary scleroderma myocardial disease

Coronary Flow Velocity Reserve Assessed by Transthoracic Doppler

DEFF Research Database (Denmark)

Michelsen, Marie M; Peña, Adam; Mygind, Naja D

2016-01-01

the feasibility and factors associated with the quality of CFVR obtained in a large prospective study of women suspected of having microvascular disease. METHODS: Women with angina-like chest pain and no obstructive coronary artery disease on coronary angiography (

Peripheral Endothelial Function and Coronary Flow Velocity Reserve Are Not Associated in Women with Angina and No Obstructive Coronary Artery Disease

DEFF Research Database (Denmark)

Flintholm Raft, Kristoffer; Frestad, Daria; Michelsen, Marie Mide

2017-01-01

PURPOSE: We investigated whether impaired flow-mediated dilation (FMD) and plasma biomarkers reflecting endothelial dysfunction are associated with coronary microvascular dysfunction (CMD) in women with angina and no obstructive coronary artery disease (CAD). METHODS: Patients (n = 194) were rand...

Association of insulin resistance and coronary artery remodeling: an intravascular ultrasound study

OpenAIRE

Kim, Sang-Hoon; Moon, Jae-Youn; Lim, Yeong Min; Kim, Kyung Ho; Yang, Woo-In; Sung, Jung-Hoon; Yoo, Seung Min; Kim, In Jai; Lim, Sang-Wook; Cha, Dong-Hun; Cho, Seung-Yun

2015-01-01

Background There are few studies that investigated the correlation between insulin resistance (IR) and the coronary artery remodeling. The aim of the study is to investigate the association of IR measured by homeostasis model assessment of insulin resistance (HOMA-IR) and coronary artery remodeling evaluated by intravascular ultrasound (IVUS). Methods A total of 298 consecutive patients who received percutaneous coronary interventions under IVUS guidance were retrospectively enrolled. The val...

Corrected thrombolysis in myocardial infarction frame counts in diabetic patients with angiographically normal coronary arteries

International Nuclear Information System (INIS)

Turkoglu, S.; Ozdemir, M.; Tacoy, G.; Tavil, Y.; Abaci, A.; Timurkaynak, T.; Cengel, A.

2008-01-01

Objective was to evaluate corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) in patients with angiographically normal coronary arteries and diabetes mellitus, a condition known to be associated with microvascular dysfunction. Patients who underwent coronary angiography in Gazi University Hospital, Ankara, Turkey between January 2000 and January 2005 were studied. Corrected TIMI frame count was left circumflex (Cx) and right coronary arteries (RCA) in 118 diabetic and 122 non-diabetic patients with normal coronary angiogram. The mean CTFC values of the LAD, Cx and the RCA were similar in diabetics and nondiabetics (21.0+-7.5 versus 21.3+-9.6, 23.3+-9.7 versus 23.5+-10.8, 17.9+-6.7 versus 18.7+-7.4 respectively, p>0.05 for all comparisons). In stepwise multivariate linear regression analysis, body surface area had a significant correlation with CTFC of all the 3 coronary arteries. We conclude that CTFC in diabetics and non-diabetics with angiographically normal coronary arteries is similar. Since microvascular disease is an inherent component of diabetes, our finding may reflect the inadequacy of CTFC in predicting microvascular disease in diabetic patients with normal coronary angiograms. (author)

Comparison of Myocardial Perfusion Scintigraphy and Coronary Angiography Results

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Umut Elboga

2017-05-01

Full Text Available Aim: Coronary artery disease (CAD is one of the most frequent causes of mortality and morbidity worldwide. Coronary angiography is the gold standard for the anatomical diagnosis of coronary artery stenosis. Myocardial Perfusion Scintigraphy (MPS is a non-invasive imaging modality used for the diagnosis of CAD. In this study, we aimed to compare the findings of MPS and coronary angiogram. Material and Method: Eighty-one patients (37 males, 44 females; mean age 55 ± 10.95 years with angina and detected perfusion defects on MPS were included in this study. All of the patients underwent coronary angiogram. A narrowing %u2265 50% was considered pathological on the coronary angiography. Results: Findings of the coronary angiogram and MPS were compared and found consistent in 51 (63% patients. A coronary narrowing < 50% was detected by coronary angiogram in 4 (5% of the remaining patients. Coronary angiogram was found to be normal in the remaining 26 patients (32% and these patients were evaluated as cardiac syndrome X (CSX known as microvascular angina (MA. Discussion: The findings showed that MPS is superior to coronary angiogram in the early diagnosis of myocardial perfusion disorders at the microvascular level. Therefore, we concluded that MPS should be the primary diagnostic tool to begin treatment before an anatomically large narrowing occurs in the coronaries.

Increase in stenotic resistance following a brief coronary occlusion in the anesthetized open-chest dog.

OpenAIRE

Saito, Daiji; Yasuhara, Koichiro; Takeda, Hikaru; Hyodo, Tatuo; Yamada, Nobuyuki; Uchida, Toshiaki; Haraoka, Shoichi; Nagashima, Hideo

1982-01-01

Changes in the stenotic resistance of a coronary artery following brief coronary occlusion were studied in the anesthetized open-chest dog. A critical coronary stenosis was constructed by tying a thick string around the circumflex coronary artery (LCx) near its origin. The LCx was occluded for 5, 10, 15, 20 and 30 seconds with and without coronary stenosis then the reactive hyperemia was observed. In the absence of the stenosis, resistance of the segment of the large coronary artery remained ...

What can we learn about treating heart failure from the heart's response to acute exercise? Focus on the coronary microcirculation.

Science.gov (United States)

Heinonen, Ilkka; Sorop, Oana; de Beer, Vincent J; Duncker, Dirk J; Merkus, Daphne

2015-10-15

Coronary microvascular function and cardiac function are closely related in that proper cardiac function requires adequate oxygen delivery through the coronary microvasculature. Because of the close proximity of cardiomyocytes and coronary microvascular endothelium, cardiomyocytes not only communicate their metabolic needs to the coronary microvasculature, but endothelium-derived factors also directly modulate cardiac function. This review summarizes evidence that the myocardial oxygen balance is disturbed in the failing heart because of increased extravascular compressive forces and coronary microvascular dysfunction. The perturbations in myocardial oxygen balance are exaggerated during exercise and are due to alterations in neurohumoral influences, endothelial function, and oxidative stress. Although there is some evidence from animal studies that the myocardial oxygen balance can partly be restored by exercise training, it is largely unknown to what extent the beneficial effects of exercise training include improvements in endothelial function and/or oxidative stress in the coronary microvasculature and how these improvements are impacted by risk factors such as diabetes, obesity, and hypercholesterolemia. Copyright © 2015 the American Physiological Society.

Coronary Flow Reserve Predicts Cardiopulmonary Fitness in Patients with Coronary Artery Disease Independently of Systolic and Diastolic Function

DEFF Research Database (Denmark)

Snoer, Martin; Olsen, Rasmus Huan; Monk-Hansen, Tea

2014-01-01

Aims Despite revascularization and optimal medical treatment, patients with coronary artery disease (CAD) have reduced exercise capacity. In the absence of coronary artery stenosis, coronary flow reserve (CFR) is a measure of coronary microvascular function, and a marker of future poor outcome...... in CAD patients. The aim of this study was to examine the relationship among CFR, systolic and diastolic function, peripheral vascular function, and cardiopulmonary fitness in CAD patients. Methods and Results Forty patients with median left ventricular ejection fraction (LVEF) 49 (interquartile 46....... Conclusions Coronary flow reserve measured noninvasively predicts cardiopulmonary fitness independently of resting systolic and diastolic function in CAD patients, indicating that cardiac output during maximal exercise is dependent on the ability of the coronary circulation to adapt to the higher metabolic...

Coronary Physiology During Exercise and Vasodilation in the Healthy Heart and in Severe Aortic Stenosis.

Science.gov (United States)

Lumley, Matthew; Williams, Rupert; Asrress, Kaleab N; Arri, Satpal; Briceno, Natalia; Ellis, Howard; Rajani, Ronak; Siebes, Maria; Piek, Jan J; Clapp, Brian; Redwood, Simon R; Marber, Michael S; Chambers, John B; Perera, Divaka

2016-08-16

Severe aortic stenosis (AS) can manifest as exertional angina even in the presence of unobstructed coronary arteries. The authors describe coronary physiological changes during exercise and hyperemia in the healthy heart and in patients with severe AS. Simultaneous intracoronary pressure and flow velocity recordings were made in unobstructed coronary arteries of 22 patients with severe AS (mean effective orifice area 0.7 cm(2)) and 38 controls, at rest, during supine bicycle exercise, and during hyperemia. Stress echocardiography was performed to estimate myocardial work. Wave intensity analysis was used to quantify waves that accelerate and decelerate coronary blood flow (CBF). Despite a greater myocardial workload in AS patients compared with controls at rest (12,721 vs. 9,707 mm Hg/min(-1); p = 0.003) and during exercise (27,467 vs. 20,841 mm Hg/min(-1); p = 0.02), CBF was similar in both groups. Hyperemic CBF was less in AS compared with controls (2,170 vs. 2,716 cm/min(-1); p = 0.05). Diastolic time fraction was greater in AS compared with controls, but minimum microvascular resistance was similar. With exercise and hyperemia, efficiency of perfusion improved in the healthy heart, demonstrated by an increase in the relative contribution of accelerating waves. By contrast, in AS, perfusion efficiency decreased due to augmentation of early systolic deceleration and an attenuated rise in systolic acceleration waves. Invasive coronary physiological evaluation can be safely performed during exercise and hyperemia in patients with severe aortic stenosis. Ischemia in AS is not related to microvascular disease; rather, it is driven by abnormal cardiac-coronary coupling. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Sex-Related Differences in Vasomotor Function in Patients With Angina and Unobstructed Coronary Arteries

DEFF Research Database (Denmark)

Aziz, Ahmed; Hansen, Henrik Steen; Sechtem, Udo

2017-01-01

BACKGROUND Coronary vasomotor dysfunction is an important mechanism for angina in patients with unobstructed coronary arteries. OBJECTIVES The purpose of this study was to determine sex differences in the prevalence and clinical presentation of vasomotor dysfunction in a European population...... and to examine sex differences in the dose of acetylcholine leading to a positive acetylcholine provocation test (ACH test). METHODS Between 2007 and 2014, we included 1,379 consecutive patients with stable angina, unobstructed coronaries and ACH test performed for epicardial vasospasm or coronary microvascular...... dysfunction (CMD) due to microvascular spasm. The predictive value of sex, risk factors, symptoms, and noninvasive test results was analyzed by means of logistic regression. RESULTS The mean patient age was 62 years, and 42% were male. There were 813 patients (59 with a pathological ACH test, 33% for CMD...

Cardiac rehabilitation: a good measure to improve quality of life in peri- and postmenopausal women with microvascular angina

OpenAIRE

Wojciech Szot; Joanna Zając; Magdalena Kostkiewicz; Jakub Owoc; Iwona Bojar

2015-01-01

Cardiac Syndrome X (CSX) was considered a stable coronary syndrome, yet due to its nature, CSX symptoms often have a great impact on patients’ Quality of Life (QoL). According to ESC 2013 stable coronary artery disease criteria, CSX was replaced by Microvascular Angina (MA).Unfortunately, most CSX or MA patients, after classical angina (involving main coronary vessels) has been ruled out, often do not receive proper treatment. Indications for pharmacological treatment of MA patients were intr...

Endothelial Progenitor Cells in Diabetic Microvascular Complications: Friends or Foes?

Science.gov (United States)

Yu, Cai-Guo; Zhang, Ning; Yuan, Sha-Sha; Ma, Yan; Yang, Long-Yan; Feng, Ying-Mei; Zhao, Dong

2016-01-01

Despite being featured as metabolic disorder, diabetic patients are largely affected by hyperglycemia-induced vascular abnormality. Accumulated evidence has confirmed the beneficial effect of endothelial progenitor cells (EPCs) in coronary heart disease. However, antivascular endothelial growth factor (anti-VEGF) treatment is the main therapy for diabetic retinopathy and nephropathy, indicating the uncertain role of EPCs in the pathogenesis of diabetic microvascular disease. In this review, we first illustrate how hyperglycemia induces metabolic and epigenetic changes in EPCs, which exerts deleterious impact on their number and function. We then discuss how abnormal angiogenesis develops in eyes and kidneys under diabetes condition, focusing on "VEGF uncoupling with nitric oxide" and "competitive angiopoietin 1/angiopoietin 2" mechanisms that are shared in both organs. Next, we dissect the nature of EPCs in diabetic microvascular complications. After we overview the current EPCs-related strategies, we point out new EPCs-associated options for future exploration. Ultimately, we hope that this review would uncover the mysterious nature of EPCs in diabetic microvascular disease for therapeutics.

Prevalence, predictors, and outcomes in treatment-resistant hypertension in patients with coronary disease.

Science.gov (United States)

Bangalore, Sripal; Fayyad, Rana; Laskey, Rachel; Demicco, David A; Deedwania, Prakash; Kostis, John B; Messerli, Franz H

2014-01-01

Increasingly, apparent treatment-resistant hypertension has been recognized. However, much of the prevalence, predictors, and outcomes are largely unknown, especially in patients with coronary artery disease. We evaluated 10,001 patients with coronary artery disease who were enrolled in the Treating to New Targets trial. Apparent treatment-resistant hypertension was defined as blood pressure ≥ 140 mm Hg despite 3 antihypertensive agents or hypertension. In a multivariable model adjusting for baseline differences, the treatment-resistant hypertension group had a 64% increase in primary outcome (hazard ratio [HR], 1.64; 95% confidence interval [CI], 1.39-1.94; P hypertension group. In addition, patients with apparent treatment-resistant hypertension had a 71% increase in major coronary event (P hypertension group. Results were largely similar whether the definition of apparent treatment-resistant hypertension was based on a blood pressure ≥ 140 mm Hg despite 3 agents or a blood pressure hypertension is associated with a marked increase in the risk of cardiovascular morbidity and mortality, including an increase in all-cause death. Copyright © 2014 Elsevier Inc. All rights reserved.

A mathematical model of coronary blood flow control: simulation of patient-specific three-dimensional hemodynamics during exercise

Science.gov (United States)

Lau, Kevin D.; Asrress, Kaleab N.; Redwood, Simon R.; Figueroa, C. Alberto

2016-01-01

This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input. The model can be used in zero-dimensional lumped parameter network studies or as a boundary condition for three-dimensional multidomain Navier-Stokes blood flow simulations. For the first time, this model provides feedback control of the coronary vascular resistance, which can be used to enhance the physiological accuracy of any hemodynamic simulation, which includes both a heart model and coronary arteries. This has particular relevance to patient-specific simulation for which heart rate and aortic pressure recordings are available. In addition to providing a simulation tool, under our assumptions, the derivation of our model shows that β-feedforward control of the coronary microvascular resistance is a mathematical necessity and that the metabolic feedback control must be dependent on two error signals: the historical myocardial oxygen debt, and the instantaneous myocardial oxygen deficit. PMID:26945076

A mathematical model of coronary blood flow control: simulation of patient-specific three-dimensional hemodynamics during exercise.

Science.gov (United States)

Arthurs, Christopher J; Lau, Kevin D; Asrress, Kaleab N; Redwood, Simon R; Figueroa, C Alberto

2016-05-01

This work presents a mathematical model of the metabolic feedback and adrenergic feedforward control of coronary blood flow that occur during variations in the cardiac workload. It is based on the physiological observations that coronary blood flow closely follows myocardial oxygen demand, that myocardial oxygen debts are repaid, and that control oscillations occur when the system is perturbed and so are phenomenological in nature. Using clinical data, we demonstrate that the model can provide patient-specific estimates of coronary blood flow changes between rest and exercise, requiring only the patient's heart rate and peak aortic pressure as input. The model can be used in zero-dimensional lumped parameter network studies or as a boundary condition for three-dimensional multidomain Navier-Stokes blood flow simulations. For the first time, this model provides feedback control of the coronary vascular resistance, which can be used to enhance the physiological accuracy of any hemodynamic simulation, which includes both a heart model and coronary arteries. This has particular relevance to patient-specific simulation for which heart rate and aortic pressure recordings are available. In addition to providing a simulation tool, under our assumptions, the derivation of our model shows that β-feedforward control of the coronary microvascular resistance is a mathematical necessity and that the metabolic feedback control must be dependent on two error signals: the historical myocardial oxygen debt, and the instantaneous myocardial oxygen deficit. Copyright © 2016 the American Physiological Society.

Optimization of flow reserve measurement using SPECT technology to evaluate the determinants of coronary microvascular dysfunction in diabetes

Energy Technology Data Exchange (ETDEWEB)

Marini, Cecilia [CNR Institute of Bioimages and Molecular Physiology, Milan, Section of Genoa (Italy); Bezante, GianPaolo; Modonesi, Elisa; Rollando, Daniela; Balbi, Manrico; Brunelli, Claudio [University of Genoa, Department of Internal Medicine, Cardiology, Genoa (Italy); Gandolfo, Patrizia; Morbelli, Silvia D.; Armonino, Riccardo [University of Genoa, Department of Internal Medicine, Nuclear Medicine, Genoa (Italy); DePascale, Angelo; Maggi, Davide; Albertelli, Manuela; Cordera, Renzo [University of Genoa, Department of Endocrinological Metabolic Sciences, Diabetology, Genoa (Italy); Sambuceti, Gianmario [University of Genoa, Department of Internal Medicine, Nuclear Medicine, Genoa (Italy); Advanced Biotechnology Center, Genoa (Italy)

2010-02-15

The aim of this study was to validate a new method to measure regional myocardial perfusion reserve (MPR) with technetium-labelled tracers in patients with type 2 diabetes mellitus (DM2). A total of 40 consecutive DM2 patients without history of coronary artery disease (CAD) and 7 control subjects were recruited. Dipyridamole myocardial blood flow index (MBF) was assessed by measuring first transit counts in the pulmonary artery and myocardial count rate from gated SPECT images using {sup 99m}Tc-labelled tracers. The corresponding MBF index was estimated 2 h later according to the same procedure. Regional myocardial perfusion reserve (MPR) was defined as the ratio between dipyridamole and baseline MBF using a 17-segment left ventricular (LV) model. Coronary flow reserve (CFR) was estimated by transthoracic contrast echo Doppler monitoring of flow velocity in the left anterior descending coronary artery (LAD) during the same session. Estimated MPR was higher in control subjects than in patients (3.36 {+-} 0.66 vs 1.91 {+-} 0.61, respectively, p < 0.01). In patients, LAD CFR and LAD MPR were 2.01 {+-} 0.78 vs 1.93 {+-} 0.63, respectively (p = ns). The agreement between the two techniques was documented by their close correlation (r = 0.92, p < 0.001) and confirmed by the Bland-Altman analysis. Reversible perfusion defects occurred in 13 patients (32%) who showed similar MPR values as the remaining 27 (2.10 {+-} 0.71 vs 1.83 {+-} 0.71, respectively, p = ns). Finally, MPR was closely correlated with age (r = -0.50, p < 0.01) and time elapsed from the diagnosis of DM2 (r = -0.51, p < 0.01). LV regional MPR can be accurately estimated with the broadly available single photon technology. Application of this method to DM2 patients documents the presence of a microvascular dysfunction homogeneously distributed throughout the LV walls and most frequently not associated with reversible perfusion defects. (orig.)

Tumor necrosis factor-alpha increases myocardial microvascular transport in vivo

DEFF Research Database (Denmark)

Hansen, P R; Svendsen, Jesper Hastrup; Høyer, S

1994-01-01

Tumor necrosis factor-alpha (TNF-alpha) is a primary mediator in the pathogenesis of tissue injury, and high circulating levels of TNF-alpha are found in a variety of pathological conditions. In open-chest anesthetized dogs, the effects of intracoronary recombinant human TNF-alpha (rTNF-alpha; 100...... in cardiac output and was associated with the appearance of areas with myocardial necrosis in the regional left ventricular wall. The myocardial plasma flow rate and maximum plasma flow rate in response to a 30-s coronary occlusion were not influenced by rTNF-alpha, although a decrease in the myocardial...... ng/kg for 60 min) on myocardial microvascular transport of a small hydrophilic indicator was examined by the single-injection, residue-detection method. Intracoronary infusion of rTNF-alpha increased myocardial microvascular transport after 120 min. This increase was preceded by a sustained decline...

Obese but not normal-weight women with polycystic ovary syndrome are characterized by metabolic and microvascular insulin resistance.

Science.gov (United States)

Ketel, Iris J G; Stehouwer, Coen D A; Serné, Erik H; Korsen, Ted J M; Hompes, Peter G A; Smulders, Yvo M; de Jongh, Renate T; Homburg, Roy; Lambalk, Cornelis B

2008-09-01

Polycystic ovary syndrome (PCOS) and obesity are associated with diabetes and cardiovascular disease, but it is unclear to what extent PCOS contributes independently of obesity. The objective of the study was to investigate whether insulin sensitivity and insulin's effects on the microcirculation are impaired in normal-weight and obese women with PCOS. Thirty-five women with PCOS (19 normal weight and 16 obese) and 27 age- and body mass index-matched controls (14 normal weight and 13 obese) were included. Metabolic Insulin sensitivity (isoglycemic-hyperinsulinemic clamp) and microvascular insulin sensitivity [endothelium dependent (acetylcholine [ACh])] and endothelium-independent [sodium nitroprusside (SNP)] vasodilation with laser Doppler flowmetry was assessed at baseline and during hyperinsulinemia. Metabolic insulin sensitivity (M/I value) and the area under the response curves to ACh and SNP curves were measured to assess microcirculatory function at baseline and during insulin infusion (microvascular insulin sensitivity). Obese women were more insulin resistant than normal-weight women (P PCOS women were more resistant than obese controls (P = 0.02). In contrast, normal-weight women with PCOS had similar insulin sensitivity, compared with normal-weight women without PCOS. Baseline responses to ACh showed no difference in the four groups. ACh responses during insulin infusion were significantly greater in normal-weight PCOS and controls than in obese PCOS and controls. PCOS per se had no significant influence on ACh responses during insulin infusion. During hyperinsulinemia, SNP-dependent vasodilatation did not significantly increase, compared with baseline in the four groups. PCOS per se was not associated with impaired metabolic insulin sensitivity in normal-weight women but aggravates impairment of metabolic insulin sensitivity in obese women. In obese but not normal-weight women, microvascular and metabolic insulin sensitivity are decreased, independent

Identification of canine coronary resistance and intramyocardial compliance on the basis of the waterfall model.

Science.gov (United States)

Burattini, R; Sipkema, P; van Huis, G A; Westerhof, N

1985-01-01

This study was performed to elucidate the effects of cardiac contraction on coronary pressure-flow relations. On the basis of the waterfall mechanism, a lumped model of the coronary arterial system is presented consisting of a proximal (epicardial) compliance, a coronary resistance, and an intramyocardial compliance. A "back"-pressure, assumed to be proportional (constant k) to left ventricular pressure, impedes flow. From steady-state measurements of circumflex coronary artery flow and inflow pressure, together with left ventricular pressure, the values of the three model parameters and the constant k have been estimated. In the control condition proximal compliance is found to be 1.7 X 10(-12) m4s2kg-1, intramyocardial compliance 110 X 10(-12)m4s2kg-1, and resistance 7.5 X 10(9) kgm-4s-1. The proportionality constant k is close to unity. Effects of changes in left ventricular pressure and inflow pressure and the effect of vasoactive drugs on the parameters are also investigated. Changes in coronary resistance are always opposite to changes in intramyocardial compliance. Sensitivity analysis showed that epicardial compliance plays its major role during isovolumic contraction and relaxation; resistance plays a role throughout the cardiac cycle but is more important in diastole than in systole, whereas intramyocardial compliance plays a role in systole and in early diastole.

Hypothyroidism Is Associated With Coronary Endothelial Dysfunction in Women

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Sara, Jaskanwal D; Zhang, Ming; Gharib, Hossein; Lerman, Lilach O; Lerman, Amir

2015-01-01

Background Hypothyroidism is associated with an increased risk of coronary artery disease, beyond that which can be explained by its association with conventional cardiovascular risk factors. Coronary endothelial dysfunction precedes atherosclerosis, has been linked to adverse cardiovascular events, and may account for some of the increased risk in patients with hypothyroidism. The aim of this study was to determine whether there is an association between epicardial and microvascular coronary endothelial dysfunction and hypothyroidism. Methods and Results In 1388 patients (mean age 50.5 [12.3] years, 34% male) presenting with stable chest pain to Mayo Clinic, Rochester, MN for diagnostic coronary angiography, and who were found to have nonobstructive coronary artery disease (hypothyroidism, defined as a documented history of hypothyroidism or a thyroid-stimulating hormone (TSH) >10.0 mU/mL, n=188, and euthyroidism, defined as an absence of a history of hypothyroidism in the clinical record and/or 0.3hypothyroidism had a significantly lower % Δ CBF Ach (48.26 [80.66] versus 64.58 [128.30]) compared to patients with euthyroidism, while the % Δ CAD Ach did not vary significantly between groups. After adjusting for covariates, females with hypothyroidism still had a significantly lower % Δ CBF Ach (estimated difference in % Δ CBF Ach [SE]: −16.79 [8.18]). Conclusions Hypothyroidism in women is associated with microvascular endothelial dysfunction, even after adjusting for confounders, and may explain some of the increased risk of cardiovascular disease in these patients. PMID:26224049

Microvascular Cranial Nerve Palsy

Science.gov (United States)

... Español Eye Health / Eye Health A-Z Microvascular Cranial Nerve Palsy Sections What Is Microvascular Cranial Nerve Palsy? ... Microvascular Cranial Nerve Palsy Treatment What Is Microvascular Cranial Nerve Palsy? Leer en Español: ¿Qué es una parálisis ...

CMR of microvascular obstruction and hemorrhage in myocardial infarction

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Wu Katherine C

2012-09-01

Full Text Available Abstract Microvascular obstruction (MO or no-reflow phenomenon is an established complication of coronary reperfusion therapy for acute myocardial infarction. It is increasingly recognized as a poor prognostic indicator and marker of subsequent adverse LV remodeling. Although MO can be assessed using various imaging modalities including electrocardiography, myocardial contrast echocardiography, nuclear scintigraphy, and coronary angiography, evaluation by cardiovascular magnetic resonance (CMR is particularly useful in enhancing its detection, diagnosis, and quantification, as well as following its subsequent effects on infarct evolution and healing. MO assessment has become a routine component of the CMR evaluation of acute myocardial infarction and will increasingly play a role in clinical trials of adjunctive reperfusion agents and strategies. This review will summarize the pathophysiology of MO, current CMR approaches to diagnosis, clinical implications, and future directions needed for improving our understanding of this common clinical problem.

Potential Biomarkers of Insulin Resistance and Atherosclerosis in Type 2 Diabetes Mellitus Patients with Coronary Artery Disease

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Sharifah Intan Qhadijah Syed Ikmal

2013-01-01

Full Text Available Type 2 diabetes mellitus patients with coronary artery disease have become a major public health concern. The occurrence of insulin resistance accompanied with endothelial dysfunction worsens the state of atherosclerosis in type 2 diabetes mellitus patients. The combination of insulin resistance and endothelial dysfunction leads to coronary artery disease and ischemic heart disease complications. A recognized biological marker, high-sensitivity C-reactive protein, has been used widely to assess the progression of atherosclerosis and inflammation. Along with coronary arterial damage and inflammatory processes, high-sensitivity C-reactive protein is considered as an essential atherosclerosis marker in patients with cardiovascular disease, but not as an insulin resistance marker in type 2 diabetes mellitus patients. A new biological marker that can act as a reliable indicator of both the exact state of insulin resistance and atherosclerosis is required to facilitate optimal health management of diabetic patients. Malfunctioning of insulin mechanism and endothelial dysfunction leads to innate immune activation and released several biological markers into circulation. This review examines potential biological markers, YKL-40, alpha-hydroxybutyrate, soluble CD36, leptin, resistin, interleukin-18, retinol binding protein-4, and chemerin, as they may play significant roles in insulin resistance and atherosclerosis in type 2 diabetes mellitus patients with coronary artery disease.

Tetrahydrobiopterin restores impaired coronary microvascular dysfunction in hypercholesterolaemia

Energy Technology Data Exchange (ETDEWEB)

Wyss, Christophe A.; Koepfli, Pascal; Namdar, Mehdi; Siegrist, Patrick T.; Kaufmann, Philipp A. [University Hospital, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Luscher, Thomas F. [University Hospital, Division of Cardiology, Cardiovascular Center, Zurich (Switzerland); Camici, Paolo G. [Hammersmith Hospital, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College of Science, Technology and Medicine, London (United Kingdom)

2005-01-01

Tetrahydrobiopterin (BH{sub 4}) is an essential co-factor for the synthesis of nitric oxide (NO), and BH{sub 4} deficiency may cause impaired NO synthase (NOS) activity. We studied whether BH{sub 4} deficiency contributes to the coronary microcirculatory dysfunction observed in patients with hypercholesterolaemia. Myocardial blood flow (MBF; ml min{sup -1} g{sup -1}) was measured at rest, during adenosine-induced (140 {mu}g kg{sup -1} min{sup -1} over 7 min) hyperaemia (mainly non-endothelium dependent) and immediately after supine bicycle exercise (endothelium-dependent) stress in ten healthy volunteers and in nine hypercholesterolaemic subjects using {sup 15}O-labelled water and positron emission tomography. Measurements were repeated 60 min later, after intravenous infusion of BH{sub 4} (10 mg kg{sup -1} body weight over 30 min). Adenosine-induced hyperaemic MBF is considered to represent (near) maximal flow. Flow reserve utilisation was calculated as the ratio of exercise-induced to adenosine-induced hyperaemic MBF and expressed as percent to indicate how much of the maximal (adenosine-induced) hyperaemia can be achieved by bicycle stress. BH{sub 4} increased exercise-induced hyperaemia in controls (2.96{+-}0.58 vs 3.41{+-}0.73 ml min{sup -1} g{sup -1}, p<0.05) and hypercholesterolaemic subjects (2.47{+-}0.78 vs 2.70{+-}0.72 ml min{sup -1} g{sup -1}, p<0.01) but had no influence on MBF at rest or during adenosine-induced hyperaemia in controls (4.52{+-}1.10 vs 4.85{+-}0.45 ml min{sup -1} g{sup -1}, p=NS) or hypercholesterolaemic subjects (4.86{+-}1.18 vs 4.53{+-}0.93 ml min{sup -1} g{sup -1}, p=NS). Flow reserve utilisation remained unchanged in controls (70{+-}17% vs 71{+-}19%, p=NS) but increased significantly in hypercholesterolaemic subjects (53{+-}15% vs 66{+-}14%, p<0.05). BH{sub 4} restores flow reserve utilisation of the coronary microcirculation in hypercholesterolaemic subjects, suggesting that BH{sub 4} deficiency may contribute to coronary

Resistance training and predicted risk of coronary heart disease in ...

African Journals Online (AJOL)

The purpose of this study was to determine the impact of resistance training, designed to prevent the development of coronary heart disease (CHD) based on the Framingham Risk Assessment (FRA) score. Twenty-five healthy sedentary men with low CHD risk were assigned to participate in a 16-week (three days per week) ...

Peripheral Reactive Hyperemia Index and Coronary Microvascular Function in Women With no Obstructive CAD

DEFF Research Database (Denmark)

Michelsen, Marie Mide; Mygind, Naja Dam; Pena, Adam

2016-01-01

and the endothelial-independent aspect of CMD assessed as a coronary flow velocity reserve (CFVR). METHODS: We included 339 women with chest pain suggestive of angina pectoris and a diagnostic invasive coronary angiogram without significant coronary artery stenosis (

Effects of exercise training on coronary collateralization and control of collateral resistance

Science.gov (United States)

Parker, Janet L.

2011-01-01

Coronary collateral vessels serve as a natural protective mechanism to provide coronary flow to ischemic myocardium secondary to critical coronary artery stenosis. The innate collateral circulation of the normal human heart is typically minimal and considerable variability occurs in extent of collateralization in coronary artery disease patients. A well-developed collateral circulation has been documented to exert protective effects upon myocardial perfusion, contractile function, infarct size, and electrocardiographic abnormalities. Thus therapeutic augmentation of collateral vessel development and/or functional adaptations in collateral and collateral-dependent arteries to reduce resistance into the ischemic myocardium represent a desirable goal in the management of coronary artery disease. Tremendous evidence has provided documentation for the therapeutic benefits of exercise training programs in patients with coronary artery disease (and collateralization); mechanisms that underlie these benefits are numerous and multifaceted, and currently under investigation in multiple laboratories worldwide. The role of enhanced collateralization as a major beneficial contributor has not been fully resolved. This topical review highlights literature that examines the effects of exercise training on collateralization in the diseased heart, as well as effects of exercise training on vascular endothelial and smooth muscle control of regional coronary tone in the collateralized heart. Future directions for research in this area involve further delineation of cellular/molecular mechanisms involved in effects of exercise training on collateralized myocardium, as well as development of novel therapies based on emerging concepts regarding exercise training and coronary artery disease. PMID:21565987

The influence of hyperthyroidism on vasoconstrictor and vasodilator responses in isolated coronary and renal resistance arteries

NARCIS (Netherlands)

Zwaveling, J.; Pfaffendorf, M.; van Zwieten, P. A.

1997-01-01

The influence of hyperthyroidism on the functional vascular responsiveness of isolated coronary and renal resistance vessels was investigated. Hyperthyroidism was established by feeding rats for 1 and 4 weeks with 5 mg/kg L-thyroxine (T4)-containing rat chow. Preparations of either coronary or renal

The prognostic value of coronary endothelial and microvascular dysfunction in subjects with normal or non-obstructive coronary artery disease

DEFF Research Database (Denmark)

Brainin, Philip; Frestad, Daria; Prescott, Eva

2018-01-01

AIMS: Coronary vascular dysfunction is linked with poor cardiovascular prognosis in patients without obstructive coronary artery disease (CAD) but a critical appraisal of the literature is lacking. METHODS AND RESULTS: We performed a systematic review and meta-analysis to quantify...

Management standards for stable coronary artery disease in India

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Sundeep Mishra

2016-12-01

Full Text Available Coronary artery disease (CAD is one of the important causes of cardiovascular morbidity and mortality globally, giving rise to more than 7 million deaths annually. An increasing burden of CAD in India is a major cause of concern with angina being the leading manifestation. Stable coronary artery disease (SCAD is characterised by episodes of transient central chest pain (angina pectoris, often triggered by exercise, emotion or other forms of stress, generally triggered by a reversible mismatch between myocardial oxygen demand and supply resulting in myocardial ischemia or hypoxia. A stabilised, frequently asymptomatic phase following an acute coronary syndrome (ACS is also classified as SCAD. This definition of SCAD also encompasses vasospastic and microvascular angina under the common umbrella.

Acute effects of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers

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Vikas Thakran

2015-01-01

Full Text Available Background: Long-term adverse cardiovascular effects of smokeless tobacco are well established, however, the effect of chewing tobacco on coronary microcirculation and hemodynamic have not been studied. We intended to analyze the acute effect of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers with stable coronary artery disease undergoing elective percutaneous coronary intervention (PCI. Materials and Methods: We prospectively enrolled seven habitual tobacco chewers with stable coronary artery disease with single vessel disease or double vessel disease satisfying the criteria for elective PCI. Patients were instructed to keep 1 g of crushed dried tobacco leaves in the mouth after a successful PCI. Lesion in last stented vessels was evaluated for fractional flow reserve (FFR, coronary flow reserve (CFR, and index of microcirculatory resistance (IMR post-PCI, after 15 min and 30 min of tobacco chewing along with the measurement of serum cotinine levels. Results: Oral tobacco led to high levels of cotinine in the majority of patients. There was an insignificant rise in heart rate, systolic and diastolic blood pressure following tobacco consumption. Baseline CFR (median 1.6, range 1.1–5.5 was low in tobacco chewers after PCI even after optimum FFR (0.9 ± 0.05 in the majority of patients suggesting abnormal microvascular hemodynamics (high IMR in 3 patients, overall median 14.2, range 7–36.2. However, there was no significant change in the estimated CFR or IMR values following tobacco chewing. One patient had bradycardia and hypotension which may be related to vagal reaction or acute nicotine poisoning. Conclusion: Tobacco chewers have abnormal coronary microcirculation hemodynamics even following a successful PCI. However, the coronary micocirculation and hemodynamics do not change acutely following tobacco chewing despite high serum cotinine concentrations.

Bcl-2 silencing attenuates hypoxia-induced apoptosis resistance in pulmonary microvascular endothelial cells.

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Cao, Yongmei; Jiang, Zhen; Zeng, Zhen; Liu, Yujing; Gu, Yuchun; Ji, Yingying; Zhao, Yupeng; Li, Yingchuan

2016-01-01

Pulmonary arterial hypertension (PAH) is a life-threatening disorder that ultimately causes heart failure. While the underlying causes of this condition are not well understood, previous studies suggest that the anti-apoptotic nature of pulmonary microvascular endothelial cells (PMVECs) in hypoxic environments contributes to PAH pathogenesis. In this study, we focus on the contribution of Bcl-2 and hypoxia response element (HRE) to apoptosis-resistant endothelial cells and investigate the mechanism. PMVECs obtained from either normal rats or apoptosis-resistant PMVECs obtained from PAH rats were transduced with recombinant lentiviral vectors carrying either Bcl-2-shRNA or HRE combined Bcl-2-shRNA, and then cultured these cells for 24 h under hypoxic (5% O2) or normoxic (21% O2) conditions. In normal PMVECs, Bcl-2-shRNA or HRE combined with Bcl-2-shRNA transduction successfully decreased Bcl-2 expression, while increasing apoptosis as well as caspase-3 and P53 expression in a normoxic environment. In a hypoxic environment, the effects of Bcl-2-shRNA treatment on cell apoptosis, and on Bcl-2, caspase-3, P53 expression were significantly suppressed. Conversely, HRE activation combined with Bcl-2-shRNA transduction markedly enhanced cell apoptosis and upregulated caspase-3 and P53 expression, while decreasing Bcl-2 expression. Furthermore, in apoptosis-resistant PMVECs, HRE-mediated Bcl-2 silencing effectively enhanced cell apoptosis and caspase-3 activity. The apoptosis rate was significantly depressed when Lv-HRE-Bcl-2-shRNA was combined with Lv-P53-shRNA or Lv-caspase3-shRNA transduction in a hypoxic environment. These results suggest that HRE-mediated Bcl-2 inhibition can effectively attenuate hypoxia-induced apoptosis resistance in PMVECs by downregulating Bcl-2 expression and upregulating caspase-3 and P53 expression. This study therefore reveals critical insight into potential therapeutic targets for treating PAH.

Early outcome of high energy Laser (Excimer) facilitated coronary angioplasty ON hARD and complex calcified and balloOn-resistant coronary lesions: LEONARDO Study

International Nuclear Information System (INIS)

Ambrosini, Vittorio; Sorropago, Giovanni; Laurenzano, Eugenio; Golino, Luca; Casafina, Alfredo; Schiano, Vittorio; Gabrielli, Gabriele; Ettori, Federica; Chizzola, Giuliano; Bernardi, Guglielmo; Spedicato, Leonardo; Armigliato, Pietro; Spampanato, Carmine; Furegato, Martina

2015-01-01

Aim: An innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) has been recently used for the treatment of complex coronary lesions, as calcified stenosis, chronic total occlusions and non-compliant plaques. Such complex lesions are difficult to adequately treat with balloon angioplasty and/or intracoronary stenting. The aim of this study was to examine the acute outcome of this approach on a cohort of patients with coronary lesions. Methods and Results: Eighty patients with 100 lesions were enrolled through four centers, and excimer laser coronary angioplasty was performed on 96 lesions (96%). Safety and effectiveness data were compared between patients treated with standard laser therapy and those treated with increased laser therapy. Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success in was obtained in 87 lesions (90.6%). There was no perforation, major side branch occlusion, spasm, no-reflow phenomenon, dissection nor acute vessel closure. Increased laser parameters were used successfully for 49 resistant lesions without complications. Conclusions: This study suggests that laser-facilitated coronary angioplasty is a simple, safe and effective device for the management of complex coronary lesions. Furthermore, higher laser energy levels delivered by this catheter improved the device performance without increasing complications. - Highlights: • We planned this multicenter study to examine the acute outcome of an innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) for treatment of complex coronary lesions. • We enrolled 80 patients with 100 lesions and performed excimer laser coronary angioplasty in 96 lesions (96%). • Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success was obtained in 87 lesions (90.6%). • Increased laser parameters were used successfully for 49 resistant

Early outcome of high energy Laser (Excimer) facilitated coronary angioplasty ON hARD and complex calcified and balloOn-resistant coronary lesions: LEONARDO Study

Energy Technology Data Exchange (ETDEWEB)

Ambrosini, Vittorio; Sorropago, Giovanni; Laurenzano, Eugenio [Montevergine Clinic, Mercogliano (Italy); Golino, Luca, E-mail: lucagolino.jazz@alice.it [Montevergine Clinic, Mercogliano (Italy); Moriggia-Pelascini Hospital, Gravedona, Como (Italy); Casafina, Alfredo; Schiano, Vittorio [Montevergine Clinic, Mercogliano (Italy); Gabrielli, Gabriele [University Hospital Ospedali Riuniti, Ancona (Italy); Ettori, Federica; Chizzola, Giuliano [Spedali Civili University Hospital, Brescia (Italy); Bernardi, Guglielmo; Spedicato, Leonardo [University Hospital S. Maria Misericordia, Udine (Italy); Armigliato, Pietro [Istituto Italiano Ricerche Mediche, Verona (Italy); Spampanato, Carmine [Telethon Institute of Genetics and Medicine (TIGEM), Naples (Italy); Furegato, Martina [Istituto Italiano Ricerche Mediche, Verona (Italy)

2015-04-15

Aim: An innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) has been recently used for the treatment of complex coronary lesions, as calcified stenosis, chronic total occlusions and non-compliant plaques. Such complex lesions are difficult to adequately treat with balloon angioplasty and/or intracoronary stenting. The aim of this study was to examine the acute outcome of this approach on a cohort of patients with coronary lesions. Methods and Results: Eighty patients with 100 lesions were enrolled through four centers, and excimer laser coronary angioplasty was performed on 96 lesions (96%). Safety and effectiveness data were compared between patients treated with standard laser therapy and those treated with increased laser therapy. Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success in was obtained in 87 lesions (90.6%). There was no perforation, major side branch occlusion, spasm, no-reflow phenomenon, dissection nor acute vessel closure. Increased laser parameters were used successfully for 49 resistant lesions without complications. Conclusions: This study suggests that laser-facilitated coronary angioplasty is a simple, safe and effective device for the management of complex coronary lesions. Furthermore, higher laser energy levels delivered by this catheter improved the device performance without increasing complications. - Highlights: • We planned this multicenter study to examine the acute outcome of an innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) for treatment of complex coronary lesions. • We enrolled 80 patients with 100 lesions and performed excimer laser coronary angioplasty in 96 lesions (96%). • Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success was obtained in 87 lesions (90.6%). • Increased laser parameters were used successfully for 49 resistant

Measurement of microvascular function in patients presenting with thrombolysis for ST elevation myocardial infarction, and PCI for non-ST elevation myocardial infarction.

Science.gov (United States)

Palmer, Sonny; Layland, Jamie; Adams, Heath; Ashokkumar, Srikkumar; Williams, Paul D; Judkins, Christopher; La Gerche, Andre; Burns, Andrew T; Whitbourn, Robert J; MacIsaac, Andrew I; Wilson, Andrew M

2018-04-12

In this prospective study, we compared the invasive measures of microvascular function in two subsets: patients with pharmacoinvasive thrombolysis for STEMI, and patients undergoing percutaneous coronary intervention (PCI) for NSTEMI. The study consisted of 17 patients with STEMI referred for cardiac catheterisation post thrombolysis, and 20 patients with NSTEMI. Coronary physiological indexes were measured in each patient before and after PCI. The median pre-PCI index of microcirculatory function (IMR) at baseline was significantly higher in the STEMI group than the NSTEMI group (26 units vs. 15 units, p = 0.02). Following PCI, IMR decreased in both groups (STEMI 20 units vs. NSTEMI 14 units, p = 0.10). There was an inverse correlation between post PCI IMR and left ventricular ejection fraction (LVEF) (r = -0.52, p = 0.001). Furthermore, post PCI IMR was an independent predictor of index admission LVEF in the total population (β = -0.388, p = 0.02). Invasive measures of microvascular function are inferior in a pharmacoinvasive STEMI group compared to a clinically stable NSTEMI group. In the STEMI population, the IMR following coronary intervention appears to predict LVEF. Copyright © 2018 Elsevier Inc. All rights reserved.

Differential effects of androgens on coronary blood flow regulation and arteriolar diameter in intact and castrated swine

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O’Connor Erin K

2012-05-01

Full Text Available Abstract Background Low endogenous testosterone levels have been shown to be a risk factor for the development of cardiovascular disease and cardiovascular benefits associated with testosterone replacement therapy are being advocated; however, the effects of endogenous testosterone levels on acute coronary vasomotor responses to androgen administration are not clear. The objective of this study was to compare the effects of acute androgen administration on in vivo coronary conductance and in vitro coronary microvascular diameter in intact and castrated male swine. Methods Pigs received intracoronary infusions of physiologic levels (1–100 nM of testosterone, the metabolite 5α-dihydrotestosterone, and the epimer epitestosterone while left anterior descending coronary blood flow and mean arterial pressure were continuously monitored. Following sacrifice, coronary arterioles were isolated, cannulated, and exposed to physiologic concentrations (1–100 nM of testosterone, 5α-dihydrotestosterone, and epitestosterone. To evaluate effects of the androgen receptor on acute androgen dilation responses, real-time PCR and immunohistochemistry for androgen receptor were performed on conduit and resistance coronary vessels. Results In vivo, testosterone and 5α-dihydrotestosterone produced greater increases in coronary conductance in the intact compared to the castrated males. In vitro, percent maximal dilation of microvessels was similar between intact and castrated males for testosterone and 5α-dihydrotestosterone. In both studies epitestosterone produced significant increases in conductance and microvessel diameter from baseline in the intact males. Androgen receptor mRNA expression and immunohistochemical staining were similar in intact and castrated males. Conclusions Acute coronary vascular responses to exogenous androgen administration are increased by endogenous testosterone, an effect unrelated to changes in androgen receptor expression.

Cutaneous microvascular perfusion responses to insulin iontophoresis are differentially affected by insulin resistance after spinal cord injury.

Science.gov (United States)

La Fountaine, Michael F; Cirnigliaro, Christopher M; Azarelo, Frank; Hobson, Joshua C; Tascione, Oriana; Swonger, Kirsten N; Dyson-Hudson, Trevor; Bauman, William A

2017-09-01

What is the central question of this study? What impact does insulin resistance have on cutaneous perfusion responses to insulin iontophoresis in vascular beds with markedly reduced or functionally ablated sympathetic nervous system vasomotor function resulting from spinal cord injury? What is the main finding and its importance? Persons with spinal cord injury have sublesional microvascular endothelial dysfunction, as indicated by a blunted cutaneous perfusion response to acetylcholine iontophoresis, and the presence of insulin resistance has a further confounding effect on endothelium-mediated changes to cutaneous perfusion in the lower extremities. Endothelium-mediated mechanisms that regulate skin blood flow might play an integral role in optimizing skin perfusion in vascular beds with sympathetic nervous system vasomotor impairment, such as in spinal cord injury (SCI). Insulin is a vasoactive hormone and second messenger of nitric oxide that facilitates endothelium-mediated dilatation. The effects of insulin resistance (IR) on sublesional cutaneous perfusion responses to insulin provocation have yet to be described in persons with SCI. Persons with SCI and an able-bodied (AB) cohort were divided into subgroups based upon fasting plasma insulin concentration cut-offs for IR (≥13.13 mIU ml -1 ) or insulin sensitivity (IS; insulin, acetylcholine or placebo iontophoresis in the lower extremities; BPU responses were log 10 transformed to facilitate comparisons, and the net insulin response (NetIns) BPU response was calculated (insulin minus placebo BPU response). The NetIns was significantly greater in both IS groups compared with their corresponding IR group. The acetylcholine-mediated BPU responses in the SCI subgroups were significantly lower than those in the ABIS group. The proportional BPU responses of NetIns to acetylcholine in the IS cohorts (i.e. ABIS and SCIS) were significantly greater (P < 0.05) than that of each IR subgroup. The presence of IR

Complete blood cell count components and coronary slow-flow phenomenon

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Arjmand N

2016-12-01

Full Text Available Nasim Arjmand, Mohammad Reza Dehghani Department of Cardiology, Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, IranDespite the implementation of preventive strategies, ischemic heart disease and stroke remain the main causes of mortality and morbidity worldwide.1,2 Of the cardiovascular diseases, coronary slow-flow phenomenon (CSFP, with a prevalence rate of 1%–7% among patients undergoing diagnostic coronary angiography, has been found to be associated with cardiovascular events, including cardiac arrhythmia and acute coronary syndrome.3–5 However, the potential mechanisms involved in the pathogenesis of CSFP remain unknown. Microvascular and endothelial dysfunctions, inflammation, diffuse atherosclerosis, and increased platelet aggregability have been reported to be the main possible etiologies for CSFP.6,7View original paper by Atlas and colleagues.

Transthoracic Doppler echocardiography – noninvasive diagnostic window for coronary flow reserve assessment

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Dimitrow Paweł

2003-04-01

Full Text Available Abstract This review focuses on transthoracic Doppler echocardiography as noninvasive method used to assess coronary flow reserve (CFR in a wide spectrum of clinical settings. Transthoracic Doppler echocardiography is rapidly gaining appreciation as popular tool to measure CFR both in stenosed and normal epicardial coronary arteries (predominantly in left anterior descending coronary artery. Post-stenotic CFR measurement is helpful in: functional assessment of moderate stenosis, detection of significant or critical stenosis, monitoring of restenosis after revascularization. In the absence of stenosis in the epicardial coronary artery, decreased CFR enable to detect impaired microvascular vasodilatation in: reperfused myocardial infarct, arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy. In these diseases, noninvasive transthoracic Doppler echocardiography allows for serial CFR evaluations to explore the effect of various pharmacological therapies.

Coronary hemodynamics in vasospastic angina

International Nuclear Information System (INIS)

Matsumura, Kentaro; Kubota, Shinobu; Serizawa, Takashi; Nakase, Emiko; Kawai, Ichiro; Saito, Takayuki

1991-01-01

To evaluate the coronary circulation and myocardial perfusion dynamics, we performed left coronary digital subtraction angiography (DSA) in 35 patients with vasospastic angina. The left coronary circulation time (CCT) measured from the proximal left coronary artery to the coronary sinus was 5.77±0.86 sec, and the left epicardial conducting artery transmission time (CAT) measured from the proximal left coronary artery to the apical area was 2.65±0.82 sec in normal controls. The CCT and CAT were significantly prolonged in patients with vasospastic angina, indicating that the coronary peripheral vascular resistance is probably greater after the cessation of nitrates and Ca ++ -antagonists. After the intracoronary injection of ergonovine malate, the CCT was slightly shortened, but the apical T 1/2 was significantly prolonged in patients with vasospastic angina. This suggested that coronary vasospasm is present not only in the epicardial arteries but also in coronary arteries with peripheral resistance. These phenomena were not observed in normal controls. We performed left coronary DSA after conventional left coronary cineangiography. When the CCT exceeded 6.7 sec, we considered that the coronary circulation was significantly impaired. We concluded that the coronary DSA is very useful for evaluating abnormal coronary circulation in patients with vasospastic angina during myocardial perfusion. (author)

Transmural Variation and Anisotropy of Microvascular Flow Conductivity in the Rat Myocardium

KAUST Repository

Smith, Amy F.

2014-05-28

Transmural variations in the relationship between structural and fluid transport properties of myocardial capillary networks are determined via continuum modeling approaches using recent three-dimensional (3D) data on the microvascular structure. Specifically, the permeability tensor, which quantifies the inverse of the blood flow resistivity of the capillary network, is computed by volume-averaging flow solutions in synthetic networks with geometrical and topological properties derived from an anatomically-detailed microvascular data set extracted from the rat myocardium. Results show that the permeability is approximately ten times higher in the principal direction of capillary alignment (the "longitudinal" direction) than perpendicular to this direction, reflecting the strong anisotropy of the microvascular network. Additionally, a 30% increase in capillary diameter from subepicardium to subendocardium is shown to translate to a 130% transmural rise in permeability in the longitudinal capillary direction. This result supports the hypothesis that perfusion is preferentially facilitated during diastole in the subendocardial microvasculature to compensate for the severely-reduced systolic perfusion in the subendocardium.

Vasomotor Regulation of Coronary Microcirculation by Oxidative Stress: Role of Arginase

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Lih eKuo

2013-08-01

Full Text Available Overproduction of reactive oxygen species, i.e., oxidative stress, is associated with the activation of redox signaling pathways linking to inflammatory insults and cardiovascular diseases by impairing endothelial function and consequently blood flow dysregulation due to microvascular dysfunction. This review focuses on the regulation of vasomotor function in the coronary microcirculation by endothelial nitric oxide (NO during oxidative stress and inflammation related to the activation of L-arginine consuming enzyme arginase. Superoxide produced in the vascular wall compromises vasomotor function by not only scavenging endothelium-derived NO but also inhibiting prostacyclin synthesis due to formation of peroxynitrite. The upregulation of arginase contributes to the deficiency of endothelial NO and microvascular dysfunction in various vascular diseases by initiating or following oxidative stress and inflammation. Hydrogen peroxide, a diffusible and stable oxidizing agent, exerts vasodilator function and plays important roles in the physiological regulation of coronary blood flow. In occlusive coronary ischemia, the release of hydrogen peroxide from the microvasculature helps to restore vasomotor function of coronary collateral microvessels with exercise training. However, excessive production and prolonged exposure of microvessels to hydrogen peroxide impairs NO-mediated endothelial function by reducing L-arginine availability through hydroxyl radical-dependent upregulation of arginase. The redox signaling can be a double-edged sword in the microcirculation, which helps tissue survival in one way by improving vasomotor regulation and elicits oxidative stress and tissue injury in the other way by causing vascular dysfunction. The impact of vascular arginase on the development of vasomotor dysfunction associated with angiotensin II receptor activation, hypertension, ischemia-reperfusion, hypercholesterolemia and inflammatory insults is discussed.

A review of methods for assessment of coronary microvascular disease in both clinical and experimental settings

DEFF Research Database (Denmark)

Pries, A.R.; Habazettl, H.; Ambrosio, G.

2008-01-01

-will certainly result in more rational diagnostic and therapeutic interventions for patients with ischaemic heart disease. Specifically targeted research based on improved assessment modalities is needed to improve the diagnosis of CMD and to translate current molecular, cellular, and physiological knowledge......Obstructive disease of the large coronary arteries is the prominent cause for angina pectoris. However, angina may also occur in the absence of significant coronary atherosclerosis or coronary artery spasm, especially in women. Myocardial ischaemia in these patients is often associated...

Influence of abnormal glucose metabolism on coronary microvascular function after a recent myocardial infarction

DEFF Research Database (Denmark)

Løgstrup, Brian B; Høfsten, Dan E; Christophersen, Thomas B

2009-01-01

OBJECTIVES: This study sought to assess the association between abnormal glucose metabolism and abnormal coronary flow reserve (CFR) in patients with a recent acute myocardial infarction (AMI). BACKGROUND: Mortality and morbidity after AMI is high among patients with abnormal glucose metabolism, ...... (140 microg/kg/min) to obtain the hyperemic flow profiles. The CFR was defined as the ratio of hyperemic to baseline peak diastolic coronary flow velocities. RESULTS: Median CFR was 1.9 (interquartile range [IQR] 1.4 to 2.4], and 109 (60%) patients had a CFR...

Myocardial tissue deformation is reduced in subjects with coronary microvascular dysfunction but not rescued by treatment with Ranolazine

Science.gov (United States)

Nelson, Michael D.; Sharif, Behzad; Shaw, Jaime L.; Cook-Wiens, Galen; Wei, Janet; Shufelt, Chrisandra; Mehta, Puja K.; Thomson, Louise EJ; Berman, Daniel S.; Thompson, Richard B.; Handberg, Eileen M.; Pepine, Carl J.; Li, Debiao; Bairey Merz, C. Noel

2016-01-01

Background Patients with coronary microvascular dysfunction (CMD) often have diastolic dysfunction, representing an important therapeutic target. Ranolazine—a late-sodium current inhibitor—improves diastolic function in animal models, and subjects with obstructive CAD. We hypothesized that ranolazine would beneficially alter diastolic function in CMD. Methods To test this hypothesis, we performed retrospective tissue tracking analysis to evaluate systolic/diastolic strain, using cardiac magnetic resonance imaging cine images: a) acquired in a recently completed, randomized, double-blind, placebo-controlled, crossover trial of short-term ranolazine in subjects with CMD, and b) from 43 healthy reference controls. Results Diastolic strain rate was impaired in CMD vs. controls (circumferential diastolic strain rate: 99.9 ± 2.5%/s vs. 120.1 ± 4.0%/s, p=0.0003; radial diastolic strain rate: −199.5 ± 5.5%/s vs. −243.1 ± 9.6%/s, p=0.0008, case vs. control). Moreover, peak systolic circumferential (CS) and radial (RS) strain were also impaired in cases vs. controls (CS: −18.8 ± 0.3% vs. −20.7 ± 0.3%; RS: 35.8 ± 0.7% vs. 41.4 ± 0.9%; respectively; both p < 0.0001), despite similar and preserved ejection fraction. In contrast to our hypothesis however, we observed no significant changes in left ventricular diastolic function in CMD cases after two weeks of ranolazine vs. placebo. Conclusions The case-control comparison both confirms and extends our prior observations of diastolic dysfunction in CMD. That CMD cases were also found to have sub-clinical systolic dysfunction is a novel finding, highlighting the utility of this retrospective approach. In contrast to previous studies in obstructive CAD, ranolazine did not improve diastolic function in CMD. PMID:28004395

Coronary physiological assessment combining fractional flow reserve and index of microcirculatory resistance in patients undergoing elective percutaneous coronary intervention with grey zone fractional flow reserve.

Science.gov (United States)

Niida, Takayuki; Murai, Tadashi; Yonetsu, Taishi; Kanaji, Yoshihisa; Usui, Eisuke; Matsuda, Junji; Hoshino, Masahiro; Araki, Makoto; Yamaguchi, Masao; Hada, Masahiro; Ichijyo, Sadamitsu; Hamaya, Rikuta; Kanno, Yoshinori; Isobe, Mitsuaki; Kakuta, Tsunekazu

2018-03-08

The aim of this study is to investigate the association between fractional flow reserve (FFR) values and change in coronary physiological indices after elective percutaneous coronary intervention (PCI). Decision making for revascularization when FFR is 0.75-0.80 is controversial. A retrospective analysis was performed of 296 patients with stable angina pectoris who underwent physiological examinations before and after PCI. To investigate the differences of coronary flow improvement between territories with low-FFR (zone FFR (0.75-0.80), serial changes in physiological indices including mean transit time (Tmn), coronary flow reserve (CFR), and index of microcirculatory resistance (IMR) were compared between these two groups. Compared to low-FFR territories, grey-zone FFR territories showed significantly lower prevalence of Tmn shortening, CFR improvement, and decrease in IMR (Tmn shorting, 63.9% vs. 87.0%, P 51.3% vs. 63.3%, P = .040) and lower extent of their absolute changes (Tmn shorting, 0.06 (-0.03 to 0.16) vs. 0.22 (0.07-0.45), P zone FFR. Physiological assessment combining FFR and IMR may help identify patients who may benefit by PCI, particularly those in the grey zone. © 2018 Wiley Periodicals, Inc.

Vasospastic angina and microvascular angina are differentially influenced by PON1 A632G polymorphism in the Japanese.

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Mashiba, Junko; Koike, George; Kamiunten, Hitoshi; Ikeda, Manami; Sunagawa, Kenji

2005-12-01

Ethnicity and smoking are well-known risk factors for the pathogenesis of coronary vasospasm. Oxidative stress induced by smoking plays a crucial role in coronary vasospasm, but is not enough to account for the pathogenesis of coronary vasospasm, indicating that genetic factors are strongly involved. The study group comprised 162 vasospastic angina patients (VSAs), 61 microvascular angina patients (MVAs) and 61 non-responders (NRs) diagnosed by acetylcholine provocation test. Four polymorphisms of the oxidative stress related genes, cytochrome b-245, alpha polypeptide gene (CYBA) C242T and A640G, paraoxonase 1 gene (PON1) A632G, phospholipase A2 group VII gene (PLA2G7) G994T were genotyped. Allele frequency of PON1 632-G was significantly higher in both the VSA with dominant fashion and the MVA with recessive fashion compared with NR. This association was strongly influenced by gender in the MVA only. There were no significant associations between the other polymorphisms and coronary vasospasm. In addition, the allele frequency of PON1 632-G in the Japanese was higher than in Caucasians. There was a significant association between PON1 A632G polymorphism and MVA as well as VSA, but the impact of this on VSA and MVA is different in the Japanese.

Microvascular resistance in response to iodinated contrast media in normal and functionally impaired kidneys.

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Kurihara, Osamu; Takano, Masamichi; Uchiyama, Saori; Fukuizumi, Isamu; Shimura, Tetsuro; Matsushita, Masato; Komiyama, Hidenori; Inami, Toru; Murakami, Daisuke; Munakata, Ryo; Ohba, Takayoshi; Hata, Noritake; Seino, Yoshihiko; Shimizu, Wataru

2015-12-01

Contrast-induced nephropathy (CIN) is considered to result from intrarenal vasoconstriction, and occurs more frequently in impaired than in normal kidneys. It was hypothesized that iodinated contrast media would markedly change renal blood flow and vascular resistance in functionally impaired kidneys. Thirty-six patients were enrolled (32 men; mean age, 75.3 ± 7.6 years) undergoing diagnostic coronary angiography and were divided into two groups based on the presence of chronic kidney disease (CKD), defined as an estimated glomerular filtration rate (eGFR) of contrast media. The APV and the RI were positively and inversely correlated with the eGFR at baseline, respectively (APV, R = 0.545, P = 0.001; RI, R = -0.627, P contrast media administration in the non-CKD group, but not in the CKD group (APV, P = 0.258; RI, P = 0.707). Although renal arterial resistance was higher in patients with CKD, it was not affected by contrast media administration, suggesting that patients with CKD could have an attenuated response to contrast media. © 2015 The Authors. Clinical and Experimental Pharmacology and Physiology Published by Wiley Publishing Asia Pty Ltd.

The relationship of insulin resistance estimated by triglyceride glucose index and coronary plaque characteristics.

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Won, Ki-Bum; Kim, Yun Seok; Lee, Byoung Kwon; Heo, Ran; Han, Donghee; Lee, Ji Hyun; Lee, Sang-Eun; Sung, Ji Min; Cho, Iksung; Park, Hyung-Bok; Cho, In-Jeong; Chang, Hyuk-Jae

2018-05-01

The triglyceride glucose (TyG) index is a useful surrogate marker for insulin resistance, which is an important risk factor for coronary artery disease (CAD). However, data on the relationship of the TyG index and coronary plaque characteristics are limited.This study included 2840 participants with near-normal renal function who underwent coronary computed tomography angiography. CAD was defined as the presence of any plaques, and obstructive CAD was defined as the presence of plaques with ≥50% stenosis. The relationship between the TyG index and noncalcified plaque (NCP), calcified or mixed plaque (CMP), and coronary artery calcium score (CACS) was evaluated.All participants were stratified into 4 groups based on the quartiles of the TyG index. The prevalence of CAD and obstructive CAD significantly increased with increasing quartiles. The risk for NCP and obstructive NCP was not different among all groups. However, compared with group I (lowest quartile), the risk for CMP was higher in groups III (odds ratio [OR]: 1.438) and IV (highest quartile) (OR: 1.895) (P index was associated with an increased risk for CAD (OR: 1.700), obstructive CAD (OR: 1.692), and CACS >400 (OR: 1.448) (P index was independently associated with the presence and severity of CAD due to an increased risk for CMP.

PET measurements of myocardial blood flow post myocardial infarction: Relationship to invasive and cardiac magnetic resonance studies and potential clinical applications.

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Gewirtz, Henry

2017-12-01

This review focuses on clinical studies concerning assessment of coronary microvascular and conduit vessel function primarily in the context of acute and sub acute myocardial infarction (MI). The ability of quantitative PET measurements of myocardial blood flow (MBF) to delineate underlying pathophysiology and assist in clinical decision making in this setting is discussed. Likewise, considered are physiological metrics fractional flow reserve, coronary flow reserve, index of microvascular resistance (FFR, CFR, IMR) obtained from invasive studies performed in the cardiac catheterization laboratory, typically at the time of PCI for MI. The role both of invasive studies and cardiac magnetic resonance (CMR) imaging in assessing microvascular function, a key determinant of prognosis, is reviewed. The interface between quantitative PET MBF measurements and underlying pathophysiology, as demonstrated both by invasive and CMR methodology, is discussed in the context of optimal interpretation of the quantitative PET MBF exam and its potential clinical applications.

Retinol Binding Protein-4 Is Associated with TNF-α and Not Insulin Resistance in Subjects with Type 2 Diabetes Mellitus and Coronary Heart Disease

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Nasser M. Al-Daghri

2009-01-01

Full Text Available We studied the association between RBP4 and various markers related to insulin resistance and diabetic complications as well as inflammatory markers in Saudi population suffering from type 2 diabetes and coronary heart disease. Patients with type 2 diabetes were divided into 3 groups according to the type of treatment and involvement of coronary artery disease. Serum RBP4, TNF-α, insulin, CRP, resistin, leptin and adiponectin were analysed in all samples. RBP4 levels increased significantly in the group of diabetic subjects treated with oral hypoglycemic agents and diabetic patients with coronary heart disease (30.2 ± 11.8; 33.4 ± 13.6 respectively, while there was no significant change in the other group for diabetic subjects on low-carbohydrate diet (25.1 ± 10.9 compared to control group (22.6 ± 9.5. RPB4 levels were positively correlated with TNF-α in the group of diabetic subjects on oral hypoglycemic agents and diabetic patients with coronary heart disease (r = 0.52, P < 0.05; r = 0.58, P < 0.05 respectively. No correlations were found between RBP4 levels and insulin resistance in all studied groups. Our findings suggest that serum RBP4 levels is associated with pro-inflammatory cytokine (TNF-α and is not associated with insulin resistance among patients with type 2 diabetes and coronary heart disease.

Endothelial glycocalyx dysfunction in disease: albuminuria and increased microvascular permeability.

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Salmon, Andrew H J; Satchell, Simon C

2012-03-01

Appreciation of the glomerular microcirculation as a specialized microcirculatory bed, rather than as an entirely separate entity, affords important insights into both glomerular and systemic microvascular pathophysiology. In this review we compare regulation of permeability in systemic and glomerular microcirculations, focusing particularly on the role of the endothelial glycocalyx, and consider the implications for disease processes. The luminal surface of vascular endothelium throughout the body is covered with endothelial glycocalyx, comprising surface-anchored proteoglycans, supplemented with adsorbed soluble proteoglycans, glycosaminoglycans and plasma constituents. In both continuous and fenestrated microvessels, this endothelial glycocalyx provides resistance to the transcapillary escape of water and macromolecules, acting as an integral component of the multilayered barrier provided by the walls of these microvessels (ie acting in concert with clefts or fenestrae across endothelial cell layers, basement membranes and pericytes). Dysfunction of any of these capillary wall components, including the endothelial glycocalyx, can disrupt normal microvascular permeability. Because of its ubiquitous nature, damage to the endothelial glycocalyx alters the permeability of multiple capillary beds: in the glomerulus this is clinically apparent as albuminuria. Generalized damage to the endothelial glycocalyx can therefore manifest as both albuminuria and increased systemic microvascular permeability. This triad of altered endothelial glycocalyx, albuminuria and increased systemic microvascular permeability occurs in a number of important diseases, such as diabetes, with accumulating evidence for a similar phenomenon in ischaemia-reperfusion injury and infectious disease. The detection of albuminuria therefore has implications for the function of the microcirculation as a whole. The importance of the endothelial glycocalyx for other aspects of vascular function

Mapping genetic determinants of coronary microvascular remodeling in the spontaneously hypertensive rat

Czech Academy of Sciences Publication Activity Database

Mancini, M.; Petretto, E.; Kleinert, C.; Scavone, A.; De, T.; Cook, S.; Šilhavý, Jan; Zídek, Václav; Pravenec, Michal; d´Amati, G.; Camici, P.G.

2013-01-01

Roč. 108, č. 1 (2013), s. 316 ISSN 0300-8428 R&D Projects: GA MŠk(CZ) LH11049; GA MŠk(CZ) LL1204; GA ČR(CZ) GAP301/12/0696 Institutional support: RVO:67985823 Keywords : arterial hypertension * coronary circulation * myocardial ischemia * spontaneously hypertensive rat * recombinant inbred strains Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.955, year: 2013

Skeletal muscle microvascular and interstitial PO2 from rest to contractions.

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Hirai, Daniel M; Craig, Jesse C; Colburn, Trenton D; Eshima, Hiroaki; Kano, Yutaka; Sexton, William L; Musch, Timothy I; Poole, David C

2018-03-01

Oxygen pressure gradients across the microvascular walls are essential for oxygen diffusion from blood to tissue cells. At any given flux, the magnitude of these transmural gradients is proportional to the local resistance. The greatest resistance to oxygen transport into skeletal muscle is considered to reside in the short distance between red blood cells and myocytes. Although crucial to oxygen transport, little is known about transmural pressure gradients within skeletal muscle during contractions. We evaluated oxygen pressures within both the skeletal muscle microvascular and interstitial spaces to determine transmural gradients during the rest-contraction transient in anaesthetized rats. The significant transmural gradient observed at rest was sustained during submaximal muscle contractions. Our findings support that the blood-myocyte interface provides substantial resistance to oxygen diffusion at rest and during contractions and suggest that modulations in microvascular haemodynamics and red blood cell distribution constitute primary mechanisms driving increased transmural oxygen flux with contractions. Oxygen pressure (PO2) gradients across the blood-myocyte interface are required for diffusive O 2 transport, thereby supporting oxidative metabolism. The greatest resistance to O 2 flux into skeletal muscle is considered to reside between the erythrocyte surface and adjacent sarcolemma, although this has not been measured during contractions. We tested the hypothesis that O 2 gradients between skeletal muscle microvascular (PO2 mv ) and interstitial (PO2 is ) spaces would be present at rest and maintained or increased during contractions. PO2 mv and PO2 is   were determined via phosphorescence quenching (Oxyphor probes G2 and G4, respectively) in the exposed rat spinotrapezius during the rest-contraction transient (1 Hz, 6 V; n = 8). PO2 mv was higher than PO2 is in all instances from rest (34.9 ± 6.0 versus 15.7 ± 6.4) to contractions (28.4 ± 5

[Low-dose aspirin in patients with diabete melitus: risks and benefits regarding macro and microvascular complications].

Science.gov (United States)

Camargo, Eduardo G; Gross, Jorge Luiz; Weinert, Letícia S; Lavinsky, Joel; Silveiro, Sandra P

2007-04-01

Aspirin is recommended as cardiovascular disease prevention in patients with diabetes mellitus. Due to the increased risk of bleeding and because of the hypothesis that there could be a worsening of microvascular complications related to aspirin, there has been observed an important underutilization of the drug. However, it is now known that aspirin is not associated with a deleterious effect on diabetic retinopathy and there is evidence indicating that it also does not affect renal function with usual doses (150 mg/d). On the other hand, higher doses may prove necessary, since recent data suggest that diabetic patients present the so called "aspirin resistance". The mechanisms of this resistance are not yet fully understood, being probably related to an abnormal intrinsic platelet activity. The employment of alternative antiplatelet strategies or the administration of higher aspirin doses (150-300 mg/d) should be better evaluated regarding effective cardiovascular disease prevention in diabetes as well as the possible effects on microvascular complications.

Differentiation state determines neural effects on microvascular endothelial cells

International Nuclear Information System (INIS)

Muffley, Lara A.; Pan, Shin-Chen; Smith, Andria N.; Ga, Maricar; Hocking, Anne M.; Gibran, Nicole S.

2012-01-01

Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells. Our results suggest that neural progenitor cells and mature sensory neurons have unique secretory profiles and distinct effects on dermal microvascular endothelial cell proliferation, migration, and nitric oxide production. Neural progenitor cells and dorsal root ganglion neurons secrete different proteins related to angiogenesis. Specific to neural progenitor cells were dipeptidyl peptidase-4, IGFBP-2, pentraxin-3, serpin f1, TIMP-1, TIMP-4 and VEGF. In contrast, endostatin, FGF-1, MCP-1 and thrombospondin-2 were specific to dorsal root ganglion neurons. Microvascular endothelial cell proliferation was inhibited by dorsal root ganglion neurons but unaffected by neural progenitor cells. In contrast, microvascular endothelial cell migration in a scratch wound assay was inhibited by neural progenitor cells and unaffected by dorsal root ganglion neurons. In addition, nitric oxide production by microvascular endothelial cells was increased by dorsal root ganglion neurons but unaffected by neural progenitor cells. -- Highlights: ► Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell proliferation. ► Neural progenitor cells, not dorsal root ganglion neurons, regulate microvascular endothelial cell migration. ► Neural progenitor cells and dorsal root ganglion neurons do not effect microvascular endothelial tube formation. ► Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell production of nitric oxide. ► Neural progenitor cells and dorsal root

Fast Virtual Fractional Flow Reserve Based Upon Steady-State Computational Fluid Dynamics Analysis: Results From the VIRTU-Fast Study.

Science.gov (United States)

Morris, Paul D; Silva Soto, Daniel Alejandro; Feher, Jeroen F A; Rafiroiu, Dan; Lungu, Angela; Varma, Susheel; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

2017-08-01

Fractional flow reserve (FFR)-guided percutaneous intervention is superior to standard assessment but remains underused. The authors have developed a novel "pseudotransient" analysis protocol for computing virtual fractional flow reserve (vFFR) based upon angiographic images and steady-state computational fluid dynamics. This protocol generates vFFR results in 189 s (cf >24 h for transient analysis) using a desktop PC, with <1% error relative to that of full-transient computational fluid dynamics analysis. Sensitivity analysis demonstrated that physiological lesion significance was influenced less by coronary or lesion anatomy (33%) and more by microvascular physiology (59%). If coronary microvascular resistance can be estimated, vFFR can be accurately computed in less time than it takes to make invasive measurements.

Fast Virtual Fractional Flow Reserve Based Upon Steady-State Computational Fluid Dynamics Analysis

Directory of Open Access Journals (Sweden)

Paul D. Morris, PhD

2017-08-01

Full Text Available Fractional flow reserve (FFR-guided percutaneous intervention is superior to standard assessment but remains underused. The authors have developed a novel “pseudotransient” analysis protocol for computing virtual fractional flow reserve (vFFR based upon angiographic images and steady-state computational fluid dynamics. This protocol generates vFFR results in 189 s (cf >24 h for transient analysis using a desktop PC, with <1% error relative to that of full-transient computational fluid dynamics analysis. Sensitivity analysis demonstrated that physiological lesion significance was influenced less by coronary or lesion anatomy (33% and more by microvascular physiology (59%. If coronary microvascular resistance can be estimated, vFFR can be accurately computed in less time than it takes to make invasive measurements.

Dynamic damping of the aortic pressure trace during hyperemia: the impact on fractional flow reserve measurement

NARCIS (Netherlands)

Lockie, Tim; Rolandi, M. Cristina; Piek, Jan J.

2013-01-01

We report on two cases that illustrate an important caveat in the measurement of fractional flow reserve (FFR) in coronary arteries. To obtain accurate FFR measurements, two fundamental requirements must be fulfilled. One is to minimize microvascular resistance; the other is that there is no damping

The degree of coronary atherosclerosis as a marker of insulin resistance in non-diabetics

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Parapid Biljana

2010-01-01

Full Text Available Introduction. The metabolic syndrome and its influence on coronary artery disease development and progression remains in focus of international research debates, while insulin resistance, which represents its core, is the key component of hypertension, dyslipidaemias, glucose intolerance and obesity. Objective. The aim of this study was to establish relationship between basal glucose and insulin levels, insulin sensitivity and lipid panel and the degree of coronary atherosclerosis in nondiabetic patients. Methods. The coronary angiograms were evaluated for the presence of significant stenosis, insulin sensitivity was assessed using the intravenous glucose tolerance test with a minimal model according to Bergman, while baseline glucose (G0, insulin (I0 and lipid panel measurements (TC, HDL, LDL, TG were taken after a 12-hour fasting. Results. The protocol encompassed 40 patients (19 men and 21 women treated at the Institute for Cardiovascular Diseases of the Clinical Centre of Serbia, Belgrade. All were non-diabetics who were divided into 3 groups based on their angios: Group A (6 patients, 15%, with no significant stenosis, Group B (18 patients, 45%, with a single-vessel disease and Group C (16 patients, 40%, with multi-vessel disease. Presence of lower insulin sensitivity, higher I0 and TC in the group of patients with a more severe degree of coronary atherosclerosis (insulin sensitivity: F=4.279, p=0.023, A vs. C p=0.012, B vs. C p=0.038; I0: F=3.461 p=0.042, A vs. B p=0.045, A vs. C p=0.013; TC: F=2.572, p=0.09, while no significant difference was found for G0, LDL, HDL and TG. Conclusion. Baseline insulinaemia, more precisely, fasting hyperinsulinaemia could be a good predictor of significant coronary atherosclerosis in non-diabetic patients, which enables a more elegant cardiometabolic risk assessment in the setting of everyday clinical practice.

Observations on the presence of insulin resistance in patients with essential hypertension and coronary heart disease

International Nuclear Information System (INIS)

Zhu Mei; Wu Guo

2006-01-01

Objective: To investigate the presence of insulin resistance in patients with essential hypertension (EH) and coronary heart disease (CHD). Methods: Fasting and 2h post oral 75g glucose blood sugar (with oxidase method), insulin and C-peptide (with RIA) levels were examined in 52 patients with EH, 40 patients with CHD and 35 controls. Results: The fasting and 2h post o- ral glucose serum levels of glucose, insulin and C-peptide in the patients were significantly higher than those in the controls (P < 0.01), suggesting presence of impaired glucose tolerance and insulin resistance. Conclusion: Impaired glucose tolerance due to insulin resistance was demonstrated in the studied patients with EH or CHD. (authors)

Nailfold capillaroscopy is useful for the diagnosis and follow-up of autoimmune rheumatic diseases. A future tool for the analysis of microvascular heart involvement?

Science.gov (United States)

Cutolo, M; Sulli, A; Secchi, M E; Paolino, S; Pizzorni, C

2006-10-01

Raynaud's phenomenon (RP) represents the most frequent clinical aspect of cardio/microvascular involvement and is a key feature of several autoimmune rheumatic diseases. Moreover, RP is associated in a statistically significant manner with many coronary diseases. In normal conditions or in primary RP (excluding during the cold-exposure test), the normal nailfold capillaroscopic pattern shows a regular disposition of the capillary loops along with the nailbed. On the contrary, in subjects suffering from secondary RP, one or more alterations of the capillaroscopic findings should alert the physician of the possibility of a connective tissue disease not yet detected. Nailfold capillaroscopy (NV) represents the best method to analyse microvascular abnormalities in autoimmune rheumatic diseases. Architectural disorganization, giant capillaries, haemorrhages, loss of capillaries, angiogenesis and avascular areas characterize >95% of patients with overt scleroderma (SSc). The term 'SSc pattern' includes, all together, these sequential capillaroscopic changes typical to the microvascular involvement in SSc. The capillaroscopic aspects observed in dermatomyositis and in the undifferentiated connective tissue disease are generally reported as 'SSc-like pattern'. Effectively, and early in the disease, the peripheral microangiopathy may be well recognized and studied by nailfold capillaroscopy, or better with nailfold video capillaroscopy (NVC). The early differential diagnosis between primary and secondary RP is the best advantage NVC may offer. In addition, interesting capillaroscopic changes have been observed in systemic lupus erythematosus, anti-phospholipid syndrome and Sjogren's syndrome. Further epidemiological and clinical studies are needed to better standardize the NCV patterns. In future, the evaluation of nailfold capillaroscopy in autoimmune rheumatic diseases might represent a tool for the prediction of microvascular heart involvement by considering the systemic

Quantitative Measurement of Dissection Resistance in Intimal and Medial Layers of Human Coronary Arteries

Science.gov (United States)

Wang, Ying; Johnson, John A.; Spinale, Francis G.; Sutton, Michael A.; Lessner, Susan M.

2014-01-01

The left anterior descending (LAD) coronary artery is the most frequently involved vessel in coronary artery dissection, a cause of acute coronary syndrome or sudden cardiac death. The biomechanical mechanisms underlying arterial dissection are not well understood. This study investigated the dissection properties of LAD specimens harvested from explanted hearts at the time of cardiac transplantation, from patients with primary dilated cardiomyopathy (n=12). Using a previously validated approach uniquely modified for these human LAD specimens, we quantified the local energy release rate, G, within different arterial layers during experimental dissection events (tissue tearing). Results show that the mean values of G during arterial dissection within the intima and within the media in human LADs are 20.7±16.5 J/m2 and 10.3±5.0 J/m2, respectively. The difference in dissection resistance between tearing events occurring within the intima and within the media is statistically significant. Our data fall in the same order of magnitude as most previous measurements of adhesive strength in other human arteries, with the differences in measured values of G within the layers most likely due to histologically observed differences in the structure and composition of arterial layers. PMID:24729631

Perfusion MRI derived indices of microvascular shunting and flow control correlate with tumor grade and outcome in patients with cerebral glioma

DEFF Research Database (Denmark)

Tietze, Anna; Mouridsen, Kim; Lassen-Ramshad, Yasmin

2015-01-01

Objectives: Deficient microvascular blood flow control is thought to cause tumor hypoxia and increase resistance to therapy. In glioma patients, we tested whether perfusion-weighted MRI (PWI) based indices of microvascular flow control provide more information on tumor grade and patient outcome...... than does the established PWI angiogenesis marker, cerebral blood volume (CBV). Material and Methods: Seventy-two glioma patients (sixty high-grade, twelve low-grade gliomas) were included. Capillary transit time heterogeneity (CTH) and COV, its ratio to blood mean transit time, provide indices...... of microvascular flow control and the extent to which oxygen can be extracted by tumor tissue. The ability of these parameters and CBV to differentiate tumor grade were assessed by receiver operating characteristic curves and logistic regression. Their ability to predict time to progression and overall survival...

Dual antiplatelet therapy in patients with aspirin resistance following coronary artery bypass grafting: study protocol for a randomized controlled trial [NCT01159639

Directory of Open Access Journals (Sweden)

Gasparovic Hrvoje

2012-08-01

Full Text Available Abstract Background Coronary artery disease remains the dominant cause of mortality in developed countries. While platelets have been recognized to play a pivotal role in atherothrombosis, the ideal antiplatelet regime after coronary artery surgery remains elusive. The evolution of CABG has presently moved beyond technical improvements to involve modulation of pharmacologic management designed to improve patient outcomes. The aim of this trial will be to test the hypothesis that the addition of clopidogrel to patients with documented postoperative aspirin resistance will reduce the incidence of major cardiovascular events. Methods Patients scheduled for isolated coronary artery surgery will be eligible for the study. Patients in whom postoperative multiple electrode aggregometry documents aspirin resistance will be randomized into two groups. The control group will receive 300 mg of aspirin. The dual antiplatelet group will receive 75 mg of clopidogrel in addition to 300 mg of aspirin. Patients will be followed for 6 months. Major adverse cardiac and cerebrovascular events (death from any cause, myocardial infarction, stroke, hospitalization due to cardiovascular pathology as well as bleeding events will be recorded. Discussion This will be the first trial that will specifically address the issue of dual antiplatelet therapy in patients undergoing coronary artery surgery who have been found to be aspirin resistant. In the event that the addition of clopidogrel proves to be beneficial in this subset of surgical patients, this study could significantly impact their future antiplatelet management. This randomized controlled trial has been registered at the ClinicalTrials.gov website (Identifier NCT01159639.

Experimental diode laser-assisted microvascular anastomosis.

Science.gov (United States)

Reali, U M; Gelli, R; Giannotti, V; Gori, F; Pratesi, R; Pini, R

1993-05-01

An experimental study to evaluate a diode-laser approach to microvascular end-to-end anastomoses is reported. Studies were carried out on the femoral arteries and veins of Wistar rats, and effective welding of vessel tissue was obtained at low laser power, by enhancing laser absorption with indocyanine green (Cardio-green) solution. The histologic and surgical effects of this laser technique were examined and compared with those of conventional microvascular sutured anastomoses.

Acetylcholine versus cold pressor testing for evaluation of coronary endothelial function.

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Ahmed AlBadri

Full Text Available Assessment of coronary endothelial function with intracoronary acetylcholine (IC-Ach provides diagnostic and prognostic data in patients with suspected coronary microvascular dysfunction (CMD, but is often not feasible due in part to the time and expertise needed for pharmacologic mixing. Cold pressor testing (CPT is a simple and safe stimulus useful for either invasive or non-invasive endothelial function testing and myocardial perfusion imaging but has not been specifically evaluated among symptomatic women with signs of ischemic heart disease (IHD who have no obstructive coronary artery disease (CAD.163 women with signs and symptoms of IHD and no obstructive CAD from the NHLBI- Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD study underwent coronary reactivity testing with a Doppler flow wire (FloWire® Volcano, San Diego, CA in the proximal left anterior descending artery. Coronary artery diameter and coronary blood flow (CBF assessed by core lab using QCA before and after IC-Ach (18.2 μg/ml infused over 3 minutes and during CPT.Mean age was 55 ± 12 years. Rate pressure product (RPP in response to IC-Ach did not change (baseline to peak, P = 0.26, but increased during CPT (363±1457; P = 0.0028. CBF in response to CPT was poorly correlated to IC-Ach CBF. Change in coronary artery diameter after IC-Ach correlated with change after CPT (r = 0.59, P<0.001. The correlation coefficient was stronger in subjects with coronary dilation to IC-Ach (r = 0.628, P<0.001 versus those without dilation (r = 0.353, P = 0.002, suggesting that other factors may be important to this relationship when endothelium is abnormal.In women with no obstructive CAD and suspected CMD, coronary diameter changes with IC-Ach and CPT are moderately-well correlated suggesting that CPT testing may be of some use, particularly among patients with normal endothelial function, however, not an alternative to IC-Ach for diagnosis of coronary

Coronary microvascular function and myocardial fibrosis in women with angina pectoris and no obstructive coronary artery disease

DEFF Research Database (Denmark)

Mygind, Naja Dam; Michelsen, Marie Mide; Peña, Adam

2016-01-01

had focal fibrosis. Median (IQR) CFVR was 2.3 (1.9; 2.7), 23 (36 %) had CFVR significant correlations were found between CFVR and ECV or native T1 (R (2)  = 0.02; p = 0.......27 and R (2)  = 0.004; p = 0.61, respectively). There were also no correlations between MBFR and ECV or native T1 (R (2)  = 0.1; p = 0.13 and R (2)  = 0.004, p = 0.64, respectively). CFVR and MBFR were correlated to hypertension and heart rate. CONCLUSION: In women with angina and no obstructive coronary...

Major prognostic impact of persistent microvascular obstruction as assessed by contrast-enhanced cardiac magnetic resonance in reperfused acute myocardial infarction

International Nuclear Information System (INIS)

Cochet, Alexandre A.; Lalande, Alain; Walker, Paul M.; Touzery, Claude; Brunotte, Francois; Lorgis, Luc; Beer, Jean-Claude; Cottin, Yves; Zeller, Marianne; Wolf, Jean-Eric

2009-01-01

The aim of this study was to compare the prognostic significance of microvascular obstruction (MO) and persistent microvascular obstruction (PMO) as assessed by cardiac magnetic resonance (CMR) in patients with acute myocardial infarction (AMI). CMR was performed in 184 patients within the week following successfully reperfused first AMI. First-pass images were performed to evaluate extent of MO and late gadolinium-enhanced images to assess PMO and infarct size (IS). Major adverse cardiac events (MACE) were collected at 1-year follow-up. MO and PMO were found in 127 (69%) and 87 (47%) patients, respectively. By using univariate logistic regression analysis, high Global Registry of Acute Coronary Events (GRACE) risk score (odds ratio [OR] 95% confidence interval [CI]: 3.6 [1.8-7.4], p < 0.001), IS greater than 10% (OR [95% CI]: 2.7 [1.1-6.9], p = 0.036), left ventricular ejection fraction less than 40% (OR [95% CI]: 2.4 [1.1-5.2], p = 0.027), presence of MO (OR [95% CI]: 3.1 [1.3-7.3], p = 0.004) and presence of PMO (OR [95% CI]:10 [4.1-23.9], p < 0.001) were shown to be significantly associated with the outcome. By using multivariate analysis, presence of MO (OR [95% CI]: 2.5 [1.0-6.2], p = 0.045) or of PMO (OR [95% CI]: 8.7 [3.6-21.1], p < 0.001), associated with GRACE score, were predictors of MACE. Presence of microvascular obstruction and persistent microvascular obstruction is very common in AMI patients even after successful reperfusion and is associated with a dramatically higher risk of subsequent cardiovascular events, beyond established prognostic markers. Moreover, our data suggest that the prognostic impact of PMO might be superior to MO. (orig.)

Hyperemic stenosis resistance index for evaluation of functional coronary lesion severity

NARCIS (Netherlands)

Meuwissen, Martijn; Siebes, Maria; Chamuleau, Steven A. J.; van Eck-Smit, Berthe L. F.; Koch, Karel T.; de Winter, Robbert J.; Tijssen, Jan G. P.; Spaan, Jos A. E.; Piek, Jan J.

2002-01-01

Background-Both coronary blood flow velocity reserve (CFVR) and myocardial fractional flow reserve (FFR) are used to evaluate the hemodynamic severity of coronary lesions. However, discordant results between CFVR and FFR have been observed in 25%, to 30% of intermediate coronary lesions. An index of

Correlates of time to microvascular complications among diabetes ...

African Journals Online (AJOL)

Socio-demographic and clinical factors have been known to affect the time to microvascular complications and survival probabilities of diabetes mellitus patients. The objective of this study was to identify risk factors and estimate average survival times for the time to the development of microvascular complications of ...

Microvascular pericytes in healthy and diseased kidneys

Science.gov (United States)

Pan, Szu-Yu; Chang, Yu-Ting; Lin, Shuei-Liong

2014-01-01

Pericytes are interstitial mesenchymal cells found in many major organs. In the kidney, microvascular pericytes are defined anatomically as extensively branched, collagen-producing cells in close contact with endothelial cells. Although many molecular markers have been proposed, none of them can identify the pericytes with satisfactory specificity or sensitivity. The roles of microvascular pericytes in kidneys were poorly understood in the past. Recently, by using genetic lineage tracing to label collagen-producing cells or mesenchymal cells, the elusive characteristics of the pericytes have been illuminated. The purpose of this article is to review recent advances in the understanding of microvascular pericytes in the kidneys. In healthy kidney, the pericytes are found to take part in the maintenance of microvascular stability. Detachment of the pericytes from the microvasculature and loss of the close contact with endothelial cells have been observed during renal insult. Renal microvascular pericytes have been shown to be the major source of scar-forming myofibroblasts in fibrogenic kidney disease. Targeting the crosstalk between pericytes and neighboring endothelial cells or tubular epithelial cells may inhibit the pericyte–myofibroblast transition, prevent peritubular capillary rarefaction, and attenuate renal fibrosis. In addition, renal pericytes deserve attention for their potential to produce erythropoietin in healthy kidneys as pericytes stand in the front line, sensing the change of oxygenation and hemoglobin concentration. Further delineation of the mechanisms underlying the reduced erythropoietin production occurring during pericyte–myofibroblast transition may be promising for the development of new treatment strategies for anemia in chronic kidney disease. PMID:24465134

Graft microvascular disease in solid organ transplantation.

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Jiang, Xinguo; Sung, Yon K; Tian, Wen; Qian, Jin; Semenza, Gregg L; Nicolls, Mark R

2014-08-01

Alloimmune inflammation damages the microvasculature of solid organ transplants during acute rejection. Although immunosuppressive drugs diminish the inflammatory response, they do not directly promote vascular repair. Repetitive microvascular injury with insufficient regeneration results in prolonged tissue hypoxia and fibrotic remodeling. While clinical studies show that a loss of the microvascular circulation precedes and may act as an initiating factor for the development of chronic rejection, preclinical studies demonstrate that improved microvascular perfusion during acute rejection delays and attenuates tissue fibrosis. Therefore, preservation of a functional microvasculature may represent an effective therapeutic strategy for preventing chronic rejection. Here, we review recent advances in our understanding of the role of the microvasculature in the long-term survival of transplanted solid organs. We also highlight microvessel-centered therapeutic strategies for prolonging the survival of solid organ transplants.

Comparison between invasive and noninvasive techniques of evaluation of microvascular structural alterations.

Science.gov (United States)

De Ciuceis, Carolina; Agabiti Rosei, Claudia; Caletti, Stefano; Trapletti, Valentina; Coschignano, Maria A; Tiberio, Guido A M; Duse, Sarah; Docchio, Franco; Pasinetti, Simone; Zambonardi, Federica; Semeraro, Francesco; Porteri, Enzo; Solaini, Leonardo; Sansoni, Giovanna; Pileri, Paola; Rossini, Claudia; Mittempergher, Francesco; Portolani, Nazario; Ministrini, Silvia; Agabiti-Rosei, Enrico; Rizzoni, Damiano

2018-05-01

The evaluation of the morphological characteristics of small resistance arteries in humans is challenging. The gold standard method is generally considered to be the measurement by wire or pressure micromyography of the media-to-lumen ratio of subcutaneous small vessels obtained by local biopsies. However, noninvasive techniques for the evaluation of retinal arterioles were recently proposed; in particular, two approaches, scanning laser Doppler flowmetry (SLDF) and adaptive optics, seem to provide useful information; both of them provide an estimation of the wall-to-lumen ratio (WLR) of retinal arterioles. Moreover, a noninvasive measurement of basal and total capillary density may be obtained by videomicroscopy/capillaroscopy. No direct comparison of these three noninvasive techniques in the same population was previously performed; in particular, adaptive optics was never validated against micromyography. In the current study, we enrolled 41 controls and patients: 12 normotensive lean controls, 12 essential hypertensive lean patients, nine normotensive obese patients and eight hypertensive obese patients undergoing elective surgery. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance artery structure was assessed by wire micromyography and the media-to-lumen ratio was calculated. WLR of retinal arterioles was obtained by SLDF and adaptive optics. Functional (basal) and structural (total) microvascular density was evaluated by capillaroscopy before and after venous congestion. Our data suggest that adaptive optics has a substantial advantage over SLDF in terms of evaluation of microvascular morphology, as WLR measured with adaptive optics is more closely correlated with the M/L of subcutaneous small arteries (r = 0.84, P < 0.001 vs. r = 0.52, P < 0.05, slopes of the relations: P < 0.01 adaptive optics vs. SLDF). In addition, the reproducibility of the evaluation of the WLR with adaptive optics is

Multimodal reconstruction of microvascular-flow distributions using combined two-photon microscopy and Doppler optical coherence tomography.

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Gagnon, Louis; Sakadžić, Sava; Lesage, Fréderic; Mandeville, Emiri T; Fang, Qianqian; Yaseen, Mohammad A; Boas, David A

2015-01-01

Computing microvascular cerebral blood flow ([Formula: see text]) in real cortical angiograms is challenging. Here, we investigated whether the use of Doppler optical coherence tomography (DOCT) flow measurements in individual vessel segments can help in reconstructing [Formula: see text] across the entire vasculature of a truncated cortical angiogram. A [Formula: see text] computational framework integrating DOCT measurements is presented. Simulations performed on a synthetic angiogram showed that the addition of DOCT measurements, especially close to large inflowing or outflowing vessels, reduces the impact of pressure boundary conditions and estimated vessel resistances resulting in a more accurate reconstruction of [Formula: see text]. Our technique was then applied to reconstruct microvascular flow distributions in the mouse cortex down to [Formula: see text] by combining two-photon laser scanning microscopy angiography with DOCT.

Coronary atherosclerosis in sudden cardiac death: An autopsy study

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Sudha M

2009-10-01

Full Text Available Background: The incidence of ischemic heart disease (IHD has markedly increased in India over the past few years. Considering the variations in racial, dietary and lifestyle patterns in our population, it is essential to study the biology of coronary atherosclerosis in our patients. Vulnerable plaques have a large number of foam cells, extracellular lipid, thin fibrous caps and clusters of inflammatory cells and are more prone to rupture. These plaques are nourished by the microvessels arising from the vasa vasorum of the blood vessels and by lumen-derived microvessels through the fibrous cap. This autopsy study was designed to analyse the coronary arterial tree in cases of sudden cardiac death, classify coronary atherosclerotic plaques and to assess the factors contributing to vulnerability of the plaques including inflammation, calcification and microvascular density. Materials and Methods: Seven cases of sudden cardiac death were included in the study. The hearts were perfusion-fixed and the coronary arteries along with their main branches were dissected and studied. The location of the plaques, type of plaques, presence of inflammation and calcification were assessed. The cap thickness and microvessel density per 1000um 2 were assessed. The statistical significance was estimated. Results and Conclusions: Extensive high-grade coronary atherosclerotic disease was seen in all sudden cardiac death cases. Majority of the plaques were vulnerable. High-grade inflammation was seen in most of the vulnerable and ruptured plaques. All the ruptured plaques were uncalcified indicating that calcification probably stabilizes the plaques and protects against rupture. Increased microvessel density was noted in ruptured plaques compared to vulnerable plaques. However, it was not statistically significant.

Estimation of coronary flow reserve by sestamibi imaging in patients with mild hypertension and normal coronary arteries

International Nuclear Information System (INIS)

Storto, G.; Gallicchio, R.; Maddalena, F.; Pellegrino, T.; Petretta, M.; Fiumara, G.; Cuocolo, A.

2015-01-01

Patients with hypertension may exhibit abnormal vasodilator capacity during pharmacological vasodilatation. We assessed coronary flow reserve (CFR) by sestamibi imaging in hypertensive patients with normal coronary vessels. Twenty-five patients with untreated mild essential hypertension and normal coronary vessels and 10 control subjects underwent dipyridamole-rest Tc-99m sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in pulmonary artery and myocardial counts from tomograhic images. CFR was expressed as the ratio of stress to rest MBF. Coronary vascular resistances (CVR) were computed as the ratio between mean arterial pressure and MBF. Estimated MBF at rest was not different in patients and controls (1.11±0.59 vs. 1.14±0.28 counts/pixel/s; P=0.87). Conversely, stress MBF was lower in patients than in controls (1.55±0.47 vs. 2.68±0.53 counts/pixel/s; P<0.001). Thus, CFR was reduced in patients compared to controls (1.61±0.58 vs. 2.43±0.62; P<0.001). Rest and stress CVR values were higher in patients (P<0.001), while stress-induced changes in CVR were not different (P=0.08) between patients (-51%) and controls (-62%). In the overall study population, a significant relation between CFR and stress-induced changes in CVR was observed (r=-0.86; P<0.001). Sestamibi imaging may detect impaired coronary vascular function in response to dipyridamole in patients with untreated mild essential hypertension and normal coronary arteries. A mild increase in arterial blood pressure does not affect baseline MBF, but impairs coronary reserve due to the amplified resting coronary resistances.

Microvascular Anastomosis Training in Neurosurgery: A Review

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Vadim A. Byvaltsev

2018-01-01

Full Text Available Cerebrovascular diseases are among the most widespread diseases in the world, which largely determine the structure of morbidity and mortality rates. Microvascular anastomosis techniques are important for revascularization surgeries on brachiocephalic and carotid arteries and complex cerebral aneurysms and even during resection of brain tumors that obstruct major cerebral arteries. Training in microvascular surgery became even more difficult with less case exposure and growth of the use of endovascular techniques. In this text we will briefly discuss the history of microvascular surgery, review current literature on simulation models with the emphasis on their merits and shortcomings, and describe the views and opinions on the future of the microvascular training in neurosurgery. In “dry” microsurgical training, various models created from artificial materials that simulate biological tissues are used. The next stage in training more experienced surgeons is to work with nonliving tissue models. Microvascular training using live models is considered to be the most relevant due to presence of the blood flow. Training on laboratory animals has high indicators of face and constructive validity. One of the future directions in the development of microsurgical techniques is the use of robotic systems. Robotic systems may play a role in teaching future generations of microsurgeons. Modern technologies allow access to highly accurate learning environments that are extremely similar to real environment. Additionally, assessment of microsurgical skills should become a fundamental part of the current evaluation of competence within a microneurosurgical training program. Such an assessment tool could be utilized to ensure a constant level of surgical competence within the recertification process. It is important that this evaluation be based on validated models.

Effect of a Tibetan herbal mixture on microvascular endothelial function, heart rate variability and biomarkers of inflammation, clotting and coagulation.

Science.gov (United States)

Schäfer, Daniela; Lambrecht, Julia; Radtke, Thomas; Wilhelm, Matthias; Saner, Hugo

2015-08-01

In this 6-week prospective, randomized, placebo-controlled and double-blind study, we investigated the effects of a natural herbal remedy based on a recipe from Tibet (Padma® 28), on microvascular endothelial function, heart rate variability and biomarkers of inflammation, clotting and coagulation in 80 coronary artery disease (CAD) patients (age 66 ± 8 years) on guideline-based medication for secondary prevention. We found no significant effects of Padma 28 and conclude that the addition of Padma 28 to guideline-based secondary prevention treatment of CAD did not lead to significant effects on important surrogate markers in elderly male CAD patients. © The European Society of Cardiology 2014.

Apolipoprotein B level and diabetic microvascular complications ( is there a correlation?

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Mary N. Rizk

2013-01-01

Conclusion Apo B levels are strongly correlated to diabetic microvascular complications. The higher the degree of nephropathy, the higher the Apo B level. The presence of more than one microvascular complication correlates positively with high levels of Apo B. This suggests the possible use of Apo B as a sensitive biomarker of the presence of early diabetic microvascular complications.

Role of coronary physiology in the contemporary management of coronary artery disease

Science.gov (United States)

Ruparelia, Neil; Kharbanda, Rajesh K

2015-01-01

Coronary artery disease (CAD) remains the leading cause of death worldwide with approximately 1 in 30 patients with stable CAD experiencing death or acute myocardial infarction each year. The presence and extent of resultant myocardial ischaemia has been shown to confer an increased risk of adverse outcomes. Whilst, optimal medical therapy (OMT) forms the cornerstone of the management of patients with stable CAD, a significant number of patients present with ischaemia refractory to OMT. Historically coronary angiography alone has been used to determine coronary lesion severity in both stable and acute settings. It is increasingly clear that this approach fails to accurately identify the haemodynamic significance of lesions; especially those that are visually “intermediate” in severity. Revascularisation based upon angiographic appearances alone may not reduce coronary events above OMT. Technological advances have enabled the measurement of physiological indices including the fractional flow reserve, the index of microcirculatory resistance and the coronary flow reserve. The integration of these parameters into the routine management of patients presenting to the cardiac catheterization laboratory with CAD represents a critical adjunctive tool in the optimal management of these patients by identifying patients that would most benefit from revascularisation and importantly also highlighting patients that would not gain benefit and therefore reducing the likelihood of adverse outcomes associated with coronary revascularisation. Furthermore, these techniques are applicable to a broad range of patients including those with left main stem disease, proximal coronary disease, diabetes mellitus, previous percutaneous coronary intervention and with previous coronary artery bypass grafting. This review will discuss current concepts relevant to coronary physiology assessment, its role in the management of both stable and acute patients and future applications. PMID

Role of coronary physiology in the contemporary management of coronary artery disease.

Science.gov (United States)

Ruparelia, Neil; Kharbanda, Rajesh K

2015-02-16

Coronary artery disease (CAD) remains the leading cause of death worldwide with approximately 1 in 30 patients with stable CAD experiencing death or acute myocardial infarction each year. The presence and extent of resultant myocardial ischaemia has been shown to confer an increased risk of adverse outcomes. Whilst, optimal medical therapy (OMT) forms the cornerstone of the management of patients with stable CAD, a significant number of patients present with ischaemia refractory to OMT. Historically coronary angiography alone has been used to determine coronary lesion severity in both stable and acute settings. It is increasingly clear that this approach fails to accurately identify the haemodynamic significance of lesions; especially those that are visually "intermediate" in severity. Revascularisation based upon angiographic appearances alone may not reduce coronary events above OMT. Technological advances have enabled the measurement of physiological indices including the fractional flow reserve, the index of microcirculatory resistance and the coronary flow reserve. The integration of these parameters into the routine management of patients presenting to the cardiac catheterization laboratory with CAD represents a critical adjunctive tool in the optimal management of these patients by identifying patients that would most benefit from revascularisation and importantly also highlighting patients that would not gain benefit and therefore reducing the likelihood of adverse outcomes associated with coronary revascularisation. Furthermore, these techniques are applicable to a broad range of patients including those with left main stem disease, proximal coronary disease, diabetes mellitus, previous percutaneous coronary intervention and with previous coronary artery bypass grafting. This review will discuss current concepts relevant to coronary physiology assessment, its role in the management of both stable and acute patients and future applications.

Physiological basis of clinically used coronary hemodynamic indices

NARCIS (Netherlands)

Spaan, Jos A. E.; Piek, Jan J.; Hoffman, Julien I. E.; Siebes, Maria

2006-01-01

In deriving clinically used hemodynamic indices such as fractional flow reserve and coronary flow velocity reserve, simplified models of the coronary circulation are used. In particular, myocardial resistance is assumed to be independent of factors such as heart contraction and driving pressure.

Quantitative analysis of vasodilatory action of quercetin on intramural coronary resistance arteries of the rat in vitro.

Directory of Open Access Journals (Sweden)

Anna Monori-Kiss

Full Text Available BACKGROUND: Dietary quercetin improves cardiovascular health, relaxes some vascular smooth muscle and has been demonstrated to serve as a substrate for the cyclooxygenase enzyme. AIMS: 1. To test quantitatively a potential direct vasodilatory effect on intramural coronary resistance artery segments, in different concentrations. 2. To scale vasorelaxation at different intraluminal pressure loads on such vessels of different size. 3. To test the potential role of prostanoids in vasodilatation induced by quercetin. METHODS: Coronary arterioles (70-240 µm were prepared from 24 rats and pressurized in PSS, using a pressure microangiometer. RESULTS: The spontaneous tone that developed at 50 mmHg was relaxed by quercetin in the 10(-9 moles/lit concentration (p<0.05, while 10(-5 moles/lit caused full relaxation. Significant relaxation was observed at all pressure levels (10-100 mmHg at 10(-7 moles/lit concentration of quercetin. The cyclooxygenase blocker indomethacin (10(-5 moles/lit induced no relaxation but contraction when physiological concentrations of quercetin were present in the tissue bath (p<0.02 with Anova, this contraction being more prominent in smaller vessels and in the higher pressure range (p<0.05, Pearson correlation. A further 2-8% contraction could be elicited by the NO blocker L-NAME (10(-4 moles/lit. CONCLUSION: These results demonstrate that circulating levels of quercetin (10(-7 moles/lit exhibit a substantial coronary vasodilatory effect. The extent of it is commeasurable with that of several other physiological mechanisms of coronary blood flow control. At least part of this relaxation is the result of an altered balance toward the production of endogenous vasodilatory prostanoids in the coronary arteriole wall.

Renal microvascular disease in an aging population: a reversible process?

Science.gov (United States)

Futrakul, Narisa; Futrakul, Prasit

2008-01-01

Renal microvascular disease and tubulointerstitial fibrosis are usually demonstrated in aging in humans and animals. It has recently been proposed that renal microvascular disease is the crucial determinant of tubulointerstitial disease or fibrosis. Enhanced circulating endothelial cell loss is a biomarker that reflects glomerular endothelial injury or renal microvascular disease, and fractional excretion of magnesium (FE Mg) is a sensitive biomarker that reflects an early stage of tubulointerstitial fibrosis. In aging in humans, both of these biomarkers are abnormally elevated. In addition, a glomerular endothelial dysfunction determined by altered hemodynamics associated with peritubular capillary flow reduction is substantiated. A correction of such hemodynamic alteration with vasodilators can effectively improve renal perfusion and restore renal function. Thus, anti-aging therapy can reverse the renal microvascular disease and dysfunction associated with the aging process.

Differential regulation of TRPV1 channels by H2O2: implications for diabetic microvascular dysfunction

Science.gov (United States)

DelloStritto, Daniel J.; Connell, Patrick J.; Dick, Gregory M.; Fancher, Ibra S.; Klarich, Brittany; Fahmy, Joseph N.; Kang, Patrick T.; Chen, Yeong-Renn; Damron, Derek S.; Thodeti, Charles K.

2016-01-01

We demonstrated previously that TRPV1-dependent coupling of coronary blood flow (CBF) to metabolism is disrupted in diabetes. A critical amount of H2O2 contributes to CBF regulation; however, excessive H2O2 impairs responses. We sought to determine the extent to which differential regulation of TRPV1 by H2O2 modulates CBF and vascular reactivity in diabetes. We used contrast echocardiography to study TRPV1 knockout (V1KO), db/db diabetic, and wild type C57BKS/J (WT) mice. H2O2 dose-dependently increased CBF in WT mice, a response blocked by the TRPV1 antagonist SB366791. H2O2-induced vasodilation was significantly inhibited in db/db and V1KO mice. H2O2 caused robust SB366791-sensitive dilation in WT coronary microvessels; however, this response was attenuated in vessels from db/db and V1KO mice, suggesting H2O2-induced vasodilation occurs, in part, via TRPV1. Acute H2O2 exposure potentiated capsaicin-induced CBF responses and capsaicin-mediated vasodilation in WT mice, whereas prolonged luminal H2O2 exposure blunted capsaicin-induced vasodilation. Electrophysiology studies re-confirms acute H2O2 exposure activated TRPV1 in HEK293A and bovine aortic endothelial cells while establishing that H2O2 potentiate capsaicin-activated TRPV1 currents, whereas prolonged H2O2 exposure attenuated TRPV1 currents. Verification of H2O2-mediated activation of intrinsic TRPV1 specific currents were found in isolated mouse coronary endothelial cells from WT mice and decreased in endothelial cells from V1KO mice. These data suggest prolonged H2O2 exposure impairs TRPV1-dependent coronary vascular signaling. This may contribute to microvascular dysfunction and tissue perfusion deficits characteristic of diabetes. PMID:26907473

Verocytotoxin-induced apoptosis of human microvascular endothelial cells.

Science.gov (United States)

Pijpers, A H; van Setten, P A; van den Heuvel, L P; Assmann, K J; Dijkman, H B; Pennings, A H; Monnens, L A; van Hinsbergh, V W

2001-04-01

The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

[Recent advances on pericytes in microvascular dysfunction and traditional Chinese medicine prevention].

Science.gov (United States)

Liu, Lei; Liu, Jian-Xun; Guo, Hao; Ren, Jian-Xun

2017-08-01

Pericytesis a kind of widespread vascular mural cells embedded within the vascular basement membrane of blood microvessels, constituting the barrier of capillaries and tissue spaces together with endothelial cells. Pericytes communicate with microvascular endothelial cells through cell connections or paracrine signals, playing an important role in important physiological processes such as blood flow, vascular permeability and vascular formation. Pericytes dysfunction may participate in some microvascular dysfunction, and also mediate pathological repair process, therefore pericytes attracted more and more attention. Traditional Chinese medicine suggests that microvascular dysfunction belongs to the collaterals disease; Qi stagnation and blood stasis in collaterals result in function imbalance of internal organs. Traditional Chinese medicine (TCM) has shown effects on pericytes in microvascular dysfunction, for example qi reinforcing blood-circulation activating medicines can reduce the damage of retinal pericytes in diabetic retinopathy. However, there are some limitations of research fields, inaccuracy of research techniques and methods, and lack of mechanism elaboration depth in the study of microvascular lesion pericytes. This paper reviewed the biological characteristics of pericytes and pericytes in microvascular dysfunction, as well as the intervention study of TCM on pericytes. The article aims to provide reference for the research of pericytes in microvascular dysfunction and the TCM study on pericytes. Copyright© by the Chinese Pharmaceutical Association.

[Evaluation and Optimization of Microvascular Arterial Anastomoses by Transit Time Flow Measurement].

Science.gov (United States)

Herberhold, S; Röttker, J; Bartmann, D; Solbach, A; Keiner, S; Welz, A; Bootz, F; Laffers, W

2016-03-01

INDRODUCTION: The regular application of transit time flow measurement in microvascular anastomoses during heart surgery has lead to improvements of the outcome of coronary artery bypass grafts. Our study was meant to discover whether this measurement method was also applicable for evaluation and optimization of microvascular arterial anastomoses of radial forearm flaps. In this prospective examination a combining ultrasound imaging and transit time flow measurement device (VeriQ, MediStim) was used during surgery to assess anastomotic quality of 15 radial forearm flaps. Pulsatility index (PI) and mean blood flow were measured immediately after opening the arterial anastomosis as well as 15 min afterwards. Furthermore, application time and description of handling were recorded seperately for every assessment. Mean blood flow immediately after opening the anastomosis and 15 min later were 3.9 and 3.4 ml/min resepectively showing no statistically significant difference (p=0.96). There was no significance in the increase of pulsatility index from 22.1 to 27.2 (p=0.09) during the same time range, either. Due to measurement results showing atypical pulse curves in 2 cases decision for surgical revision of the anastomoses was made. All forearm flaps showed good vascularisation during follow-up. Time for device set up, probe placement and measurements was about 20 min. Handling was described to be uncomplicated without exception. There were no noteworthy problems. Transit time flow measurement contributes to the improvement of anastomotic quality and therefore to the overall outcome of radial forearm flaps. The examined measurement method provides objective results and is useful for documentation purposes. © Georg Thieme Verlag KG Stuttgart · New York.

Percutaneous coronary intervention for poor coronary microcirculation reperfusion of patients with stable angina pectoris.

Science.gov (United States)

Li, J S; Zhao, X J; Ma, B X; Wang, Z

2016-01-01

Percutaneous coronary intervention (PCI) has been extensively applied to repair the forward flow of diseased coronary artery and can achieve significant curative results. However, some patients with acute myocardial infarction (AMI) develop non-perfusion or poor perfusion of cardiac muscle tissue after PCI, which increases the incidence of cardiovascular events and the death rate. PCI can dredge narrowed or infarct-related artery (IRA) and thus induce full reperfusion of ischemic myocardium. It is found in practice that some cases of AMI still have no perfusion or poor perfusion in myocardial tissue even though coronary angiography suggests opened coronary artery after PCI, which increases the incidence of vascular events and mortality. Therefore, to explore the detailed mechanism of PCI in treating coronary microcirculation of patients with stable angina pectoris, we selected 140 patients with stable angina pectoris for PCI, observing the index of microcirculatory resistance (IMR) of descending branch and changes of myocardial injury markers and left ventricular systolic function, and made a subgroup analysis based on the correlation between clinical indexes, IMR and other variables of diabetic and non-diabetic patients, PCI-related and non-PCI-related myocardial infarction patients. The results suggest that IMR of anterior descending branch after PCI was higher compared to that before PCI, and the difference was significant (P less than 0.05); creatine kinase-MB (CK-MB), myohemoglobin and high sensitive troponin T were all increased after PCI, and the difference was also significant (P less than 0.05); brain natriuretic peptide (BNP) level became higher after PCI, with significant difference (P less than 0.05); left ventricular ejection fraction (LVEF) declined after PCI, and the difference before and after PCI was statistically significant (P less than 0.05). Moreover, subgroup analysis results of the three groups all demonstrated statistically significant

Invasive angiography and revascularization in patients with stable angina following prior coronary artery bypass grafting

DEFF Research Database (Denmark)

Joshi, Francis R; Biasco, Luigi; Pedersen, Frants

2017-01-01

. Follow-up data were available for all patients, by means of records linked to each Danish social security number. RESULTS: In patients with prior CABG and stable angina (n = 2,309), diagnostic angiography led to revascularization in 574 (24.9%) cases. Chronic kidney disease (HR 1.93 [1.08-3.44], P = 0......BACKGROUND: There are limited data to guide the optimum approach to patients presenting with angina after coronary artery bypass grafting (CABG). Although often referred for invasive angiography, the effectiveness of this is unknown; angina may also result from diffuse distal or micro......-vascular coronary disease and it is not known how often targets for intervention are identified. METHODS: Retrospective review of 50,460 patients undergoing angiography in East Denmark between January 2010 and December 2014. Clinical and procedural data were prospectively stored in a regional electronic database...

Shaker-related voltage-gated K+ channel expression and vasomotor function in human coronary resistance arteries.

Science.gov (United States)

Nishijima, Yoshinori; Korishettar, Ankush; Chabowski, Dawid S; Cao, Sheng; Zheng, Xiaodong; Gutterman, David D; Zhang, David X

2018-01-01

K V channels are important regulators of vascular tone, but the identity of specific K V channels involved and their regulation in disease remain less well understood. We determined the expression of K V 1 channel subunits and their role in cAMP-mediated dilation in coronary resistance arteries from subjects with and without CAD. HCAs from patients with and without CAD were assessed for mRNA and protein expression of K V 1 channel subunits with molecular techniques and for vasodilator response with isolated arterial myography. Assays of mRNA transcripts, membrane protein expression, and vascular cell-specific localization revealed abundant expression of K V 1.5 in vascular smooth muscle cells of non-CAD HCAs. Isoproterenol and forskolin, two distinct cAMP-mediated vasodilators, induced potent dilation of non-CAD arterioles, which was inhibited by both the general K V blocker 4-AP and the selective K V 1.5 blocker DPO-1. The cAMP-mediated dilation was reduced in CAD and was accompanied by a loss of or reduced contribution of 4-AP-sensitive K V channels. K V 1.5, as a major 4-AP-sensitive K V 1 channel expressed in coronary VSMCs, mediates cAMP-mediated dilation in non-CAD arterioles. The cAMP-mediated dilation is reduced in CAD coronary arterioles, which is associated with impaired 4-AP-sensitive K V channel function. © 2017 John Wiley & Sons Ltd.

Aborted Sudden Cardiac Death in a Female Patient Presenting with Takotsubo-Like Cardiomyopathy due to Epicardial Coronary Vasospasm

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Sorin Giusca

2017-01-01

Full Text Available Takotsubo cardiomyopathy is characterized by apical ballooning of the left ventricle (LV in the absence of relevant coronary artery stenosis, which typically occurs in elderly women after emotional stress. Catecholamine cardiotoxicity, metabolic disturbance, and coronary microvascular impairment have previously been proposed as underlying pathophysiologic mechanisms of takotsubo cardiomyopathy, whereas myocardial stunning resulting from epicardial coronary artery vasospasm is not generally accepted as a cause of takotsubo cardiomyopathy. The prognosis of takotsubo cardiomyopathy is generally more favourable compared to myocardial infarction; however, severe complications such as rupture of the LV and life-threatening arrhythmias may occur. Herein, we describe a case of an 84-year-old female, who presented with aborted sudden cardiac death due to ventricular fibrillation. Echocardiography suggested LV apical ballooning with severely impaired LV-function, so that takotsubo cardiomyopathy was suspected. However, coronary angiography revealed epicardial spasm of the left anterior ascending, which resolved after intracoronary injection of 0.2 mg nitroglycerine. Cardiac magnetic resonance exhibited subendocardial late enhancement and echocardiography showed normalization of LV dysfunction during follow-up. The patient was put on conservative treatment with nitrates and calcium inhibitors and ICD implantation were deferred.

Active cooling of microvascular composites for battery packaging

Science.gov (United States)

Pety, Stephen J.; Chia, Patrick X. L.; Carrington, Stephen M.; White, Scott R.

2017-10-01

Batteries in electric vehicles (EVs) require a packaging system that provides both thermal regulation and crash protection. A novel packaging scheme is presented that uses active cooling of microvascular carbon fiber reinforced composites to accomplish this multifunctional objective. Microvascular carbon fiber/epoxy composite panels were fabricated and their cooling performance assessed over a range of thermal loads and experimental conditions. Tests were performed for different values of coolant flow rate, channel spacing, panel thermal conductivity, and applied heat flux. More efficient cooling occurs when the coolant flow rate is increased, channel spacing is reduced, and thermal conductivity of the host composite is increased. Computational fluid dynamics (CFD) simulations were also performed and correlate well with the experimental data. CFD simulations of a typical EV battery pack confirm that microvascular composite panels can adequately cool battery cells generating 500 W m-2 heat flux below 40 °C.

Microvascular imaging: techniques and opportunities for clinical physiological measurements

International Nuclear Information System (INIS)

Allen, John; Howell, Kevin

2014-01-01

The microvasculature presents a particular challenge in physiological measurement because the vessel structure is spatially inhomogeneous and perfusion can exhibit high variability over time. This review describes, with a clinical focus, the wide variety of methods now available for imaging of the microvasculature and their key applications. Laser Doppler perfusion imaging and laser speckle contrast imaging are established, commercially-available techniques for determining microvascular perfusion, with proven clinical utility for applications such as burn-depth assessment. Nailfold capillaroscopy is also commercially available, with significant published literature that supports its use for detecting microangiopathy secondary to specific connective tissue diseases in patients with Raynaud's phenomenon. Infrared thermography measures skin temperature and not perfusion directly, and it has only gained acceptance for some surgical and peripheral microvascular applications. Other emerging technologies including imaging photoplethysmography, optical coherence tomography, photoacoustic tomography, hyperspectral imaging, and tissue viability imaging are also described to show their potential as techniques that could become established tools for clinical microvascular assessment. Growing interest in the microcirculation has helped drive the rapid development in perfusion imaging of the microvessels, bringing exciting opportunities in microvascular research. (topical review)

Correlation Factor Analysis of Retinal Microvascular Changes in Patients With Essential Hypertension

Institute of Scientific and Technical Information of China (English)

Huang Duru; Huang Zhongning

2006-01-01

Objectives To investigate correlation between retinal microvascular signs and essential hypertension classification. Methods The retinal microvascular signs in patients with essential hypertension were assessed with the indirect biomicroscopy lens, the direct and the indirect ophthalmoscopes were used to determine the hypertensive retinopathy grades and retinal arteriosclerosis grades.The rank correlation analysis was used to analysis the correlation these grades with the risk factors concerned with hypertension. Results Of 72 cases with essential hypertension, 28 cases complicated with coronary disease, 20 cases diabetes, 41 cases stroke,17 cases renal malfunction. Varying extent retinal arterioscleroses were found in 71 cases, 1 case with retinal hemorrhage, 2 cases with retina edema, 4 cases with retinal hard exudation, 5 cases with retinal hemorrhage complicated by hard exudation, 2 cases with retinal hemorrhage complicated by hard exudation and cotton wool spot, 1 case with retinal hemorrhage complicated by hard exudation and microaneurysms,1 case with retinal edema and hard exudation, 1 case with retinal microaneurysms, 1 case with branch retinal vein occlusion. The rank correlation analysis showed that either hypertensive retinopathy grades or retinal arteriosclerosis grades were correlated with risk factor lamination of hypertension (r=0.25 or 0.31, P＜0.05), other correlation factors included age and blood high density lipoprotein concerned about hypertensive retinopathy grades or retinal arteriosclerosis grades, but other parameters, namely systolic or diastolic pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, fasting blood glucose,blood urea nitrogen and blood creatinine were not confirmed in this correlation analysis (P ＞ 0.05).Conclusions Either hypertensive retinopathy grade or retinal arteriosclerosis grade is close with the hypertension risk factor lamination, suggesting that the fundus examination of patients with

Impairment of skin blood flow during post-occlusive reactive hyperhemy assessed by laser Doppler flowmetry correlates with renal resistive index.

Science.gov (United States)

Coulon, P; Constans, J; Gosse, P

2012-01-01

We lack non-invasive tools for evaluating the coronary and renal microcirculations. Since cutaneous Doppler laser exploration has evidenced impaired cutaneous microvascular responses in coronary artery disease and in impaired renal function, we wanted to find out if there was a link between the impairments in the cutaneous and renal microcirculations. To specify the significance of the rise in the renal resistive index (RI), which is still unclear, we also sought relations between RI and arterial stiffness. We conducted a cross-sectional controlled study in a heterogeneous population including hypertensive patients of various ages with or without a history of cardiovascular disease along with a healthy control group. The cutaneous microcirculation was evaluated by laser Doppler flowmetry of the post-occlusive reactive hyperhemy (PORH) and of the hyperhemy to heat. The renal microcirculation was evaluated by measurement of the RI. Arterial stiffness was evaluated from an ambulatory measurement of the corrected QKD(100-60) interval. We included 22 hypertensives and 11 controls of mean age 60.6 vs 40.8 years. In this population, there was a correlation between RI and basal zero to peak flow variation (BZ-PF) (r=-0.42; P=0.02) and a correlation between RI and rest flow to peak flow variation (RF-PF) (r=-0.44; P=0.01). There was also a significant correlation between RI and the corrected QKD(100-60) (r=-0.47; P=0.01). The significant correlation between PORH parameters and RI indicates that the functional modifications of the renal and cutaneous microcirculations tend to evolve in parallel during ageing or hypertension. The relation between RI and arterial stiffness shows that RI is a compound index of both renal microvascular impairment and the deterioration of macrovascular mechanics.

Blood-based biomarkers of microvascular pathology in Alzheimer's disease.

LENUS (Irish Health Repository)

Ewers, Michael

2012-02-01

Sporadic Alzheimer\\'s disease (AD) is a genetically complex and chronically progressive neurodegenerative disorder with molecular mechanisms and neuropathologies centering around the amyloidogenic pathway, hyperphosphorylation and aggregation of tau protein, and neurofibrillary degeneration. While cerebrovascular changes have not been traditionally considered to be a central part of AD pathology, a growing body of evidence demonstrates that they may, in fact, be a characteristic feature of the AD brain as well. In particular, microvascular abnormalities within the brain have been associated with pathological AD hallmarks and may precede neurodegeneration. In vivo assessment of microvascular pathology provides a promising approach to develop useful biological markers for early detection and pathological characterization of AD. This review focuses on established blood-based biological marker candidates of microvascular pathology in AD. These candidates include plasma concentration of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) that are increased in AD. Measures of endothelial vasodilatory function including endothelin (ET-1), adrenomedullin (ADM), and atrial natriuretic peptide (ANP), as well as sphingolipids are significantly altered in mild AD or during the predementia stage of mild cognitive impairment (MCI), suggesting sensitivity of these biomarkers for early detection and diagnosis. In conclusion, the emerging clinical diagnostic evidence for the value of blood-based microvascular biomarkers in AD is promising, however, still requires validation in phase II and III diagnostic trials. Moreover, it is still unclear whether the described protein dysbalances are early or downstream pathological events and how the detected systemic microvascular alterations relate to cerebrovascular and neuronal pathologies in the AD brain.

Vitamin D levels and microvascular complications in type 2 diabetes

Directory of Open Access Journals (Sweden)

Sarita Bajaj

2014-01-01

Full Text Available Background: Vitamin D has important actions on glucose metabolism. These include improved insulin exocytosis, direct stimulation of insulin receptor, improved uptake of glucose by peripheral tissues, improving insulin resistance. It has got various pleiotropic effects like suppression of cell mediated immunity, regulation of cell proliferation, stimulation of neurotropic factors such as nerve growth factor, Glial cell line-derived neurotrophic factor, neurotropin, suppression of RAAS, reduction of albuminuria, immunomodulatory effects, and anti-inflammatory effects. Thus, vitamin D is implicated in many ways in the pathogenesis of retinopathy, neuropathy and nephropathy. Objectives: To study the correlation of vitamin D levels with microvascular complications in type 2 diabetes. Materials and Methods: Cross-sectional case-control study of 18 patients (18-70 years, who met the American Diabetes Association 2011 criteria for type 2 diabetes, was conducted. Age and sex matched healthy controls were taken. Subjects were evaluated for the presence of microvascular complications by clinical evaluation, urine examination, fundus examination, nerve conduction studies, and various biochemical tests. 25-OH cholecalciferol levels were done for each. Cut off level for vitamin D deficiency was 20 ng/ml. Results: Mean vitamin D was lower in type 2 diabetics than healthy subjects (19.046 vs. 27.186 ng/ml. Prevalence of vitamin D deficiency and insufficiency was found to significantly higher in diabetics when compared to healthy subjects (P = 0.0001. Vitamin D deficiency was found to be significantly associated with neuropathy (χ2 = 5.39, df = 1, P = 0.020, retinopathy, (χ2 = 6.6, df = 1, P = 0.010 and nephropathy (χ2 = 10. 52, df = 1, P = 0.001. Lower levels of vitamin D were found to be associated with increasing prevalence of combinations of microvascular complications namely neuropathy with retinopathy (P = 0.036, neuropathy with nephropathy (P = 0

Relation between the Change in Mean Platelet Volume and Clopidogrel Resistance in Patients Undergoing Percutaneous Coronary Intervention.

Science.gov (United States)

Koh, Young-Youp; Kim, Hyung Ho; Choi, Dong-Hyun; Lee, Young-Min; Ki, Young-Jae; Kang, Seong-Ho; Park, Geon; Chung, Joong-Wha; Chang, Kyong-Sig; Hong, Soon-Pyo

2015-01-01

We aimed to determine the association between the change in mean platelet volume (MPV) over time and aspirin/ clopidogrel resistance in patients undergoing percutaneous coronary intervention (PCI). The MPV and platelet function were analysed in 302 patients who underwent PCI. MPV changes were associated with increased aspirin reaction units (ARU, r = 0.114; P = 0.047), increased P2Y12 reaction units (PRU, r = 0.193; P = 0.001), and decreased P2Y12% inhibition (PI%, r = - 0.273; P resistant group (≥235 PRU or ≤15% of PI%) showed a significantly higher positive change in MPV (ΔMPV) values than the clopidogrel responder group (0.53 ± 0.78 vs. 0.13 ± 0.69 fL, P resistant and responder groups were 72.6% and 59.3%, respectively. After adjusting for traditional risk factors, the odds ratio in the clopidogrel resistant group with ΔMPV ≥0.2 fL was 4.10 (95% confidence interval; 1.84-9.17). In conclusion, ΔMPV was associated with PRU and PI%; a positive ΔMPV was an independent predictive marker for clopidogrel resistance after PCI.

Pilot study on microvascular anastomosis: performance and future educational prospects.

Science.gov (United States)

Berretti, G; Colletti, G; Parrinello, G; Iavarone, A; Vannucchi, P; Deganello, A

2017-11-30

The introduction of microvascular free flaps has revolutionised modern reconstructive surgery. Unfortunately, access to training opportunities at standardised training courses is limited and expensive. We designed a pilot study on microvascular anastomoses with the aim of verifying if a short course, easily reproducible, could transmit microvascular skills to participants; if the chosen pre-test was predictive of final performance; and if age could influence the outcome. A total of 30 participants (10 students, 10 residents and 10 surgeons) without any previous microvascular experience were instructed and tested during a single 3 to 5 hour course. The two microanastomoses evaluated were the first ever performed by each participant. More than the half of the cohort was able to produce both patent microanastomoses in less than 2 hours; two-thirds of the attempted microanastomoses were patent. The pretest predicted decent scores from poor performances with a sensitivity of 61.5%, specificity of 100%, positive predictive value of 100% and negative predictive value of 40%. Students and residents obtained significantly higher scores than surgeons. Since our course model is short, cost-effective and highly reproducible, it could be introduced and implemented anywhere as an educational prospect for preselecting young residents showing talent and natural predisposition and having ambitions towards microvascular reconstructive surgery. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

Microvascular responses to (hyper-)gravitational stress by short-arm human centrifuge: arteriolar vasoconstriction and venous pooling.

Science.gov (United States)

Habazettl, H; Stahn, Alexander; Nitsche, Andrea; Nordine, Michael; Pries, A R; Gunga, H-C; Opatz, O

2016-01-01

We hypothesized that lower body microvessels are particularly challenged during exposure to gravity and hypergravity leading to failure of resistance vessels to withstand excessive transmural pressure during hypergravitation and gravitation-dependent microvascular blood pooling. Using a short-arm human centrifuge (SAHC), 12 subjects were exposed to +1Gz, +2Gz and +1Gz, all at foot level, for 4 min each. Laser Doppler imaging and near-infrared spectroscopy were used to measure skin perfusion and tissue haemoglobin concentrations, respectively. Pretibial skin perfusion decreased by 19% during +1Gz and remained at this level during +2Gz. In the dilated area, skin perfusion increased by 24 and 35% during +1Gz and +2Gz, respectively. In the upper arm, oxygenated haemoglobin (Hb) decreased, while deoxy Hb increased with little change in total Hb. In the calf muscle, O2Hb and deoxy Hb increased, resulting in total Hb increase by 7.5 ± 1.4 and 26.6 ± 2.6 µmol/L at +1Gz and +2Gz, respectively. The dynamics of Hb increase suggests a fast and a slow component. Despite transmural pressures well beyond the upper myogenic control limit, intact lower body resistance vessels withstand these pressures up to +2Gz, suggesting that myogenic control may contribute only little to increased vascular resistance. The fast component of increasing total Hb indicates microvascular blood pooling contributing to soft tissue capacitance. Future research will have to address possible alterations of these acute adaptations to gravity after deconditioning by exposure to micro-g.

Which side of the balance determines the frequency of vaso-occlusive crises in children with sickle cell anemia: Blood viscosity or microvascular dysfunction?

Science.gov (United States)

Charlot, Keyne; Romana, Marc; Moeckesch, Berenike; Jumet, Stéphane; Waltz, Xavier; Divialle-Doumdo, Lydia; Hardy-Dessources, Marie-Dominique; Petras, Marie; Tressières, Benoît; Tarer, Vanessa; Hue, Olivier; Etienne-Julan, Maryse; Antoine-Jonville, Sophie; Connes, Philippe

2016-01-01

Vascular resistance and tissue perfusion may be both affected by impaired vascular function and increased blood viscosity. Little is known about the effects of vascular function on the occurrence of painful vaso-occlusive crises (VOC) in children with sickle cell anemia (SCA). The aim of the present study was to determine which side of the balance (blood viscosity or vascular function) is the most deleterious in SCA and increases the risk for frequent hospitalized VOC. Microvascular function, microcirculatory oxygenation and blood viscosity were determined in a group of 22 SCA children/adolescents at steady state and a group of 13 healthy children/adolescents. Univariate analyses demonstrated blunted microvascular reactivity during local thermal heating test and decreased microcirculatory oxygenation in SCA children compared to controls. Multivariate analysis revealed that increased blood viscosity and decreased microcirculatory oxygenation were independent risk factors of frequent VOC in SCA. In contrast, the level of microvascular dysfunction does not predict VOC rate. In conclusion, increased blood viscosity is usually well supported in healthy individuals where vascular function is not impaired. However, in the context of SCA, microvascular function is impaired and any increase of blood viscosity or decrease in microcirculatory oxygenation would increase the risks for frequent VOC. Copyright © 2015 Elsevier Inc. All rights reserved.

Cross-talk between cardiac muscle and coronary vasculature.

Science.gov (United States)

Westerhof, Nico; Boer, Christa; Lamberts, Regis R; Sipkema, Pieter

2006-10-01

The cardiac muscle and the coronary vasculature are in close proximity to each other, and a two-way interaction, called cross-talk, exists. Here we focus on the mechanical aspects of cross-talk including the role of the extracellular matrix. Cardiac muscle affects the coronary vasculature. In diastole, the effect of the cardiac muscle on the coronary vasculature depends on the (changes in) muscle length but appears to be small. In systole, coronary artery inflow is impeded, or even reversed, and venous outflow is augmented. These systolic effects are explained by two mechanisms. The waterfall model and the intramyocardial pump model are based on an intramyocardial pressure, assumed to be proportional to ventricular pressure. They explain the global effects of contraction on coronary flow and the effects of contraction in the layers of the heart wall. The varying elastance model, the muscle shortening and thickening model, and the vascular deformation model are based on direct contact between muscles and vessels. They predict global effects as well as differences on flow in layers and flow heterogeneity due to contraction. The relative contributions of these two mechanisms depend on the wall layer (epi- or endocardial) and type of contraction (isovolumic or shortening). Intramyocardial pressure results from (local) muscle contraction and to what extent the interstitial cavity contracts isovolumically. This explains why small arterioles and venules do not collapse in systole. Coronary vasculature affects the cardiac muscle. In diastole, at physiological ventricular volumes, an increase in coronary perfusion pressure increases ventricular stiffness, but the effect is small. In systole, there are two mechanisms by which coronary perfusion affects cardiac contractility. Increased perfusion pressure increases microvascular volume, thereby opening stretch-activated ion channels, resulting in an increased intracellular Ca2+ transient, which is followed by an increase in Ca

Myocardial blood flow reserve is impaired in patients with aortic valve calcification and unobstructed epicardial coronary arteries.

Science.gov (United States)

Nel, Karen; Nam, Michael C Y; Anstey, Chris; Boos, Christopher J; Carlton, Edward; Senior, Roxy; Kaski, Juan Carlos; Khattab, Ahmed; Shamley, Delva; Byrne, Christopher D; Stanton, Tony; Greaves, Kim

2017-12-01

Although calcific aortic valve disease (CAVD) is associated with coronary atherosclerosis, it is not known whether early CAVD is associated with coronary microcirculatory dysfunction (CMD). We sought to investigate the relationship between myocardial blood flow reserve (MBFR) - a measure of CMD, and early CAVD in the absence of obstructive epicardial coronary artery disease. We also determined whether this relationship was independent of coronary artery disease (CAD) and hs-CRP, a marker of systemic inflammation. 183 patients with chest pain and unobstructed coronary arteries were studied. Aortic valve calcification score (AVCS), coronary total plaque length (TPL), and coronary calcium score were quantified from multislice CT. MBFR was assessed using vasodilator myocardial contrast echocardiography. Hs-CRP was measured from venous blood using a particle-enhanced immunoassay. Mean (±SD) participant age was 59.8 (9.6) years. Mean AVCS was 68 (258) AU, TPL was 15.6 (22.2) mm, and median coronary calcification score was 43.5AU. Mean MBFR was 2.20 (0.52). Mean hs-CRP was 2.52 (3.86) mg/l. Multivariable linear regression modelling incorporating demographics, coronary plaque characteristics, MBFR, and inflammatory markers, demonstrated that age (β=0.05, 95% CI: 0.02, 0.08, P=0.007), hs-CRP (β=0.09, CI: 0.02, 0.16, P=0.010) and diabetes (β=1.03, CI: 0.08, 1.98, P=0.033), were positively associated with AVCS. MBFR (β=-0.87, CI: -1.44, -0.30, P=0.003), BMI (β=-0.11, CI: -0.21, -0.01, P=0.033), and LDL (β=-0.32, CI: -0.61, -0.03, P=0.029) were negatively associated with AVCS. TPL and coronary calcium score were not independently associated with AVCS when included in the regression model. Coronary microvascular function as determined by measurement of myocardial blood flow reserve is independently associated with early CAVD. This effect is independent of the presence of coronary artery disease and also systemic inflammation. Copyright © 2017 Elsevier B.V. All rights

Radionuclide assessment of pulmonary microvascular permeability

Energy Technology Data Exchange (ETDEWEB)

Groeneveld, A.B.J. [Medical Intensive Care Unit, Department of Internal Medicine, Free University Hospital, De Boelelaan 1117, 1081 HV Amsterdam (Netherlands)

1997-04-01

The literature has been reviewed to evaluate the technique and clinical value of radionuclide measurements of microvascular permeability and oedema formation in the lungs. Methodology, modelling and interpretation vary widely among studies. Nevertheless, most studies agree on the fact that the measurement of permeability via pulmonary radioactivity measurements of intravenously injected radiolabelled proteins versus that in the blood pool, the so-called pulmonary protein transport rate (PTR), can assist the clinician in discriminating between permeability oedema of the lungs associated with the adult respiratory distress syndrome (ARDS) and oedema caused by an increased filtration pressure, for instance in the course of cardiac disease, i.e. pressure-induced pulmonary oedema. Some of the techniques used to measure PTR are also able to detect subclinical forms of lung microvascular injury not yet complicated by permeability oedema. This may occur after cardiopulmonary bypass and major vascular surgery, for instance. By paralleling the clinical severity and course of the ARDS, the PTR method may also serve as a tool to evaluate new therapies for the syndrome. Taken together, the currently available radionuclide methods, which are applicable at the bedside in the intensive care unit, may provide a gold standard for detecting minor and major forms of acute microvascular lung injury, and for evaluating the severity, course and response to treatment. (orig.). With 2 tabs.

Quantitative relationship between coronary calcium content and coronary flow reserve as assessed by integrated PET/CT imaging

Energy Technology Data Exchange (ETDEWEB)

Curillova, Zelmira [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); VA Boston Healthcare System, Division of Cardiology, Department of Medicine, West Roxbury, MA (United States); Yaman, Bettina F.; Sitek, Arkadius; El Fakhri, Georges [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Dorbala, Sharmila [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Kwong, Raymond Y. [Harvard Medical School, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women' s Hospital, Boston, MA (United States); Brigham and Women' s Hospital, Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Anagnostopoulos, Constantinos [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Royal Brompton Hospital, Department of Nuclear Medicine, London (United Kingdom); Di Carli, Marcelo F. [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Harvard Medical School, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women' s Hospital, Boston, MA (United States); Brigham and Women' s Hospital, Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Boston, MA (United States)

2009-10-15

To evaluate the relationship between coronary artery calcium (CAC) and coronary vasodilator function. We evaluated 136 patients without known coronary artery disease (CAD) undergoing vasodilator stress {sup 82}Rb PET/CT and CAC scoring who showed normal myocardial perfusion. The CAC score, resting and hyperemic myocardial blood flow (MBF), coronary flow reserve (CFR) and coronary vascular resistance were analyzed. Global and regional CAC scores showed significant but weak inverse correlations with hyperemic MBF (r=-0.31 and r=-0.26, p{<=}0.0002 respectively) and CFR (r=-0.28 and r=-0.2, p{<=}0.001 respectively). With increasing CAC score, there was a modest stepwise decline in CFR on a per-patient basis (1.8{+-}0.5 vs 1.7{+-}0.5 vs 1.5{+-}0.4, p=0.048, with total CAC=0, 1-400 and >400, respectively) and on a per-vessel basis. In multivariable modeling only body mass index and CAC score were predictive of CFR. In patients with an intermediate likelihood of, but without overt, CAD, there is a statistically significant but weak inverse correlation between CAC content and coronary vasodilator function. The strength of this association weakens after adjusting CAC scores for age, gender and coronary risk factors. This suggests that CAC and coronary vasodilator function provide biologically different information regarding atherosclerosis. (orig.)

Quantitative relationship between coronary calcium content and coronary flow reserve as assessed by integrated PET/CT imaging

International Nuclear Information System (INIS)

Curillova, Zelmira; Yaman, Bettina F.; Sitek, Arkadius; El Fakhri, Georges; Dorbala, Sharmila; Kwong, Raymond Y.; Anagnostopoulos, Constantinos; Di Carli, Marcelo F.

2009-01-01

To evaluate the relationship between coronary artery calcium (CAC) and coronary vasodilator function. We evaluated 136 patients without known coronary artery disease (CAD) undergoing vasodilator stress 82 Rb PET/CT and CAC scoring who showed normal myocardial perfusion. The CAC score, resting and hyperemic myocardial blood flow (MBF), coronary flow reserve (CFR) and coronary vascular resistance were analyzed. Global and regional CAC scores showed significant but weak inverse correlations with hyperemic MBF (r=-0.31 and r=-0.26, p≤0.0002 respectively) and CFR (r=-0.28 and r=-0.2, p≤0.001 respectively). With increasing CAC score, there was a modest stepwise decline in CFR on a per-patient basis (1.8±0.5 vs 1.7±0.5 vs 1.5±0.4, p=0.048, with total CAC=0, 1-400 and >400, respectively) and on a per-vessel basis. In multivariable modeling only body mass index and CAC score were predictive of CFR. In patients with an intermediate likelihood of, but without overt, CAD, there is a statistically significant but weak inverse correlation between CAC content and coronary vasodilator function. The strength of this association weakens after adjusting CAC scores for age, gender and coronary risk factors. This suggests that CAC and coronary vasodilator function provide biologically different information regarding atherosclerosis. (orig.)

Profile of Microvascular Disease in Type 2 Diabetes in a Tertiary ...

African Journals Online (AJOL)

Background: Diabetes mellitus (DM) is a metabolic disorder complicated by microvascular and macrovascular diseases. The clinical profile of these complications has not been adequately studied in many tertiary health care centers in India. Aim: The authors studied the clinical profile of microvascular diabetes ...

Coronary flow velocity reserve by echocardiography

DEFF Research Database (Denmark)

Olsen, Rasmus Huan; Pedersen, Lene Rørholm; Snoer, Martin

2016-01-01

BACKGROUND: Coronary flow velocity reserve (CFVR) measured by transthoracic Doppler echocardiography of the LAD is used to assess microvascular function but validation studies in clinical settings are lacking. We aimed to assess feasibility, reproducibility and agreement with myocardial flow...... performed within a week (1-week) and for all scans regardless of time gap (total) and to account for scar tissue for patients with and without previous myocardial infarction (MI). RESULTS: Eighty-six patients with median BMI 30.9 (IQR 29.4-32.9) kg × m(-2) and CFVR 2.29 (1.90-2.63) were included. CFVR...... was feasible in 83 (97 %) using a contrast agent in 14 %. For reproducibility overall (n = 21) limits of agreement (LOA) were (-0.75;0.71), within-subjects coefficient of variation (CV) 11 %, and reliability 0.84. For reproducibility within 1-week (n = 13) LOA were (-0.33;0.25), within-subjects CV 5...

Engineering Microvascularized 3D Tissue Using Alginate-Chitosan Microcapsules

OpenAIRE

Zhang, Wujie; Choi, Jung K.; He, Xiaoming

2017-01-01

Construction of vascularized tissues is one of the major challenges of tissue engineering. The goal of this study was to engineer 3D microvascular tissues by incorporating the HUVEC-CS cells with a collagen/alginate-chitosan (AC) microcapsule scaffold. In the presence of AC microcapsules, a 3D vascular-like network was clearly observable. The results indicated the importance of AC microcapsules in engineering microvascular tissues -- providing support and guiding alignment of HUVEC-CS cells. ...

Integration of Self-Assembled Microvascular Networks with Microfabricated PEG-Based Hydrogels.

Science.gov (United States)

Cuchiara, Michael P; Gould, Daniel J; McHale, Melissa K; Dickinson, Mary E; West, Jennifer L

2012-11-07

Despite tremendous efforts, tissue engineered constructs are restricted to thin, simple tissues sustained only by diffusion. The most significant barrier in tissue engineering is insufficient vascularization to deliver nutrients and metabolites during development in vitro and to facilitate rapid vascular integration in vivo. Tissue engineered constructs can be greatly improved by developing perfusable microvascular networks in vitro in order to provide transport that mimics native vascular organization and function. Here a microfluidic hydrogel is integrated with a self-assembling pro-vasculogenic co-culture in a strategy to perfuse microvascular networks in vitro. This approach allows for control over microvascular network self-assembly and employs an anastomotic interface for integration of self-assembled micro-vascular networks with fabricated microchannels. As a result, transport within the system shifts from simple diffusion to vessel supported convective transport and extra-vessel diffusion, thus improving overall mass transport properties. This work impacts the development of perfusable prevascularized tissues in vitro and ultimately tissue engineering applications in vivo.

Therapeutic Effects of PPARα on Neuronal Death and Microvascular Impairment

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Elizabeth P. Moran

2015-01-01

Full Text Available Peroxisome-proliferator activated receptor-alpha (PPARα is a broadly expressed nuclear hormone receptor and is a transcription factor for diverse target genes possessing a PPAR response element (PPRE in the promoter region. The PPRE is highly conserved, and PPARs thus regulate transcription of an extensive array of target genes involved in energy metabolism, vascular function, oxidative stress, inflammation, and many other biological processes. PPARα has potent protective effects against neuronal cell death and microvascular impairment, which have been attributed in part to its antioxidant and anti-inflammatory properties. Here we discuss PPARα’s effects in neurodegenerative and microvascular diseases and also recent clinical findings that identified therapeutic effects of a PPARα agonist in diabetic microvascular complications.

Transthoracic Doppler echocardiography compared with positron emission tomography for assessment of coronary microvascular dysfunction

DEFF Research Database (Denmark)

Michelsen, Marie Mide; Mygind, Naja Dam; Pena, Adam

2017-01-01

stenosis at invasive coronary angiography, TTDE CFVR by dipyridamole induced stress and MBFR by rubidium-82 PET with adenosine was successfully measured in 107 subjects. Repeatability of TTDE CFVR was assessed in 10 symptomatic women and in 10 healthy individuals. RESULTS: MBFR was systematically higher...... by time-interval between examinations. Results were similar when adjusting for rate pressure product or focusing on perfusion of the left anterior descending artery region. Limits of agreement (CI) for repeated CFVR in 10 healthy individuals and in 10 women with angina was 0.44 (0.21;0.68) and 0.48 (0...

Impact of type 2 diabetes and the metabolic syndrome on myocardial structure and microvasculature of men with coronary artery disease

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Yii Michael

2011-09-01

Full Text Available Abstract Background Type 2 diabetes and the metabolic syndrome are associated with impaired diastolic function and increased heart failure risk. Animal models and autopsy studies of diabetic patients implicate myocardial fibrosis, cardiomyocyte hypertrophy, altered myocardial microvascular structure and advanced glycation end-products (AGEs in the pathogenesis of diabetic cardiomyopathy. We investigated whether type 2 diabetes and the metabolic syndrome are associated with altered myocardial structure, microvasculature, and expression of AGEs and receptor for AGEs (RAGE in men with coronary artery disease. Methods We performed histological analysis of left ventricular biopsies from 13 control, 10 diabetic and 23 metabolic syndrome men undergoing coronary artery bypass graft surgery who did not have heart failure or atrial fibrillation, had not received loop diuretic therapy, and did not have evidence of previous myocardial infarction. Results All three patient groups had similar extent of coronary artery disease and clinical characteristics, apart from differences in metabolic parameters. Diabetic and metabolic syndrome patients had higher pulmonary capillary wedge pressure than controls, and diabetic patients had reduced mitral diastolic peak velocity of the septal mitral annulus (E', consistent with impaired diastolic function. Neither diabetic nor metabolic syndrome patients had increased myocardial interstitial fibrosis (picrosirius red, or increased immunostaining for collagen I and III, the AGE Nε-(carboxymethyllysine, or RAGE. Cardiomyocyte width, capillary length density, diffusion radius, and arteriolar dimensions did not differ between the three patient groups, whereas diabetic and metabolic syndrome patients had reduced perivascular fibrosis. Conclusions Impaired diastolic function of type 2 diabetic and metabolic syndrome patients was not dependent on increased myocardial fibrosis, cardiomyocyte hypertrophy, alteration of the

Gap filling of 3-D microvascular networks by tensor voting.

Science.gov (United States)

Risser, L; Plouraboue, F; Descombes, X

2008-05-01

We present a new algorithm which merges discontinuities in 3-D images of tubular structures presenting undesirable gaps. The application of the proposed method is mainly associated to large 3-D images of microvascular networks. In order to recover the real network topology, we need to fill the gaps between the closest discontinuous vessels. The algorithm presented in this paper aims at achieving this goal. This algorithm is based on the skeletonization of the segmented network followed by a tensor voting method. It permits to merge the most common kinds of discontinuities found in microvascular networks. It is robust, easy to use, and relatively fast. The microvascular network images were obtained using synchrotron tomography imaging at the European Synchrotron Radiation Facility. These images exhibit samples of intracortical networks. Representative results are illustrated.

Microvascular endothelial function and cognitive performance: The ELSA-Brasil cohort study.

Science.gov (United States)

Brant, Luisa; Bos, Daniel; Araujo, Larissa Fortunato; Ikram, M Arfan; Ribeiro, Antonio Lp; Barreto, Sandhi M

2018-06-01

Impaired microvascular endothelial function may be implicated in the etiology of cognitive decline. Yet, current data on this association are inconsistent. Our objective is to investigate the relation of microvascular endothelial function to cognitive performance in the ELSA-Brasil cohort study. A total of 1521 participants from ELSA-Brasil free of dementia underwent peripheral arterial tonometry (PAT) to quantify microvascular endothelial function (PAT-ratio and mean baseline pulse amplitude (BPA)) and cognitive tests that covered the domains of memory, verbal fluency, and executive function at baseline. Cognitive tests in participants aged 55 years old and above were repeated during the second examination (mean follow-up: 3.5 (0.3) years). Linear regression and generalized linear models were used to evaluate the association between endothelial function, global cognitive performance, and performance on specific cognitive domains. In unadjusted cross-sectional analyses, we found that BPA and PAT-ratio were associated with worse global cognitive performance (mean difference for BPA: -0.07, 95% CI: -0.11; -0.03, p<0.01; mean difference for PAT-ratio: 0.11, 95% CI: 0.01; 0.20, p=0.02), worse performance on learning, recall, and word recognition tests (BPA: -0.87, 95% CI: -1.21; -0.52, p<0.01; PAT-ratio: 1.58, 95% CI: 0.80; 2.36, p<0.01), and only BPA was associated with worse performance in verbal fluency tests (-0.70, 95% CI: -1.19; -0.21, p<0.01). Adjustments for age, sex, and level of education rendered the associations statistically non-significant. Longitudinally, there was no association between microvascular endothelial and cognitive functions. The associations between microvascular endothelial function and cognition are explained by age, sex, and educational level. Measures of microvascular endothelial function may be of limited value with regard to preclinical cognitive deficits.

Identifying coronary artery disease in men with type 2 diabetes: osteoprotegerin, pulse wave velocity, and other biomarkers of cardiovascular risk.

LENUS (Irish Health Repository)

Davenport, Colin

2012-02-01

OBJECTIVES: In patients with type 2 diabetes, high serum levels of osteoprotegerin (OPG) have been associated with a greater risk of cardiovascular events. However, it remains unclear how well OPG performs when compared with traditional biomarkers of cardiovascular risk such as high-sensitivity C-reactive protein (hsCRP). Furthermore, OPG levels are also high in the presence of diabetes-related microvascular disease, and it is unclear whether OPG can distinguish microvascular disease from large-vessel atherosclerosis. The first aim of this study was to compare OPG levels against other biomarkers of cardiovascular risk in the identification of patients with documented multivessel coronary artery disease (CAD). The second aim was to compare OPG levels in patients with microvascular complications (microalbuminuria) against those with established CAD. METHODS: Three groups of male patients with type 2 diabetes were recruited: patients without microvascular complications or large-vessel atherosclerosis (n = 24), patients with microalbuminuria only (n = 23), and patients with microalbuminuria and documented multivessel CAD (n = 25). OPG, hsCRP, interleukin 6, urate, and pulse wave velocity were measured. RESULTS: Serum OPG levels were significantly higher in patients with a combination of microalbuminuria and CAD than in those with microalbuminuria alone. There were no significant differences in any of the other biomarkers between the groups. CONCLUSION: OPG was found to be superior to the other biomarkers studied in identifying patients with documented CAD. The presence of CAD was a greater determinant of serum OPG levels than microalbuminuria in our population. These findings support the use of OPG as a biomarker of cardiovascular risk.

Perioperative antibiotics in the setting of microvascular free tissue transfer: current practices

NARCIS (Netherlands)

Reiffel, Alyssa J.; Kamdar, Mehul R.; Kadouch, Daniel J. M.; Rohde, Christine H.; Spector, Jason A.

2010-01-01

Microvascular free tissue transfer is a ubiquitous and routine method of restoring anatomic defects. There is a paucity of data regarding the role of perioperative antibiotics in free tissue transfer. We designed a survey to explore usage patterns among microvascular surgeons and thereby define a

Interactions of the gasotransmitters contribute to microvascular tone (dysregulation in the preterm neonate.

Directory of Open Access Journals (Sweden)

Rebecca M Dyson

Full Text Available Hydrogen sulphide (H2S, nitric oxide (NO, and carbon monoxide (CO are involved in transitional microvascular tone dysregulation in the preterm infant; however there is conflicting evidence on the interaction of these gasotransmitters, and their overall contribution to the microcirculation in newborns is not known. The aim of this study was to measure the levels of all 3 gasotransmitters, characterise their interrelationships and elucidate their combined effects on microvascular blood flow.90 preterm neonates were studied at 24h postnatal age. Microvascular studies were performed by laser Doppler. Arterial COHb levels (a measure of CO were determined through co-oximetry. NO was measured as nitrate and nitrite in urine. H2S was measured as thiosulphate by liquid chromatography. Relationships between levels of the gasotransmitters and microvascular blood flow were assessed through partial correlation controlling for the influence of gestational age. Structural equation modelling was used to examine the combination of these effects on microvascular blood flow and derive a theoretical model of their interactions.No relationship was observed between NO and CO (p = 0.18, r = 0.18. A positive relationship between NO and H2S (p = 0.008, r = 0.28 and an inverse relationship between CO and H2S (p = 0.01, r = -0.33 exists. Structural equation modelling was used to examine the combination of these effects on microvascular blood flow. The model with the best fit is presented.The relationships between NO and H2S, and CO and H2S may be of importance in the preterm newborn, particularly as NO levels in males are associated with higher H2S levels and higher microvascular blood flow and CO in females appears to convey protection against vascular dysregulation. Here we present a theoretical model of these interactions and their overall effects on microvascular flow in the preterm newborn, upon which future mechanistic studies may be based.

Engineering Microvascularized 3D Tissue Using Alginate-Chitosan Microcapsules.

Science.gov (United States)

Zhang, Wujie; Choi, Jung K; He, Xiaoming

2017-02-01

Construction of vascularized tissues is one of the major challenges of tissue engineering. The goal of this study was to engineer 3D microvascular tissues by incorporating the HUVEC-CS cells with a collagen/alginate-chitosan (AC) microcapsule scaffold. In the presence of AC microcapsules, a 3D vascular-like network was clearly observable. The results indicated the importance of AC microcapsules in engineering microvascular tissues -- providing support and guiding alignment of HUVEC-CS cells. This approach provides an alternative and promising method for constructing vascularized tissues.

Differential effects of glucagon-like peptide-1 on microvascular recruitment and glucose metabolism in short- and long-term Insulin resistance

DEFF Research Database (Denmark)

Sjøberg, Kim Anker; Rattigan, Stephen; Jeppesen, Jacob Fuglsbjerg

2015-01-01

Acute infusion of glucagon-like-peptide-1 (GLP-1) has potent effects on blood flow distribution through the microcirculation in healthy humans and rats. High fat diet induces impairments in insulin-mediated microvascular recruitment (MVR) and muscle glucose uptake, and here we examined whether......-mediated glucose uptake in skeletal muscle by 90% (Prights...

Dietary sodium loading impairs microvascular function independent of blood pressure in humans: role of oxidative stress

Science.gov (United States)

Greaney, Jody L; DuPont, Jennifer J; Lennon-Edwards, Shannon L; Sanders, Paul W; Edwards, David G; Farquhar, William B

2012-01-01

Animal studies have reported dietary salt-induced reductions in vascular function independent of increases in blood pressure (BP). The purpose of this study was to determine if short-term dietary sodium loading impairs cutaneous microvascular function in normotensive adults with salt resistance. Following a control run-in diet, 12 normotensive adults (31 ± 2 years) were randomized to a 7 day low-sodium (LS; 20 mmol day−1) and 7 day high-sodium (HS; 350 mmol day−1) diet (controlled feeding study). Salt resistance, defined as a ≤5 mmHg change in 24 h mean BP determined while on the LS and HS diets, was confirmed in all subjects undergoing study (LS: 84 ± 1 mmHg vs. HS: 85 ± 2 mmHg; P > 0.05). On the last day of each diet, subjects were instrumented with two microdialysis fibres for the local delivery of Ringer solution and 20 mm ascorbic acid (AA). Laser Doppler flowmetry was used to measure red blood cell flux during local heating-induced vasodilatation (42°C). After the established plateau, 10 mm l-NAME was perfused to quantify NO-dependent vasodilatation. All data were expressed as a percentage of maximal cutaneous vascular conductance (CVC) at each site (28 mm sodium nitroprusside; 43°C). Sodium excretion increased during the HS diet (P sodium loading impairs cutaneous microvascular function independent of BP in normotensive adults and suggest a role for oxidative stress. PMID:22907057

Is endothelial microvascular function equally impaired among patients with chronic Chagas and ischemic cardiomyopathy?

Science.gov (United States)

Borges, Juliana Pereira; Mendes, Fernanda de Souza Nogueira Sardinha; Lopes, Gabriella de Oliveira; Sousa, Andréa Silvestre de; Mediano, Mauro Felippe Felix; Tibiriçá, Eduardo

2018-08-15

Chronic Chagas cardiomyopathy (CCC) and cardiomyopathies due to other etiologies involve differences in pathophysiological pathways that are still unclear. Systemic microvascular abnormalities are associated with the pathogenesis of ischemic heart disease. However, systemic microvascular endothelial function in CCC remains to be elucidated. Thus, we compared the microvascular endothelial function of patients presenting with CCC to those with ischemic cardiomyopathy disease. Microvascular reactivity was assessed in 21 patients with cardiomyopathy secondary to Chagas disease, 21 patients with cardiomyopathy secondary to ischemic disease and 21 healthy controls. Microvascular blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh). Peak increase in forearm blood flow with ACh iontophoresis in relation to baseline was greater in healthy controls than in patients with heart disease (controls: 162.7 ± 58.4% vs. ischemic heart disease: 74.1 ± 48.3% and Chagas: 85.1 ± 68.1%; p < 0.0001). Patients with Chagas and ischemic cardiomyopathy presented similar ACh-induced changes from baseline in skin blood flow (p = 0.55). Endothelial microvascular function was equally impaired among patients with CCC and ischemic cardiomyopathy. Copyright © 2018 Elsevier B.V. All rights reserved.

Microvascular oxygen pressure in the pig intestine during haemorrhagic shock and resuscitation

NARCIS (Netherlands)

Sinaasappel, M.; van Iterson, M.; Ince, C.

1999-01-01

1. The aim of this study was to investigate the relation between microvascular and venous oxygen pressures during haemorrhagic shock and resuscitation in the pig intestine. To this end microvascular PO2 (microPO2) was measured by quenching of Pd-porphyrin phosphorescence by oxygen and validated for

Emergence of Nonobstructive Coronary Artery Disease: A Woman's Problem and Need for Change in Definition on Angiography

Science.gov (United States)

Pepine, Carl J.; Ferdinand, Keith C.; Shaw, Leslee J; Light-McGroary, KellyAnn; Shah, Rashmee U.; Gulati, Martha; Duvernoy, Claire; Walsh, Mary Norine; Bairey Merz, C. Noel

2015-01-01

Recognition of ischemic heart disease (IHD) is often delayed or deferred in women. Thus, many at risk for adverse outcomes are not provided specific diagnostic, preventive, and/or treatment strategies. This lack of recognition is related to sex-specific IHD pathophysiology that differs from traditional models using data from men with flow-limiting coronary artery disease (CAD) obstructions. Symptomatic women are less likely to have obstructive CAD than men with similar symptoms, and tend to have coronary microvascular dysfunction, plaque erosion, and thrombus formation. Emerging data document that more extensive, nonobstructive CAD involvement, hypertension, and diabetes are associated with major adverse events similar to those with obstructive CAD. A central emerging paradigm is the concept of nonobstructive CAD as a cause of IHD and related adverse outcomes among women. This position paper summarizes currently available knowledge and gaps in that knowledge, and recommends management options that could be useful until additional evidence emerges. PMID:26493665

Transfer of Learning from Practicing Microvascular Anastomosis on Silastic Tubes to Rat Abdominal Aorta.

Science.gov (United States)

Mokhtari, Pooneh; Tayebi Meybodi, Ali; Lawton, Michael T; Payman, Andre; Benet, Arnau

2017-12-01

Learning to perform microvascular anastomosis is difficult. Laboratory practice models using artificial vessels are frequently used for this purpose. However, the efficacy of such practice models has not been objectively assessed for the performance of microvascular anastomosis during live surgical settings. This study was conducted to assess the transfer of learning from practicing microvascular anastomosis on tubes to anastomosing rat abdominal aorta. Ten surgeons without any experience in microvascular anastomosis were randomly assigned to an experimental or a control group. Both groups received didactic and visual training on end-to-end microvascular anastomosis. The experimental group received 24 sessions of hands-on training on microanastomosis using Silastic tubes. Next, both groups underwent recall tests on weeks 1, 2, and 8 after training. The recall test consisted of completing an end-to-end anastomosis on the rat's abdominal aorta. Anastomosis score, the time to complete the anastomosis, and the average time to place 1 stitch on the vessel perimeter were compared between the 2 groups. Compared with the control group, the experimental group did significantly better in terms of anastomosis score, total time, and per-stitch time. The measured variables showed stability and did not change significantly between the 3 recall tests. The skill of microvascular anastomosis is transferred from practicing on Silastic tubes to rat's abdominal aorta. Considering the relative advantages of Silastic tubes to live rodent surgeries, such as lower cost and absence of ethical issues, our results support the widespread use of Silastic tubes in training programs for microvascular anastomosis. Copyright © 2017 Elsevier Inc. All rights reserved.

COAGULATION PROFILE IN DIABETES MELLITUS AND ITS ASSOCIATION WITH MICROVASCULAR COMPLICATIONS

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Uma Shankar Mishra

2017-12-01

Full Text Available BACKGROUND This study intends to assess the changes in the simple routine coagulation parameters in diabetes mellitus and to investigate whether any relationship exists among changes in these coagulation parameters and development of microvascular complication in diabetes mellitus. MATERIALS AND METHODS Period of study was from 2010-2012. It was done in M.K.C.G. Medical College with the approval from Berhampur University. It is a case control study. 50 diabetic patients and 50 age and sex matched non-diabetic patients were randomly selected. Simple coagulation parameters like Activated Partial Thromboplastin Time (aPTT, Prothrombin Time (PT, serum fibrinogen, platelet count and Plasminogen Activator Inhibitor-1 (PAI-1 were measured. Statistical study was done using unpaired t-test and analysis and calculations were done using GraphPad software. RESULTS Serum fibrinogen was found to be increased in diabetic patients when compared to non-diabetic patients (mean 278 ± 26.9 v/s 232.52 ± 16.5, P value - 0.009, significant. PAI-1 levels was found to be higher among the diabetics when compared to nondiabetics (47.64 ± 8.82 v/s 31.06 ± 7.12, the two-tailed P value is <0.0001, considered extremely significant. Platelet count through within normal limits. It was found to be decreased in diabetic patient when compared to non-diabetic (2.25 ± 0.18 v/s 2.33 ± 0.03, P value - 0.022. Prothrombin Time (PT (13.15 ± 0.52 v/s 13.04 ± 0.49, P value - 0.28 and PTT (33.04 ± 1.31 v/s 32.99 ± 1.29, P value 0.85, found to be statistically insignificant. Among 50 diabetic patients, 24 had neuropathy, 20 had nephropathy, 10 had retinopathy and 21 had none of these complications. On comparing diabetic patients with microvascular complications and without microvascular complications, significant age difference was observed (59.55 ± 5.06 v/s 51.00 ± 3.31, P=0.003. This probably was a reflection of increase in microvascular complications with increasing duration

Microvascular transplantation and replantation of the dog submandibular gland.

Science.gov (United States)

Su, Wan Fu; Jen, Yee Min; Chen, Shyi Gen; Nieh, Shin; Wang, Chih-Hung

2006-05-01

Transplantation and replantation of the submandibular gland with microvascular techniques were demonstrated in a previous study, with good gland survival. The application of radiation on the neck bed was attempted to address an actual clinical scenario in this study. Five canine submandibular glands were transplanted using microvascular techniques to the ipsilateral femoral system. Radiotherapy at a dosage level of 3,600 cGy using 600 cGy q.d was delivered to the nasopharyngeal and neck regions 2 weeks after transplantation. The transferred glands were then reintroduced into the original but radiated neck bed. The glands were harvested for histological examination 8 weeks later. Four of five canine submandibular glands can withstand microvascular transplantation and then replantation into a radiated neck bed for at least 8 weeks. However, the salivary function was depleted. The canine submandibular gland can survive the transplantation and replantation for at least 8 weeks in spite of precipitating radiation insult on the neck bed for 3 weeks. Neurorraphy is, however, essential to maintaining the glandular function.

Insufficient platelet inhibition is related to silent embolic cerebral infarctions after coronary angiography.

Science.gov (United States)

Kim, Bum Joon; Lee, Seung-Whan; Park, Seong-Wook; Kang, Dong-Wha; Kim, Jong S; Kwon, Sun U

2012-03-01

Considering that insufficient platelet inhibition is related to thrombotic complications after coronary angiography, we hypothesized that the extent of platelet inhibition by antiplatelet agents is related to the occurrence of silent embolic cerebral infarction (SECI) after coronary angiography. Among the patients scheduled for coronary artery bypass surgery, we retrospectively analyzed the location of SECI on diffusion-weighted imaging of 272 patients, which was performed after coronary angiography, as a presurgical evaluation in Phase 1 study. In Phase 2 study, we have prospectively recruited 102 patients to compare the extent of platelet inhibition measured by the VerifyNow system among patients with and without SECI. SECI is observed in 45 patients (16.5%) in Phase 1 and 17 (16.7%) in Phase 2. The lesions were slightly more frequent in the right hemisphere. In the Phase 2 study, aspirin reaction units and P(2)Y(12) reaction units were higher in the patients with SECI than those without (aspirin reaction units: 490±72 versus 446±53, P=0.03; P(2)Y(12) reaction units: 352±65 versus 300±77, P=0.009). The incidence of SECI increased with the number of resistant antiplatelets; resistance to both antiplatelet agent (50%), resistance to 1 antiplatelet agent (22%), and no resistance (4%; P=0.023). From the result of logistic regression, higher aspirin reaction units, white blood cell count, low hemoglobin, and nonresponsiveness to antiplatelet agents were independent risk factors. Insufficient platelet inhibition after administration of antiplatelet agents is related with SECI appearing after coronary angiography.

Intractable lung abscess successfully treated with cavernostomy and free omental plombage using microvascular surgery.

Science.gov (United States)

Shimizu, Junzo; Arano, Yoshihiko; Adachi, Iwao; Ikeda, Chikako; Ishikawa, Norihiko; Ohtake, Hiroshi

2009-11-01

A 68-year-old man, complaining of fever and puriform sputum, was referred to our hospital. A giant abscess was detected in the upper lobe of the right lung. Percutaneous drainage of a lung abscess was carried out. When the pus collected was cultured, Candida was 1+ and Escherichia coli was 2+. Later, it became difficult to control the abscess by drainage, and cavernostomy was selected. The contents of the abscess cavity were removed, and the cavity was opened, followed by exchange of gauze every day. For 14 months after cavernostomy, once-weekly gauze exchange was continued at the outpatient clinic to clean the abscess cavity. Finally, the abscess was filled with a free greater omentum flap, accompanied by microvascular anastomosis. In this way, the intractable lung abscess was successfully cured. Conventionally, surgical treatment, particularly cavernostomy, has been applied only to limited cases when dealing with a lung abscess. Our experience with the present case suggests that surgical treatment, including cavernostomy as one option, should also be considered when dealing with lung abscesses resisting medical treatment and causing compromised respiratory function. To enable maximum utilization of the greater omental flap, which is available in only a limited amount, it seems useful to prepare and graft a free omental flap making use of microvascular surgery.

Quantitative Measurement of Dissection Resistance in Intimal and Medial Layers of Human Coronary Arteries

OpenAIRE

Wang, Ying; Johnson, John A.; Spinale, Francis G.; Sutton, Michael A.; Lessner, Susan M.

2013-01-01

The left anterior descending (LAD) coronary artery is the most frequently involved vessel in coronary artery dissection, a cause of acute coronary syndrome or sudden cardiac death. The biomechanical mechanisms underlying arterial dissection are not well understood. This study investigated the dissection properties of LAD specimens harvested from explanted hearts at the time of cardiac transplantation, from patients with primary dilated cardiomyopathy (n=12). Using a previously validated appro...

Association Between the P2RY12 Receptor Gene Polymorphism and Aspirin Resistance in Patients with Coronary Artery Disease

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Ludmila Karazhanova

2014-12-01

Full Text Available Introduction. Platelet activation and aggregation are key elements in the development of coronary atherosclerosis. Recent studies have shown that the two polymorphisms of platelet ADP receptor P2RY12 (haplotypes H2 and 34T are associated with increased platelet aggregation and atherothrombotic risk. It was shown that these polymorphisms promote reduced body response to antiplatelet therapy.Aim. We investigated the association of P2RY12 gene polymorphisms with aspirin resistance in patients with coronary artery disease (CAD.Methods. This case-control study included 100 cases with CAD (mean age 57.6 ± 2.8 years treated in the cardiology department of the city hospital Semey, Kazakhstan, 90 of whom suffered from myocardial infarction. The control group (n = 100 were healthy people without a history of CAD, matched on sex and age. Genotyping of polymorphisms H1/H2 in P2RY12 gene was performed by PCR. Statistical analysis was performed using SPSS v.19.0.Results. The distribution of H1/H2 genotypes P2RY12 was 42%, 34%, and 24%, respectively, in cases and 42%, 58%, and 0%, respectively, in controls. All allele frequencies were consistent with the Hardy Weinberg equilibrium (p = 0.0036 and p = 0.0001 in cases and controls, respectively. Genotype H2 was associated with risk of CAD with aspirin resistance (co-dominant model: OR = 3.75, 95% CI 0.14 - 99.88, p = 0.05 and dominant model: OR = 2.78, 95% CI 0.11 - 70.93, p = 0.05. We found significant differences in the distribution of the mutant genotype H2 between CAD patients with aspirin resistance and healthy controls (χ2 = 30.3, p < 0.05.Conclusion. We found an association of H2 haplotype in P2RY12 gene with aspirin resistance in patients with CAD. However, in order to obtain definitive conclusions about the role of genetic variants with the development of aspirin resistance in patients with CAD, there is a need for further research with a larger sample size as well as the use of selective thromboxane

Regulation of Muscle Pyruvate Dehydrogenase Complex in Insulin Resistance: Effects of Exercise and Dichloroacetate

Directory of Open Access Journals (Sweden)

Dumitru Constantin-Teodosiu

2013-10-01

Full Text Available Since the mitochondrial pyruvate dehydrogenase complex (PDC controls the rate of carbohydrate oxidation, impairment of PDC activity mediated by high-fat intake has been advocated as a causative factor for the skeletal muscle insulin resistance, metabolic syndrome, and the onset of type 2 diabetes (T2D. There are also situations where muscle insulin resistance can occur independently from high-fat dietary intake such as sepsis, inflammation, or drug administration though they all may share the same underlying mechanism, i.e., via activation of forkhead box family of transcription factors, and to a lower extent via peroxisome proliferator-activated receptors. The main feature of T2D is a chronic elevation in blood glucose levels. Chronic systemic hyperglycaemia is toxic and can lead to cellular dysfunction that may become irreversible over time due to deterioration of the pericyte cell's ability to provide vascular stability and control to endothelial proliferation. Therefore, it may not be surprising that T2D's complications are mainly macrovascular and microvascular related, i.e., neuropathy, retinopathy, nephropathy, coronary artery, and peripheral vascular diseases. However, life style intervention such as exercise, which is the most potent physiological activator of muscle PDC, along with pharmacological intervention such as administration of dichloroacetate or L-carnitine can prove to be viable strategies for treating muscle insulin resistance in obesity and T2D as they can potentially restore whole body glucose disposal.

GM-CSF ameliorates microvascular barrier integrity via pericyte-derived Ang-1 in wound healing.

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Yan, Min; Hu, Yange; Yao, Min; Bao, Shisan; Fang, Yong

2017-11-01

Skin wound healing involves complex coordinated interactions of cells, tissues, and mediators. Maintaining microvascular barrier integrity is one of the key events for endothelial homeostasis during wound healing. Vasodilation is observed after vasoconstriction, which causes blood vessels to become porous, facilitates leukocyte infiltration and aids angiogenesis at the wound-area, postinjury. Eventually, vessel integrity has to be reestablished for vascular maturation. Numerous studies have found that granulocyte macrophage colony-stimulating factor (GM-CSF) accelerates wound healing by inducing recruitment of repair cells into the injury area and releases of cytokines. However, whether GM-CSF is involving in the maintaining of microvascular barrier integrity and the underlying mechanism remain still unclear. Aim of this study was to investigate the effects of GM-CSF on modulation of microvascular permeability in wound healing and underlying mechanisms. Wound closure and microvascular leakage was investigated using a full-thickness skin wound mouse model after GM-CSF intervention. The endothelial permeability was measured by Evans blue assay in vivo and in vitro endothelium/pericyte co-culture system using a FITC-Dextran permeability assay. To identify the source of angiopoietin-1 (Ang-1), double staining is used in vivo and ELISA and qPCR are used in vitro. To determine the specific effect of Ang-1 on GM-CSF maintaining microvascular stabilization, Ang-1 siRNA was applied to inhibit Ang-1 production in vivo and in vitro. Wound closure was significantly accelerated and microvascular leakage was ameliorated after GM-CSF treatment in mouse wound sites. GM-CSF decreased endothelial permeability through tightening endothelial junctions and increased Ang-1 protein level that was derived by perictye. Furthermore, applications of siRNAAng-1 inhibited GM-CSF mediated protection of microvascular barrier integrity both in vivo and in vitro. Our data indicate that GM

Free and microvascular bone grafting in the irradiated dog mandible

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Altobelli, D.E.; Lorente, C.A.; Handren, J.H. Jr.; Young, J.; Donoff, R.B.; May, J.W. Jr.

1987-01-01

Microvascular and free rib grafts were placed in 4.5 cm defects in an edentate mandibular body defect 18 to 28 days after completion of 50 Gy of irradiation from a 60 Co source. The animals were sacrificed from two to forty weeks postoperatively and evaluated clinically, radiographically, and histologically. There was a marked difference in the alveolar mucosal viability with the two grafts. Mucosal dehiscence was not observed over any of the microvascular grafts, but was present in seven-eighths of the free grafts. Union of the microvascular bone graft to the host bone occurred within six weeks. In contrast, after six weeks the free graft was sequestered in all the animals. An unexpected finding with both types of graft was the marked subperiosteal bone formation. This bone appeared to be derived from the host bed, stabilizing and bridging the defects bilaterally. The results suggest that radiated periosteum may play an important role in osteogenesis

Microvascular Anastomosis: Proposition of a Learning Curve.

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Mokhtari, Pooneh; Tayebi Meybodi, Ali; Benet, Arnau; Lawton, Michael T

2018-04-14

Learning to perform a microvascular anastomosis is one of the most difficult tasks in cerebrovascular surgery. Previous studies offer little regarding the optimal protocols to maximize learning efficiency. This failure stems mainly from lack of knowledge about the learning curve of this task. To delineate this learning curve and provide information about its various features including acquisition, improvement, consistency, stability, and recall. Five neurosurgeons with an average surgical experience history of 5 yr and without any experience in bypass surgery performed microscopic anastomosis on progressively smaller-caliber silastic tubes (Biomet, Palm Beach Gardens, Florida) during 24 consecutive sessions. After a 1-, 2-, and 8-wk retention interval, they performed recall test on 0.7-mm silastic tubes. The anastomoses were rated based on anastomosis patency and presence of any leaks. Improvement rate was faster during initial sessions compared to the final practice sessions. Performance decline was observed in the first session of working on a smaller-caliber tube. However, this rapidly improved during the following sessions of practice. Temporary plateaus were seen in certain segments of the curve. The retention interval between the acquisition and recall phase did not cause a regression to the prepractice performance level. Learning the fine motor task of microvascular anastomosis adapts to the basic rules of learning such as the "power law of practice." Our results also support the improvement of performance during consecutive sessions of practice. The objective evidence provided may help in developing optimized learning protocols for microvascular anastomosis.

Triglyceride glucose index, a marker of insulin resistance, is associated with coronary artery stenosis in asymptomatic subjects with type 2 diabetes.

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Lee, Eun Young; Yang, Hae Kyung; Lee, Joonyub; Kang, Borami; Yang, Yeoree; Lee, Seung-Hwan; Ko, Seung-Hyun; Ahn, Yu-Bae; Cha, Bong Yun; Yoon, Kun-Ho; Cho, Jae Hyoung

2016-09-15

Insulin resistance is one of the most important contributing factors to cardiovascular disease. This study aimed to investigate the association between coronary artery stenosis (CAS) and triglyceride glucose index (TyG index), a simple insulin resistance marker, in asymptomatic subjects with type 2 diabetes. We recruited asymptomatic adults with type 2 diabetes but without previous history of coronary heart disease (n = 888). Significant CAS was defined as maximum intraluminal stenosis ≥70 % by coronary CT angiography. TyG index was calculated as log [fasting triglycerides (mg/dl) x fasting glucose (mg/dl)/2]. Mean age was 63.8 ± 9.5 and 58.9 % of the subjects were men. We analyzed the participants according to the tertile of TyG index. The TyG index was correlated with HOMA-IR (r = 0.397, P index were younger but showed worse clinical and metabolic parameters. The prevalence of CAS was higher in subjects with higher tertile of TyG compared with those with lower tertile of TyG (14 % vs. 7.8 %, P = 0.022). On multiple regression analysis, the highest tertile of TyG index was an independent risk factor for CAS after adjustment for other confounders (odds ratio, 3.19 [95 % CI, 1.371-7.424]). Subgroup analysis showed that TyG index showed more significant association with CAS in patients with risk factors such as old age, longer duration of diabetes, poor glycemic control, no statin use, and male gender. Higher TyG index is associated with increased risk of CAS in asymptomatic subjects with type 2 diabetes, particularly when they have risk factors for cardiovascular disease. This study was retrospectively registered in ClinicalTrials. gov with the registration number of NCT02070926 in Feb 23, 2014.

Quercetin protects human brain microvascular endothelial cells from fibrillar β-amyloid1–40-induced toxicity

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Yongjie Li

2015-01-01

Full Text Available Amyloid beta-peptides (Aβ are known to undergo active transport across the blood-brain barrier, and cerebral amyloid angiopathy has been shown to be a prominent feature in the majority of Alzheimer׳s disease. Quercetin is a natural flavonoid molecule and has been demonstrated to have potent neuroprotective effects, but its protective effect on endothelial cells under Aβ-damaged condition is unclear. In the present study, the protective effects of quercetin on brain microvascular endothelial cells injured by fibrillar Aβ1–40 (fAβ1–40 were observed. The results show that fAβ1–40-induced cytotoxicity in human brain microvascular endothelial cells (hBMECs can be relieved by quercetin treatment. Quercetin increases cell viability, reduces the release of lactate dehydrogenase, and relieves nuclear condensation. Quercetin also alleviates intracellular reactive oxygen species generation and increases superoxide dismutase activity. Moreover, it strengthens the barrier integrity through the preservation of the transendothelial electrical resistance value, the relief of aggravated permeability, and the increase of characteristic enzyme levels after being exposed to fAβ1–40. In conclusion, quercetin protects hBMECs from fAβ1–40-induced toxicity.

Admission Glycaemia and Acute Insulin Resistance in Heart Failure Complicating Acute Coronary Syndrome.

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Lazzeri, Chiara; Valente, Serafina; Chiostri, Marco; D'Alfonso, Maria Grazia; Spini, Valentina; Angelotti, Paola; Gensini, Gian Franco

2015-11-01

Few data are so far available on the relation between increased glucose values and insulin resistance and mortality at short-term in patients with acute heart failure (AHF). The present investigation, performed in 409 consecutive patients with AHF complicating acute coronary syndrome (ACS), was aimed at assessing the prognostic role of admission glycaemia and acute insulin resistance (as indicated by the Homeostatic Model Assessment - HOMA index) for death during Intensive Cardiac Care (ICCU) stay. Admission glucose tertiles were considered. In our series, diabetic patients accounted for the 33%. Patients in the third glucose tertiles exhibited the lowest LVEF (both on admission and at discharge), a higher use of mechanical ventilation, intra-aortic balloon pump and inotropic drugs and the highest in-ICCU mortality rate. In the overall population, hyperglycaemic patients (both diabetic and non diabetic) were 227 (227/409, 55.5%). Admission glycaemia was an independent predictor of in-ICCU mortality, together with admission LVEF and eGFR, while acute insulin resistance (as indicated by HOMA-index) was not associated with early death. The presence of admission hyperglycaemia in non-diabetic patients was independently associated with in-ICCU death while hyperglycaemia in diabetic patients was not. According to our results, hyperglycaemia is a common finding in patients with ACS complicated by AHF and it is an independent predictor of early death. Non-diabetic patients with hyperglycaemia are the subgroup with the highest risk of early death. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

The effect of progressive resistance training on aerobic fitness and strength in adults with coronary heart disease: A systematic review and meta-analysis of randomised controlled trials.

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Hollings, Matthew; Mavros, Yorgi; Freeston, Jonathan; Fiatarone Singh, Maria

2017-08-01

Design We aimed to evaluate the effect of progressive resistance training on cardiorespiratory fitness and muscular strength in coronary heart disease, when compared to control or aerobic training, and when combined with aerobic training. Secondary aims were to evaluate the safety and efficacy of progressive resistance training on other physiological and clinical outcomes. Methods and results Electronic databases were searched from inception until July 2016. Designs included progressive resistance training vs control, progressive resistance training vs aerobic training, and combined training vs aerobic training. From 268,778 titles, 34 studies were included (1940 participants; 71.9% male; age 60 ± 7 years). Progressive resistance training was more effective than control for lower (standardized mean difference 0.57, 95% confidence interval (0.17-0.96)) and upper (1.43 (0.73-2.13)) body strength. Aerobic fitness improved similarly after progressive resistance training (16.9%) or aerobic training (21.0%); (standardized mean difference -0.13, 95% confidence interval (-0.35-0.08)). Combined training was more effective than aerobic training for aerobic fitness (0.21 (0.09-0.34), lower (0.62 (0.32-0.92)) and upper (0.51 (0.27-0.74)) body strength. Twenty studies reported adverse event information, with five reporting 64 cardiovascular complications, 63 during aerobic training. Conclusion Isolated progressive resistance training resulted in an increase in lower and upper body strength, and improved aerobic fitness to a similar degree as aerobic training in coronary heart disease cohorts. Importantly, when progressive resistance training was added to aerobic training, effects on both fitness and strength were enhanced compared to aerobic training alone. Reporting of adverse events was poor, and clinical gaps were identified for women, older adults, high intensity progressive resistance training and long-term outcomes, warranting future trials to confirm safety and

Cardiac rehabilitation: a good measure to improve quality of life in peri- and postmenopausal women with microvascular angina

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Wojciech Szot

2015-05-01

Full Text Available Cardiac Syndrome X (CSX was considered a stable coronary syndrome, yet due to its nature, CSX symptoms often have a great impact on patients’ Quality of Life (QoL. According to ESC 2013 stable coronary artery disease criteria, CSX was replaced by Microvascular Angina (MA.Unfortunately, most CSX or MA patients, after classical angina (involving main coronary vessels has been ruled out, often do not receive proper treatment. Indications for pharmacological treatment of MA patients were introduced only recently. Another problematic issue is that scientists describing the pathophysiology of both CSX and MA stress a lack of a deeper insight into the multifactorial etiology of the source of pain associated with this disease. In the presented article we have attempted to study the influence of cardiac rehabilitation (3 months programme on the QoL of patients recognized as suffering from MA, as well as to check if changes in myocardial perfusion in these patients at baseline and after completion of cardiac rehabilitation match changes in their QoL. Therefore, after screening 436 women for MA, we studied 55 of them who were confirmed as having MA and who agreed to participate in the study. Exercise tests, Myocardial Perfusion Imaging, and QoL questionnaires were studied at baseline and after completing 3 months period of cardiac rehabilitation. Results were subsequently compared, which showed a link between improved perfusion score in SPECT study and improved overall physical capacity, on one hand, and improved QoL score on the other. These results confirm that cardiac rehabilitation is a very useful treatment option for MA patients. It seems that training during cardiac rehabilitation is a very important factor (improved physical efficiency –> increase in self-belief, and that taking into consideration the multifactor pathophysiology of pain, it is connected with a better quality of life for MA patients.

Cardiac rehabilitation: a good measure to improve quality of life in peri- and postmenopausal women with microvascular angina

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Wojciech Szot

2015-05-01

Full Text Available Cardiac Syndrome X (CSX was considered a stable coronary syndrome, yet due to its nature, CSX symptoms often have a great impact on patients’ Quality of Life (QoL. According to ESC 2013 stable coronary artery disease criteria, CSX was replaced by Microvascular Angina (MA.Unfortunately, most CSX or MA patients, after classical angina (involving main coronary vessels has been ruled out, often do not receive proper treatment. Indications for pharmacological treatment of MA patients were introduced only recently. Another problematic issue is that scientists describing the pathophysiology of both CSX and MA stress a lack of a deeper insight into the multifactorial etiology of the source of pain associated with this disease. In the presented article we have attempted to study the influence of cardiac rehabilitation (3 months programme on the QoL of patients recognized as suffering from MA, as well as to check if changes in myocardial perfusion in these patients at baseline and after completion of cardiac rehabilitation match changes in their QoL. Therefore, after screening 436 women for MA, we studied 55 of them who were confirmed as having MA and who agreed to participate in the study. Exercise tests, Myocardial Perfusion Imaging, and QoL questionnaires were studied at baseline and after completing 3 months period of cardiac rehabilitation. Results were subsequently compared, which showed a link between improved perfusion score in SPECT study and improved overall physical capacity, on one hand, and improved QoL score on the other. These results confirm that cardiac rehabilitation is a very useful treatment option for MA patients. It seems that training during cardiac rehabilitation is a very important factor (improved physical efficiency –> increase in self-belief, and that taking into consideration the multifactor pathophysiology of pain, it is connected with a better quality of life for MA patients.

Microvascular Remodeling and Wound Healing: A Role for Pericytes

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Dulmovits, Brian M.; Herman, Ira M.

2012-01-01

Physiologic wound healing is highly dependent on the coordinated functions of vascular and non-vascular cells. Resolution of tissue injury involves coagulation, inflammation, formation of granulation tissue, remodeling and scarring. Angiogenesis, the growth of microvessels the size of capillaries, is crucial for these processes, delivering blood-borne cells, nutrients and oxygen to actively remodeling areas. Central to angiogenic induction and regulation is microvascular remodeling, which is dependent upon capillary endothelial cell and pericyte interactions. Despite our growing knowledge of pericyte-endothelial cell crosstalk, it is unclear how the interplay among pericytes, inflammatory cells, glia and connective tissue elements shape microvascular injury response. Here, we consider the relationships that pericytes form with the cellular effectors of healing in normal and diabetic environments, including repair following injury and vascular complications of diabetes, such as diabetic macular edema and proliferative diabetic retinopathy. In addition, pericytes and stem cells possessing “pericyte-like” characteristics are gaining considerable attention in experimental and clinical efforts aimed at promoting healing or eradicating ocular vascular proliferative disorders. As the origin, identification and characterization of microvascular pericyte progenitor populations remains somewhat ambiguous, the molecular markers, structural and functional characteristics of pericytes will be briefly reviewed. PMID:22750474

[Microvascular decompression for hemifacial spasm. Ten years of experience].

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Revuelta-Gutiérrez, Rogelio; Vales-Hidalgo, Lourdes Olivia; Arvizu-Saldaña, Emiliano; Hinojosa-González, Ramón; Reyes-Moreno, Ignacio

2003-01-01

Hemifacial spasm characterized by involuntary paroxistic contractions of the face is more frequent on left side and in females. Evolution is progressive and in a few cases may disappear. Management includes medical treatment, botulinum toxin, and microvascular decompression of the nerve. We present the results of 116 microvascular decompressions performed in 88 patients over 10 years. All patients had previous medical treatment. All patients were operated on with microsurgical technique by asterional craniotomy. Vascular compression was present in all cases with one exception. Follow-up was from 1 month to 133 months. Were achieved excellent results in 70.45% of cases after first operation, good results in 9.09%, and poor results in 20.45% of patients. Long-term results were excellent in 81.82%, good in 6.82%, and poor in 11.36% of patients. Hypoacusia and transitory facial palsy were the main complications. Hemifacial spasm is a painless but disabling entity. Medical treatment is effective in a limited fashion. Injection of botulinum toxin has good response but benefit is transitory. Microvascular decompression is treatment of choice because it is minimally invasive, not destructive, requires minimum technical support, and yields best long-term results.

Direct numerical simulation of cellular-scale blood flow in microvascular networks

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Balogh, Peter; Bagchi, Prosenjit

2017-11-01

A direct numerical simulation method is developed to study cellular-scale blood flow in physiologically realistic microvascular networks that are constructed in silico following published in vivo images and data, and are comprised of bifurcating, merging, and winding vessels. The model resolves large deformation of individual red blood cells (RBC) flowing in such complex networks. The vascular walls and deformable interfaces of the RBCs are modeled using the immersed-boundary methods. Time-averaged hemodynamic quantities obtained from the simulations agree quite well with published in vivo data. Our simulations reveal that in several vessels the flow rates and pressure drops could be negatively correlated. The flow resistance and hematocrit are also found to be negatively correlated in some vessels. These observations suggest a deviation from the classical Poiseuille's law in such vessels. The cells are observed to frequently jam at vascular bifurcations resulting in reductions in hematocrit and flow rate in the daughter and mother vessels. We find that RBC jamming results in several orders of magnitude increase in hemodynamic resistance, and thus provides an additional mechanism of increased in vivo blood viscosity as compared to that determined in vitro. Funded by NSF CBET 1604308.

Progressive epicardial coronary blood flow reduction fails to produce ST-segment depression at normal heart rates.

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de Chantal, Marilyn; Diodati, Jean G; Nasmith, James B; Amyot, Robert; LeBlanc, A Robert; Schampaert, Erick; Pharand, Chantal

2006-12-01

ST-segment depression is commonly seen in patients with acute coronary syndromes. Most authors have attributed it to transient reductions in coronary blood flow due to nonocclusive thrombus formation on a disrupted atherosclerotic plaque and dynamic focal vasospasm at the site of coronary artery stenosis. However, ST-segment depression was never reproduced in classic animal models of coronary stenosis without the presence of tachycardia. We hypothesized that ST-segment depression occurring during acute coronary syndromes is not entirely explained by changes in epicardial coronary artery resistance and thus evaluated the effect of a slow, progressive epicardial coronary artery occlusion on the ECG and regional myocardial blood flow in anesthetized pigs. Slow, progressive occlusion over 72 min (SD 27) of the left anterior descending coronary artery in 20 anesthetized pigs led to a 90% decrease in coronary blood flow and the development of ST-segment elevation associated with homogeneous and transmural myocardial blood flow reductions, confirmed by microspheres and myocardial contrast echocardiography. ST-segment depression was not observed in any ECG lead before the development of ST-segment elevation. At normal heart rates, progressive epicardial stenosis of a coronary artery results in myocardial ischemia associated with homogeneous, transmural reduction in regional myocardial blood flow and ST-segment elevation, without preceding ST-segment depression. Thus, in coronary syndromes with ST-segment depression and predominant subendocardial ischemia, factors other than mere increases in epicardial coronary resistance must be invoked to explain the heterogeneous parietal distribution of flow and associated ECG changes.

Microvascular lesions of the true vocal fold.

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Postma, G N; Courey, M S; Ossoff, R H

1998-06-01

Microvascular lesions, also called varices or capillary ectasias, in contrast to vocal fold polyps with telangiectatic vessels, are relatively small lesions arising from the microcirculation of the vocal fold. Varices are most commonly seen in female professional vocalists and may be secondary to repetitive trauma, hormonal variations, or repeated inflammation. Microvascular lesions may either be asymptomatic or cause frank dysphonia by interrupting the normal vibratory pattern, mass, or closure of the vocal folds. They may also lead to vocal fold hemorrhage, scarring, or polyp formation. Laryngovideostroboscopy is the key in determining the functional significance of vocal fold varices. Management of patients with a varix includes medical therapy, speech therapy, and occasionally surgical vaporization. Indications for surgery are recurrent hemorrhage, enlargement of the varix, development of a mass in conjunction with the varix or hemorrhage, and unacceptable dysphonia after maximal medical and speech therapy due to a functionally significant varix.

Preventing microvascular complications in type 1 diabetes mellitus

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Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c) level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c 20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour. PMID:25941647

Baseline High-Sensitivity C-Reactive Protein Predicts Macrovascular and Microvascular Complications of Type 2 Diabetes: A Population-Based Study.

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Aryan, Zahra; Ghajar, Alireza; Faghihi-Kashani, Sara; Afarideh, Mohsen; Nakhjavani, Manouchehr; Esteghamati, Alireza

2018-04-25

This prospective study is aimed at examining the predictive value of high-sensitivity C-reactive protein (hs-CRP) for coronary heart disease (CHD) events and microvascular complications of type 2 diabetes mellitus (T2DM). A population-based study (NCT02958579) was conducted on 1,301 participants with T2DM (mean follow-up of 7.5 years). Risk assessment for vascular events was done at baseline, and serum hs-CRP was measured. End points of this study include CHD events, diabetic retinopathy, neuropathy, and diabetic kidney disease. Individuals with unavailable data or hs-CRP >20 mg/L were excluded. The discrimination and reclassification improvement of study end points were tested after addition of hs-CRP to traditional risk factors. Median serum hs-CRP was 2.00 ranging from 0.1 to 17 mg/L. Hazards ratio of each SD increment in baseline hs-CRP was 1.028 (1.024-1.032) for CHD, 1.025 (1.021-1.029) for diabetic neuropathy, 1.037 (1.030-1.043) for diabetic retinopathy, and 1.035 (1.027-1.043) for diabetic kidney disease. The addition of hs-CRP to traditional risk factors of vascular complications of T2DM improved discrimination of all end points (p < 0.001). Net reclassification improvement ranged from 8% for diabetic neuropathy to 31% for diabetic kidney disease (p < 0.05). Baseline hs-CRP predicts both of CHD events and microvascular complications of patients with T2D. © 2018 S. Karger AG, Basel.

The association of systemic microvascular changes with lung function and lung density: a cross-sectional study.

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Bianca Harris

Full Text Available Smoking causes endothelial dysfunction and systemic microvascular disease with resultant end-organ damage in the kidneys, eyes and heart. Little is known about microvascular changes in smoking-related lung disease. We tested if microvascular changes in the retina, kidneys and heart were associated with obstructive spirometry and low lung density on computed tomography. The Multi-Ethnic Study of Atherosclerosis recruited participants age 45-84 years without clinical cardiovascular disease. Measures of microvascular function included retinal arteriolar and venular caliber, urine albumin-to-creatinine ratio and, in a subset, myocardial blood flow on magnetic resonance imaging. Spirometry was measured following ATS/ERS guidelines. Low attenuation areas (LAA were measured on lung fields of cardiac computed tomograms. Regression models adjusted for pulmonary and cardiac risk factors, medications and body size. Among 3,397 participants, retinal venular caliber was inversely associated with forced expiratory volume in one second (FEV(1 (P<0.001 and FEV(1/forced vital capacity (FVC ratio (P = 0.04. Albumin-to-creatinine ratio was inversely associated with FEV(1 (P = 0.002 but not FEV(1/FVC. Myocardial blood flow (n = 126 was associated with lower FEV(1 (P = 0.02, lower FEV(1/FVC (P = 0.001 and greater percentage LAA (P = 0.04. Associations were of greater magnitude among smokers. Low lung function was associated with microvascular changes in the retina, kidneys and heart, and low lung density was associated with impaired myocardial microvascular perfusion. These cross-sectional results suggest that microvascular damage with end-organ dysfunction in all circulations may pertain to the lung, that lung dysfunction may contribute to systemic microvascular disease, or that there may be a shared predisposition.

The Relationship of Body Composition and Coronary Artery Calcification in Apparently Healthy Korean Adults

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Jung-Hee Yu

2013-03-01

Full Text Available BackgroundWe investigated the association of coronary artery calcium score (CACS with body composition and insulin resistance in apparently healthy Korean adults.MethodsNine hundred forty-five participants (mean age, 48.9 years; 628 men in a medical check-up program were selected for analysis. Body composition was assessed by bioelectrical impedance analysis (BIA. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR. The CACS was assessed by multidetector computed tomography.ResultsOne hundred forty-six subjects (15.4% showed coronary artery calcification and 148 subjects (15.7% had metabolic syndrome. CACS showed a significant positive correlation with age, fasting glucose level, waist circumference (WC, blood pressure, hemoglobin A1c, HOMA-IR, and waist-hip ratio (WHR assessed by BIA. CACS had a negative correlation with high density lipoprotein cholesterol (HDL-C. Subjects with high CACS showed significantly higher mean WHRs and lower mean values for lean body mass compared with subjects without coronary artery calcification. In logistic regression analyses with coronary artery calcification as the dependent variable, the highest quartile of WHR showed a 3.125-fold increased odds ratio for coronary artery calcification compared with the lowest quartile after adjustment for confounding variables. When receiver operating characteristics analyses were performed with coronary artery calcification as the result variable, WHR showed the largest area under the curve (AUC value among other variables except for age and WC in women (AUC=0.696 for WHR, 0.790 for age, and 0.719 for WC in women.ConclusionIn our study population of apparently healthy Korean adults, WHR was the most significant predictor for coronary artery calcification among other confounding factors, suggesting that it may have implication as a marker for early atherosclerosis.

The effects of anti-obesity intervention with orlistat and sibutramine on microvascular endothelial function.

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Al-Tahami, Belqes Abdullah Mohammad; Ismail, Ab Aziz Al-Safi; Bee, Yvonne Tee Get; Awang, Siti Azima; Salha Wan Abdul Rani, Wan Rimei; Sanip, Zulkefli; Rasool, Aida Hanum Ghulam

2015-01-01

Obesity is associated with impaired microvascular endothelial function. We aimed to determine the effects of orlistat and sibutramine treatment on microvascular endothelial function, anthropometric and lipid profile, blood pressure (BP), and heart rate (HR). 76 subjects were recruited and randomized to receive orlistat 120 mg three times daily or sibutramine 10 mg daily for 9 months. Baseline weight, BMI, BP, HR and lipid profile were taken. Microvascular endothelial function was assessed using laser Doppler fluximetry and iontophoresis process. Maximum change (max), percent change (% change) and peak flux (peak) in perfusion to acetylcholine (ACh) and sodium nitroprusside (SNP) iontophoresis were used to quantify endothelium dependent and independent vasodilatations. 24 subjects in both groups completed the trial. After treatment, weight and BMI were decreased for both groups. AChmax, ACh % change and ACh peak were increased in orlistat-treated group but no difference was observed for sibutramine-treated group. BP and total cholesterol (TC) were reduced for orlistat-treated group. HR was reduced for orlistat-treated group but was increased in sibutramine-treated group. 9 months treatment with orlistat significantly improved microvascular endothelial function. This was associated with reductions in weight, BMI, BP, HR, TC and low density lipoprotein cholesterol. No effect was seen in microvascular endothelial function with sibutramine.

Supracristal ventricular septal defect with severe right coronary cusp prolapse

International Nuclear Information System (INIS)

Hussain, A.H.; Hanif, B.; Khan, G.; Hasan, K.

2011-01-01

The case of a 20 years old male, diagnosed as supracristal ventricular septal defect (VSD) for last 6 years is being presented. He came in emergency department with decompensated congestive cardiac failure. After initial stabilization, he underwent trans thoracic echocardiogram which showed large supracristal VSD, severely prolapsing right coronary cusp, severe aortic regurgitation and severe pulmonary hypertension. Right heart catheterization was performed which documented reversible pulmonary vascular resistance after high flow oxygen inhalation. He underwent VSD repair, right coronary cusp was excised and aortic valve was replaced by mechanical prosthesis. Post operative recovery was uneventful. He was discharged home in one week.The case of a 20 years old male, diagnosed as supracristal ventricular septal defect (VSD) for last 6 years is being presented. He came in emergency department with decompensated congestive cardiac failure. After initial stabilization, he underwent trans thoracic echocardiogram which showed large supracristal VSD, severely prolapsing right coronary cusp, severe aortic regurgitation and severe pulmonary hypertension. Right heart catheterization was performed which documented reversible pulmonary vascular resistance after high flow oxygen inhalation. He underwent VSD repair, right coronary cusp was excised and aortic valve was replaced by mechanical prosthesis. Post operative recovery was uneventful. He was discharged home in one week. (author)

Glucagon-Like Peptide 1 Recruits Muscle Microvasculature and Improves Insulin’s Metabolic Action in the Presence of Insulin Resistance

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Chai, Weidong; Zhang, Xingxing; Barrett, Eugene J.

2014-01-01

Glucagon-like peptide 1 (GLP-1) acutely recruits muscle microvasculature, increases muscle delivery of insulin, and enhances muscle use of glucose, independent of its effect on insulin secretion. To examine whether GLP-1 modulates muscle microvascular and metabolic insulin responses in the setting of insulin resistance, we assessed muscle microvascular blood volume (MBV), flow velocity, and blood flow in control insulin-sensitive rats and rats made insulin-resistant acutely (systemic lipid infusion) or chronically (high-fat diet [HFD]) before and after a euglycemic-hyperinsulinemic clamp (3 mU/kg/min) with or without superimposed systemic GLP-1 infusion. Insulin significantly recruited muscle microvasculature and addition of GLP-1 further expanded muscle MBV and increased insulin-mediated glucose disposal. GLP-1 infusion potently recruited muscle microvasculature in the presence of either acute or chronic insulin resistance by increasing muscle MBV. This was associated with an increased muscle delivery of insulin and muscle interstitial oxygen saturation. Muscle insulin sensitivity was completely restored in the presence of systemic lipid infusion and significantly improved in rats fed an HFD. We conclude that GLP-1 infusion potently expands muscle microvascular surface area and improves insulin’s metabolic action in the insulin-resistant states. This may contribute to improved glycemic control seen in diabetic patients receiving incretin-based therapy. PMID:24658303

Possible increase in insulin resistance and concealed glucose-coupled potassium-lowering mechanisms during acute coronary syndrome documented by covariance structure analysis.

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Ito, Satoshi; Nagoshi, Tomohisa; Minai, Kosuke; Kashiwagi, Yusuke; Sekiyama, Hiroshi; Yoshii, Akira; Kimura, Haruka; Inoue, Yasunori; Ogawa, Kazuo; Tanaka, Toshikazu D; Ogawa, Takayuki; Kawai, Makoto; Yoshimura, Michihiro

2017-01-01

Although glucose-insulin-potassium (GIK) therapy ought to be beneficial for ischemic heart disease in general, variable outcomes in many clinical trials of GIK in acute coronary syndrome (ACS) had a controversial impact. This study was designed to examine whether "insulin resistance" is involved in ACS and to clarify other potential intrinsic compensatory mechanisms for GIK tolerance through highly statistical procedure. We compared the degree of insulin resistance during ACS attack and remission phase after treatment in individual patients (n = 104). During ACS, homeostasis model assessment of insulin resistance (HOMA-IR) values were significantly increased (Pcovariance structure analysis with a strong impact (β: 0.398, P = 0.015). Intriguingly, a higher incidence of myocardial infarction relative to unstable angina pectoris, as well as a longer hospitalization period were observed in patients with larger ΔK, indicating that ΔK also reflects disease severity of ACS. Insulin resistance most likely increases during ACS; however, ΔK was positively correlated with plasma glucose level, which overwhelmed insulin resistance condition. The present study with covariance structure analysis suggests that there are potential endogenous glucose-coupled potassium lowering mechanisms, other than insulin, regulating glucose metabolism during ACS.

Fatty liver is associated with insulin resistance, risk of coronary heart disease, and early atherosclerosis in a large European population

DEFF Research Database (Denmark)

Gastaldelli, Amalia; Kozakova, Michaela; Højlund, Kurt

2009-01-01

Patients with fatty liver (FL) disease have a high risk of developing diabetes and cardiovascular diseases. The aim was to evaluate the association between FL, insulin resistance (IR), coronary heart disease (CHD) risk, and early atherosclerosis in a large European population (RISC Study). In 1...... cholesterol (r = 0.33), alanine aminotransferase (r = 0.48), aspartate aminotransferase (r = 0.25), systolic blood pressure (r = 0.39) and IMT (r = 0.30), and reduced insulin sensitivity (r = -0.43), high-density lipoprotein cholesterol (r = -0.50), adiponectin (r = -0.42), and physical activity (r = -0...

[Construction of 2-dimensional tumor microvascular architecture phenotype in non-small cell lung cancer].

Science.gov (United States)

Liu, Jin-kang; Wang, Xiao-yi; Xiong, Zeng; Zhou, Hui; Zhou, Jian-hua; Fu, Chun-yan; Li, Bo

2008-08-01

To construct a technological platform of 2-dimensional tumor microvascular architecture phenotype (2D-TAMP) expression. Thirty samples of non-small cell lung cancer (NSCLC) were collected after surgery. The corresponding sections of tumor tissue specimens to the slice of CT perfusion imaging were selected. Immunohistochemical staining,Gomori methenamine silver stain, and electron microscope observation were performed to build a technological platform of 2D-TMAP expression by detecting the morphology and the integrity of basement membrane of microvasculature, microvascular density, various microvascular subtype, the degree of the maturity and lumenization of microvasculature, and the characteristics of immunogenetics of microvasculature. The technological platform of 2D-TMAP expression was constructed successfully. There was heterogeneity in 2D-TMAP expression of non-small cell lung cancer. The microvascular of NSCLC had certain characteristics. 2D-TMAP is a key technology that can be used to observe the overall state of micro-environment in tumor growth.

Microvascular and Macrovascular Abnormalities and Cognitive and Physical Function in Older Adults: Cardiovascular Health Study.

Science.gov (United States)

Kim, Dae Hyun; Grodstein, Francine; Newman, Anne B; Chaves, Paulo H M; Odden, Michelle C; Klein, Ronald; Sarnak, Mark J; Lipsitz, Lewis A

2015-09-01

To evaluate and compare the associations between microvascular and macrovascular abnormalities and cognitive and physical function Cross-sectional analysis of the Cardiovascular Health Study (1998-1999). Community. Individuals with available data on three or more of five microvascular abnormalities (brain, retina, kidney) and three or more of six macrovascular abnormalities (brain, carotid artery, heart, peripheral artery) (N = 2,452; mean age 79.5). Standardized composite scores derived from three cognitive tests (Modified Mini-Mental State Examination, Digit-Symbol Substitution Test, Trail-Making Test (TMT)) and three physical tests (gait speed, grip strength, 5-time sit to stand) Participants with high microvascular and macrovascular burden had worse cognitive (mean score difference = -0.30, 95% confidence interval (CI) = -0.37 to -0.24) and physical (mean score difference = -0.32, 95% CI = -0.38 to -0.26) function than those with low microvascular and macrovascular burden. Individuals with high microvascular burden alone had similarly lower scores than those with high macrovascular burden alone (cognitive function: -0.16, 95% CI = -0.24 to -0.08 vs -0.13, 95% CI = -0.20 to -0.06; physical function: -0.15, 95% CI = -0.22 to -0.08 vs -0.12, 95% CI = -0.18 to -0.06). Psychomotor speed and working memory, assessed using the TMT, were only impaired in the presence of high microvascular burden. Of the 11 vascular abnormalities considered, white matter hyperintensity, cystatin C-based glomerular filtration rate, large brain infarct, and ankle-arm index were independently associated with cognitive and physical function. Microvascular and macrovascular abnormalities assessed using noninvasive tests of the brain, kidney, and peripheral artery were independently associated with poor cognitive and physical function in older adults. Future research should evaluate the usefulness of these tests in prognostication. © 2015, Copyright the Authors Journal compilation © 2015

Emergence of Nonobstructive Coronary Artery Disease: A Woman's Problem and Need for Change in Definition on Angiography.

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Pepine, Carl J; Ferdinand, Keith C; Shaw, Leslee J; Light-McGroary, Kelly Ann; Shah, Rashmee U; Gulati, Martha; Duvernoy, Claire; Walsh, Mary Norine; Bairey Merz, C Noel

2015-10-27

Recognition of ischemic heart disease (IHD) is often delayed or deferred in women. Thus, many at risk for adverse outcomes are not provided specific diagnostic, preventive, and/or treatment strategies. This lack of recognition is related to sex-specific IHD pathophysiology that differs from traditional models using data from men with flow-limiting coronary artery disease (CAD) obstructions. Symptomatic women are less likely to have obstructive CAD than men with similar symptoms, and tend to have coronary microvascular dysfunction, plaque erosion, and thrombus formation. Emerging data document that more extensive, nonobstructive CAD involvement, hypertension, and diabetes are associated with major adverse events similar to those with obstructive CAD. A central emerging paradigm is the concept of nonobstructive CAD as a cause of IHD and related adverse outcomes among women. This position paper summarizes currently available knowledge and gaps in that knowledge, and recommends management options that could be useful until additional evidence emerges. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Cell proliferation along vascular islands during microvascular network growth

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Kelly-Goss Molly R

2012-06-01

Full Text Available Abstract Background Observations in our laboratory provide evidence of vascular islands, defined as disconnected endothelial cell segments, in the adult microcirculation. The objective of this study was to determine if vascular islands are involved in angiogenesis during microvascular network growth. Results Mesenteric tissues, which allow visualization of entire microvascular networks at a single cell level, were harvested from unstimulated adult male Wistar rats and Wistar rats 3 and 10 days post angiogenesis stimulation by mast cell degranulation with compound 48/80. Tissues were immunolabeled for PECAM and BRDU. Identification of vessel lumens via injection of FITC-dextran confirmed that endothelial cell segments were disconnected from nearby patent networks. Stimulated networks displayed increases in vascular area, length density, and capillary sprouting. On day 3, the percentage of islands with at least one BRDU-positive cell increased compared to the unstimulated level and was equal to the percentage of capillary sprouts with at least one BRDU-positive cell. At day 10, the number of vascular islands per vascular area dramatically decreased compared to unstimulated and day 3 levels. Conclusions These results show that vascular islands have the ability to proliferate and suggest that they are able to incorporate into the microcirculation during the initial stages of microvascular network growth.

Hydroxychloroquine, a promising choice for coronary artery disease?

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Sun, Lizhe; Liu, Mengping; Li, Ruifeng; Zhao, Qiang; Liu, Junhui; Yang, Yanjie; Zhang, Lisha; Bai, Xiaofang; Wei, Yuanyuan; Ma, Qiangqiang; Zhou, Juan; Yuan, Zuyi; Wu, Yue

2016-08-01

Coronary artery disease is a common disease that seriously threaten the health of more than 150 million people per year. Atherosclerosis is considered to be the main cause of coronary artery disease which begins with damage or injury to the inner layer of a coronary artery, sometimes as early as childhood. The damage may be caused by various factors, including: smoking, high blood pressure, hypercholesterolemia, sedentary lifestyle, diabetes and insulin resistance. Once a coronary artery disease has developed, all patients need to be treated with long term standard treatment, including heart-healthy lifestyle changes, medicines, and medical procedures or surgery. Hydroxychloroquine, an original antimalarial drug, prevents inflammation caused by lupus erythematosus and rheumatoid arthritis. It is relatively safe and well-tolerated during the treatment. Since atherosclerosis and rheumatoid arthritis have resemble mechanism and increasing clinical researches confirm that hydroxychloroquine has an important role in both anti-rheumatoid arthritis and cardiovascular protection (such as anti-platelet, anti-thrombotic, lipid-regulating, anti-hypertension, hypoglycemia, and so on), we hypothesize that hydroxychloroquine might be a promising choice to coronary artery disease patients for its multiple benefits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of macrovascular endothelial function using pulse wave analysis and its association with microvascular reactivity in healthy subjects.

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Ibrahim, N N I N; Rasool, A H G

2017-08-01

Pulse wave analysis (PWA) and laser Doppler fluximetry (LDF) are non-invasive methods of assessing macrovascular endothelial function and microvascular reactivity respectively. The aim of this study was to assess the correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF. 297 healthy and non-smoking subjects (159 females, mean age (±SD) 23.56 ± 4.54 years) underwent microvascular reactivity assessment using LDF followed by macrovascular endothelial function assessments using PWA. Pearson's correlation showed no correlation between macrovascular endothelial function and microvascular reactivity (r = -0.10, P = 0.12). There was no significant correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF in healthy subjects. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Preventing microvascular complications in type 1 diabetes mellitus

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Vijay Viswanathan

2015-01-01

Full Text Available Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c 20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour.

Ischemia and No Obstructive Coronary Artery Disease (INOCA): Developing Evidence-based Therapies and Research Agenda for the Next Decade

Science.gov (United States)

Merz, C. Noel Bairey; Pepine, Carl J.; Walsh, Mary Norine; Fleg, Jerome L.

2017-01-01

The Cardiovascular Disease in Women Committee of the American College of Cardiology, in conjunction with interested parties (from the National Heart, Lung, and Blood Institute, American Heart Association, European Society of Cardiology), convened a working group to develop a consensus on the syndrome of myocardial ischemia with no obstructive coronary arteries (INOCA). In general, these patients have elevated risk for a cardiovascular event (including acute coronary syndrome, heart failure hospitalization, stroke, and repeated cardiovascular procedures) vs reference subjects, and appear to be at higher risk for development of heart failure with preserved ejection fraction (HFpEF). A subgroup of these patients also has coronary microvascular dysfunction (CMD) and evidence of inflammation. This document provides a summary of findings and recommendations toward the development of an integrated approach for identifying and managing patients with INOCA, and outlining knowledge gaps in the area. Working group members critically reviewed available literature and current practices for risk assessment and state-of-the-science techniques in multiple areas, with a focus on next steps needed to develop evidence-based therapies. This report presents highlights of this working group review and a summary of suggested research directions to advance this field in the next decade. PMID:28289007

Calcified Plaque of Coronary Artery: Factors Influencing Overestimation of Coronary Artery Stenosis on Coronary CT Angiography

International Nuclear Information System (INIS)

Kim, Mok Hee; Kim, Yun Hyeon; Choi, Song; Seon, Hyun Ju; Jeong, Gwang Woo; Park, Jin Gyoon; Kang, Heoung Keun; Ko, Joon Seok

2010-01-01

To assess the influence of calcified plaque characteristics on the overestimation of coronary arterial stenosis on a coronary CT angiography (CCTA). The study included 271 coronary arteries with calcified plaques identified by CCTA, and based on 928 coronary arteries from 232 patients who underwent both CCTA and invasive coronary angiography (ICA). Individual coronary arteries were classified into two groups by agreement based on the degree of stenosis from each CCTA and ICA: 1) group A includes patients with concordant CCTA and ICA results and, 2) group B includes patients with an overestimation of CCTA compared to ICA. Parameters including total calcium score, calcium score of an individual coronary artery, calcium burden number of an individual coronary artery, and the density of each calcified plaque (calcium score / number of calcium burden) for each individual coronary artery were compared between the two groups. Of the 271 coronary arteries, 164 (60.5%) were overestimated on CCTA. The left anterior descending artery (LAD) had a significantly low rate of overestimation (47.1%) compared to the other coronary arteries (p=0.001). No significant differences for total calcium score, calcium score of individual coronary artery, and the density of each calcified plaque from individual coronary arteries between two groups was observed. However, a decreasing tendency for the rate of overestimation on CCTA was observed with an increase in calcium burden of individual coronary arteries (p<0.05). The evaluation of coronary arteries suggests that the degree of coronary arterial stenosis had a tendency to be overestimated by calcified plaques on CCTA. However, the rate of overestimation for the degree of coronary arterial stenosis by calcified plaques was not significantly influenced by total calcium score, calcium score of individual coronary artery, and density of each calcified plaque

Biomarker for early renal microvascular and diabetic kidney diseases.

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Futrakul, Narisa; Futrakul, Prasit

2017-11-01

Recognition of early stage of diabetic kidney disease, under common practice using biomarkers, namely microalbuminuria, serum creatinine level above 1 mg/dL and accepted definition of diabetic kidney disease associated with creatinine clearance value below 60 mL/min/1.73 m 2 , is unlikely. This would lead to delay treatment associated with therapeutic resistance to vasodilator due to a defective vascular homoeostasis. Other alternative biomarkers related to the state of microalbuminuria is not sensitive to screen for early diabetic kidney disease (stages I, II). In this regard, a better diagnostic markers to serve for this purpose are creatinine clearance, fractional excretion of magnesium (FE Mg), cystatin C. Recently, renal microvascular disease and renal ischemia have been demonstrated to correlate indirectly with the development of diabetic kidney disease and its function. Among these are angiogenic and anti-angiogenic factors, namely VEGF, VEGF receptors, angiopoietins and endostatin. With respect to therapeutic prevention, implementation of treatment at early stage of diabetic and nondiabetic kidney disease is able to restore renal perfusion and function.

Microvascular versus macrovascular cerebral vasomotor reactivity in patients with severe internal carotid artery stenosis or occlusion.

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Zirak, Peyman; Delgado-Mederos, Raquel; Dinia, Lavinia; Martí-Fàbregas, Joan; Durduran, Turgut

2014-02-01

In patients with severe internal carotid artery steno-occlusive lesions (ISOL), impaired cerebrovascular reactivity (CVR) is predictive of future ischemic stroke (IS) or transient ischemic attack (TIA). Therefore, the evaluation of CVR in ISOL patients may be a means to evaluate the risk for IS/TIA and decide on an intervention. Our aim was (1) to explore the feasibility of concurrent near-infrared spectroscopy (NIRS-DOS), diffuse correlation spectroscopy, and transcranial Doppler for CVR assessment in ISOL patients, and (2) to compare macrovascular and microvascular CVR in ISOL patients and explore its potential for IS/TIA risk stratification. Twenty-seven ISOL patients were recruited. The changes in continuous microvascular and macrovascular hemodynamics upon acetazolamide injection were used to determine CVR. Oxyhemoglobin (HbO2, by near-infrared spectroscopy), microvascular cerebral blood flow (CBF, by diffuse correlation spectroscopy) and CBF velocity (by transcranial Doppler) showed significant increases upon acetazolamide injection in all subjects (P < .03). Only macrovascular CVR (P = .024) and none of the microvascular measures were significantly dependent on the presence of ISOL. In addition, while CBF was significantly correlated with HbO2, neither of these microvascular measures correlated with macrovascular CBF velocity. We demonstrated the simultaneous, continuous, and noninvasive evaluation of CVR at both the microvasculature and macrovasculature. We found that macrovascular CVR response depends on the presence of ISOL, whereas the microvascular CVR did not significantly depend on the ISOL presence, possibly due to the role of collaterals other than those of the circle of Willis. The concurrent microvascular and macrovascular CVR measurement in the ISOL patients might improve future IS/TIA risk assessment. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Long noncoding RNA-MEG3 is involved in diabetes mellitus-related microvascular dysfunction

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Qiu, Gui-Zhen [Department of Health, Linyi People' s Hospital, Shandong University, Shandong (China); Tian, Wei [Department of Nursing, Linyi Oncosurgical Hospital, Shandong (China); Fu, Hai-Tao [Department of Ophthalmology, Linyi People' s Hospital, Shandong University, Shandong (China); Li, Chao-Peng, E-mail: lcpcn@163.com [Eye Institute of Xuzhou, Jiangsu (China); Liu, Ban, E-mail: liuban@126.com [Department of Cardiology, Shanghai Tenth People' s Hospital, Tongji University School of Medicine, Shanghai (China)

2016-02-26

Microvascular dysfunction is an important characteristic of diabetic retinopathy. Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. In this study, we investigated the role of lncRNA-MEG3 in diabetes-related microvascular dysfunction. We show that MEG3 expression level is significantly down-regulated in the retinas of STZ-induced diabetic mice, and endothelial cells upon high glucose and oxidative stress. MEG3 knockdown aggravates retinal vessel dysfunction in vivo, as shown by serious capillary degeneration, and increased microvascular leakage and inflammation. MEG3 knockdown also regulates retinal endothelial cell proliferation, migration, and tube formation in vitro. The role of MEG3 in endothelial cell function is mainly mediated by the activation of PI3k/Akt signaling. MEG3 up-regulation may serve as a therapeutic strategy for treating diabetes-related microvascular complications. - Highlights: • LncRNA-MEG3 level is down-regulated upon diabetic stress. • MEG3 knockdown aggravates retinal vascular dysfunction in vivo. • MEG3 regulates retinal endothelial cell function in vitro. • MEG3 regulates endothelial cell function through PI3k/Akt signaling.

Long noncoding RNA-MEG3 is involved in diabetes mellitus-related microvascular dysfunction

International Nuclear Information System (INIS)

Qiu, Gui-Zhen; Tian, Wei; Fu, Hai-Tao; Li, Chao-Peng; Liu, Ban

2016-01-01

Microvascular dysfunction is an important characteristic of diabetic retinopathy. Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. In this study, we investigated the role of lncRNA-MEG3 in diabetes-related microvascular dysfunction. We show that MEG3 expression level is significantly down-regulated in the retinas of STZ-induced diabetic mice, and endothelial cells upon high glucose and oxidative stress. MEG3 knockdown aggravates retinal vessel dysfunction in vivo, as shown by serious capillary degeneration, and increased microvascular leakage and inflammation. MEG3 knockdown also regulates retinal endothelial cell proliferation, migration, and tube formation in vitro. The role of MEG3 in endothelial cell function is mainly mediated by the activation of PI3k/Akt signaling. MEG3 up-regulation may serve as a therapeutic strategy for treating diabetes-related microvascular complications. - Highlights: • LncRNA-MEG3 level is down-regulated upon diabetic stress. • MEG3 knockdown aggravates retinal vascular dysfunction in vivo. • MEG3 regulates retinal endothelial cell function in vitro. • MEG3 regulates endothelial cell function through PI3k/Akt signaling.

Prediabetes as a toxic environment for the initiation of microvascular and macrovascular complications

Science.gov (United States)

Brannick, Ben; Wynn, Anne

2016-01-01

Prediabetes is a state characterized by impaired fasting glucose or impaired glucose tolerance. Evidence is increasingly demonstrating that prediabetes is a toxic state, in addition to being a harbinger of future development of diabetes mellitus. This minireview discusses the pathophysiology and clinical significance of prediabetes, and approach to its management, in the context of the worldwide diabetes epidemic. The pathophysiologic defects underlying prediabetes include insulin resistance, β cell dysfunction, increased lipolysis, inflammation, suboptimal incretin effect, and possibly hepatic glucose overproduction. Recent studies have revealed that the long-term complications of diabetes may manifest in some people with prediabetes; these complications include classical microvascular and macrovascular disorders, and our discussion explores the role of glycemia in their development. Finally, landmark intervention studies in prediabetes, including lifestyle modification and pharmacologic treatment, are reviewed. PMID:27302176

Design, manufacture and in-vitro evaluation of a new microvascular anastomotic device.

Science.gov (United States)

Huang, Shao-Fu; Wang, Tien-Hsiang; Wang, Hsuan-Wen; Huang, Shu-Wei; Lin, Chun-Li; Kuo, Hsien-Nan; Yu, Tsung-Chih

2013-01-01

Many microvascular anastomoses have been proposed for use with physical assisted methods, such as cuff, ring-pin, stapler, clip to the anastomose blood vessel. The ring-pin type anastomotic device (e.g., 3M Microvascular Anastomotic System) is the most commonly used worldwide because the anastomotic procedure can be conducted more rapidly and with fewer traumas than using sutures. However, problems including vessel leakage, ring slippage, high cost and high surgical skill demand need to be resolved. The aim of this study is to design and manufacture a new anastomotic device for microvascular anastomosis surgery and validate the device functions with in-vitro testing. The new device includes one pair of pinned rings and a set of semi-automatic flap apparatus designed and made using computer-aided design / computer-aided manufacture program. A pair of pinned rings was used to impale vessel walls and establish fluid communication with rings joined. The semi-automatic flap apparatus was used to assist the surgeon to invert the vessel walls and impale onto each ring pin, then turning the apparatus knob to bring the rings together. The device was revised until it became acceptable for clinical requires. An in-vitro test was performed using a custom-made seepage micro-fluid system to detect the leakage of the anastomotic rings. The variation between input and output flow for microvascular anastomoses was evaluated. The new microvascular anastomotic device was convenient and easy to use. It requires less time than sutures to invert and impale vessel walls onto the pinned rings using the semi-automatic flap apparatus. The in-vitro test data showed that there were no tears from the joined rings seam during the procedures. The new anastomotic devices are effective even with some limitations still remaining. This device can be helpful to simplify the anastomosis procedure and reduce the surgery time.

Dual energy spectral CT imaging for the evaluation of small hepatocellular carcinoma microvascular invasion.

Science.gov (United States)

Yang, Chuang-Bo; Zhang, Shuang; Jia, Yong-Jun; Yu, Yong; Duan, Hai-Feng; Zhang, Xi-Rong; Ma, Guang-Ming; Ren, Chenglong; Yu, Nan

2017-10-01

To study the clinical value of dual-energy spectral CT in the quantitative assessment of microvascular invasion of small hepatocellular carcinoma. This study was approved by our ethics committee. 50 patients with small hepatocellular carcinoma who underwent contrast enhanced spectral CT in arterial phase (AP) and portal venous phase (VP) were enrolled. Tumour CT value and iodine concentration (IC) were measured from spectral CT images. The slope of spectral curve, normalized iodine concentration (NIC, to abdominal aorta) and ratio of IC difference between AP and VP (RIC AP-VP : [RIC AP-VP =(IC AP -IC VP )/IC AP ]) were calculated. Tumours were identified as either with or without microvascular invasion based on pathological results. Measurements were statistically compared using independent samples t test. The receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of tumours microvascular invasion assessment. The 70keV images were used to simulate the results of conventional CT scans for comparison. 56 small hepatocellular carcinomas were detected with 37 lesions (Group A) with microvascular invasion and 19 (Group B) without. There were significant differences in IC, NIC and slope in AP and RIC AP-VP between Group A (2.48±0.70mg/ml, 0.23±0.05, 3.39±1.01 and 0.28±0.16) and Group B (1.65±0.47mg/ml, 0.15±0.05, 2.22±0.64 and 0.03±0.24) (all phepatocellular carcinoma with and without microvascular invasion. Quantitative iodine concentration measurement in spectral CT may be used to provide a new method to improve the evaluation for small hepatocellular carcinoma microvascular invasion. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhaled nitric oxide pretreatment but not posttreatment attenuates ischemia-reperfusion-induced pulmonary microvascular leak.

Science.gov (United States)

Chetham, P M; Sefton, W D; Bridges, J P; Stevens, T; McMurtry, I F

1997-04-01

Ischemia-reperfusion (I/R) pulmonary edema probably reflects a leukocyte-dependent, oxidant-mediated mechanism. Nitric oxide (NO) attenuates leukocyte-endothelial cell interactions and I/R-induced microvascular leak. Cyclic adenosine monophosphate (cAMP) agonists reverse and prevent I/R-induced microvascular leak, but reversal by inhaled NO (INO) has not been tested. In addition, the role of soluble guanylyl cyclase (sGC) activation in the NO protection effect is unknown. Rat lungs perfused with salt solution were grouped as either I/R, I/R with INO (10 or 50 ppm) on reperfusion, or time control. Capillary filtration coefficients (Kfc) were estimated 25 min before ischemia (baseline) and after 30 and 75 min of reperfusion. Perfusate cell counts and lung homogenate myeloperoxidase activity were determined in selected groups. Additional groups were treated with either INO (50 ppm) or isoproterenol (ISO-10 microM) after 30 min of reperfusion. Guanylyl cyclase was inhibited with 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ-15 microM), and Kfc was estimated at baseline and after 30 min of reperfusion. (1) Inhaled NO attenuated I/R-induced increases in Kfc. (2) Cell counts were similar at baseline. After 75 min of reperfusion, lung neutrophil retention (myeloperoxidase activity) and decreased perfusate neutrophil counts were similar in all groups. (3) In contrast to ISO, INO did not reverse microvascular leak. (4) 8-bromoguanosine 3',5'-cyclic monophosphate (8-br-cGMP) prevented I/R-induced microvascular leak in ODQ-treated lungs, but INO was no longer effective. Inhaled NO attenuates I/R-induced pulmonary microvascular leak, which requires sGC activation and may involve a mechanism independent of inhibition of leukocyte-endothelial cell interactions. In addition, INO is ineffective in reversing I/R-induced microvascular leak.

In vitro analysis of human periodontal microvascular endothelial cells.

Science.gov (United States)

Tsubokawa, Mizuki; Sato, Soh

2014-08-01

Endothelial cells (ECs) participate in key aspects of vascular biology, such as maintenance of capillary permeability, initiation of coagulation, and regulation of inflammation. According to previous reports, ECs have revealed highly specific characteristics depending on the organs and tissues. However, some reports have described the characteristics of the capillaries formed by human periodontal ECs. Therefore, the aim of the present study is to examine the functional characteristics of the periodontal microvascular ECs in vitro. Human periodontal ligament-endothelial cells (HPDL-ECs) and human gingiva-endothelial cells (HG-ECs) were isolated by immunoprecipitation with magnetic beads conjugated to a monoclonal anti-CD31 antibody. The isolated HPDL-ECs and HG-ECs were characterized to definitively demonstrate that these cell cultures represented pure ECs. Human umbilical-vein ECs and human dermal microvascular ECs were used for comparison. These cells were compared according to the proliferation potential, the formation of capillary-like tubes, the transendothelial electric resistance (TEER), and the expression of tight junction proteins. HPDL-ECs and HG-ECs with characteristic cobblestone monolayer morphology were obtained, as determined by light microscopy at confluence. Furthermore, the HPDL-ECs and HG-ECs expressed the EC markers platelet endothelial cell adhesion molecule-1 (also known as CD31), von Willebrand factor, and Ulex europaeus agglutinin 1, and the cells stained strongly positive for CD31 and CD309. In addition, the HPDL-ECs and HG-ECs were observed to form capillary-like tubes, and they demonstrated uptake of acetylated low-density lipoprotein. Functional analyses of the HPDL-ECs and HG-ECs showed that, compared to the control cells, tube formation persisted for only a brief period of time, and TEER was substantially reduced at confluence. Furthermore, the cells exhibited delocalization of zonula occludens-1 and occludin at cell-cell contact sites

Effect of the glucagon-like peptide-1 analogue liraglutide on coronary microvascular function in patients with type 2 diabetes – a randomized, single-blinded, cross-over pilot study

DEFF Research Database (Denmark)

Faber, Rebekka; Zander, Mette; Pena, Adam

2015-01-01

dipyridamole induced stress. Peripheral microvascular endothelial function was assessed by Endo-PAT2000®. Interventions were compared by two-sample t-test after ensuring no carry over effect. RESULTS: A total of 24 patients were included. Twenty patients completed the study (15 male; mean age 57 ± 9; mean BMI...

Early microvascular changes in the preterm neonate: a comparative study of the human and guinea pig.

Science.gov (United States)

Dyson, Rebecca M; Palliser, Hannah K; Lakkundi, Anil; de Waal, Koert; Latter, Joanna L; Clifton, Vicki L; Wright, Ian M R

2014-09-17

Dysfunction of the transition from fetal to neonatal circulatory systems may be a major contributor to poor outcome following preterm birth. Evidence exists in the human for both a period of low flow between 5 and 11 h and a later period of increased flow, suggesting a hypoperfusion-reperfusion cycle over the first 24 h following birth. Little is known about the regulation of peripheral blood flow during this time. The aim of this study was to conduct a comparative study between the human and guinea pig to characterize peripheral microvascular behavior during circulatory transition. Very preterm (≤28 weeks GA), preterm (29-36 weeks GA), and term (≥37 weeks GA) human neonates underwent laser Doppler analysis of skin microvascular blood flow at 6 and 24 h from birth. Guinea pig neonates were delivered prematurely (62 day GA) or at term (68-71 day GA) and laser Doppler analysis of skin microvascular blood flow was assessed every 2 h from birth. In human preterm neonates, there is a period of high microvascular flow at 24 h after birth. No period of low flow was observed at 6 h. In preterm animals, microvascular flow increased after birth, reaching a peak at 10 h postnatal age. Blood flow then steadily decreased, returning to delivery levels by 24 h. Preterm birth was associated with higher baseline microvascular flow throughout the study period in both human and guinea pig neonates. The findings do not support a hypoperfusion-reperfusion cycle in the microcirculation during circulatory transition. The guinea pig model of preterm birth will allow further investigation of the mechanisms underlying microvascular function and dysfunction during the initial extrauterine period. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Sleep quality and duration are related to microvascular function: the Amsterdam Growth and Health Longitudinal Study

NARCIS (Netherlands)

Bonsen, T.; Wijnstok, N.J.; Hoekstra, T.; Eringa, E.C.; Serne, E.H.; Smulders, Y.M.; Twisk, J.W.R.

2015-01-01

Sleep and sleep disorders are related to cardiovascular disease, and microvascular function is an early cardiovascular disease marker. Therefore, the relationship of sleep (measured in sleep quality and duration) with microvascular function was examined in healthy adults. Sleep quality was assessed

Uptake of Single-Walled Carbon Nanotubes Conjugated with DNA by Microvascular Endothelial Cells

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Joseph Harvey

2012-01-01

Full Text Available Single-walled carbon nanotubes (SWCNTs have been proposed to have great therapeutic potential. SWCNTs conjugated with drugs or genes travel in the systemic circulation to reach target cells or tissues following extravasation from microvessels although the interaction between SWCNT conjugates and the microvascular endothelial cells (ECs remains unknown. We hypothesized that SWCNT-DNA conjugates would be taken up by microvascular ECs and that this process would be facilitated by SWCNTs compared to facilitation by DNA alone. ECs were treated with various concentrations of SWCNT-DNA-FITC conjugates, and the uptake and intracellular distribution of these conjugates were determined by a confocal microscope imaging system followed by quantitative analysis of fluorescence intensity. The uptake of SWCNT-DNA-FITC conjugates (2 μg/mL by microvascular ECs was significantly greater than that of DNA-FITC (2 μg/mL, observed at 6 hrs after treatment. For the intracellular distribution, SWCNT-DNA-FITC conjugates were detected in the nucleus of ECs, while DNA-FITC was restricted to the cytoplasm. The fluorescence intensity and distribution of SWCNTs were concentration and time independent. The findings demonstrate that SWCNTs facilitate DNA delivery into microvascular ECs, thus suggesting that SWCNTs serving as drug and gene vehicles have therapeutic potential.

Microvascular filtration is increased in the forearms of patients with breast cancer-related lymphedema

DEFF Research Database (Denmark)

Jensen, Mads Radmer; Simonsen, Lene; Karlsmark, Tonny

2013-01-01

-enhanced ultrasound; venous occlusion strain-gauge plethysmography; lower-body negative pressure; noninvasive blood pressure measurements; and skin (99m)Tc-pertechnetate clearance technique. Measurements were performed bilaterally and simultaneously in the forearms, enabling use of the nonedematous forearm...... relative microvascular volume, forearm blood flow, skin blood flow, or central or local sympathetic vascular reflexes. Forearm microvascular filtration is increased in patients with BCRL, and more so in the edematous arm. The vascular sympathetic control mechanisms seem to be preserved. We propose...... with unilateral BCRL, the following aspects of upper extremity peripheral circulation were examined: muscle relative microvascular volume; capillary filtration coefficient; central and local sympathetic vascular reflexes; skin blood flow; and forearm blood flow. These were studied via real-time, contrast...

Inhalation exposure to three-dimensional printer emissions stimulates acute hypertension and microvascular dysfunction.

Science.gov (United States)

Stefaniak, A B; LeBouf, R F; Duling, M G; Yi, J; Abukabda, A B; McBride, C R; Nurkiewicz, T R

2017-11-15

Fused deposition modeling (FDM™), or three-dimensional (3D) printing has become routine in industrial, occupational and domestic environments. We have recently reported that 3D printing emissions (3DPE) are complex mixtures, with a large ultrafine particulate matter component. Additionally, we and others have reported that inhalation of xenobiotic particles in this size range is associated with an array of cardiovascular dysfunctions. Sprague-Dawley rats were exposed to 3DPE aerosols via nose-only exposure for ~3h. Twenty-four hours later, intravital microscopy was performed to assess microvascular function in the spinotrapezius muscle. Endothelium-dependent and -independent arteriolar dilation were stimulated by local microiontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP). At the time of experiments, animals exposed to 3DPE inhalation presented with a mean arterial pressure of 125±4mmHg, and this was significantly higher than that for the sham-control group (94±3mmHg). Consistent with this pressor response in the 3DPE group, was an elevation of ~12% in resting arteriolar tone. Endothelium-dependent arteriolar dilation was significantly impaired after 3DPE inhalation across all iontophoretic ejection currents (0-27±15%, compared to sham-control: 15-120±21%). Endothelium-independent dilation was not affected by 3DPE inhalation. These alterations in peripheral microvascular resistance and reactivity are consistent with elevations in arterial pressure that follow 3DPE inhalation. Future studies must identify the specific toxicants generated by FDM™ that drive this acute pressor response. Copyright © 2017 Elsevier Inc. All rights reserved.

Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease

NARCIS (Netherlands)

P.W.J.C. Serruys (Patrick); M-C. Morice (Marie-Claude); A.P. Kappetein (Arie Pieter); A. Colombo (Antonio); D.R. Holmes Jr (David); M.J. Mack (Michael); E. Stahle (Elisabeth); T.E. Feldman (Ted); M.J.B.M. van den Brand (Marcel); E.J. Bass (Eric); N. van Dyck (Nic); K. Leadly (Katrin); K.D. Dawkins (Keith); F.W. Mohr (Friedrich)

2009-01-01

textabstractBACKGROUND Percutaneous coronary intervention (PCI) involving drug-eluting stents is increasingly used to treat complex coronary artery disease, although coronary-artery bypass grafting (CABG) has been the treatment of choice historically. Our trial compared PCI and CABG for treating

Insulin resistance and exercise tolerance in heart failure patients

DEFF Research Database (Denmark)

Snoer, Martin; Monk-Hansen, Tea; Olsen, Rasmus Huan

2012-01-01

Insulin resistance has been linked to exercise intolerance in heart failure patients. The aim of this study was to assess the potential role of coronary flow reserve (CFR), endothelial function and arterial stiffness in explaining this linkage.......Insulin resistance has been linked to exercise intolerance in heart failure patients. The aim of this study was to assess the potential role of coronary flow reserve (CFR), endothelial function and arterial stiffness in explaining this linkage....

Microvascularization on collared peccary placenta

DEFF Research Database (Denmark)

Santos, Tatiana Carlesso; Oliveira, Moacir Franco; Dantzer, Vibeke

2012-01-01

and fetal compartments of the placentae. The immunolocalization of vimentin in the vascular endothelium and in the smooth muscle cells of blood vessels showed indented capillaries along the uterine epithelium and the trophoblast at the sides of complementary maternal and fetal microfolds, or rugae...... into a microvascular network wall in a basket-like fashion. At the base of these baskets venules were formed. On the fetal side, arterioles branched centrally in the fetal rugae into a capillary network in a bulbous form, complementary to the opposite maternal depressions forming the baskets. At the base...

CT coronary angiography vs. invasive coronary angiography in CHD

Directory of Open Access Journals (Sweden)

Anja Hagen

2012-04-01

Full Text Available Scientific background: Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT coronary angiography are used in the diagnosis of coronary heart disease (CHD. Research questions: The present report aims to evaluate the clinical efficacy, diagnostic accuracy, prognostic value cost-effectiveness as well as the ethical, social and legal implications of CT coronary angiography versus invasive coronary angiography in the diagnosis of CHD. Methods: A systematic literature search was conducted in electronic data bases (MEDLINE, EMBASE etc. in October 2010 and was completed with a manual search. The literature search was restricted to articles published from 2006 in German or English. Two independent reviewers were involved in the selection of the relevant publications. The medical evaluation was based on systematic reviews of diagnostic studies with invasive coronary angiography as the reference standard and on diagnostic studies with intracoronary pressure measurement as the reference standard. Study results were combined in a meta-analysis with 95 % confidence intervals (CI. Additionally, data on radiation doses from current non-systematic reviews were taken into account. A health economic evaluation was performed by modelling from the social perspective with clinical assumptions derived from the meta-analysis and economic assumptions derived from contemporary German sources. Data on special indications (bypass or in-stent-restenosis were not included in the evaluation. Only data obtained using CT scanners with at least 64 slices were considered. Results: No studies were found regarding the clinical efficacy or prognostic value of CT coronary angiography versus conventional invasive coronary angiography in the diagnosis of CHD. Overall, 15 systematic reviews with data from 44 diagnostic studies using invasive coronary angiography as the reference standard (identification of obstructive

Prediabetes as a toxic environment for the initiation of microvascular and macrovascular complications.

Science.gov (United States)

Brannick, Ben; Wynn, Anne; Dagogo-Jack, Samuel

2016-06-01

Prediabetes is a state characterized by impaired fasting glucose or impaired glucose tolerance. Evidence is increasingly demonstrating that prediabetes is a toxic state, in addition to being a harbinger of future development of diabetes mellitus. This minireview discusses the pathophysiology and clinical significance of prediabetes, and approach to its management, in the context of the worldwide diabetes epidemic. The pathophysiologic defects underlying prediabetes include insulin resistance, β cell dysfunction, increased lipolysis, inflammation, suboptimal incretin effect, and possibly hepatic glucose overproduction. Recent studies have revealed that the long-term complications of diabetes may manifest in some people with prediabetes; these complications include classical microvascular and macrovascular disorders, and our discussion explores the role of glycemia in their development. Finally, landmark intervention studies in prediabetes, including lifestyle modification and pharmacologic treatment, are reviewed. © 2016 by the Society for Experimental Biology and Medicine.

Microvascular Architecture of Hepatic Metastases in a Mouse Model

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Darshini Kuruppu

1997-01-01

Full Text Available Development of effective treatment for hepatic metastases can be initiated by a better understanding of tumour vasculature and blood supply. This study was designed to characterise the microvascular architecture of hepatic metastases and observe the source of contributory blood supply from the host. Metastases were induced in mice by an intrasplenic injection of colon carcinoma cells (106 cells/ml. Vascularization of tumours was studied over a three week period by scanning electron microscopy of microvascular corrosion casts. Metastatic liver involvement was observed initially within a week post induction, as areas approximately 100 μm in diameter not perfused by the casting resin. On histology these spaces corresponded to tumour cell aggregates. The following weeks highlighted the angiogenesis phase of these tumours as they received a vascular supply from adjacent hepatic sinusoids. Direct sinusoidal supply of metastases was maintained throughout tumour growth. At the tumour periphery most sinusoids were compressed to form a sheath demarcating the tumour from the hepatic vasculature. No direct supply from the hepatic artery or the portal vein was observed. Dilated vessels termed vascular lakes dominated the complex microvascular architecture of the tumours, most tapering as they traversed towards the periphery. Four vascular branching patterns could be identified as true loops, bifurcations and trifurcations, spirals and capillary networks. The most significant observation in this study was the direct sinusoidal supply of metastases, together with the vascular lakes and the peripheral sinusoidal sheaths of the tumour microculature.

Left coronary aneurysmal dilation and subaortic stenosis in a dog.

Science.gov (United States)

Hernandez, Juan L; Bélanger, Marie-Claude; Benoit-Biancamano, Marie-Odile; Girard, Christiane; Pibarot, Philippe

2008-06-01

A 6-month-old German shepherd dog was referred for evaluation of a cardiac murmur. Upon physical examination, the auscultated heart rate was 120 beats/min, and a grade IV/VI systolic heart murmur with a point of maximal intensity over the left heart base radiating up the neck was heard. The standard echocardiographic examination showed subaortic stenosis and an anechoic tubular structure extending from the sinus of Valsalva to the left ventricular posterior wall. Aneurysmal left coronary artery (CA) was confirmed by angiography. The dog was euthanized and post-mortem examination showed severe dilatation of the proximal left CA and confirmed the subaortic stenosis. Histopathology did not demonstrate abnormalities in the walls of the CA, aorta or pulmonary artery. The exact cause of the CA aneurysmal dilation remains unknown. Subaortic stenosis, elevated coronary vascular resistance or a congenital anomaly may have contributed to the dilation. To our knowledge, coronary aneurysmal dilation has never been described in dogs. Standard echocardiography provides reliable information on coronary anatomy.

Role of coronary endothelium in cyclic AMP formation by the heart

International Nuclear Information System (INIS)

Kroll, K.; Schrader, J.

1986-01-01

In order to quantify the activation of adenylate cyclase of the coronary endothelium in vivo, endothelial adenine nucleotides of isolated guinea pig hearts were selectively pre-labeled by intracoronary infusion of tritiated (H3)-adenosine, and the coronary efflux of H3-cAMP was measured. The adenosine receptor agonist, NECA (12 μM), increased total cAMP release 4 fold, and raised H3-cAMP release 22 fold. Several classes of coronary vasodilators (adenosine, L-PIA, D-PIA, the beta 2-adrenergic agonist procaterol, and PGE1) caused dose-dependent increases in endothelial-derived H3-cAMP release. These increases were accompanied by decreases in vascular resistance, at agonist doses without positive intropic effects. Hypoxic perfusion also raised H3-cAMP release, and this was antagonized by theophylline. It is concluded: (1) cyclic AMP formation by coronary endothelium can dominate total cAMP production by the heart; (2) coronary endothelial adenylate cyclase-coupled receptors for adenosine (A2), catecholamines (beta2) and prostaglandins are activated in parallel with coronary vasodilation; (3) endothelial adenylate cyclase can be activated by endogenous adenosine

Body mass index is associated with microvascular endothelial dysfunction in patients with treated metabolic risk factors and suspected coronary artery disease

NARCIS (Netherlands)

D.J. Van Der Heijden (Dirk J.); M.A.H. van Leeuwen (Maarten); G.N. Janssens (Gladys N.); M.J. Lenzen (Mattie); P.M. van de Ven (Peter); E.C. Eringa (Etto ); N. van Royen (Niels)

2017-01-01

textabstractBackground--Obesity is key feature of the metabolic syndrome and is associated with high cardiovascular morbidity and mortality. Obesity is associated with macrovascular endothelial dysfunction, a determinant of outcome in patients with coronary artery disease. Here, we compared the

Conflicting interactions of apolipoprotein A and high density lipoprotein cholesterol with microvascular complications of type 2 diabetes.

Science.gov (United States)

Aryan, Zahra; Afarideh, Mohsen; Ghajar, Alireza; Esteghamati, Sadaf; Esteghamati, Alireza; Nakhjavani, Manouchehr

2017-11-01

This study is amid at investigating the associations, and interactions of serum lipid biomarkers with microvascular complications of type 2 diabetes (T2D). A nested case-control study was conducted within an ongoing prospective study on patients with T2D. Microvascular complications of T2D including diabetic neuropathy, diabetic retinopathy and diabetic nephropathy were investigated. A total of 444 cases with at least one of the microvascular complications of T2D and 439 age- and gender-matched controls free of any of the chronic microvascular complications of T2D were included. The associations and interactions of a panel of serum lipid biomarkers with the microvascular complications of T2D were investigated. Serum triglyceride had the strongest association with microvascular complications of T2D (crude model: β=0.632, P value=0.045). Each standard deviation increment in serum TG was associated with 3.7 times increased frequency of microvascular complications. Despite high density lipoprotein cholesterol (HDL-C), serum apolipoprotein A1 (Apo A1) was positively associated with the presence of diabetic neuropathy. Each standard deviation increment in serum ApoA1 was associated with increased frequency of diabetic neuropathy (OR, 1.2, 95% CI, (1.1-1.3), P value=0.006). The frequency of diabetic neuropathy was higher in 2nd and 3rd quartiles of serum Lp(a) compared to diabetic patients in the first quartile (OR, 5.52, 95% (1.17-25.8), P value=0.047). ApoA1 but not HDL-C is straightly associated with diabetic neuropathy. Even Slight rise in serum Lp(a) is associated with increased frequency of diabetic retinopathLipid variables could serve as specific predictors of vascular complications in diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

Upregulation of SK3 and IK1 channels contributes to the enhanced endothelial calcium signaling and the preserved coronary relaxation in obese Zucker rats.

Directory of Open Access Journals (Sweden)

Belén Climent

Full Text Available Endothelial small- and intermediate-conductance KCa channels, SK3 and IK1, are key mediators in the endothelium-derived hyperpolarization and relaxation of vascular smooth muscle and also in the modulation of endothelial Ca2+ signaling and nitric oxide (NO release. Obesity is associated with endothelial dysfunction and impaired relaxation, although how obesity influences endothelial SK3/IK1 function is unclear. Therefore we assessed whether the role of these channels in the coronary circulation is altered in obese animals.In coronary arteries mounted in microvascular myographs, selective blockade of SK3/IK1 channels unmasked an increased contribution of these channels to the ACh- and to the exogenous NO- induced relaxations in arteries of Obese Zucker Rats (OZR compared to Lean Zucker Rats (LZR. Relaxant responses induced by the SK3/IK1 channel activator NS309 were enhanced in OZR and NO- endothelium-dependent in LZR, whereas an additional endothelium-independent relaxant component was found in OZR. Fura2-AM fluorescence revealed a larger ACh-induced intracellular Ca2+ mobilization in the endothelium of coronary arteries from OZR, which was inhibited by blockade of SK3/IK1 channels in both LZR and OZR. Western blot analysis showed an increased expression of SK3/IK1 channels in coronary arteries of OZR and immunohistochemistry suggested that it takes place predominantly in the endothelial layer.Obesity may induce activation of adaptive vascular mechanisms to preserve the dilator function in coronary arteries. Increased function and expression of SK3/IK1 channels by influencing endothelial Ca2+ dynamics might contribute to the unaltered endothelium-dependent coronary relaxation in the early stages of obesity.

Integral diagnosis of coronary atherosclerosis by coronary multidetector computed tomography and by invasive coronary angiography

International Nuclear Information System (INIS)

Llerena Rojas, Luis Roberto; Llerena Rojas, Lorenzo D; Mendoza Rodriguez, Vladimir

2013-01-01

Coronary angiography by multidetector computed tomography (CMDCT) visualizes the wall and lumen of coronary arteries. Invasive coronary angiography (INVCA) only visualizes the arterial lumen but with better resolution

Adipose tissue-derived microvascular fragments from aged donors exhibit an impaired vascularisation capacity

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MW Laschke

2014-10-01

Full Text Available Adipose tissue-derived microvascular fragments are promising vascularisation units for applications in the field of tissue engineering. Elderly patients are the major future target population of such applications due to an increasing human life expectancy. Therefore, we herein investigated the effect of aging on the fragments’ vascularisation capacity. Microvascular fragments were isolated from epididymal fat pads of adult (8 months and aged (16 months C57BL/6 donor mice. These fragments were seeded onto porous polyurethane scaffolds, which were implanted into dorsal skinfold chambers to study their vascularisation using intravital fluorescence microscopy, histology and immunohistochemistry. Scaffolds seeded with fragments from aged donors exhibited a significantly lower functional microvessel density and intravascular blood flow velocity. This was associated with an impaired vessel maturation, as indicated by vessel wall irregularities, constantly elevated diameters and a lower fraction of CD31/α-smooth muscle actin double positive microvessels in the implants’ border and centre zones. Additional in vitro analyses revealed that microvascular fragments from adult and aged donors do not differ in their stem cell content as well as in their release of angiogenic growth factors, survival and proliferative activity under hypoxic conditions. However, fragments from aged donors exhibit a significantly lower number of matrix metalloproteinase -9-positive perivascular cells. Taken together, these findings demonstrate that aging is a crucial determinant for the vascularisation capacity of isolated microvascular fragments.

Three-dimensional dynamic contrast-enhanced MRI for the accurate, extensive quantification of microvascular permeability in atherosclerotic plaques

NARCIS (Netherlands)

Calcagno, Claudia; Lobatto, Mark E.; Dyvorne, Hadrien; Robson, Philip M.; Millon, Antoine; Senders, Max L.; Lairez, Olivier; Ramachandran, Sarayu; Coolen, Bram F.; Black, Alexandra; Mulder, Willem J. M.; Fayad, Zahi A.

2015-01-01

Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI

Coronary microvascular dysfunction is not associated with a history of reproductive risk factors in women with angina pectoris-An iPOWER substudy

DEFF Research Database (Denmark)

Suhrs, Hannah Elena; Kristensen, Anna Meta; Rask, Anna Bay

2018-01-01

factors was associated with CMD in women with angina pectoris and no obstructive coronary artery disease (CAD). METHODS: Participants from the iPOWER study, including women with angina pectoris and no obstructive CAD (

The significance of adiponectin as a biomarker in metabolic syndrome and/or coronary artery disease.

Science.gov (United States)

Stojanović, Sanja; Ilić, Marina Deijanin; Ilić, Stevan; Petrović, Dejan; Djukić, Svetlana

2015-09-01

BACKGROUND/AIM. Adiponectin exerts profound protective actions during insulin resistence or prediabetes progression towards more severe clinical entities such as metabolic syndrome and/or cardiovascular disease. Since hypoadiponectinaemia contributes to the pathophysiology of the metabolic syndrome and coronary artery disease the level of circulating adiponectin may be an early marker of cardiovascular events. The aim of this study was to determine the relationships between serum adiponectin levels and parameters of both insulin sensitivity and obesity in patients with the metabolic syndrome and/or coronary artery disease, as well as to assess predictive value of adiponectin serum levels as a biomarker of these entitetis. The study included 100 patients with metabolic syndrome and/or coronary artery disease with different degree of insulin resistance and healthy, normoglycemic individuals. The control group comprising healthy, normoglycemic individuals was used for comparison. Serum level of adiponectin, fasting glucose, fasting insulinemia Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) index and anthropometric parameters were determined in all the subjects. Adiponectin was measured by using the ultrasensitive ELISA method. Insulinemia was measured by the radioimmunoassay (RIA) method. The presence of glycemic disorders was assessed on the basis of oral glucose tolerance test (OGTT). Results. Adiponectin level was inversely correlated with age (ρ = -0.015), parameters of both obesity (R = 0.437;p insulin resistance (R = 0.374; p insulin resistance. Most importantly, a statistically significant rapid decrease ih adiponectin was in the prediabetic stages (p < 0.01). The predictor value of adiponectin was 1,356.32 ± 402.65 pg/mL. The obtained resultats suggest that adiponectin may be a useful marker in identification of individuals with risk of developing metabolic syndrome and coronary artery disease, as well as a predictor of prediabetes.

The significance of adiponectin as a biomarker in metabolic syndrome and/or coronary artery disease

Directory of Open Access Journals (Sweden)

Stojanović Sanja

2015-01-01

Full Text Available Introduction/Aim. Adiponectin exerts profound protective actions during insulin resistence or prediabetes progression towards more severe clinical entities such as metabolic syndrome and/or cardiovascular disease. Since hypoadiponectinaemia contributes to the pathophysiology of the metabolic syndrome and coronary artery disease the level of circulating adiponectin may be an early marker of cardiovascular events. The aim of this study was to determine the relationships between serum adiponectin levels and parameters of both insulin sensitivity and obesity in patients with the metabolic syndrome and/or coronary artery disease, as well as to assess predictive value of adiponectin serum levels as a biomarker of these entitetis. Methods. The study included 100 patients with metabolic syndrome and/or coronary artery disease with different degree of insulin resistance and healthy, normoglycemic individuals. The control group comprising healthy, normoglycemic individuals was used for comparison. Serum level of adiponectin, fasting glucose, fasting insulinemia Homeostasis Model Assessment of Insulin Resistance (HOMAIR index and anthropometric parameters were determined in all the subjects. Adiponectin was measured by using the ultrasensitive ELISA method. Insulinemia was measured by the radioimmunoassay (RIA method. The presence of glycemic disorders was assessed on the basis of oral glucose tolerance test (OGTT. Results. Adiponectin level was inversely correlated with age (ρ = - 0.015, parameters of both obesity (R = 0.437; p < 0.001 and insulin resistance (R = 0.374; p < 0.01. Decreasing in the level of adiponectin was strongly implicated in the development of insulin resistance. Most importantly, a statistically significant rapid decrease in adiponectin was in the prediabetic stages (p < 0.01. The predictor value of adiponectin was 1,356.32 ± 402.65 рg/mL. Conclusions. The obtained resultats suggest that adiponectin may be a useful marker in

Transcranial diffuse optical monitoring of microvascular cerebral hemodynamics after thrombolysis in ischemic stroke

Science.gov (United States)

Zirak, Peyman; Delgado-Mederos, Raquel; Dinia, Lavinia; Carrera, David; Martí-Fàbregas, Joan; Durduran, Turgut

2014-01-01

The ultimate goal of therapeutic strategies for ischemic stroke is to reestablish the blood flow to the ischemic region of the brain. However, currently, the local cerebral hemodynamics (microvascular) is almost entirely inaccessible for stroke clinicians at the patient bed-side, and the recanalization of the major cerebral arteries (macrovascular) is the only available measure to evaluate the therapy, which does not always reflect the local conditions. Here we report the case of an ischemic stroke patient whose microvascular cerebral blood flow and oxygenation were monitored by a compact hybrid diffuse optical monitor during thrombolytic therapy. This monitor combined diffuse correlation spectroscopy and near-infrared spectroscopy. The reperfusion assessed by hybrid diffuse optics temporally correlated with the recanalization of the middle cerebral artery (assessed by transcranial-Doppler) and was in agreement with the patient outcome. This study suggests that upon further investigation, diffuse optics might have a potential for bed-side acute stroke monitoring and therapy guidance by providing hemodynamics information at the microvascular level.

Microvascular anastomosis simulation using a chicken thigh model: Interval versus massed training.

Science.gov (United States)

Schoeff, Stephen; Hernandez, Brian; Robinson, Derek J; Jameson, Mark J; Shonka, David C

2017-11-01

To compare the effectiveness of massed versus interval training when teaching otolaryngology residents microvascular suturing on a validated microsurgical model. Otolaryngology residents were placed into interval (n = 7) or massed (n = 7) training groups. The interval group performed three separate 30-minute practice sessions separated by at least 1 week, and the massed group performed a single 90-minute practice session. Both groups viewed a video demonstration and recorded a pretest prior to the first training session. A post-test was administered following the last practice session. At an academic medical center, 14 otolaryngology residents were assigned using stratified randomization to interval or massed training. Blinded evaluators graded performance using a validated microvascular Objective Structured Assessment of Technical Skill tool. The tool is comprised of two major components: task-specific score (TSS) and global rating scale (GRS). Participants also received pre- and poststudy surveys to compare subjective confidence in multiple aspects of microvascular skill acquisition. Overall, all residents showed increased TSS and GRS on post- versus pretest. After completion of training, the interval group had a statistically significant increase in both TSS and GRS, whereas the massed group's increase was not significant. Residents in both groups reported significantly increased levels of confidence after completion of the study. Self-directed learning using a chicken thigh artery model may benefit microsurgical skills, competence, and confidence for resident surgeons. Interval training results in significant improvement in early development of microvascular anastomosis skills, whereas massed training does not. NA. Laryngoscope, 127:2490-2494, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Pathways for insulin access to the brain: the role of the microvascular endothelial cell.

Science.gov (United States)

Meijer, Rick I; Gray, Sarah M; Aylor, Kevin W; Barrett, Eugene J

2016-11-01

Insulin affects multiple important central nervous system (CNS) functions including memory and appetite, yet the pathway(s) by which insulin reaches brain interstitial fluid (bISF) has not been clarified. Recent studies demonstrate that to reach bISF, subarachnoid cerebrospinal fluid (CSF) courses through the Virchow-Robin space (VRS) which sheaths penetrating pial vessels down to the capillary level. Whether insulin predominantly enters the VRS and bISF by local transport through the blood-brain barrier, or by being secreted into the CSF by the choroid plexus, is unknown. We injected 125 I-TyrA14-insulin or regular insulin intravenously and compared the rates of insulin reaching subarachnoid CSF with its plasma clearance by brain tissue samples (an index of microvascular endothelial cell binding/uptake/transport). The latter process was more than 40-fold more rapid. We then showed that selective insulin receptor blockade or 4 wk of high-fat feeding each inhibited microvascular brain 125 I-TyrA14-insulin clearance. We further confirmed that 125 I-TyrA14-insulin was internalized by brain microvascular endothelial cells, indicating that the in vivo tissue association reflected cellular transport, not simply microvascular tracer binding. Copyright © 2016 the American Physiological Society.

Cardiac Autonomic Function Is Associated With the Coronary Microcirculatory Function in Patients With Type 2 Diabetes

DEFF Research Database (Denmark)

von Scholten, Bernt Johan; Hansen, Christian Stevns; Hasbak, Philip

2016-01-01

Cardiac autonomic dysfunction and cardiac microvascular dysfunction are diabetic complications associated with increased mortality, but the association between these has been difficult to assess. We applied new and sensitive methods to assess this in patients with type 2 diabetes mellitus (T2DM......). In a cross-sectional design, coronary flow reserve (CFR) assessed by cardiac (82)Rb-positron emission tomography/computed tomography, cardiac autonomic reflex tests, and heart rate variability indices were performed in 55 patients with T2DM, without cardiovascular disease, and in 28 control subjects. Cardiac....... A heart rate variability index, reflecting sympathetic and parasympathetic function (low-frequency power), and the late heart-to-mediastinum ratio, reflecting the function of adrenergic receptors and sympathetic activity, were positively correlated with CFR after adjustment for age and heart rate...

VEGF expression and microvascular density in relation to high-risk ...

African Journals Online (AJOL)

Bassma M. El Sabaa

2012-01-13

Jan 13, 2012 ... Eleven cases were low grade and 19 were high-grade cases. VEGF expression .... increasing microvascular permeability,26 degradation of extra- ...... soluble receptors in pre-invasive, invasive and recurrent cervical cancer.

Low Birth Weight as The Risk factor of Coronary Heart Diseases

Directory of Open Access Journals (Sweden)

Joko Wahyu Wibowo

2011-12-01

Full Text Available Low birth weight, a nutritional deficiency is related to the increased in the coronary heart disease insidence. Low birth weight is correlated with the hipotalamus-pituitary-adrenal responsible for the the concentration of cortisol in sirculation, increased in homosistein, insuline resistence and increased C reactive protein playing role on the aterosclerosis process predispose the corronary disease. This paper will discuss the relationship between the low birth weight and the ateroclesoris process leading to coronary heart disesase (Sains Medika, 3(2:185-200.

Impaired myocardial blood flow reserve in subjects with metabolic syndrome analyzed using positron emission tomography and N-13 labeled ammonia

Energy Technology Data Exchange (ETDEWEB)

Teragawa, Hiroki; Kihara, Yasuki [Hiroshima University Graduate School of Biomedical Sciences, Department of Cardiovascular Medicine, Hiroshima (Japan); Morita, Koichi; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Shishido, Hiroki; Otsuka, Nobuaki; Hirokawa, Yutaka [Hiroshima Heiwa Clinic, Hiroshima (Japan); Chayama, Kazuaki [Hiroshima University Graduate School of Biomedical Sciences, Department of Molecular Science and Medicine, Hiroshima (Japan)

2010-02-15

Coronary vasomotor response might be impaired in metabolic syndrome (MS); however, the precise abnormality has not been elucidated. The aim of this study was to assess coronary-vasomotor response in MS subjects using N-13 labeled ammonia and positron emission tomography. Myocardial blood flow (MBF) was measured at rest and during adenosine infusion in MS subjects (n = 13, MS group) with no definite evidence of heart disease and in subjects without MS (n = 14, non-MS group). Coronary vascular resistance (CVR) was calculated by dividing the mean aortic blood pressure by MBF. Myocardial blood flow reserve (MFR) was calculated as the ratio of the MBF during adenosine infusion to that during rest. Blood chemical parameters were measured to evaluate their relationship with MFR. During adenosine infusion, MBF was lower (p = 0.0085) and CVR higher (p = 0.0128) in the MS group than in the non-MS group and MFR was significantly lower in the MS group than in the non-MS group (2.13 {+-} 0.99 vs. 3.38 {+-} 0.95, p = 0.0027). Multivariate analysis demonstrated that the homeostasis model assessment-insulin resistance (p < 0.05) and the presence of hypertension (p < 0.05) were independent determinants of MFR. The results indicate that MFR was impaired in MS subjects, suggesting that an abnormal coronary microvascular response occurred in these subjects. This abnormality may have been partially due to insulin resistance and hypertension. (orig.)

Impaired myocardial blood flow reserve in subjects with metabolic syndrome analyzed using positron emission tomography and N-13 labeled ammonia

International Nuclear Information System (INIS)

Teragawa, Hiroki; Kihara, Yasuki; Morita, Koichi; Tamaki, Nagara; Shishido, Hiroki; Otsuka, Nobuaki; Hirokawa, Yutaka; Chayama, Kazuaki

2010-01-01

Coronary vasomotor response might be impaired in metabolic syndrome (MS); however, the precise abnormality has not been elucidated. The aim of this study was to assess coronary-vasomotor response in MS subjects using N-13 labeled ammonia and positron emission tomography. Myocardial blood flow (MBF) was measured at rest and during adenosine infusion in MS subjects (n = 13, MS group) with no definite evidence of heart disease and in subjects without MS (n = 14, non-MS group). Coronary vascular resistance (CVR) was calculated by dividing the mean aortic blood pressure by MBF. Myocardial blood flow reserve (MFR) was calculated as the ratio of the MBF during adenosine infusion to that during rest. Blood chemical parameters were measured to evaluate their relationship with MFR. During adenosine infusion, MBF was lower (p = 0.0085) and CVR higher (p = 0.0128) in the MS group than in the non-MS group and MFR was significantly lower in the MS group than in the non-MS group (2.13 ± 0.99 vs. 3.38 ± 0.95, p = 0.0027). Multivariate analysis demonstrated that the homeostasis model assessment-insulin resistance (p < 0.05) and the presence of hypertension (p < 0.05) were independent determinants of MFR. The results indicate that MFR was impaired in MS subjects, suggesting that an abnormal coronary microvascular response occurred in these subjects. This abnormality may have been partially due to insulin resistance and hypertension. (orig.)

Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty

NARCIS (Netherlands)

Muinck, Ebo Derk de

1994-01-01

In this thesis several aspects of passive and active coronary perfusion during coronary angioplasty are investigated. The autoperfusion balloon catheters that were evaluated are the Stack® and the RX-60® catheters (Advanced Cardiovascular Systems, inc., Santa Clara, California, U.S.A). The coronary

Acute effects of coffee on skin blood flow and microvascular function.

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Tesselaar, Erik; Nezirevic Dernroth, Dzeneta; Farnebo, Simon

2017-11-01

Studies on the acute effects of coffee on the microcirculation have shown contradicting results. This study aimed to investigate if intake of caffeine-containing coffee changes blood flow and microvascular reactivity in the skin. We measured acute changes in cutaneous vascular conductance (CVC) in the forearm and the tip of the finger, the microvascular response to transdermal iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) and post-occlusive reactive hyperemia (PORH) in the skin, after intake of caffeinated or decaffeinated coffee. Vasodilatation during iontophoresis of ACh was significantly stronger after intake of caffeinated coffee compared to after intake of decaffeinated coffee (1.26±0.20PU/mmHg vs. 1.13±0.38PU/mmHg, Pcoffee. After intake of caffeinated coffee, a more pronounced decrease in CVC in the fingertip was observed compared to after intake of decaffeinated coffee (-1.36PU/mmHg vs. -0.52PU/mmHg, P=0.002). Caffeine, as ingested by drinking caffeinated coffee acutely improves endothelium-dependent microvascular responses in the forearm skin, while endothelium-independent responses to PORH and SNP iontophoresis are not affected. Blood flow in the fingertip decreases markedly during the first hour after drinking caffeinated coffee compared to decaffeinated coffee. Copyright © 2017 Elsevier Inc. All rights reserved.

Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach.

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Panazzolo, Diogo G; Sicuro, Fernando L; Clapauch, Ruth; Maranhão, Priscila A; Bouskela, Eliete; Kraemer-Aguiar, Luiz G

2012-11-13

We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Data from 189 female subjects (34.0 ± 15.5 years, 30.5 ± 7.1 kg/m2), who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA). PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI), waist circumference, systolic and diastolic blood pressure (BP), fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), insulin, C-reactive protein (CRP), and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV) at rest and peak after 1 min of arterial occlusion (RBCV(max)), and the time taken to reach RBCV(max) (TRBCV(max)). A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCV(max) varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCV(max), but in the opposite way. Principal component 3 was associated only with microvascular

Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach

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Panazzolo Diogo G

2012-11-01

Full Text Available Abstract Background We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Methods Data from 189 female subjects (34.0±15.5 years, 30.5±7.1 kg/m2, who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA. PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI, waist circumference, systolic and diastolic blood pressure (BP, fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c, low-density lipoprotein cholesterol (LDL-c, triglycerides (TG, insulin, C-reactive protein (CRP, and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV at rest and peak after 1 min of arterial occlusion (RBCVmax, and the time taken to reach RBCVmax (TRBCVmax. Results A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCVmax varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCVmax, but in the opposite way. Principal component 3 was

Nitric oxide synthase gene G298 allele

International Nuclear Information System (INIS)

Nagib El-Kilany, Galal E.; Nayel, Ehab; Hazzaa, Sahar

2004-01-01

Background: Nitric oxide (NO) has an important effect on blood pressure, arterial wall, and the basal release of endothelial NO in hypertension (HPN) may be reduced. Until now, there is no solid data revealing the potential role of the polymorphism of the nitric oxide synthase gene (NOS) in patients with HPN and microvascular angina. Aim: The aim of the present study is to investigate the gene of endothelial nitric oxide synthase (eNOS), as the polymorphism of this gene may be a putative candidate for HPN and initiate the process of atherosclerosis. Methods: Sixty participants were recruited for this study; 50 were hypertensive patients complaining of chest pain [30 of them have electrocardiogram (EKG) changes of ischemia], 20 had isolated HPN, and 10 healthy volunteers served as control. All patients underwent stress myocardial perfusion imaging (MPI) and coronary angiography. Genotyping of eNOS for all patients and controls was performed. The linkages between HPN, microvascular angina and eNOS gene polymorphism were investigated. Results: MPI and coronary angiography revealed that 15 patients had chest pain with true ischemia and reversible myocardial perfusion defects (multiple and mild) but normal epicardial coronary arteries (microvascular angina), while 15 patients had significant coronary artery disease (CAD), and 20 hypertensive patients showed normal perfusion scan and coronary angiography. The prevalence of the NOS G 298 allele was higher in the hypertensive group with microvascular angina (documented by MPI) than it was among the control participants (P<.005). The eNOS allele was significantly higher in the hypertensive group than in the control participants, but there was no significant difference in homozygote mutants among hypertensive participants, x-syndrome and patients with CAD. Conclusion: eNOS gene polymorphism is proved to be an important etiology in microvascular angina (x-syndrome) among hypertensive patients. In addition, the eNOS mutant

HUMAN CORONARY ARTERIES- A STUDY BASED ON GROSS ANATOMY AND CORONARY CAST

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Vijayamma K. N

2018-01-01

Full Text Available BACKGROUND Present study is an attempt to throw light upon the coronary arterial pattern, variations in arterial distribution and extent of intercoronary anastomosis and arterial preponderance in different age groups. MATERIALS AND METHODS Total of 115 hearts were made use for this study. Ninety hearts were dissected for the gross anatomical study of coronary arteries and 25 hearts including three fetal hearts were used for the coronary cast study. The right and left coronary arteries were traced from aortic sinus along the atrioventricular groove to the area of its termination. The atrial ventricular and septal branches were traced and looked for anastomosis. Coronary casts were prepared by injecting coloured liquid latex through the coronary ostia and the branching pattern and anastomosis were studied. The coronary arterial pattern, extent of distribution of its branches, arterial preponderance and variations were observed. RESULTS It was found that 73 % cases of SA nodal branch arise from right coronary artery and 27 % from circumflex branch of left coronary artery. SA node has dual blood supply from both coronary arteries in 4% cases. Right coronary preponderance was observed in 83% of cases and left coronary preponderance in 11 % cases, and balanced supply in 6% cases. Coronary cast was helpful to understand the branching pattern of vessels, and the anastomosis of small capillaries. It was also seen that all 11 % of left preponderance were seen in male hearts and all of the 31 female hearts dissected were right preponderant. CONCLUSION Coronary arteries are called end arteries functionally. Right coronary artery originates from anterior aortic sinus in all cases except one which takes origin from posterior left aortic sinus along with left coronary artery. Right coronary preponderance is observed in 83% cases. Left coronary artery branching pattern shows variability. Left coronary preponderance was observed in 11% and all cases are male

Evaluation of coronary hemodynamics and exercise 201Tl-myocardial scintigraphy in patients with vasospastic angina

International Nuclear Information System (INIS)

Matsumura, Kentaro; Nakase, Emiko; Haiyama, Tohru; Hasegawa, Akira; Saito, Takayuki

1992-01-01

To clarify the coronary hemodynamics and myocardial perfusion in patients with vasospastic angina, we performed exercise 201 Tl-myocardial scintigraphy (planar and SPECT) in 72 patients and left coronary digital subtraction angiography (DSA) in 37 patients without significant organic coronary artery stenosis. Coronary artery spasm was documented by coronary angiography in all patients. Fifty-four patients (75%) developed exercise-induced 201 Tl-myocardial perfusion defect on SPECT. 201 Tl pulmonary uptake (L/H) was significantly increased in patients with vasospastic angina. Especially, L/H was higher in patients with multiple small perfusion defect on 201 Tl-SPECT, so that exercise-induced left ventricular dysfunction existed in patients with vasospastic angina and especially in cases of multiple small perfusion defect on 201 Tl-SPECT. The left coronary circulation time (CCT) was prolonged in patients with vasospastic angina. The mechanism of prolonged CCT is still unknown, but we suspected that prolonged CCT was induced by increased peripheral coronary vascular resistance in patients with vasospastic angina. It was concluded that the peripheral coronary circulation was disturbed in patients with vasospastic angina, but its abnormal coronary circulation had no relation to location of spasm-induced vessels. We concluded that impaired coronary microcirculation was taken a part of pathophysiology in vasospastic angina. (author)

Microvascular inflammation in atherosclerosis

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Laura Vitiello

2014-06-01

Full Text Available Atherogenesis is the pathogenetic process leading to formation of the atheroma lesion. It is associated to a chronic inflammatory state initially stimulated by an aberrant accumulation of lipid molecules beyond the endothelial barrier. This event triggers a cascade of deleterious events mainly through immune cell stimulation with the consequent liberation of potent pro-inflammatory and tissue damaging mediators. The atherogenetic process implies marked modifications of endothelial cell functions and a radical change in the endothelial–leukocyte interaction pattern. Moreover, accumulating evidence shows an important link between microvascular and inflammatory responses and major cardiovascular risk factors. This review illustrates the current knowledge on the effects of obesity, hypercholesterolemia and diabetes on microcirculation; their pathophysiological implications will be discussed.

A comparison of hybrid coronary revascularization and off-pump coronary revascularization.

Science.gov (United States)

Umakanthan, Ramanan; Leacche, Marzia; Gallion, Anna H; Byrne, John G

2013-04-01

Minimally invasive approaches to treat vascular disease have been accruing significant popularity over the last several decades. Due to progressive advances in technology, a variety of techniques are being now utilized in the field of cardiovascular surgery. The objectives of minimally invasive techniques are to curtail operative trauma and minimize perioperative morbidity without decreasing the quality of the treatment. The standard surgical approach for the treatment of coronary artery disease has traditionally been coronary artery bypass grafting surgery via median sternotomy. Off-pump coronary artery bypass grafting surgery offers a less invasive alternative and enables coronary revascularization to be performed without cardiopulmonary bypass. Hybrid coronary revascularization offers an even less invasive option in which minimally invasive direct coronary artery bypass can be combined with percutaneous coronary intervention. In this article, the authors review a recent publication comparing hybrid coronary revascularization and off-pump coronary artery bypass grafting surgery.

Clinical reference value of retinal microvascular changes in patients with cerebral microbleeds

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Ji-Yuan Guo

2014-12-01

Full Text Available AIM: To study clinical reference value of retinal microvascular changes in patients with cerebral microbleeds(CMBsand discuss its clinical significance. METHODS:From January 2012 to December 2013, 125 hospitalized patients were collected, including 81 cases were male, 44 cases were female, mean age 76.3±11.2 years old. For all patients, functions of liver and kidney, blood-lipoids, blood sugar and blood biochemical examination were tested, and fundus photography and cerebral MR was done. According to the fundus camera eyes, retinal arteriolar equivalent(RAE, retinal venular equivalent(RVE, retinal vein diameter ratio(AVRand arteriovenous crossing sign(AVNwere identified, CMBs were classified with cerebral MRI. All the data were processed by SPSS statistical software. RESULTS: The central retinal arteriolar equivalent(CRAE, central retinal venular equivalent(CRVEand AVR values in the eyes were found no statistical difference(PPCOCLUSION: The results show that retinal microvascular changes, especially small retinal vein arteriovenous cross width, and arteriovenous crossing phenomenon, in which CMBs will happen more likely. After sex, age, hypertension and hyperglycemia in patients with traditional cardiovascular risk factors being ruled out, the retinal microvascular changes are still relatively factors of CMB's occurrence.

What Is Coronary Microvascular Disease?

Science.gov (United States)

... the results explained to you: Blood pressure measurement. Fasting blood glucose. This test is for diabetes. Lipoprotein ... weight and height to check for overweight or obesity . He or she also may recommend tests for ...

Coronary blood flow and coronary stenosis correlations in ischemic heart patients

International Nuclear Information System (INIS)

Manukov, I.

2003-01-01

The aim of the study is the assessment of the methodology for the C-TIMI frame count by Gibson for easy and fast determination of the coronary blood flow during a selective coronary angiography. 75 patient have been studied with one-branch affection of the coronary arteries. The criteria for exclusion are: myocardial hypertrophy, valve lesions, myocardial infarction and dyslipidemia. Depending of the characteristics of the coronary stenotic changes, the patients have been divided into two groups: 1) Patients with 'ordinary' stenosis of the coronary artery and 2) Patients with 'complex' stenosis. The severity of the stenotic changes in percents is the same for the two groups - 78%±13% vs 81±12%, respectively. In the first group a pronounced correlation is observed between the severity of the coronary stenosis and the slowing of the coronary blood flow. The 'threshold' stenotic level is 89%. In the second group the lowest value of the coronary stenosis is 73% (p>0.01 vs group 1). No correlation is observed between the severity of the coronary stenosis and the slowing of the coronary blood flow. A conclusion is made that the Gibson method for the assessment of the blood flow is convenient for the daily practice not only for the assessment of the significance of the coronary changes, but also for fast analysis of the achieved reconstruction of the coronary arteries after angioplasty. Additional studies of the significance of the different signs of 'complexity' of the coronary stenosis for the slowing of the blood flow are necessary

Assessment of coronary flow reserve by sestamibi imaging in patients with typical chest pain and normal coronary arteries

International Nuclear Information System (INIS)

Storto, Giovanni; Sorrentino, Anna R.; Pellegrino, Teresa; Liuzzi, Raffaele; Cuocolo, Alberto; Petretta, Mario

2007-01-01

We assessed coronary flow reserve (CFR) by sestamibi imaging in patients with typical chest pain, positive exercise stress test and normal coronary vessels. Thirty-five patients with typical chest pain and normal angiogram and 12 control subjects with atypical chest pain underwent dipyridamole/rest 99m Tc-sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in the pulmonary artery and myocardial counts from SPECT images. Estimated CFR was expressed as the ratio of stress to rest MBF. Rest MBF and CFR were corrected for rate-pressure product (RPP) and expressed as normalised MBF (MBF n ) and normalised CFR (CFR n ). Coronary vascular resistances (CVR) were calculated as the ratio between mean arterial pressure and estimated MBF. At rest, estimated MBF and MBF n were lower in controls than in patients (0.98 ± 0.4 vs 1.30 ± 0.3 counts/pixel/s and 1.14 ± 0.5 vs 1.64 ± 0.6 counts/pixel/s, respectively, both p n was still higher in controls than in patients (2.1 ± 0.5 vs 1.29 ± 0.5, p < 0.0001). At baseline, CVR values were lower (p < 0.01) in patients than in controls. Dipyridamole-induced changes in CVR were greater (p < 0.0001) in controls (-63%) than in patients (-35%). In the overall study population, a significant correlation between dipyridamole-induced changes in CVR and CFR was observed (r = -0.88, p < 0.0001). SPECT might represent a useful non-invasive method for assessing coronary vascular function in patients with angina and a normal coronary angiogram. (orig.)

Prediction of postpercutaneous coronary intervention myocardial infarction: insights from intravascular imaging, coronary flow, and biomarker evaluation.

Science.gov (United States)

Hoole, Stephen P; Hernández-Sánchez, Jules; Brown, Adam J; Giblett, Joel P; Bennett, Martin R; West, Nick E J

2018-05-01

Percutaneous coronary intervention-induced myocardial infarction (PMI) has prognostic significance. Identifying patients at high risk for PMI is desirable as it may alter strategy and facilitate early preventative therapy. We therefore sought to establish whether preprocedural demographic, interventional (plaque characteristics and coronary microcirculatory function), and inflammatory, endothelial damage, and platelet-derived biomarker data could predict the risk of PMI. We performed target vessel pressure wire to assess fractional flow reserve, index of microcirculatory resistance (IMR) and coronary flow reserve, plaque characterization by virtual histology intravascular ultrasound, and assayed peripheral biomarkers before uncomplicated PCI in 88 patients. We then analyzed post-PCI cardiac troponin level to adjudicate PMI based on the third universal definition of myocardial infarction. Overall incidence of PMI was 27%. Women [10/15 (66%) vs. 14/73 (19%), PPMI. Preprocedural coronary flow reserve was lower in individuals with a subsequent PMI (1.8±1.2 vs. 2.1±1.3. P=0.03), and patients with higher pre-PCI IMR were more likely to sustain PMI [IMR>22: 10/23 (44%) vs. ≤22: 14/65 (22%), P=0.04], although neither was predictive after multivariate analysis. Plaque characterization by virtual histology intravascular ultrasound did not discriminate those at risk of PMI. However, peripheral venous interleukin (IL)-18 and IL-8 levels were independently negatively and positively associated with PMI, respectively. Women and those with low BMI, particularly when associated with high IL-8 and low IL-18 levels, appear to be at increased risk of PMI.

Modeling of pulsatile flow-dependent nitric oxide regulation in a realistic microvascular network.

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Wang, Ruofan; Pan, Qing; Kuebler, Wolfgang M; Li, John K-J; Pries, Axel R; Ning, Gangmin

2017-09-01

Hemodynamic pulsatility has been reported to regulate microcirculatory function. To quantitatively assess the impact of flow pulsatility on the microvasculature, a mathematical model was first developed to simulate the regulation of NO production by pulsatile flow in the microcirculation. Shear stress and pressure pulsatility were selected as regulators of endothelial NO production and NO-dependent vessel dilation as feedback to control microvascular hemodynamics. The model was then applied to a real microvascular network of the rat mesentery consisting of 546 microvessels. As compared to steady flow conditions, pulsatile flow increased the average NO concentration in arterioles from 256.8±93.1nM to 274.8±101.1nM (Pflow as compared to steady flow conditions. Network perfusion and flow heterogeneity were improved under pulsatile flow conditions, and vasodilation within the network was more sensitive to heart rate changes than pulse pressure amplitude. The proposed model simulates the role of flow pulsatility in the regulation of a complex microvascular network in terms of NO concentration and hemodynamics under varied physiological conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

The Ubiquitin-Proteasome System and Microvascular Complications of Diabetes

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Saeed Yadranji Aghdam

2013-01-01

Full Text Available The ubiquitin-proteasome system (UPS is the mainstay of protein quality control which regulates cell cycle, differentiation and various signal transduction pathways in eukaryotic cells. The timely and selective degradation of surplus and/or aberrant proteins by the UPS is essential for normal cellular physiology. Any disturbance, delay or exaggeration in the process of selection, sequestration, labeling for degradation and degradation of target proteins by the UPS will compromise cellular and tissue homeostasis. High blood glucose or hyperglycemia caused by diabetes disrupts normal vascular function in several target organs including the retina and kidney resulting in the development of diabetic retinopathy (DR and diabetic nephropathy (DN. We and others have shown that hyperglycemia and oxidative stress modulate UPS activity in the retina and kidney. The majority of studies have focused on the kidney and provided insights into the contribution of dysregulated UPS to microvascular damage in DN. The eye is a unique organ in which a semi-fluid medium, the vitreous humor, separates the neural retina and its anastomosed blood vessels from the semi-solid lens tissue. The complexity of the cellular and molecular components of the eye may require a normal functioning and well tuned UPS for healthy vision. Altered UPS activity may contribute to the development of retinal microvascular complications of diabetes. A better understanding of the molecular nature of the ocular UPS function under normal and diabetic conditions is essential for development of novel strategies targeting its activity. This review will discuss the association of retinal vascular cell UPS activity with microvascular damage in DR with emphasis on alterations of the PA28 subunits of the UPS.

[Developments in percutaneous coronary intervention and coronary stents].

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Simsek, C; Daemen, J; Zijlstra, F

2014-01-01

In The Netherlands, more than 30.000 patients undergo a percutaneous coronary intervention every year, during which a coronary stent implantation will be performed in 90% of the cases. It is estimated that more than 5 million coronary stent implantations will be performed worldwide this year. While these numbers are impressive, however, coronary stents still have as a limitation the possibility of stent thrombosis. This has been and is an important stimulus for the development of both coronary stents, from a bare metal stent via a drug eluting stent to the present-day development of bio-absorbable stents, and anti-platelet drugs,from acenocoumarol to thieropyridines. The possibility of shortening the period of use of this powerful medication by developing new kinds of non-thrombogenic stents would, for example, make it possible to achieve significant reductions in subsequent bleeding during (dental) procedures.

Barotrauma and microvascular injury in lungs of nonadult rabbits: effect of ventilation pattern.

Science.gov (United States)

Peevy, K J; Hernandez, L A; Moise, A A; Parker, J C

1990-06-01

To study the pulmonary microvascular injury produced by ventilation barotrauma, the isolated perfused lungs of 4 to 6-wk-old New Zealand white rabbits were ventilated by one of the following methods: peak inspiratory pressure (PIP) 23 cm H2O, gas flow rate 1.1 L/min (group 1); PIP 27 cm H2O, gas flow rate 6.9 L/min (group 2); PIP 50 cm H2O, gas flow rate 1.9 L/min (group 3); or PIP 53 cm H2O, gas flow rate 8.3 L/min (group 4). Microvascular permeability was assessed using the capillary filtration coefficient (Kfc) before and 5, 30, and 60 min after a 15-min period of ventilation. Baseline Kfc was not significantly different between groups. A significant increase over the baseline Kfc was noted at 60 min in group 2 and in all postventilation Kfc values in groups 3 and 4 (p less than .05). Group 1 Kfc values did not change significantly after ventilation. At all post-ventilation times, values for Kfc were significantly greater in groups 3 and 4 than in group 1 (p less than .05). Group 4 Kfc values were significantly greater than those in group 2 at 5 and 30 min postventilation. These data indicate that high PIP, and to a lesser extent, high gas flow rates cause microvascular injury in the compliant nonadult lung and suggest that the combination of high PIP and high gas flow rates are the most threatening to microvascular integrity.

Alopecia and its association with coronary heart disease and cardiovascular risk factors: a meta-analysis.

Science.gov (United States)

Trieu, Nelson; Eslick, Guy D

2014-10-20

Alopecia has been associated with an increased risk of coronary heart disease as well as the following risk factors for cardiovascular disease: hyperinsulinaemia, insulin resistance, metabolic syndrome, dyslipidaemia, and hypertension. We performed a meta-analysis to quantitatively determine the level of risk of coronary heart disease and risk factors in individuals with alopecia. A systematic literature search was conducted using several databases. We calculated pooled odds ratios and 95% confidence intervals using a random effects model. In total, 31 studies comprising 29,254 participants with alopecia were eligible for the meta-analysis and showed that alopecia is associated with an increased risk of coronary heart disease (OR 1.22, 95% CI: 1.07-1.39), hyperinsulinaemia (OR 1.97, 95% CI: 1.20-3.21), insulin resistance (OR 4.88, 95% CI: 2.05-11.64), and metabolic syndrome (OR 4.49, 95% CI: 2.36-8.53). Individuals with alopecia were also shown to be more likely compared to those without alopecia to have higher serum cholesterol levels (OR 1.60, 95% CI: 1.17-2.21), higher serum triglyceride levels (OR 2.07, 95% CI: 1.32-3.25), higher systolic blood pressures (OR 1.73, 95% CI: 1.29-2.33), and higher diastolic blood pressures (OR 1.59, 95% CI: 1.16-2.18). Alopecia is associated with an increased risk of coronary heart disease, and there appears to be a dose-response relationship with degree of baldness whereby the greater the severity of alopecia, the greater the risk of coronary heart disease. Alopecia is also associated with an increased risk of hypertension, hyperinsulinaemia, insulin resistance, metabolic syndrome, and having elevated serum total cholesterol and triglyceride levels. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

A new CFD based non-invasive method for functional diagnosis of coronary stenosis.

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Xie, Xinzhou; Zheng, Minwen; Wen, Didi; Li, Yabing; Xie, Songyun

2018-03-22

Accurate functional diagnosis of coronary stenosis is vital for decision making in coronary revascularization. With recent advances in computational fluid dynamics (CFD), fractional flow reserve (FFR) can be derived non-invasively from coronary computed tomography angiography images (FFR CT ) for functional measurement of stenosis. However, the accuracy of FFR CT is limited due to the approximate modeling approach of maximal hyperemia conditions. To overcome this problem, a new CFD based non-invasive method is proposed. Instead of modeling maximal hyperemia condition, a series of boundary conditions are specified and those simulated results are combined to provide a pressure-flow curve for a stenosis. Then, functional diagnosis of stenosis is assessed based on parameters derived from the obtained pressure-flow curve. The proposed method is applied to both idealized and patient-specific models, and validated with invasive FFR in six patients. Results show that additional hemodynamic information about the flow resistances of a stenosis is provided, which cannot be directly obtained from anatomy information. Parameters derived from the simulated pressure-flow curve show a linear and significant correlations with invasive FFR (r > 0.95, P < 0.05). The proposed method can assess flow resistances by the pressure-flow curve derived parameters without modeling of maximal hyperemia condition, which is a new promising approach for non-invasive functional assessment of coronary stenosis.

Anomalous origin of right coronary artery from left coronary sinus.

Science.gov (United States)

Hamzeh, Gadah; Crespo, Alex; Estarán, Rafael; Rodríguez, Miguel A; Voces, Roberto; Aramendi, José I

2008-08-01

Anomalous aortic origin of the coronary arteries is uncommon but clinically significant. Manifestations vary from asymptomatic patients to those who present with angina pectoris, myocardial infarction, heart failure, syncope, arrhythmias, and sudden death. We describe 4 patients, aged 34 to 59 years, who were diagnosed with right coronary artery arising from the left sinus of Valsalva, confirmed by coronary angiography, which was surgically repaired. Three patients presented dyspnea and angina, and one with acute myocardial infarction. At operation, the right coronary artery was dissected at the take-off from the intramural course, and reimplanted into the right sinus of Valsalva. There was no mortality. One patient had associated coronary artery disease that required stent placement postoperatively. This reimplantation technique provides a good physiological and anatomical repair, eliminates a slit-like ostium, avoids compression of the coronary artery between the aorta and the pulmonary artery, and gives superior results to coronary artery bypass grafting or the unroofing technique.

Coronary Collateral Growth—Back to the Future

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Chilian, William M.; Penn, Marc S.; Pung, Yuh Fen; Dong, Feng; Mayorga, Maritza; Ohanyan, Vahagn; Logan, Suzanna; Yin, Liya

2012-01-01

The coronary collateral circulation is critically important as an adaptation of the heart to prevent the damage from ischemic insults. In their native state, collaterals in the heart would be classified as part of the microcirculation, existing as arterial-arterial anastomotic connections in the range of 30 to 100 μM in diameter. However, these vessels also show a propensity to remodel into components of the macrocirculation and can become arteries larger than a 1000 μM in diameter. This process of outward remodelling is critically important in the adaptation of the heart to ischemia because the resistance to blood flow is inversely related to the fourth power of the diameter of the vessel. Thus, an expansion of a vessel from 100 to 1000 μM would reduce resistance (in this part of the circuit) to a negligible amount and enable delivery of flow to the region at risk. Our goal in this review is to highlight the voids in understanding this adaptation to ischemia—the growth of the coronary collateral circulation. In doing so we discuss the controversies and unknown aspects of the causal factors that stimulate growth of the collateral circulation, the role of genetics, and the role of endogenous stem and progenitor cells in the context of the normal, physiological situation and under more pathological conditions of ischemic heart disease or with some of the underlying risk factors, e.g., diabetes. The major conclusion of this review is that there are many gaps in our knowledge of coronary collateral growth and this knowledge is critical before the potential of stimulating collateralization in the hearts of patients can be realized. PMID:22210280

Can local application of Tranexamic acid reduce post-coronary bypass surgery blood loss? A randomized controlled trial

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Latter David

2009-06-01

Full Text Available Abstract Background Diffuse microvascular bleeding remains a common problem after cardiac procedures. Systemic use of antifibrinolytic reduces the postoperative blood loss. The purpose of this study was to examine the effectiveness of local application of tranexamic acid to reduce blood loss after coronary artery bypass grafting (CABG. Methods Thirty eight patients scheduled for primary isolated coronary artery bypass grafting were included in this double blind, prospective, randomized, placebo controlled study. Tranexamic acid (TA group (19 patients received 1 gram of TA diluted in 100 ml normal saline. Placebo group (19 patients received 100 ml of normal saline only. The solution was purred in the pericardial and mediastinal cavities. Results Both groups were comparable in their baseline demographic and surgical characteristics. During the first 24 hours post-operatively, cumulative blood loss was significantly less in TA group (median of 626 ml compared to Placebo group (median of 1040 ml (P = 0.04. There was no significant difference in the post-op Packed RBCs transfusion between both groups (median of one unit in each (P = 0.82. Significant less platelets transfusion required in TA group (median zero unit than in placebo group (median 2 units (P = 0.03. Apart from re-exploration for excessive surgical bleeding in one patient in TA group, no difference was found in morbidity or mortality between both groups. Conclusion Topical application of tranexamic acid in patients undergoing primary coronary artery bypass grafting led to a significant reduction in postoperative blood loss without adding extra risk to the patient.

Evaluation of the restenosis of coronary artery after percutaneous transluminal coronary angioplasty by three-dimensional coronary magnetic resonance angiography

International Nuclear Information System (INIS)

Arisaka, Hiraku

2000-01-01

Coronary magnetic resonance angiography (MRA) has been recently brought into clinical use, however, there has not been reports on the comparison with MRA and conventional contrast coronary angiography (CAG) in the detection of the localization and characteristics of coronary restenosis after percutaneous transluminal coronary angioplasty (PTCA). To assess the restenosis of coronary artery after PTCA, this study compared three-dimensional (3D) coronary MRA and CAG. One hundred three patients (76 males and 27 females, average age of 64.6±9.3 years old) were performed coronary MRA at 3-6 months after PTCA. The right coronary artery (RCA) group consist of 21 patients, the left anterior descending branch (LAD) 63 patients and the left circumflex branch (LCX) 19 patients. Coronary MRA was performed with the patients in supine position on a 1.5 T whole body scanner (MAGNETOM VISION, Siemens AG, Germany) using body array coil. The imaging technique used a 3-D gradient echo sequence with respiratory gating and fat suppression. The slice thickness was 2 mm, slab thickness 32 mm, a field of view of 300 mm and a matrix of 128 x 256. Other parameters were an echo time of 2.7 ms and a repetition time of 600 to 1100 msec. The measurement time of 1 imaging slab took 15 to 20 minutes depending on the patient's heart rate. The coronary arteries were reconstructed from the 3-D data set using a multiplanar reconstruction (MPR) technique. According to previous coronary MRA studies, a significant stenosis with a luminal reduction of ≥50% was assumed if a marked signal reduction or signal loss of a vessel segment was visible. In CAG, 57 of 103 patients showed restenosis. In coronary MRA, 37 of 103 patients demonstrated restenosis. The sensitivity, specificity, positive and negative predictive values were 64.9%, 100%, 100% and 69.6%, respectively. Predictive accuracy was 79.6%. Three-dimensional coronary MRA is useful in a noninvasive diagnostic method to evaluate the coronary

Coronary CT Angiography in the Quantitative Assessment of Coronary Plaques

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Zhonghua Sun

2014-01-01

Full Text Available Coronary computed tomography angiography (CCTA has been recently evaluated for its ability to assess coronary plaque characteristics, including plaque composition. Identification of the relationship between plaque composition by CCTA and patient clinical presentations may provide insight into the pathophysiology of coronary artery plaque, thus assisting identification of vulnerable plaques which are associated with the development of acute coronary syndrome. CCTA-generated 3D visualizations allow evaluation of both coronary lesions and lumen changes, which are considered to enhance the diagnostic performance of CCTA. The purpose of this review is to discuss the recent developments that have occurred in the field of CCTA with regard to its diagnostic accuracy in the quantitative assessment of coronary plaques, with a focus on the characterization of plaque components and identification of vulnerable plaques.

Detection of coronary calcification in ultrafast CT compared to coronary angiography

International Nuclear Information System (INIS)

Koesling, S.; Hoffmann, U.; Rother, T.; Lieberenz, S.; Heywang-Koebrunner, S.H.; Schulz, H.G.

1994-01-01

The angiographical findings of 24 patients with coronary artery disease were compared with qualitative and quantitative detection of coronary calcification by ultrafast CT. Doubts concerning the capabilities of the ultrafast CT for a screening of coronary artery disease arise when the results of one third false positive and fase negative findings are considered. Variations in the quantification of coronary calcification were too great to allow a realistic assessment of the degree of stenosis of the coronary arteries. (orig.) [de

Longitudinal study of microvascular involvement by nailfold capillaroscopy in children with Henoch-Schönlein purpura.

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Zampetti, Anna; Rigante, Donato; Bersani, Giulia; Rendeli, Claudia; Feliciani, Claudio; Stabile, Achille

2009-09-01

The aim of this study is to describe by video-nailfold capillaroscopy the microvascular involvement and capillary changes in children with Henoch-Schönlein purpura (HSp) and to establish a possible correlation with clinical outcome. Thirty-one patients underwent capillaroscopic evaluation through a videomicroscope during the acute phase and after 6 months. Twenty sex/age-matched controls were also examined. All capillaroscopic variables were statistically examined in combination with laboratoristic/clinical data. Architectural and morphological changes recorded during the acute phase were statistically significant in comparison to the controls (p capillaroscopy changes, laboratoristic/clinical data, and outcome. Video-nailfold capillaroscopy can be a simple tool to evaluate microvascular abnormalities in the acute phase of HSp, and the persistence of oedema could suggest an incomplete disease resolution at a microvascular level.

Depth-dependent flow and pressure characteristics in cortical microvascular networks.

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Franca Schmid

2017-02-01

Full Text Available A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding of neurovascular coupling mechanisms and the related measurement techniques. Here, numerical simulations with discrete tracking of red blood cells (RBCs are performed in three realistic microvascular networks from the mouse cerebral cortex. Our analysis is based on trajectories of individual RBCs and focuses on layer-specific flow phenomena until a cortical depth of 1 mm. The individual RBC trajectories reveal that in the capillary bed RBCs preferentially move in plane. Hence, the capillary flow field shows laminar patterns and a layer-specific analysis is valid. We demonstrate that for RBCs entering the capillary bed close to the cortical surface (< 400 μm the largest pressure drop takes place in the capillaries (37%, while for deeper regions arterioles are responsible for 61% of the total pressure drop. Further flow characteristics, such as capillary transit time or RBC velocity, also vary significantly over cortical depth. Comparison of purely topological characteristics with flow-based ones shows that a combined interpretation of topology and flow is indispensable. Our results provide evidence that it is crucial to consider layer-specific differences for all investigations related to the flow and pressure distribution in the cortical vasculature. These findings support the hypothesis that for an efficient oxygen up-regulation at least two regulation mechanisms must be playing hand in hand, namely cerebral blood flow increase and microvascular flow homogenization. However, the contribution of both regulation mechanisms to oxygen up-regulation likely varies over depth.

Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans.

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Romero, Steven A; Gagnon, Daniel; Adams, Amy N; Cramer, Matthew N; Kouda, Ken; Crandall, Craig G

2017-01-01

Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P lower limb heating improves both macro- and microvascular dilator function in an age dependent manner. We demonstrate that lower limb heating acutely improves macro- and microvascular dilator function within the atherosclerotic prone vasculature of the leg in aged adults. These findings provide evidence for a potential therapeutic use of chronic lower limb heating to improve vascular health in primary aging and various disease conditions. Copyright © 2017 the American Physiological Society.

Concomitant macro and microvascular complications in diabetic nephropathy

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Alwakeel Jamal

2009-01-01

Full Text Available To determine the prevalence of concomitant microvascular and macrovascular complica-tions of diabetic nephropathy we retrospectively reviewed the medical records of all 1,952 type 2 dia-betic patients followed-up at Security Forces Hospital, Riyadh, Saudi Arabia from January 1989 to December 2004. There were 626 (32.1% patients (294 (47% were males who developed diabetic nephropathy. Their mean age was 66.9 ± 11.4 years, mean duration of diabetes was 15.4 ± 7.5 years, mean age at the onset of nephropathy was 61.5 ± 12.4 years, and mean duration of nephropathy was 3.9 ± 3.8 years. Concomitant diabetic complications included cataract (38.2%, acute coronary syndrome (36.1%, peripheral neuropathy (24.9%, myocardial infarction (24.1%, background retinopathy (22.4%, stroke (17.6%, proliferative retinopathy (11.7%, foot infection (7.3%, limb amputation (3.7% and blindness (3%. Hypertension was documented in 577 (92.2% patients, dyslipidemia in 266 (42.5% and mortality from all causes in 86 (13.7%. There were 148 (23.6% patients with one complication, 81 (12.9% with two, 83 (13.3% with three, and 61 (9.7% with four or more. Dete-rioration of glomerular filtration rate was observed in 464 (74% patients and doubling of serum creatinine in 250 (39.9%, while 95 (15.2% developed end-stage renal disease (ESRD at the end of study and 79 (12.6% required dialysis. Complications were significantly more prevalent among males with greater number reaching ESRD level than females (P< 0.05. Relative risks of developing com-plications were significant after the onset of nephropathy; ACS (1.41, MI (1.49, stroke (1.48, diabetic foot (1.6, amputation (1.58 and death (1.93. We conclude that complications of diabetes are aggre-ssive and progressive including high prevalence of diabetic nephropathy. Careful monitoring and proper institution of management protocols should be implemented to identify diabetic patients at high risk for complications and mitigate progression

Concomitant macro and microvascular complications in diabetic nephropathy

International Nuclear Information System (INIS)

Alwakeel, Jamal S; AlSuwaida, Abdulkareem; Isnani, Arthur C; AlHarbi, Ali; Alam Awatif

2009-01-01

To determine the prevalence of concomitant microvascular and macro vascular complications of diabetic nephropathy we retrospectively reviewed the medical records of all 1,952 type 2 dia-betic patients followed-up at Security Forces Hospital, Riyadh, Saudi Arabia from January 1989 to December 2004. There were 626 (32.1%) patients (294 (47%) were males) who developed diabetic nephropathy. Their mean age was 66.9 + -11.4 years, mean duration of diabetes was 15.4 + -7.5 years, mean age at the onset of nephropathy was 61.5 + - 12.4 years, and mean duration of nephropathy was 3.9 + - 3.8 years. Concomitant diabetic complications included cataract (38.2%), acute coronary syndrome (36.1%), peripheral neuropathy (24.9%), myocardial infarction (24.1%), background retinopathy (22.4%), stroke (17.6%), proliferative retinopathy (11.7%), foot infection (7.3%), limb amputation (3.7%) and blindness (3%). Hypertension was documented in 577 (92.2%) patients, dyslipidemia in 266 (42.5%) and mortality from all causes in 86 (13.7%). There were 148 (23.6%) patients with one complication, 81 (12.9%) with two, 83 (13.3%) with three, and 61 (9.7%) with four or more. Deterioration of glomerular filtration rate was observed in 464 (74%) patients and doubling of serum creatinine in 250 (39.9%), while 95 (15.2%) developed end-stage renal disease (ESRD) at the end of study and 79 (12.6%) required dialysis. Complications were significantly more prevalent among males with greater number reaching ESRD level than females (P< 0.05). Relative risks of developing complications were significant after the onset of nephropathy; ACS (1.41), MI (1.49), stroke (1.48), diabetic foot (1.6), amputation (1.58) and death (1.93). We conclude that complications of diabetes are aggressive and progressive including high prevalence of diabetic nephropathy. Careful monitoring and proper institution of management protocols should be implemented to identify diabetic patients at high risk for complications and mitigate

Concomitant macro and microvascular complications in diabetic nephropathy

Energy Technology Data Exchange (ETDEWEB)

Alwakeel, Jamal S; AlSuwaida, Abdulkareem [Div. of Nephrology, Dept. of Medicine, King Khalid Univ., Hospital, Riyadh (Saudi Arabia); Isnani, Arthur C [Dept. of Family and Community Medicine, King Khalid Univ. Hospital, Riyadh (Saudi Arabia); AlHarbi, Ali [Coll. of Medicine and Research Center, King Khalid Univ. Hospital, Riyadh (Saudi Arabia); Awatif, Alam [Div. of Nephrology, Dept. of Medicine, Security Forces Hospital, Riyadh (Saudi Arabia)

2009-07-01

To determine the prevalence of concomitant microvascular and macro vascular complications of diabetic nephropathy we retrospectively reviewed the medical records of all 1,952 type 2 dia-betic patients followed-up at Security Forces Hospital, Riyadh, Saudi Arabia from January 1989 to December 2004. There were 626 (32.1%) patients (294 (47%) were males) who developed diabetic nephropathy. Their mean age was 66.9 + -11.4 years, mean duration of diabetes was 15.4 + -7.5 years, mean age at the onset of nephropathy was 61.5 + - 12.4 years, and mean duration of nephropathy was 3.9 + - 3.8 years. Concomitant diabetic complications included cataract (38.2%), acute coronary syndrome (36.1%), peripheral neuropathy (24.9%), myocardial infarction (24.1%), background retinopathy (22.4%), stroke (17.6%), proliferative retinopathy (11.7%), foot infection (7.3%), limb amputation (3.7%) and blindness (3%). Hypertension was documented in 577 (92.2%) patients, dyslipidemia in 266 (42.5%) and mortality from all causes in 86 (13.7%). There were 148 (23.6%) patients with one complication, 81 (12.9%) with two, 83 (13.3%) with three, and 61 (9.7%) with four or more. Deterioration of glomerular filtration rate was observed in 464 (74%) patients and doubling of serum creatinine in 250 (39.9%), while 95 (15.2%) developed end-stage renal disease (ESRD) at the end of study and 79 (12.6%) required dialysis. Complications were significantly more prevalent among males with greater number reaching ESRD level than females (P< 0.05). Relative risks of developing complications were significant after the onset of nephropathy; ACS (1.41), MI (1.49), stroke (1.48), diabetic foot (1.6), amputation (1.58) and death (1.93). We conclude that complications of diabetes are aggressive and progressive including high prevalence of diabetic nephropathy. Careful monitoring and proper institution of management protocols should be implemented to identify diabetic patients at high risk for complications and mitigate

Can the inflammatory response be evaluated using 18F-FDG within zones of microvascular obstruction after myocardial infarction?

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Prato, Frank S; Butler, John; Sykes, Jane; Keenliside, Lynn; Blackwood, Kimberley J; Thompson, R Terry; White, James A; Mikami, Yoko; Thiessen, Jonathan D; Wisenberg, Gerald

2015-02-01

Inflammation that occurs after acute myocardial infarction plays a pivotal role in healing by facilitating the creation of a supportive scar. (18)F-FDG, which is taken up avidly by macrophages, has been proposed as a marker of cell-based inflammation. However, its reliability as an accurate indicator of inflammation has not been established, particularly in the early postinfarction period when regional myocardial perfusion is often severely compromised. Nine adult dogs underwent left anterior descending coronary occlusion with or without reperfusion. Animals were imaged between 7 and 21 d after infarction with PET/MR imaging after bolus injection of gadolinium-diethylenetriaminepentaacetic acid (DTPA), bolus injection of (18)F-FDG, bolus injection of (99)Tc-DTPA to simulate the distribution of gadolinium-DTPA (which represents its partition coefficient in well-perfused tissue), and injection of (111)In-labeled white blood cells 24 h earlier. After sacrifice, myocardial tissue concentrations of (18)F, (111)In, and (99)Tc were determined in a well counter. Linear regression analysis evaluated the relationships between the concentrations of (111)In and (18)F and the dependence of the ratio of (111)In/(18)F to the apparent distribution volume of (99m)Tc-DTPA. In 7 of 9 animals, (111)In increased as (18)F increased with the other 2 animals, showing weak negative slopes. With respect to the dependence of (111)In/(18)F with partition coefficient, 4 animals showed no dependence and 4 showed a weak positive slope, with 1 animal showing a negative slope. Further, in regions of extensive microvascular obstruction, (18)F significantly underestimated the extent of the presence of (111)In. In the early post-myocardial infarction period, (18)F-FDG PET imaging after a single bolus administration may underestimate the extent and degree of inflammation within regions of microvascular obstruction. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Data set characterizing the systemic alterations of microvascular reactivity and capillary density, in patients presenting with infective endocarditis.

Science.gov (United States)

Tibirica, Eduardo; Barcelos, Amanda; Lamas, Cristiane

2018-06-01

This article represents data associated with a prior publication from our research group, under the title: Evaluation of microvascular endothelial function and capillary density in patients with infective endocarditis using laser speckle contrast imaging and video-capillaroscopy [1]. Patients with definite infective endocarditis, under stable clinical conditions, were prospectively included. The clinical and laboratory features are presented for each of them in raw form. Microvascular reactivity was evaluated using a laser speckle contrast imaging (LSCI) system with a laser wavelength of 785 nm. LSCI was used in combination with the iontophoresis of acetylcholine (ACh) or sodium nitroprusside (SNP) for the noninvasive, continuous measurement of cutaneous microvascular perfusion changes in arbitrary perfusion units (APU). The images were analyzed using the manufacturer's software. One skin site on the ventral surface of the forearm was chosen for the experiment. Microvascular reactivity was also evaluated using post-occlusive reactive hyperemia, whereby arterial occlusion was achieved with supra-systolic pressure (50 mmHg above the systolic arterial pressure) using a sphygmomanometer for three minutes. Following the release of pressure, maximum flux was measured. Data on cutaneous microvascular density were obtained using intravital video-capillaroscopy. The data obtained may be helpful by showing the usefulness of laser-based noninvasive techniques in systemic infectious diseases other than sepsis, in different clinical settings and countries.

The effect of nitroglycerin on microvascular perfusion and oxygenation during gastric tube reconstruction.

Science.gov (United States)

Buise, Marc P; Ince, Can; Tilanus, Hugo W; Klein, Jan; Gommers, Diederik; van Bommel, Jasper

2005-04-01

Esophagectomy followed by gastric tube reconstruction is the surgical treatment of choice for patients with esophageal cancer. Complications of the cervical anastomosis are associated with impaired microvascular blood flow (MBF) and ischemia in the gastric fundus. The aim of the present study was to differentiate whether the decrease in MBF is a result of arterial insufficiency or of venous congestion. To do this we assessed MBF, microvascular hemoglobin oxygen saturation (muHbSo(2)), and microvascular hemoglobin concentration (muHbcon) simultaneously during different stages of gastric tube reconstruction. In 14 patients, MBF was determined with laser Doppler flowmetry, and muHbSo(2) and muHbcon were determined with reflectance spectro- photometry. After completion of the anastomosis, nitroglycerin was applied at the fundus. Although MBF did not change significantly in the pylorus, MBF decreased progressively during surgery in the fundus from 210 +/- 18 Arbitrary Units at baseline (normal stomach) to 52 +/- 9 Arbitrary Units after completion of reconstruction (mean +/- sem; P tube reconstruction but that muHbSo(2) and muHbcon do not. This decrease might be the result of venous congestion, which can partly be counteracted by application of nitroglycerin.

ANAEMIA AS A RISK FACTOR FOR MICROVASCULAR COMPLICATIONS IN TYPE 2 DM- A CROSS-SECTIONAL STUDY

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Kamanuru Ethirajulu Govindarajulu

2016-11-01

Full Text Available BACKGROUND It is well known that diabetes adversely affects the kidneys finally leading to anaemia by various mechanisms. Several studies had postulated that anaemia developing before renal complications has an independent association with microvascular complication in type 2 diabetic patients. The aim of the study is to estimate the prevalence of anaemia in persons with type 2 diabetes mellitus and its role as a risk factor for the presence and the severity of microvascular complication in a populationbased study. MATERIALS AND METHODS This is a cross-sectional study conducted in patients coming to OPD of the Department of General Medicine in Government Vellore Medical College for a duration of 3 months from June 01, 2016, to August 31, 2016. Type 2 DM patients between the age group 20-60 years attending our diabetic clinic of both sex were included in our study. RESULTS From a total of 100 patients, 41% had anaemia including 34% with normochromic normocytic, 65.85% with hyperchromic microcytic anaemia and none of the patient had macrocytic anaemia. Patients who are anaemic had more frequent microvascular complications. There was no significant difference between males and females. The average duration of diabetes has a positive correlation with anaemia. All the microvascular complications like neuropathy, nephropathy and retinopathy had significant association with the presence of anaemia in type 2 patients. Nephropathy had a significant higher frequency compared to others as a complication in type 2 DM. CONCLUSION Our study shows that there is increased prevalence of anaemia in type 2 DM patients and the prevalence of microvascular complications is significantly higher among the diabetic patients with anaemia.

Preventing microvascular complications in type 1 diabetes mellitus

OpenAIRE

Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progressi...

Inversion prepared coronary MR angiography: direct visualization of coronary blood flow

International Nuclear Information System (INIS)

Katoh, M.; Spuentrup, E.; Buecker, A.; Guenther, R.W.; Stuber, M.; Manning, W.J.; Botnar, R.M.

2005-01-01

Purpose: visualization of coronary blood flow by means of a slice-selective inversion pre-pulse in concert with bright-blood coronary MRA. Materials and methods: coronary magnetic resonance angiography (MRA) of the right coronary artery (RCA) was performed in eight healthy adult subjects on a 1.5 Tesla MR system (Gyroscan ACS-NT, Philips Medical Systems, Best, NL) using a free-breathing navigator-gated and cardiac-triggered 3D steady-state free-precession (SSFP) sequence with radial k-space sampling. Imaging was performed with and without a slice-selective inversion pre-pulse, which was positioned along the main axis of the coronary artery but perpendicular to the imaging volume. Objective image quality parameters such as SNR, CNR, maximal visible vessel length, and vessel border definition were analyzed. Results: in contrast to conventional bright-blood 3D coronary MRA, the selective inversion pre-pulse provided a direct measure of coronary blood flow. In addition, CNR between the RCA and right ventricular blood pool was increased and the vessels had a tendency towards better delineation. Blood SNR and CNR between right coronary blood and epicardial fat were comparable in both sequences. (orig.)

Capillaries within compartments: microvascular interpretation of dynamic positron emission tomography data

DEFF Research Database (Denmark)

Munk, O L; Keiding, S; Bass, L

2003-01-01

estimation of parameters in models with more physiological realism. We explore the standard compartmental model and find that incorporation of blood flow leads to paradoxes, such as kinetic rate constants being time-dependent, and tracers being cleared from a capillary faster than they can be supplied...... single- and multi-capillary systems and include effects of non-exchanging vessels. They are suitable for analysing dynamic PET data from any capillary bed using either intravascular or diffusible tracers, in terms of physiological parameters which include regional blood flow. Udgivelsesdato: 2003-Nov-7...... by blood flow. The inability of the standard model to incorporate blood flow consequently raises a need for models that include more physiology, and we develop microvascular models which remove the inconsistencies. The microvascular models can be regarded as a revision of the input function. Whereas...

Time-Dependent Behavior of Microvascular Blood Flow and Oxygenation: A Predictor of Functional Outcomes.

Science.gov (United States)

Kuliga, Katarzyna Z; Gush, Rodney; Clough, Geraldine F; Chipperfield, Andrew John

2018-05-01

This study investigates the time-dependent behaviour and algorithmic complexity of low-frequency periodic oscillations in blood flux (BF) and oxygenation signals from the microvasculature. Microvascular BF and oxygenation (OXY: oxyHb, deoxyHb, totalHb, and SO 2 %) was recorded from 15 healthy young adult males using combined laser Doppler fluximetry and white light spectroscopy with local skin temperature clamped to 33  °C and during local thermal hyperaemia (LTH) at 43 °C. Power spectral density of the BF and OXY signals was evaluated within the frequency range (0.0095-1.6 Hz). Signal complexity was determined using the Lempel-Ziv (LZ) algorithm. Fold increase in BF during LTH was 15.6 (10.3, 22.8) and in OxyHb 4.8 (3.5, 5.9) (median, range). All BF and OXY signals exhibited multiple oscillatory components with clear differences in signal power distribution across frequency bands at 33 and 43 °C. Significant reduction in the intrinsic variability and complexity of the microvascular signals during LTH was found, with mean LZ complexity of BF and OxyHb falling by 25% and 49%, respectively ( ). These results provide corroboration that in human skin microvascular blood flow and oxygenation are influenced by multiple time-varying oscillators that adapt to local influences and become more predictable during increased haemodynamic flow. Recent evidence strongly suggests that the inability of microvascular networks to adapt to an imposed stressor is symptomatic of disease risk which might be assessed via BF and OXY via the combination signal analysis techniques described here.

Thrombin stimulates albumin transcytosis in lung microvascular endothelial cells via activation of acid sphingomyelinase.

Science.gov (United States)

Kuebler, Wolfgang M; Wittenberg, Claudia; Lee, Warren L; Reppien, Eike; Goldenberg, Neil M; Lindner, Karsten; Gao, Yizhuo; Winoto-Morbach, Supandi; Drab, Marek; Mühlfeld, Christian; Dombrowsky, Heike; Ochs, Matthias; Schütze, Stefan; Uhlig, Stefan

2016-04-15

Transcellular albumin transport occurs via caveolae that are abundant in lung microvascular endothelial cells. Stimulation of albumin transcytosis by proinflammatory mediators may contribute to alveolar protein leak in lung injury, yet the regulation of albumin transport and its underlying molecular mechanisms are so far incompletely understood. Here we tested the hypothesis that thrombin may stimulate transcellular albumin transport across lung microvascular endothelial cells in an acid-sphingomyelinase dependent manner. Thrombin increased the transport of fluorescently labeled albumin across confluent human lung microvascular endothelial cell (HMVEC-L) monolayers to an extent that markedly exceeds the rate of passive diffusion. Thrombin activated acid sphingomyelinase (ASM) and increased ceramide production in HMVEC-L, but not in bovine pulmonary artery cells, which showed little albumin transport in response to thrombin. Thrombin increased total caveolin-1 (cav-1) content in both whole cell lysates and lipid rafts from HMVEC-L, and this effect was blocked by inhibition of ASM or de novo protein biosynthesis. Thrombin-induced uptake of albumin into lung microvascular endothelial cells was confirmed in isolated-perfused lungs by real-time fluorescence imaging and electron microscopy of gold-labeled albumin. Inhibition of ASM attenuated thrombin-induced albumin transport both in confluent HMVEC-L and in intact lungs, whereas HMVEC-L treatment with exogenous ASM increased albumin transport and enriched lipid rafts in cav-1. Our findings indicate that thrombin stimulates transcellular albumin transport in an acid sphingomyelinase-dependent manner by inducing de novo synthesis of cav-1 and its recruitment to membrane lipid rafts. Copyright © 2016 the American Physiological Society.

Coronary Artery Anomalies in Animals

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Brian A. Scansen

2017-04-01

Full Text Available Coronary artery anomalies represent a disease spectrum from incidental to life-threatening. Anomalies of coronary artery origin and course are well-recognized in human medicine, but have received limited attention in veterinary medicine. Coronary artery anomalies are best described in the dog, hamster, and cow though reports also exist in the horse and pig. The most well-known anomaly in veterinary medicine is anomalous coronary artery origin with a prepulmonary course in dogs, which limits treatment of pulmonary valve stenosis. A categorization scheme for coronary artery anomalies in animals is suggested, dividing these anomalies into those of major or minor clinical significance. A review of coronary artery development, anatomy, and reported anomalies in domesticated species is provided and four novel canine examples of anomalous coronary artery origin are described: an English bulldog with single left coronary ostium and a retroaortic right coronary artery; an English bulldog with single right coronary ostium and transseptal left coronary artery; an English bulldog with single right coronary ostium and absent left coronary artery with a prepulmonary paraconal interventricular branch and an interarterial circumflex branch; and a mixed-breed dog with tetralogy of Fallot and anomalous origin of all coronary branches from the brachiocephalic trunk. Coronary arterial fistulae are also described including a coronary cameral fistula in a llama cria and an English bulldog with coronary artery aneurysm and anomalous shunting vessels from the right coronary artery to the pulmonary trunk. These examples are provided with the intent to raise awareness and improve understanding of such defects.

Evaluation of microvascular endothelial function and capillary density in patients with infective endocarditis using laser speckle contrast imaging and video-capillaroscopy.

Science.gov (United States)

Barcelos, Amanda; Tibirica, Eduardo; Lamas, Cristiane

2018-07-01

To evaluate the systemic microcirculation of patients with infective endocarditis (IE). This is a comparative study of patients with definite IE by the modified Duke criteria admitted to our center for treatment. A reference group of sex- and age-matched healthy volunteers was included. Microvascular flow was evaluated in the forearm using a laser speckle contrast imaging system, for noninvasive measurement of cutaneous microvascular perfusion, in combination with skin iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to test microvascular reactivity. Microvascular density was evaluated using skin video-capillaroscopy. We studied 22 patients with IE; 15 were male and seven female. The mean age and standard deviation (SD) were 45.5 ± 17.3 years. Basal skin microvascular conductance was significantly increased in patients with IE, compared with healthy individuals (0.36 ± 0.13 versus 0.21 ± 0.08 APU/mmHg; P < 0.0001). The increase in microvascular conductance induced by ACh in patients was 0.21 ± 0.17 and in the reference group, it was 0.37 ± 0.14 APU/mmHg (P = 0.0012). The increase in microvascular conductance induced by SNP in patients was 0.18 ± 0.14 and it was 0.29 ± 0.15 APU/mmHg (P = 0.0140) in the reference group. The basal mean skin capillary density of patients (135 ± 24 capillaries/mm 2 ) was significantly higher, compared with controls (97 ± 21 capillaries/mm 2 ; P < 0.0001). The main findings in the microcirculation of patients with IE were greater basal vasodilation and a reduction of the endothelium-dependent and -independent microvascular reactivity, as well as greater functional skin capillary density compared to healthy individuals. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of thrombus composition and viscosity on sonoreperfusion efficacy in a model of microvascular obstruction

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Black, John J.; Yu, Francois T. H.; Schnatz, Rick G.; Flordeliza, Xucai Chen; Villanueva, S.; Pacella, John J.

2016-01-01

Distal embolization of microthrombi during stenting for myocardial infarction (MI) causes microvascular obstruction (MVO). We have previously shown that sonoreperfusion (SRP), a microbubble (MB)-mediated ultrasonic (US) therapy, resolves MVO from venous microthrombi in vitro in saline. However, blood is more viscous than saline and arterial thrombi that embolize during stenting are mechanically distinct from venous clot. Therefore, we tested the hypothesis that MVO created with arterial microthrombi are more resistant to SRP therapy compared with venous microthrombi and higher viscosity further increases the US requirement for effective SRP in an in vitro model of MVO. Lipid MB suspended in plasma with adjusted viscosity (1.1 or 4.0 cP) were passed through tubing bearing a mesh with 40 μm pores to simulate a microvascular cross-section; upstream pressure reflected thrombus burden. To simulate MVO, the mesh was occluded with either arterial or venous microthrombi to increase upstream pressure to 40±5 mmHg. Therapeutic long-tone-burst US was delivered to the occluded area for 20 min. MB activity was recorded with a passive cavitation detector (PCD). MVO caused by arterial microthrombi at either blood or plasma viscosity resulted in less effective SRP therapy, compared to venous thrombi. Higher viscosity further reduced the effectiveness of SRP therapy. PCD showed a decrease in inertial cavitation when viscosity was increased while stable cavitation was affected in a more complex manner. Overall, these data suggest that arterial thrombi may require higher acoustic pressure US than venous thrombi to achieve similar SRP efficacy, increased viscosity decreases SRP efficacy, and both inertial and stable cavitation are implicated in observed SRP efficacy. PMID:27207018

An Outflow Boundary Condition Model for Noninvasive Prediction of Fractional Flow Reserve in Diseased Coronary Arteries.

Science.gov (United States)

Fayssal, Iyad A; Moukalled, Fadl; Alam, Samir; Isma'eel, Hussain

2018-04-01

This paper reports on a new boundary condition formulation to model the total coronary myocardial flow and resistance characteristics of the myocardial vascular bed for any specific patient when considered for noninvasive diagnosis of ischemia. The developed boundary condition model gives an implicit representation of the downstream truncated coronary bed. Further, it is based on incorporating patient-specific physiological parameters that can be noninvasively extracted to account for blood flow demand to the myocardium at rest and hyperemic conditions. The model is coupled to a steady three-dimensional (3D) collocated pressure-based finite volume flow solver and used to characterize the "functional significance" of a patient diseased coronary artery segment without the need for predicting the hemodynamics of the entire arterial system. Predictions generated with this boundary condition provide a deep understanding of the inherent challenges behind noninvasive image-based diagnostic techniques when applied to human diseased coronary arteries. The overall numerical method and formulated boundary condition model are validated via two computational-based procedures and benchmarked with available measured data. The newly developed boundary condition is used via a designed computational methodology to (a) confirm the need for incorporating patient-specific physiological parameters when modeling the downstream coronary resistance, (b) explain the discrepancies presented in the literature between measured and computed fractional flow reserve (FFRCT), and (c) discuss the current limitations and future challenges in shifting to noninvasive assessment of ischemia.

Neutrophil-lymphocyte ratio is a novel reliable predictor of nephropathy, retinopathy, and coronary artery disease in Indians with type-2 diabetes

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Sachin Chittawar

2017-01-01

Full Text Available Background and Aims: Neutrophil-lymphocyte ratio (NLR has been suggested to be a predictor of coronary artery disease (CAD, and end-organ damage in type-2 diabetes mellitus (T2DM. Similar data are lacking from Indians with T2DM. Hence, this study aimed to evaluate the role of NLR as a predictor of microvascular complications and CAD in T2DM. Subjects and Methods: Consecutive T2DM patients attending the outpatient services of 2 different hospitals, who gave consent, underwent clinical, anthropometric evaluation, and evaluation for the occurrence of retinopathy, nephropathy, neuropathy, and CAD. Results: A total of 298 patients were screened of which 265 patients' data were analyzed. Occurrence of hypertension, neuropathy, nephropathy, retinopathy, and CAD was 12.8%, 18.5%, 41.5%, 62.3%, and 3.8%, respectively. Patients in higher NLR quartiles had significantly higher diabetes duration, occurrence of nephropathy, albuminuria, retinopathy, CAD and lpwer glomerular filtration rate. Patients with more microvascular complications had significantly longer diabetes duration, blood pressure, NLR, creatinine, and urine albumin excretion. Binary logistic regression revealed NLR followed by body mass index were best predictors of microvascular complications. NLR had areas under the receiver operating characteristic curve (AUC of 0.888 (95% CI: 0.848–0.929; P < 0.001, 0.708 (95% CI: 0.646–0.771; P < 0.001, and 0.768 (95% CI: 0.599–938; P = 0.004 in predicting albuminuria, retinopathy, and CAD, respectively. NLR of 2.00 had sensitivity and specificity of 86.4% and 69% in predicting albuminuria; sensitivity and specificity of 64.2% and 63% in predicting retinopathy; sensitivity and specificity of 80% and 47.1% in predicting CAD. Conclusion: NLR is inexpensive, easy to use, reliable predictor of nephropathy, retinopathy, and CAD in Indian T2DM.

Diagnosing coronary artery disease after a positive coronary computed tomography angiography

DEFF Research Database (Denmark)

Nissen, L; Winther, S; Westra, J

2018-01-01

Aims: Perfusion scans after coronary computed tomography angiography (CCTA) in patients with suspected coronary artery disease (CAD) may reduce unnecessary invasive coronary angiographies (ICAs). However, the diagnostic accuracy of perfusion scans after primary CCTA is unknown. The aim...

Microvascular Endothelial Dysfunction in Sedentary, Obese Humans is mediated by NADPH Oxidase; Influence of Exercise Training

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La Favor, Justin D.; Dubis, Gabriel S.; Yan, Huimin; White, Joseph D.; Nelson, Margaret A.M.; Anderson, Ethan J.; Hickner, Robert C.

2016-01-01

Objective The objectives of this study were to determine the impact of in vivo reactive oxygen species (ROS) on microvascular endothelial function in obese human subjects and to determine the efficacy of an aerobic exercise intervention on alleviating obesity-associated dysfunctionality. Approach and Results Young, sedentary men and women were divided into lean (BMI 18–25; n=14), intermediate (BMI 28–32.5; n=13), and obese (BMI 33–40; n=15) groups. A novel microdialysis technique was utilized to detect elevated interstitial hydrogen peroxide (H2O2) and superoxide levels in the vastus lateralis of obese compared to both lean and intermediate subjects. Nutritive blood flow was monitored in the vastus lateralis via the microdialysis-ethanol technique. A decrement in acetylcholine-stimulated blood flow revealed impaired microvascular endothelial function in the obese subjects. Perfusion of apocynin, an NADPH oxidase (Nox) inhibitor, lowered (normalized) H2O2 and superoxide levels and reversed microvascular endothelial dysfunction in obese subjects. Following 8-weeks of exercise, H2O2 levels were decreased in the obese subjects and microvascular endothelial function in these subjects was restored to levels similar to lean subjects. Skeletal muscle protein expression of the Nox subunits p22phox, p47phox, and p67phox were increased in obese relative to lean subjects, where p22phox and p67phox expression was attenuated by exercise training in obese subjects. Conclusions This study implicates Nox as a source of excessive ROS production in skeletal muscle of obese individuals, and links excessive Nox derived ROS to microvascular endothelial dysfunction in obesity. Furthermore, aerobic exercise training proved to be an effective strategy for alleviating these maladies. PMID:27765769

Non-obstructive coronary artery disease assessed by coronary computed tomography angiography

DEFF Research Database (Denmark)

Nielsen, L.; Bøtker, H. E.; Sorensen, H.

2015-01-01

Introduction: Coronary CT angiography (CTA) detects non-obstructive coronary artery disease (CAD) that may not be recognized by functional testing, but the prognostic impact is not well understood. This study aimed to compare the risk of myocardial infarction (MI) and all-cause mortality...... in patients without or with non-obstructive and obstructive CAD assessed by coronary CTA. Methods: Consecutive patients without known coronary artery disease (CAD) and with chest pain who underwent coronary CTA (>64-detector row) between January 2007 and December 2012 in the 10 centers participating...... in the Western Denmark Cardiac Computed Tomography Registry were included. The endpoints were 3-year MI or all-cause mortality. The coronary CTA result was defined as normal (0% luminal stenosis), non-obstructive CAD (1%-49% luminal stenosis) or obstructive CAD (>50% luminal stenosis; 1-vessel, 2-vessel, or 3...

Value of a new multiparametric score for prediction of microvascular obstruction lesions in ST-segment elevation myocardial infarction revascularized by percutaneous coronary intervention.

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Amabile, Nicolas; Jacquier, Alexis; Gaudart, Jean; Sarran, Anthony; Shuaib, Anes; Panuel, Michel; Moulin, Guy; Bartoli, Jean-Michel; Paganelli, Franck

2010-10-01

Despite improvement in revascularization strategies, microvascular obstruction (MO) lesions remain associated with poor outcome after ST-segment elevation myocardial infarction (STEMI). To establish a bedside-available score for predicting MO lesions in STEMI, with cardiac magnetic resonance imaging (CMR) as the reference standard, and to test its prognostic value for clinical outcome. Patients with STEMI of4 accurately identified microcirculatory injuries (sensitivity 84%; specificity 82%) and independently predicted the presence of MO lesions on CMR. MO score>4 predicted adverse cardiovascular events during the first year after STEMI (relative risk 2.60 [1.10-6.60], p=0.03). MO lesions are frequent in PCI-treated STEMI and are associated with larger MIs. MO score accurately predicted MO lesions and identified patients with poor outcome post-STEMI. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Clopidogrel Resistance: Current Issues

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NS Neki

2016-05-01

Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

GLP-1 increases microvascular recruitment but not glucose uptake in human and rat skeletal muscle

DEFF Research Database (Denmark)

Sjøberg, Kim Anker; Holst, Jens Juul; Rattigan, Stephen

2014-01-01

The insulinotropic gut hormone, glucagon-like-peptide-1 (GLP-1) has been proposed to have effects on vascular function and glucose disposal. However, whether GLP-1 is able to increase microvascular recruitment (MVR) in humans has not been investigated. GLP-1 was infused in the femoral artery...... in overnight fasted healthy young men. Microvascular recruitment was measured with real time contrast-enhanced ultrasound and leg glucose uptake by the leg balance technique with and without inhibition of the insulinotropic response of GLP-1 by co-infusion of octreotide. As a positive control, MVR and leg...

Dependence of intramyocardial pressure and coronary flow on ventricular loading and contractility: a model study.

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Bovendeerd, Peter H M; Borsje, Petra; Arts, Theo; van De Vosse, Frans N

2006-12-01

The phasic coronary arterial inflow during the normal cardiac cycle has been explained with simple (waterfall, intramyocardial pump) models, emphasizing the role of ventricular pressure. To explain changes in isovolumic and low afterload beats, these models were extended with the effect of three-dimensional wall stress, nonlinear characteristics of the coronary bed, and extravascular fluid exchange. With the associated increase in the number of model parameters, a detailed parameter sensitivity analysis has become difficult. Therefore we investigated the primary relations between ventricular pressure and volume, wall stress, intramyocardial pressure and coronary blood flow, with a mathematical model with a limited number of parameters. The model replicates several experimental observations: the phasic character of coronary inflow is virtually independent of maximum ventricular pressure, the amplitude of the coronary flow signal varies about proportionally with cardiac contractility, and intramyocardial pressure in the ventricular wall may exceed ventricular pressure. A parameter sensitivity analysis shows that the normalized amplitude of coronary inflow is mainly determined by contractility, reflected in ventricular pressure and, at low ventricular volumes, radial wall stress. Normalized flow amplitude is less sensitive to myocardial coronary compliance and resistance, and to the relation between active fiber stress, time, and sarcomere shortening velocity.

Imaging of cocaine-induced global and regional myocardial ischemia

International Nuclear Information System (INIS)

Oster, Z.H.; Som, P.; Wang, G.J.; Weber, D.A.

1991-01-01

Severe and often fatal cardiac complications have been reported in cocaine users with narrowed coronary arteries caused by atherosclerosis as well as in young adults with normal coronaries. The authors have found that in normal dogs cocaine induces severe temporary hypoperfusion of the left ventricle as indicated by a significantly lower 201Tl concentration compared to the baseline state. The most significant decrease in uptake occurred 5 min after injection and was more pronounced in the septal and apical segments. Following intravenous administration of cocaine, instead of gradual disappearance of 201Tl from the left ventricle, there was continuous increase in 201Tl concentration in the left ventricle. These imaging experiments indicate that the deleterious effects of cocaine on the heart are probably due to spasm of the coronaries and decreased myocardial perfusion. Since spasm of the large subpericardial vessels does not seem to explain the magnitude of the increased coronary resistance and decreased coronary flow after cocaine as described in the literature, it is suggested that microvascular spasm of smaller vessels plays a major role in the temporary decrease in perfusion. The data may also suggest that severe temporary myocardial ischemia is probably the initiating factor for the cardiac complications induced by cocaine

Early results of coronary artery bypass grafting with coronary endarterectomy for severe coronary artery disease

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Toischer Karl

2009-09-01

Full Text Available Abstract Background Despite the existence of controversial debates on the efficiency of coronary endarterectomy (CE, it is still used as an adjunct to coronary artery bypass grafting (CABG. This is particularly true in patients with endstage coronary artery disease. Given the improvements in cardiac surgery and postoperative care, as well as the rising number of elderly patient with numerous co-morbidities, re-evaluating the pros and cons of this technique is needed. Methods Patient demographic information, operative details and outcome data of 104 patients with diffuse calcified coronary artery disease were retrospectively analyzed with respect to functional capacity (NYHA, angina pectoris (CCS and mortality. Actuarial survival was reported using a Kaplan-Meyer analysis. Results Between August 2001 and March 2005, 104 patients underwent coronary artery bypass grafting (CABG with adjunctive coronary endarterectomy (CE in the Department of Thoracic-, Cardiac- and Vascular Surgery, University of Goettingen. Four patients were lost during follow-up. Data were gained from 88 male and 12 female patients; mean age was 65.5 ± 9 years. A total of 396 vessels were bypassed (4 ± 0.9 vessels per patient. In 98% left internal thoracic artery (LITA was used as arterial bypass graft and a total of 114 vessels were endarterectomized. CE was performed on right coronary artery (RCA (n = 55, on left anterior descending artery (LAD (n = 52 and circumflex artery (RCX (n = 7. Ninety-five patients suffered from 3-vessel-disease, 3 from 2-vessel- and 2 from 1-vessel-disease. Closed technique was used in 18%, open technique in 79% and in 3% a combination of both. The most frequent endarterectomized localization was right coronary artery (RCA = 55%. Despite the severity of endstage atherosclerosis, hospital mortality was only 5% (n = 5. During follow-up (24.5 ± 13.4 months, which is 96% complete (4 patients were lost caused by unknown address 8 patients died (cardiac

Quantitative relationship between coronary vasodilator reserve assessed by {sup 82}Rb PET imaging and coronary artery stenosis severity

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Anagnostopoulos, Constantinos [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Royal Brompton Hospital, Department of Nuclear Medicine, London (United Kingdom); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); Almonacid, Alexandra; Popma, Jeffrey J. [Brigham and Women' s Hospital, Division of Cardiovascular Medicine, Department of Medicine, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); El Fakhri, Georges [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Royal Brompton Hospital, Department of Cardiology, London (United Kingdom); Curillova, Zelmira; Dorbala, Sharmila; Di Carli, Marcelo F. [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Brigham and Women' s Hospital, Cardiovascular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Division of Cardiovascular Medicine, Department of Medicine, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); Sitek, Arkadiusz [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); Roughton, Michael [Royal Brompton Hospital, Department of Cardiology, London (United Kingdom)

2008-09-15

The relationship between myocardial blood flow (MBF) and stenosis severity has been determined previously using cyclotron-produced radiotracers such as {sup 15}O-H{sub 2}O and {sup 13}N-ammonia. An attractive alternative to overcome the limitations related to the use of cyclotron might be to use the generator-produced {sup 82}Rb as a flow tracer. The current study was undertaken to investigate the relationship between MBF and coronary vasodilator reserve (CVR) as measured by {sup 82}Rb positron emission tomography (PET) and the percent diameter stenosis as defined by quantitative coronary arteriography. We prospectively evaluated 22 individuals: 15 patients (60 {+-} 11 years of age) with angiographically documented coronary artery disease (CAD) and seven age-matched (56 {+-} 9 years) asymptomatic individuals without risk factors for CAD. Dynamic {sup 82}Rb PET was performed at rest and after dipyridamole vasodilation. MBF, CVR and an index of 'minimal coronary resistance' (MCR) were assessed in each of the three main coronary territories. Rest and stress MBF in regions subtended by vessels with less than 50% diameter stenosis was similar to that of the individuals with no risk factors for CAD. As a result, CVR was also similar in the two groups (1.9, interquartile [IQ] range from 1.7 to 2.7 vs. 2.2, IQ range from 2 to 3.4 respectively, p=0.09). CVR successfully differentiated coronary lesions with stenosis severity 70% to 89% from those with 50% to 69% stenosis (1, IQ range from 1 to 1.3 vs. 1.7, IQ range from 1.4 to 2), respectively, p=0.001. In addition, hyperaemic MBF (r{sup 2}=0.74, p<0.001), CVR (r {sup 2}=0.69, p<0.001) and MCR (r{sup 2}=0.78, p<0.001) measurements were inversely and non-linearly correlated to the percent diameter stenosis on angiography. MBF and CVR are inversely and non-linearly correlated to stenosis severity. Quantitative {sup 82}Rb PET can be a clinically useful tool for an accurate functional assessment of CAD. (orig.)

[Comparison of 64 MDCT coronary CTA and coronary angiography in the detection of coronary artery stenosis in low risk patients with stable angina and acute coronary syndrome].

Science.gov (United States)

Cazalas, G; Sarran, A; Amabile, N; Chaumoitre, K; Marciano-Chagnaud, S; Jacquier, A; Paganelli, F; Panuel, M

2009-09-01

To determine the accuracy of 64 MDCT coronary CTA (CCTA) compared to coronary angiography in low risk patients with stable angina and acute coronary syndrome and determine the number of significant coronary artery stenoses ( 50%) in these patients. Materials and methods. Fifty-five patients underwent CCTA using a 32 MDCT unit with z flying focus allowing the acquisition of 64 slices of 0.6 mm thickness as well as coronary angiography (gold standard). Nine patients were excluded due to prior coronary artery bypass surgery (n=4), insufficient breath hold (n=3), calcium scoring>1000 (n=1) and delay between both examinations over 4 months (n=1). Forty-six patients: 27 males and 19 females were included. CCTA results were compared to coronary angiography per segment and artery with threshold detection of stenoses 50%. The degree of correlation between both examinations was performed using a regression analysis with a Pearson correlation coefficient<0.05 considered significant. The overall accuracy of CCTA was 90%; limitations related to the presence of calcifications, motion artifacts or insufficient vessel opacification. The correlation for all analyzed segments was 96.4%. Thirty-eight of 50 significant stenoses seen on coronary angiography were correctly detected on CCTA. Sensitivity, specificity, PPVC and NPV for detection of stenoses 50% were 76%, 98.3%, 80.3% and 97.7% respectively. Evaluation per segment had a NPV of 96.8% (interventricular and diagonal segments) to 100% (main trunk). Our results for specificity and NPV are similar to reports from the literature. This suggests that CCTA in this clinical setting may replace coronary angiography.

Morphological study on coronary ostial and clinicoangiographic analysis of isolated coronary ostial stenosis

International Nuclear Information System (INIS)

Kanoh, Tatsuji

2007-01-01

A morphological study of coronary ostia was performed in 70 autopsied human hearts, with particular attention being focused on the funnel-shaped structure, aging changes, and relation to atherosclerosis. The following results were obtained: The ostium is particularly well-defined and forms a funnel-shaped structure. The structure is predominantly a double circular shape on the right and comet-shaped on the left. The funnel-shaped structure of coronary ostia is characterized by a longitudinal smooth muscle arrangement in the inner layer and circular one in the outer layer. Including overhang formation, coronary sclerosis of the ostium appears mainly on the upper margin of the funnel-shaped structure of the right ostium and at the upper right margin of the left. In ischemic heart disease, along with changes in coronary arteries themselves, changes in the ostia of these arteries should be paid close attention. Ostial stenosis of the coronary artery in the absence of distal vessel obstructions, isolated ostial stenosis, is a rare form of coronary artery disease. In a previous review of the international literature, the incidence of coronary ostial stenosis varied between 0.13% and 2.7%. Among 7,500 patients undergoing selective coronary cineangiography at Juntendo University Hospital and Juntendo Urayasu Hospital from 1975 to 1990, five women (0.07%) were diagnosed as having ''isolated coronary ostial stenosis'', of which the cause is unknown. Atherosclerosis, particularly early premature atherome, congenital coronary anomaly, fibro-muscular dysplasia, Takayasu's aortitis, humoral factors, spasm, and iatrogenic events have been considered as its causes. In contrast to usual atherosclerotic coronary artery disease, patients with isolated coronary ostial stenosis of unknown etiology were characterized as being middle-aged, premenopausal, slender females having few coronary risk factors, experiencing severe angina pector is with marked ischemic electrocardiogram changes

Factors influencing delay time and coronary arterial density during coronary angiography with DSCT.

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Tang, Lijun; Zhu, Xiaomei; Xu, Yi; Yu, Tongfu; Xu, Hai; Tang, Jinhua; Dogra, Vikram; Wang, Dehang

2011-02-01

CT angiography (CTA) plays an important role in diagnosing coronary arterial disease. Delay time and density of the coronary arteries related with patient-specific factors are essential for getting an optimal CTA image. To investigate various factors influencing delay time and coronary arterial density during coronary CTA with dual source CT. One hundred and sixteen consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Factors including gender, age, height, weight, transversal cardiac diameter (TCD), transversal thoracic diameter (TTD), heart rate (HR), body surface area (BSA = [weight × height/3600](1/2)) and cardiothoracic ratio (CTR = TCD/TTD) were recorded, measured and calculated before administration of contrast media during coronary CT angiography. Delay time was determined as duration from the beginning of the injection to the density in the descending aorta at the level of right main pulmonary artery reaching a threshold of 100 HU. Coronary arterial density was measured at the mid portion of the right coronary artery. Regression analysis and stepwise regression analysis were used to investigate the influence of these factors on delay time and coronary arterial density. Delay time decreased with an increasing HR and it was shorter in women than men. Delay time increased with an increasing TCD. Delay time could be predicted by the formula: DT = 16.651-0.110 × HR + 1.902 × gender + 0.394 × TCD (where DT is abbreviation for delay time, gender is 0 for women and 1 for men). Coronary arterial density decreased with an increasing HR and weight. Coronary arterial density could be predicted by the formula: CAD = 923.42-4.099 × HR-3.293 × weight (CAD = coronary arterial density). There was no relationship between the other factors mentioned above and delay time or coronary arterial density. Delay time is influenced by HR, gender and TCD. Coronary arterial density also changes with HR and weight. So HR, gender, TCD and

Hemifacial spasm : Intraoperative electromyographic monitoring as a guide for microvascular decompression

NARCIS (Netherlands)

Mooij, JJA; Mustafa, MK; van Weerden, TW

2001-01-01

OBJECTIVE: Microvascular decompression is the logical and well-accepted treatment of choice for hemifacial spasm (HFS). In experienced hands, good to excellent results can be obtained. However, sometimes the exact site of the vascular compression is unclear. The aim of this study was to analyze

MICROVASCULAR CHANGES IN AGED RAT FOREBRAIN - EFFECTS OF CHRONIC NIMODIPINE TREATMENT

NARCIS (Netherlands)

de Jong, Giena; Weerd, H. de; Schuurman, T.; Traber, J.; Luiten, P.G.M.

1990-01-01

In the present study the effects of long-term treatment with the 1,4-dihydropyridine calcium antagonist nimodipine on ultrastructural alterations of the microvascular morphology were examined in the frontoparietal cortex, entorhinal cortex and CA1 of the hippocampus in the aged rat. Qualitative

The human coronary vasodilatory response to acute mental stress is mediated by neuronal nitric oxide synthase

Science.gov (United States)

Khan, Sitara G.; Melikian, Narbeh; Shabeeh, Husain; Cabaco, Ana R.; Martin, Katherine; Khan, Faisal; O’Gallagher, Kevin; Chowienczyk, Philip J.

2017-01-01

Mental stress-induced ischemia approximately doubles the risk of cardiac events in patients with coronary artery disease, yet the mechanisms underlying changes in coronary blood flow in response to mental stress are poorly characterized. Neuronal nitric oxide synthase (nNOS) regulates basal coronary blood flow in healthy humans and mediates mental stress-induced vasodilation in the forearm. However, its possible role in mental stress-induced increases in coronary blood flow is unknown. We studied 11 patients (6 men and 5 women, mean age: 58 ± 14 yr) undergoing elective diagnostic cardiac catheterization and assessed the vasodilator response to mental stress elicited by the Stroop color-word test. Intracoronary substance P (20 pmol/min) and isosorbide dinitrate (1 mg) were used to assess endothelium-dependent and -independent vasodilation, respectively. Coronary blood flow was estimated using intracoronary Doppler recordings and quantitative coronary angiography to measure coronary artery diameter. Mental stress increased coronary flow by 34 ± 7.0% over the preceding baseline during saline infusion (P coronary artery diameter by 6.9 ± 3.7% (P = 0.02) and 0.5 ± 2.8% (P = 0.51) in the presence of S-methyl-l-thiocitrulline. The response to substance P did not predict the response to mental stress (r2 = −0.22, P = 0.83). nNOS mediates the human coronary vasodilator response to mental stress, predominantly through actions at the level of coronary resistance vessels. NEW & NOTEWORTHY Acute mental stress induces vasodilation of the coronary microvasculature. Here, we show that this response involves neuronal nitric oxide synthase in the human coronary circulation. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/nnos-and-coronary-flow-during-mental-stress/. PMID:28646032

The human coronary vasodilatory response to acute mental stress is mediated by neuronal nitric oxide synthase.

Science.gov (United States)

Khan, Sitara G; Melikian, Narbeh; Shabeeh, Husain; Cabaco, Ana R; Martin, Katherine; Khan, Faisal; O'Gallagher, Kevin; Chowienczyk, Philip J; Shah, Ajay M

2017-09-01

Mental stress-induced ischemia approximately doubles the risk of cardiac events in patients with coronary artery disease, yet the mechanisms underlying changes in coronary blood flow in response to mental stress are poorly characterized. Neuronal nitric oxide synthase (nNOS) regulates basal coronary blood flow in healthy humans and mediates mental stress-induced vasodilation in the forearm. However, its possible role in mental stress-induced increases in coronary blood flow is unknown. We studied 11 patients (6 men and 5 women, mean age: 58 ± 14 yr) undergoing elective diagnostic cardiac catheterization and assessed the vasodilator response to mental stress elicited by the Stroop color-word test. Intracoronary substance P (20 pmol/min) and isosorbide dinitrate (1 mg) were used to assess endothelium-dependent and -independent vasodilation, respectively. Coronary blood flow was estimated using intracoronary Doppler recordings and quantitative coronary angiography to measure coronary artery diameter. Mental stress increased coronary flow by 34 ± 7.0% over the preceding baseline during saline infusion ( P stress increased coronary artery diameter by 6.9 ± 3.7% ( P = 0.02) and 0.5 ± 2.8% ( P = 0.51) in the presence of S -methyl-l-thiocitrulline. The response to substance P did not predict the response to mental stress ( r 2 = -0.22, P = 0.83). nNOS mediates the human coronary vasodilator response to mental stress, predominantly through actions at the level of coronary resistance vessels. NEW & NOTEWORTHY Acute mental stress induces vasodilation of the coronary microvasculature. Here, we show that this response involves neuronal nitric oxide synthase in the human coronary circulation.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/nnos-and-coronary-flow-during-mental-stress/. Copyright © 2017 the American Physiological Society.

Significance of determination of bone mineral density and osteocalcin in diabetic patients with diabetic microvascular complications

International Nuclear Information System (INIS)

Kong Xianghui; Mu Junqing; Lu Kuan

2003-01-01

Objective: To study the influence of diabetic microvascular complications on bone mineral density (BMI) and osteocalcin (BGP). Methods: 60 patients with type 2 diabetes mellitus were studied, including 33 with microvascular complications (retinopathy, nephropathy, neuropathy) (group 1) and 27 without complications (group 2). Fasting blood glucose, serum fructosamine (GSP), total alkaline phosphatase (TALP), calcium (Ca 2+ ) levels were measured by biochemical method; osteocalcin (BGP) level was detected by RIA. BMD of the lumbar spine and femur was measured by dual energy X-ray absorptiometry in all patients. Body mass index (BMI) was calculated from the height and body weight. Results: The BMI, GSP, FBG, TALP and Ca 2+ values in the two groups were not much different, but BGP and BMD in group 1 were significantly lower than those in group 2. Conclusion: Bone mineral density (BMD) and BGP values were closely related to the microvascular complications in diabetes, which could decrease bone formation and increase the frequency of osteoporosis

Myocardial flow reserve is influenced by both coronary artery stenosis severity and coronary risk factors in patients with suspected coronary artery disease

International Nuclear Information System (INIS)

Tsukamoto, Takahiro; Naya, Masanao; Tsutsui, Hiroyuki; Morita, Koichi; Katoh, Chietsugu; Inubushi, Masayuki; Kuge, Yuji; Tamaki, Nagara

2006-01-01

Myocardial flow reserve (MFR) measurement has an important role in assessing the functional severity of coronary artery stenosis. However, a discrepancy between the anatomical severity of coronary artery stenosis and MFR is often observed. Such a discrepancy may be explained by coronary risk factors. In this study, we aimed to investigate the influence of coronary artery stenosis severity and risk factors on MFR. Seventy-four patients suspected to have coronary artery disease and seven age-matched healthy volunteers were enrolled. Myocardial blood flow (MBF) and MFR were measured using 15 O-labelled water PET. Regional MFR was calculated in regions with significant coronary artery stenosis (stenotic regions) and in regions without significant stenosis (remote regions). The contributions of coronary artery stenosis severity and coronary risk factors were assessed using univariate and multivariate analyses. In stenotic regions, MFR correlated inversely with coronary artery stenosis severity (r=-0.50, p<0.01). Univariate analysis did not show any significant difference in MFR between the patients with and the patients without each risk factor. In remote regions, however, MFR was significantly decreased in the diabetes and smoking groups (each p<0.05). By multivariate analysis, diabetes and smoking were independent predictors of MFR (each p<0.05). In the group with more than one risk factor, MFR was significantly lower (2.78±0.79) than in the other group (3.40±1.22, p<0.05). MFR is influenced not only by coronary stenosis severity but also by coronary risk factors. In particular, the influence of risk factors should be considered in regions without severe coronary stenosis. (orig.)

Coronary artery aneurysms

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Koischwitz, D.; Harder, T.; Schuppan, U.; Thurn, P.

1982-04-01

Seven saccular coronary artery aneurysms have been demonstrated in the course of 1452 selective coronary artery angiograms. In six patients they were arterio-sclerotic; in one patient the aneurysm must have been congenital or of mycotic-embolic origin. The differential diagnosis between true aneurysms and other causes of vascular dilatation is discussed. Coronary artery aneurysms have a poor prognosis because of the possibility of rupture with resultant cardiac tamponade, or the development of thrombo-embolic myocardial infarction. These aneurysms can only be diagnosed by means of coronary angiography and require appropriate treatment.

Effect of atrial systole on canine and porcine coronary blood flow.

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Bellamy, R F

1981-09-01

A feature of phasic coronary flow patterns recorded in conscious chronically instrumented dogs is the atrial cove--a transient depression of arterial flow that occurs during atrial systole. The association between the hemodynamic effects of atrial systole and the atrial cove was studied in anesthetized dogs and pigs with complete heart block. Many atrial coves are available for study in these preparations because atrial activity continues unabated during the diastolic ventricular arrest that follows cessation of electrical pacing. The effect of atrial systole is to translate the pressure-flow relation found during diastole to a higher intercept pressure without change in slope. The increase in the intercept pressure equals the increase in intramyocardial pressure measured with microtransducers embedded in the left ventricular wall. The decrement in flow during the atrial cove is a direct function of the change in intramyocardial pressure and an inverse function of coronary vascular resistance. Each atrial systole is associated with a forward flow transient in the coronary veins, the peak of which occurs at the same instant as does the nadir of atrial flow. These data suggest that the coronary vessels are acting as collapsible tubes and that the waterfall model of the coronary circulation is applicable. The following sequence is proposed to account for the atrial cove. Atrial systole ejects a bolus of blood into the left ventricle increasing both ventricular cavity and intramyocardial pressures. The increase in intramyocardial pressure raises the back pressure opposing coronary flow, reducing the arterial perfusion pressure gradient and causing flow to fall.

[The role of epicardial fat and obesity parameters in the prediction of coronary heart disease].

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Prídavková, Dana; Kantárová, Daniela; Lišková, Renáta; Červeň, Peter; Kovář, František; Mokáň, Marián

2016-04-01

To assess the relationship of parameters of obesity in relationship to coronary angiography findings with correlation of epicardial fat (EF) thickness in uppermentioned context. There were 80 patients examined (43 males, 37 postmenopausal females) undergoing elective coronary angiography. We examined the regular obesity parameters - BMI, waist circumference (WC), neck circumference (NC), total body fat (TBF), and visceral fat (VF) using bioimpedance. We assessed the echocardiographically measured EF thickness. We added examination of lipidogram, glycaemia, HOMA-IR (insulin resistance index) and AIP (aterogenic index of plasma). The set was divided into group with coronarographically proved stenosis or stenoses (withCS), and a group without finding of quantifiable stenosis or stenoses (withoutCS). The average thickness of EF in withCS group was 6.3 vs 5.6 mm in group withoutCS (p obesity parameters in assessment of pre-clinical stages of coronary atherosclerosis and prediction of risk of coronary heart disease. In adipose parameters, EF thickness was correlated the most by WC. Risk stratification of coronary artery disease is supplemented by increased HOMA-IR and AIP.

Study of microvascular non-Newtonian blood flow modulated by electroosmosis.

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Tripathi, Dharmendra; Yadav, Ashu; Anwar Bég, O; Kumar, Rakesh

2018-05-01

An analytical study of microvascular non-Newtonian blood flow is conducted incorporating the electro-osmosis phenomenon. Blood is considered as a Bingham rheological aqueous ionic solution. An externally applied static axial electrical field is imposed on the system. The Poisson-Boltzmann equation for electrical potential distribution is implemented to accommodate the electrical double layer in the microvascular regime. With long wavelength, lubrication and Debye-Hückel approximations, the boundary value problem is rendered non-dimensional. Analytical solutions are derived for the axial velocity, volumetric flow rate, pressure gradient, volumetric flow rate, averaged volumetric flow rate along one time period, pressure rise along one wavelength and stream function. A plug swidth is featured in the solutions. Via symbolic software (Mathematica), graphical plots are generated for the influence of Bingham plug flow width parameter, electrical Debye length and Helmholtz-Smoluchowski velocity (maximum electro-osmotic velocity) on the key hydrodynamic variables. This study reveals that blood flow rate accelerates with decreasing the plug width (i.e. viscoplastic nature of fluids) and also with increasing the Debye length parameter. Copyright © 2018 Elsevier Inc. All rights reserved.

In-vivo assessment of microvascular functional dynamics by combination of cmOCT and wavelet transform

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Smirni, Salvatore; MacDonald, Michael P.; Robertson, Catherine P.; McNamara, Paul M.; O'Gorman, Sean; Leahy, Martin J.; Khan, Faisel

2018-02-01

The cutaneous microcirculation represents an index of the health status of the cardiovascular system. Conventional methods to evaluate skin microvascular function are based on measuring blood flow by laser Doppler in combination with reactive tests such as post-occlusive reactive hyperaemia (PORH). Moreover, the spectral analysis of blood flow signals by continuous wavelet transform (CWT) reveals nonlinear oscillations reflecting the functionality of microvascular biological factors, e.g. endothelial cells (ECs). Correlation mapping optical coherence tomography (cmOCT) has been previously described as an efficient methodology for the morphological visualisation of cutaneous micro-vessels. Here, we show that cmOCT flow maps can also provide information on the functional components of the microcirculation. A spectral domain optical coherence tomography (SD-OCT) imaging system was used to acquire 90 sequential 3D OCT volumes from the forearm of a volunteer, while challenging the micro-vessels with a PORH test. The volumes were sampled in a temporal window of 25 minutes, and were processed by cmOCT to obtain flow maps at different tissue depths. The images clearly show changes of flow in response to the applied stimulus. Furthermore, a blood flow signal was reconstructed from cmOCT maps intensities to investigate the microvascular nonlinear dynamics by CWT. The analysis revealed oscillations changing in response to PORH, associated with the activity of ECs and the sympathetic innervation. The results demonstrate that cmOCT may be potentially used as diagnostic tool for the assessment of microvascular function, with the advantage of also providing spatial resolution and structural information compared to the traditional laser Doppler techniques.

Assessment of coronary flow reserve by sestamibi imaging in patients with typical chest pain and normal coronary arteries

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Storto, Giovanni; Sorrentino, Anna R.; Pellegrino, Teresa; Liuzzi, Raffaele; Cuocolo, Alberto [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages of the National Council of Research, Naples (Italy); Petretta, Mario [University Federico II, Department of Internal Medicine, Cardiovascular and Immunological Sciences, Naples (Italy)

2007-08-15

We assessed coronary flow reserve (CFR) by sestamibi imaging in patients with typical chest pain, positive exercise stress test and normal coronary vessels. Thirty-five patients with typical chest pain and normal angiogram and 12 control subjects with atypical chest pain underwent dipyridamole/rest {sup 99m}Tc-sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in the pulmonary artery and myocardial counts from SPECT images. Estimated CFR was expressed as the ratio of stress to rest MBF. Rest MBF and CFR were corrected for rate-pressure product (RPP) and expressed as normalised MBF (MBF{sub n}) and normalised CFR (CFR{sub n}). Coronary vascular resistances (CVR) were calculated as the ratio between mean arterial pressure and estimated MBF. At rest, estimated MBF and MBF{sub n} were lower in controls than in patients (0.98 {+-} 0.4 vs 1.30 {+-} 0.3 counts/pixel/s and 1.14 {+-} 0.5 vs 1.64 {+-} 0.6 counts/pixel/s, respectively, both p < 0.02). Stress MBF was not different between controls and patients (2.34 {+-} 0.8 vs 2.01 {+-} 0.7 counts/pixel/s, p=NS). Estimated CFR was 2.40 {+-} 0.3 in controls and 1.54 {+-} 0.3 in patients (p < 0.0001). After correction for the RPP, CFR{sub n} was still higher in controls than in patients (2.1 {+-} 0.5 vs 1.29 {+-} 0.5, p < 0.0001). At baseline, CVR values were lower (p < 0.01) in patients than in controls. Dipyridamole-induced changes in CVR were greater (p < 0.0001) in controls (-63%) than in patients (-35%). In the overall study population, a significant correlation between dipyridamole-induced changes in CVR and CFR was observed (r = -0.88, p < 0.0001). SPECT might represent a useful non-invasive method for assessing coronary vascular function in patients with angina and a normal coronary angiogram. (orig.)

Severity of coronary artery disease in obese patients undergoing coronary angiography

International Nuclear Information System (INIS)

Javed, A.; Ali, J.; Kayani, A.M.

2012-01-01

Objective: To assess the relationship of severity of coronary artery disease with obesity in patients undergoing coronary angiography. Design: Cross sectional study. Place and Duration of Study: Armed Forces Institute of Cardiology - National Institute of Heart Diseases (AFIC-NIHD), 1st February 2010 to 31st August 2010 Patients and Methods: The study population included 468 patients undergoing coronary angiography. Obesity was classified according to the BMI using the National Institutes of Health (NIH) criteria as normal (BMI 21-24 kg/m2), overweight (BMI 25-29 kg/m2), obesity class I (BMI 30-34 kg/m2), obesity class II (BMI 35 to 39 kg/m2 and obesity class III (BMI 40 or above kg/m2). Coronary angiography data were obtained from the Siemens Queries software system, which maintains the database including detailed angiographic findings of all patients at this institution. Significant lesions were defined as those with >70% diameter narrowing of coronary arteries (>50% for the left main coronary artery). We attempted to quantify the 'severity of CAD' by ascertaining the prevalence of High-Risk Coronary Anatomy (HRCA). Results: Insignificant difference was observed in traditional risk factors i.e. age, diabetes mellitus and smoking except hypertension and gender. Statistically significantly low prevalence of HRCA was encountered in the obese group (57.7%) as compared to normal/overweight group (75.8%) (p < 0.05). Conclusion: We conclude that obesity is associated with less severe coronary artery disease. (author)

Prediabetes and Type 2 Diabetes Are Associated With Generalized Microvascular Dysfunction: The Maastricht Study.

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Sörensen, Ben M; Houben, Alfons J H M; Berendschot, Tos T J M; Schouten, Jan S A G; Kroon, Abraham A; van der Kallen, Carla J H; Henry, Ronald M A; Koster, Annemarie; Sep, Simone J S; Dagnelie, Pieter C; Schaper, Nicolaas C; Schram, Miranda T; Stehouwer, Coen D A

2016-11-01

Type 2 diabetes (T2DM) is associated with an increased risk of cardiovascular disease. This can be partly explained by large-artery dysfunction, which already occurs in prediabetes ("ticking clock hypothesis"). Whether a similar phenomenon also applies to microvascular dysfunction is not known. We therefore tested the hypothesis that microvascular dysfunction is already present in prediabetes and is more severe in T2DM. To do so, we investigated the associations of prediabetes, T2DM, and measures of hyperglycemia with microvascular function measured as flicker light-induced retinal arteriolar dilation and heat-induced skin hyperemia. In the Maastricht Study, a T2DM-enriched population-based cohort study (n=2213, 51% men, aged [mean±standard deviation] 59.7±8.2 years), we determined flicker light-induced retinal arteriolar %-dilation (Dynamic Vessel Analyzer), heat-induced skin %-hyperemia (laser-Doppler flowmetry), and glucose metabolism status (oral glucose tolerance test; normal glucose metabolism [n=1269], prediabetes [n=335], or T2DM [n=609]). Differences were assessed with multivariable regression analyses adjusted for age, sex, body mass index, smoking, physical activity, systolic blood pressure, lipid profile, retinopathy, estimated glomerular filtration rate, (micro)albuminuria, the use of lipid-modifying and blood pressure-lowering medication, and prior cardiovascular disease. Retinal arteriolar %-dilation was (mean±standard deviation) 3.4±2.8 in normal glucose metabolism, 3.0±2.7 in prediabetes, and 2.3±2.6 in T2DM. Adjusted analyses showed a lower arteriolar %-dilation in prediabetes (B=-0.20, 95% confidence interval -0.56 to 0.15) with further deterioration in T2DM (B=-0.61 [-0.97 to -0.25]) versus normal glucose metabolism (P for trend=0.001). Skin %-hyperemia was (mean±standard deviation) 1235±810 in normal glucose metabolism, 1109±748 in prediabetes, and 937±683 in T2DM. Adjusted analyses showed a lower %-hyperemia in prediabetes (B=-46

Coronary Anomaly and Coronary Artery Fistula as Cause of Angina Pectoris with Literature Review

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Jayanth Koneru

2011-01-01

Full Text Available Coronary artery fistulas are rare anomalies of the coronary arteries that may sometimes cause symptoms by shunting blood flow away from the myocardial capillary network. We report the case of a 46-year old lady which shows the right coronary cusp giving rise to left main coronary artery called anomalous origin of a coronary artery (AOCA, and also a fistula between the left coronary artery and pulmonary artery. We describe our diagnostic approach and review the literature on the epidemiology, pathophysiology, the diagnostic modalities, and treatment options.

Soluble Flt-1 links microvascular disease with heart failure in CKD.

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Di Marco, Giovana S; Kentrup, Dominik; Reuter, Stefan; Mayer, Anna B; Golle, Lina; Tiemann, Klaus; Fobker, Manfred; Engelbertz, Christiane; Breithardt, Günter; Brand, Eva; Reinecke, Holger; Pavenstädt, Hermann; Brand, Marcus

2015-05-01

Chronic kidney disease (CKD) is associated with an increased risk of heart failure (HF). Elevated plasma concentrations of soluble Flt-1 (sFlt-1) have been linked to cardiovascular disease in CKD patients, but whether sFlt-1 contributes to HF in CKD is still unknown. To provide evidence that concludes a pathophysiological role of sFlt-1 in CKD-associated HF, we measured plasma sFlt-1 concentrations in 586 patients with angiographically documented coronary artery disease and renal function classified according to estimated glomerular filtration rate (eGFR). sFlt-1 concentrations correlated negatively with eGFR and were associated with signs of heart failure, based on New York Heart Association functional class and reduced left ventricular ejection fraction (LVEF), and early mortality. Additionally, rats treated with recombinant sFlt-1 showed a 15 % reduction in LVEF and a 29 % reduction in cardiac output compared with control rats. High sFlt-1 concentrations were associated with a 15 % reduction in heart capillary density (number of vessels/cardiomyocyte) and a 24 % reduction in myocardial blood volume. Electron microscopy and histological analysis revealed mitochondrial damage and interstitial fibrosis in the hearts of sFlt-1-treated, but not control rats. In 5/6-nephrectomised rats, an animal model of CKD, sFlt-1 antagonism with recombinant VEGF121 preserved heart microvasculature and significantly improved heart function. Overall, these findings suggest that a component of cardiovascular risk in CKD patients could be directly attributed to sFlt-1. Assessment of patients with CKD confirmed that sFlt-1 concentrations were inversely correlated with renal function, while studies in rats suggested that sFlt-1 may link microvascular disease with HF in CKD.

Acute Thrombotic Coronary Occlusion in a Patient with Coronary Artery Anomaly

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Beganu Elena

2017-09-01

Full Text Available Patients with coronary artery anomalies are more susceptible to develop acute thrombotic coronary occlusions due to the abnormal anatomy of these arteries and the disturbance of the pathophysiological mechanisms that lead to an accelerated atherosclerosis development. The following article presents the case of a 64-year-old female patient diagnosed with anterior ST-segment elevation myocardial infarction. The patient underwent primary percutaneous coronary intervention, which revealed the absence of the right coronary artery and separated origins of the left anterior descending artery and the left circumflex artery from the aorta.

Factors influencing delay time and coronary arterial density during coronary angiography with DSCT

International Nuclear Information System (INIS)

Lijun Tang; Xiaomei Zhu; Yi Xu; Tongfu Yu; Hai Xu; Jinhua Tang; Dehang Wang; Dogra, Vikram

2011-01-01

Background: CT angiography (CTA) plays an important role in diagnosing coronary arterial disease. Delay time and density of the coronary arteries related with patient-specific factors are essential for getting an optimal CTA image. Purpose: To investigate various factors influencing delay time and coronary arterial density during coronary CTA with dual source CT. Material and Methods: One hundred and sixteen consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Factors including gender, age, height, weight, transversal cardiac diameter (TCD), transversal thoracic diameter (TTD), heart rate (HR), body surface area (BSA = [weight x height/3600]1/2) and cardiothoracic ratio (CTR = TCD/TTD) were recorded, measured and calculated before administration of contrast media during coronary CT angiography. Delay time was determined as duration from the beginning of the injection to the density in the descending aorta at the level of right main pulmonary artery reaching a threshold of 100 HU. Coronary arterial density was measured at the mid portion of the right coronary artery. Regression analysis and stepwise regression analysis were used to investigate the influence of these factors on delay time and coronary arterial density. Results: Delay time decreased with an increasing HR and it was shorter in women than men. Delay time increased with an increasing TCD. Delay time could be predicted by the formula: DT = 16.651-0.110 x HR + 1.902 x gender + 0.394 x TCD (where DT is abbreviation for delay time, gender is 0 for women and 1 for men). Coronary arterial density decreased with an increasing HR and weight. Coronary arterial density could be predicted by the formula: CAD = 923.42-4.099 x HR-3.293 x weight (CAD = coronary arterial density). There was no relationship between the other factors mentioned above and delay time or coronary arterial density. Conclusion: Delay time is influenced by HR, gender and TCD. Coronary arterial density

Correlation between dynamic contrast-enhanced MRI and quantitative histopathologic microvascular parameters in organ-confined prostate cancer

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Niekerk, Cornelis G. van; Laak, Jeroen A.W.M. van der; Kaa, Christina A.H. de [Radboud University Medical Centre, Department of Pathology, P.O. Box 9101, Nijmegen (Netherlands); Hambrock, Thomas; Huisman, Henk-Jan; Barentsz, Jelle O. [Radboud University Medical Centre, Department of Radiology, Nijmegen (Netherlands); Witjes, J.A. [Radboud University Medical Centre, Department of Urology, Nijmegen (Netherlands)

2014-10-15

To correlate pharmacokinetic parameters of 3-T dynamic contrast-enhanced (DCE-)MRI with histopathologic microvascular and lymphatic parameters in organ-confined prostate cancer. In 18 patients with unilateral peripheral zone (pT2a) tumours who underwent DCE-MRI prior to radical prostatectomy (RP), the following pharmacokinetic parameters were assessed: permeability surface area volume transfer constant (K{sup trans}), extravascular extracellular volume (Ve) and rate constant (K{sub ep}). In the RP sections blood and lymph vessels were visualised immunohistochemically and automatically examined and analysed. Parameters assessed included microvessel density (MVD), area (MVA) and perimeter (MVP) as well as lymph vessel density (LVD), area (LVA) and perimeter (LVP). A negative correlation was found between age and K{sup trans} and K{sub ep} for tumour (r = -0.60, p = 0.009; r = -0.67, p = 0.002) and normal (r = -0.54, p = 0.021; r = -0.46, p = 0.055) tissue. No correlation existed between absolute values of microvascular parameters from histopathology and DCE-MRI. In contrast, the ratio between tumour and normal tissue (correcting for individual microvascularity variations) significantly correlated between K{sub ep} and MVD (r = 0.61, p = 0.007) and MVP (r = 0.54, p = 0.022). The lymphovascular parameters showed only a correlation between LVA and K{sub ep} (r = -0.66, p = 0.003). Significant correlations between DCE-MRI and histopathologic parameters were found when correcting for interpatient variations in microvascularity. (orig.)

Hepatitis B and C seroprevalence in patients with diabetes mellitus and its relationship with microvascular complications

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Kadir Gisi

2016-12-01

Full Text Available Introduction: Diabetic patients are susceptible to bacterial, viral and fungal infections because of various deficiencies in the immune system. Aim: To investigate a possible link between hepatitis B/C prevalence and microvascular complications as well as duration of diabetes. Material and methods: In total 1263 diabetic patients (1149 type 2, 114 type 1 were enrolled in the study. The control group consisted of 1482 healthy blood donors who were over 40 years old. All diabetic patients were tested for HBsAg, anti-HBs and anti-HCV beside routine laboratory tests. Diabetic patients were divided into three groups according to their diabetes duration, and all of the patients were scanned for microvascular complications. Demographic data of all patients were recorded. Results : HBsAg seropositivity was 3.7% in diabetic patients and 1.08% in the control group; this difference was statistically significant (p < 0.001. HBsAg positivity rates in type 1 and type 2 diabetics were 0.8% and 4%, respectively (p = 0.09. HCV seropositivity was 2.2% for diabetics and 0.5% for the control group; this difference was statistically significant (p 0.05. Also, no relationship was found between microvascular complications of diabetes and hepatitis B/C seropositivity. Conclusions : Hepatitis B and C seroprevalence was found to be increased in diabetes mellitus; however, there was no relationship between hepatitis seroprevalence and the duration or microvascular complications of diabetes.

Multiple Culprit Coronary Artery Thrombosis in a Patient with Coronary Ectasia

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Bruno da Silva Matte

2018-01-01

Full Text Available We here report a case of ST-elevation myocardial infarction (STEMI due to simultaneous acute coronary artery occlusions of two major coronary arteries in a patient with coronary ectasia. The patient had been previously submitted to percutaneous coronary angioplasty with bare metal stent implantation in both culprit vessels. Very late stent thrombosis could be the cause of the first occlusion, triggering the event in the other vessel. In addition, concomitant embolic sources were not identified. Although routine aspiration thrombectomy in STEMI was not proven to be beneficial in randomized clinical trials, it was of great value in this case. We also discuss the relation between coronary ectasia, chronic inflammatory status, and increased platelet activity which may have caused plaque disruption in another already vulnerable vessel.

[Experimental evaluation of the role of the coronary sinus pressure in the regulation of coronary return volume via the coronary sinus. Surgical considerations in atrio-pulmonary diversion procedures].

Science.gov (United States)

Fantidis, P; Fernández Ruiz, M A; Madero Jarabo, R; Moreno Granados, F; Cordovilla Zurdo, G; Sanz Galeote, E

1990-11-01

In order to find out the validity of the vascular waterfall mechanism in coronary venous circulation, the role of coronary sinus pressure in the regulation of coronary return volume via the coronary sinus is studied in healthy animals. An experimental model of pressure regulation in the coronary sinus was prepared, and aortic pressure, EKG and the cardiac output (measured by thermodilution) were recorded. The return volume via the coronary sinus was measured at coronary sinus pressure of 10 or less, 15, 20, and 25 mmHg or more, for a total of 36 determinations. Increased coronary sinus pressure did not produce significant changes in aortic pressure, heart rate, cardiac index or coronary return volume via coronary sinus. When coronary sinus pressure was 25 mmHg or more, there was a significant decline in the average of coronary return volume via coronary sinus. Nevertheless, stepwise variant regression showed that the coronary sinus pressure per se does not condition the volume of coronary return via the coronary sinus. Our results suggest that in the healthy animals, the vascular waterfall mechanism in coronary venous circulation is not valid. Our results suggest that in the correction of congenital cardiac malformations using atriopulmonary anastomosis procedures, employing techniques that ensure coronary sinus drainage into the left atrium, in order to avoid the hemodynamic repercussions attributable to the vascular waterfall mechanism, is not justified.

Increased Angiotensin II Sensitivity Contributes to Microvascular Dysfunction in Women Who Have Had Preeclampsia.

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Stanhewicz, Anna E; Jandu, Sandeep; Santhanam, Lakshmi; Alexander, Lacy M

2017-08-01

Women who have had preeclampsia have increased cardiovascular disease risk; however, the mechanism(s) responsible for this association remain unclear. Microvascular damage sustained during a preeclamptic pregnancy may persist postpartum. The putative mechanisms mediating this dysfunction include a reduction in NO-dependent dilation and an increased sensitivity to angiotensin II. In this study, we evaluated endothelium-dependent dilation, angiotensin II sensitivity, and the therapeutic effect of angiotensin II receptor blockade (losartan) on endothelium-dependent dilation in vivo in the microvasculature of women with a history of preeclampsia (n=12) and control women who had a healthy pregnancy (n=12). We hypothesized that preeclampsia would have (1) reduced endothelium-dependent dilation, (2) reduced NO-mediated dilation, and (3) increased sensitivity to angiotensin II. We further hypothesized that localized losartan would increase endothelium-dependent vasodilation in preeclampsia. We assessed microvascular endothelium-dependent vasodilator function by measurement of cutaneous vascular conductance responses to graded infusion of acetylcholine (acetylcholine; 10 -7 -102 mmol/L) and a standardized local heating protocol in control sites and sites treated with 15 mmol/L L-NAME ( N G -nitro-l-arginine methyl ester; NO-synthase inhibitor) or 43 µmol/L losartan. Further, we assessed microvascular vasoconstrictor sensitivity to angiotensin II (10 -20 -10 -4 mol/L). Preeclampsia had significantly reduced endothelium-dependent dilation (-0.3±0.5 versus -1.0±0.4 log EC50 ; P Preeclampsia also had augmented vasoconstrictor sensitivity to angiotensin II (-10.2±1.3 versus -8.3±0.5; P =0.006). Angiotensin II type I receptor inhibition augmented endothelium-dependent vasodilation and NO-dependent dilation in preeclampsia but had no effect in healthy pregnancy. These data suggest that women who have had preeclampsia have persistent microvascular dysfunction postpartum

Photocoagulation of microvascular and hemorrhagic lesions of the vocal fold with the KTP laser.

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Hirano, Shigeru; Yamashita, Masaru; Kitamura, Morimasa; Takagita, Shin-ichi

2006-04-01

Ectasias and varices of the vocal fold are microvascular lesions that are often due to chronic abuse of the voice, and are occasionally encountered in association with other disorders such as polyps, Reinke's edema, and hematoma. The KTP laser can be used for photocoagulation of small vascular lesions, because the laser beam is well absorbed by hemoglobin, and damage to the epithelium is minimal. The present pilot study examined how the KTP laser could be used for microvascular lesions and their associated lesions. Twelve patients who had undergone phonomicrosurgery were enrolled in the present study. The microvascular lesions were treated by photocoagulation with the laser set at a low power of 1.5 W in the continuous mode, while preserving the epithelium, and associated lesions were then treated by microdissection with cold instruments. The postoperative phonatory function was assessed by maximum phonation time, a perceptual test rating (GRBAS scale), and stroboscopy. The procedures were completed successfully in all cases. An exceptional case of a small hemorrhagic polyp allowed treatment with the laser only. The postoperative stroboscopic findings, maximum phonation time, and perceptual test rating all showed significant improvement compared with the preoperative state. No adverse effects, such as scarring or reduction of the mucosal wave, were observed in the current series. KTP laser photocoagulation is a relatively simple and safe procedure for treating microvascular lesions of the vocal fold. It is not recommended for photocoagulation of hemorrhagic polyps or hematomas, because such lesions have little blood flow inside and thus photocoagulation is usually impossible or requires too much laser energy. However, photocoagulation of perimeter or feeding vessels of such disorders may facilitate the following procedure by avoiding unnecessary bleeding, as well as preventing recurrence of hemorrhagic lesions.

Phase coherence of 0.1 Hz microvascular tone oscillations during the local heating

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Mizeva, I. A.

2017-06-01

The origin of the mechanisms of blood flow oscillations at low frequencies is discussed. It is known that even isolated arteriole demonstrates oscillations with the frequency close to 0.1 Hz, which is caused by the synchronous activity of myocyte cells. On the other hand, oscillations with close frequency are found in the heart rate, which are associated with quite different mechanism. The main purpose of this work is to study phase coherence of the blood flow oscillations in the peripheral vessels under basal and perturbed conditions. Local heating which locally influences the microvascular tone, as one of currently elucidated in sufficient detail physiological test, was chosen. During such provocation blood flow though the small vessels significantly increases because of vasodilation induced by the local synthesis of nitric oxide. In the first part of the paper microvascular response to the local test is quantified in healthy and pathological conditions of diabetes mellitus type 1. It is obtained that regardless of the pathology, subjects with high basal perfusion had lower reserve for vasodilation, which can be caused by the low elasticity of microvascular structure. Further synchronization of pulsations of the heated and undisturbed skin was evaluated on the base of wavelet phase coherency analysis. Being highly synchronised in basal conditions 0.1 Hz pulsations became more independent during heating, especially during NO-mediated vasodilation.

Three-Dimensional Respiratory-Gated Coronary Mr Angiography with Reference to X-Ray Coronary Angiography

International Nuclear Information System (INIS)

Ikonen, A. E. J.; Manninen, H. I.; Vainio, P.; Vanninen, R. L.; Matsi, P. J.; Soimakallio, S.; Hirvonen, T.P.J.; Hartikainen, J.E.K.

2003-01-01

Purpose: To assess the clinical value of three-dimensional coronary MR angiography (CMRA) in the detection of significant coronary artery stenosis using conventional X-ray angiography as the standard reference. Material and Methods: Sixty-nine patients underwent X-ray coronary angiography and CMRA because of suspected or previously diagnosed coronary artery disease. MRI was performed with a 1.5-T whole body imaging system using ECG-triggered 3D gradient echo sequence with retrospective navigator echo respiratory gating and fat suppression. Results: A total of 276 coronary artery segments were analyzed. The X-ray coronary angiography was normal in 22 patients. Significant proximal stenoses (exceeding 50%) or occlusions were present in 102 coronary artery segments. In all, 120 stenoses or occlusions were identified in CMRA. Sixteen percent of the coronary artery segments had to be excluded because of poor image quality. The overall sensitivity and specificity for MRA for identification of significant stenosis were 75% and 62%, respectively. CMRA correctly detected 89% of patients with at least one vessel disease, but 6 patients with coronary artery disease would have been missed. Conclusions: Because of the high data exclusion and false-negative case rate, CMRA with retrospective navigator echo triggering is at present not suitable as a clinical screening method in coronary artery disease

Coronary artery anomalies in adults: imaging at dual source CT coronary angiography

International Nuclear Information System (INIS)

Laspas, Fotios; Roussakis, Arkadios; Mourmouris, Christos; Kritikos, Nikolaos; Efthimiadou, Roxani; Andreou, John

2013-01-01

Congenital abnormalities of the coronary arteries have an incidence of 1%, and most of these are benign. However, a small number are associated with myocardial ischaemia and sudden death. Various imaging modalities are available for coronary artery assessment. Recently, multi-detector CT has emerged as an accurate diagnostic tool for defining coronary artery anomalies. The purpose of this pictorial essay is to review the dual source CT appearance of congenital anomalies of the coronary arteries in adults.

The value of coronary artery calcium score assessed by dual-source computed tomography coronary angiography for predicting presence and severity of coronary artery disease

International Nuclear Information System (INIS)

Almasi, Alireza; Pouraliakbar, Hamidreza; Sedghian, Ahmad; Karimi, Mohammad Ali; Firouzi, Ata; Tehrai, Mahmood

2014-01-01

Measuring coronary artery calcium score (CACS) using a dual-source CT scanner is recognized as a major indicator for assessing coronary artery disease. The present study aimed to validate the clinical significance of CACS in predicting coronary artery stenosis and its severity. This prospective study was conducted on 202 consecutive patients who underwent both conventional coronary angiography and dual-source (256-slice) computed tomography coronary angiography (CTA) for any reason in our cardiac imaging center from March to September 2013. CACS was measured by Agatston algorithm on non-enhanced CT. The severity of coronary artery disease was assessed by Gensini score on conventional angiography. There was a significant relationship between the number of diseased coronary vessels and mean calcium score, i.e. the mean calcium score was 202.25±450.06 in normal coronary status, 427.50±607.24 in single-vessel disease, 590.03±511.34 in two-vessel disease, and 953.35±1023.45 in three-vessel disease (p<0.001). There was a positive association between calcium score and Gensini score (r=0.636, p<0.001). In a linear regression model, calcium score was a strong determinant of the severity of coronary artery disease. Calcium scoring had an acceptable value for discriminating coronary disease from normal condition with optimal cutoff point of 350, yielding a sensitivity and specificity of 83% and 70%, respectively. Our study confirmed the strong relationship between the coronary artery calcium score and the presence and severity of stenosis in coronary arteries assessed by both the number of diseased coronary vessels and also by the Gnesini score

Better microvascular function on long-term treatment with lisinopril than with nifedipine in renal transplant recipients.

Science.gov (United States)

Asberg, A; Midtvedt, K; Vassbotn, T; Hartmann, A

2001-07-01

The prevalence of hypertension in renal transplant recipients is high but the pathophysiology is poorly defined. Impaired endothelial function may be a factor of major importance. The present study addresses the effects of long-term treatment with either lisinopril or slow-release nifedipine on microvascular function and plasma endothelin in renal transplant recipients on cyclosporin A (CsA). Seventy-five hypertensive renal transplant recipients were double-blind randomized to receive slow-release nifedipine (NIF, n=40) or lisinopril (LIS, n=35). Ten normotensive, age-matched recipients served as controls. All patients received CsA-based immunosuppressive therapy including prednisolone and azathioprine. Microvascular function was assessed in the forearm skin vasculature, using laser Doppler flowmetry in combination with post-occlusive reactive hyperaemia and endothelial-dependent function during local acetylcholine (ACh) stimulation. The analysis of microvascular function (AUC(rh)) showed that nifedipine-treated patients had significantly lower responses compared with lisinopril-treated patients (20+/-17 and 43+/-20 AU x min respectively, P=0.0016). Endothelial function was borderline significantly lower in the NIF group compared with the LIS group (640+/-345 and 817+/-404 AU x min respectively, P=0.056). The responses in the LIS group were comparable with those in non-hypertensive controls (AUC(rh) was 37+/-16 and AUC(ACh) was 994+/-566 AU x min). Plasma endothelin-1 concentrations were significantly higher in the NIF group compared with the LIS group (0.44+/-0.19 vs. 0.34+/-0.10 fmol/ml respectively, P=0.048), and were 0.29+/-0.09 fmol/ml in the control patients. AUC(ACh) was associated with plasma endothelin-1 (P=0.0053), while AUC(rh) was not (P=0.080). The study indicates that long-term treatment with lisinopril, when compared with nifedipine, yields a more beneficial effect on microvascular function in hypertensive renal transplant recipients on CsA. The

Magnetic alginate microfibers as scaffolding elements for the fabrication of microvascular-like structures.

Science.gov (United States)

Sun, Tao; Shi, Qing; Huang, Qiang; Wang, Huaping; Xiong, Xiaolu; Hu, Chengzhi; Fukuda, Toshio

2018-01-15

Traditional cell-encapsulating scaffolds may elicit adverse host responses and inhomogeneity in cellular distribution. Thus, fabrication techniques for cellular self-assembly with micro-scaffold incorporation have been used recently to generate toroidal cellular modules for the bottom-up construction of vascular-like structures. The micro-scaffolds show advantage in promoting tissue formation. However, owing to the lack of annular cell micro-scaffolds, it remains a challenge to engineer micro-scale toroidal cellular modules (micro-TCMs) to fabricate microvascular-like structures. Here, magnetic alginate microfibers (MAMs) are used as scaffolding elements, where a winding strategy enables them to be formed into micro-rings as annular cell micro-scaffolds. These micro-rings were investigated for NIH/3T3 fibroblast growth as a function of surface chemistry and MAM size. Afterwards, micro-TCMs were successfully fabricated with the formation of NIH/3T3 fibroblasts and extracellular matrix layers on the three-dimensional micro-ring surfaces. Simple non-contact magnetic assembly was used to stack the micro-TCMs along a micro-pillar, after which cell fusion rapidly connected the assembled micro-TCMs into a microvascular-like structure. Endothelial cells or drugs encapsulated in the MAMs could be included in the microvascular-like structures as in vitro cellular models for vascular tissue engineering, or as miniaturization platforms for pharmaceutical drug testing in the future. Magnetic alginate microfibers functioned as scaffolding elements for guiding cell growth in micro-scale toroidal cellular modules (micro-TCMs) and provided a magnetic functionality to the micro-TCMs for non-contact 3D assembly in external magnetic fields. By using the liquid/air interface, the non-contact spatial manipulation of the micro-TCMs in the liquid environment was performed with a cost-effective motorized electromagnetic needle. A new biofabrication paradigm of construct of microvascular

Induction of complement proteins in a mouse model for cerebral microvascular Aβ deposition

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DeFilippis Kelly

2007-09-01

Full Text Available Abstract The deposition of amyloid β-protein (Aβ in cerebral vasculature, known as cerebral amyloid angiopathy (CAA, is a common pathological feature of Alzheimer's disease and related disorders. In familial forms of CAA single mutations in the Aβ peptide have been linked to the increase of vascular Aβ deposits accompanied by a strong localized activation of glial cells and elevated expression of neuroinflammatory mediators including complement proteins. We have developed human amyloid-β precursor protein transgenic mice harboring two CAA Aβ mutations (Dutch E693Q and Iowa D694N that mimic the prevalent cerebral microvascular Aβ deposition observed in those patients, and the Swedish mutations (K670N/M671L to increase Aβ production. In these Tg-SwDI mice, we have reported predominant fibrillar Aβ along microvessels in the thalamic region and diffuse plaques in cortical region. Concurrently, activated microglia and reactive astrocytes have been detected primarily in association with fibrillar cerebral microvascular Aβ in this model. Here we show that three native complement components in classical and alternative complement pathways, C1q, C3, and C4, are elevated in Tg-SwDI mice in regions rich in fibrillar microvascular Aβ. Immunohistochemical staining of all three proteins was increased in thalamus, hippocampus, and subiculum, but not frontal cortex. Western blot analysis showed significant increases of all three proteins in the thalamic region (with hippocampus as well as the cortical region, except C3 that was below detection level in cortex. Also, in the thalamic region (with hippocampus, C1q and C3 mRNAs were significantly up-regulated. These complement proteins appeared to be expressed largely by activated microglial cells associated with the fibrillar microvascular Aβ deposits. Our findings demonstrate that Tg-SwDI mice exhibit elevated complement protein expression in response to fibrillar vascular Aβ deposition that is

Diastolic coronary artery pressure-flow velocity relationships in conscious man.

Science.gov (United States)

Dole, W P; Richards, K L; Hartley, C J; Alexander, G M; Campbell, A B; Bishop, V S

1984-09-01

We characterised the diastolic pressure-flow velocity relationship in the normal left coronary artery of conscious man before and after vasodilatation with angiographic contrast medium. Phasic coronary artery pressure and flow velocity were measured in ten patients during individual diastoles (0.5 to 1.0 s) using a 20 MHz catheter-tipped, pulsed Doppler transducer. All pressure-flow velocity curves were linear over the diastolic pressure range of 110 +/- 15 (SD) mmHg to 71 +/- 7 mmHg (r = 0.97 +/- 0.01). In the basal state, values for slope and extrapolated zero flow pressure intercept averaged 0.35 +/- 0.12 cm X s-1 X mmHg-1 and 51.7 +/- 8.6 mmHg, respectively. Vasodilatation resulted in a 2.5 +/- 0.5 fold increase in mean flow velocity. The diastolic pressure-flow velocity relationship obtained during peak vasodilatation compared to that during basal conditions was characterised by a steeper slope (0.80 +/- 0.48 cm X s-1 X mmHg-1, p less than 0.001) and lower extrapolated zero flow pressure intercept (37.9 +/- 9.8 mmHg, p less than 0.05). Mean right atrial pressure for the group averaged 4.4 +/- 1.7 mmHg, while left ventricular end-diastolic pressure averaged 8.7 +/- 2.8 mmHg. These observations in man are similar to data reported in the canine coronary circulation which are consistent with a vascular waterfall model of diastolic flow regulation. In this model, coronary blood flow may be regulated by changes in diastolic zero flow pressure as well as in coronary resistance.

Development of Coronary Pulse Wave Velocity: New Pathophysiological Insight Into Coronary Artery Disease.

Science.gov (United States)

Harbaoui, Brahim; Courand, Pierre-Yves; Cividjian, Andrei; Lantelme, Pierre

2017-02-02

Although aortic stiffness assessed by pulse wave velocity (PWV) is a strong predictor of coronary artery disease, the significance of local coronary stiffness has never been tackled. The first objective of this study was to describe a method of measuring coronary PWV (CoPWV) invasively and to describe its determinants. The second objective was to assess both CoPWV and aortic PWV in patients presenting with acute coronary syndromes or stable coronary artery disease. In 53 patients, CoPWV was measured from the delay in pressure wave and distance traveled as a pressure wire was withdrawn from the distal to the proximal coronary segment. Similarly, aortic PWV was measured invasively when the wire was pulled across the ascending aorta; carotid-femoral PWV was also measured noninvasively using the SphygmoCor system (AtCor Medical). Mean CoPWV was 10.3±6.1 m/s. Determinants of increased CoPWV were fractional flow reserve, diastolic blood pressure, and previous stent implantation in the recorded artery. CoPWV was lower in patients with acute coronary syndromes versus stable coronary artery disease (7.6±3 versus 11.5±6.4 m/s; P=0.02), and this persisted after adjustment for confounders. In contrast, aortic stiffness, assessed by aortic and carotid-femoral PWV, did not differ significantly. CoPWV seems associated with acute coronary events more closely than aortic PWV. High coronary compliance, whether per se or because it leads to a distal shift in compliance mismatch, may expose vulnerable plaques to high cyclic stretch. CoPWV is a new tool to assess local compliance at the coronary level; it paves the way for a new field of research. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature.

Science.gov (United States)

Li, Wei; Maloney, Ronald E; Aw, Tak Yee

2015-08-01

We previously demonstrated that in normal glucose (5mM), methylglyoxal (MG, a model of carbonyl stress) induced brain microvascular endothelial cell (IHEC) dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC). Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER) was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia); moreover, barrier function remained disrupted 6h after cell transfer to normal glucose media (acute glycemic fluctuation). Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH) synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal) levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG-occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG-occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature

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Wei Li

2015-08-01

Full Text Available We previously demonstrated that in normal glucose (5 mM, methylglyoxal (MG, a model of carbonyl stress induced brain microvascular endothelial cell (IHEC dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC. Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia; moreover, barrier function remained disrupted 6 h after cell transfer to normal glucose media (acute glycemic fluctuation. Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG–occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG–occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes.

Coronary MR angiography: current status

International Nuclear Information System (INIS)

Danias, P.G.; Manning, W.J.

2000-01-01

Since first described in the early 1990s, coronary magnetic resonance angiography (MRA) has evolved as a promising noninvasive modality for imaging of the coronary arteries and evaluation of coronary artery disease. Despite technical limitations, coronary MRA has established value for imaging of anomalous coronary arteries and assessment of bypass graft patency. Current research focuses on the development of optimal respiratory compensation strategies, improved spatial and temporal resolution and faster acquisition of image data. The accurate detection of stenoses and assessment of the severity of coronary atherosclerosis is presently being evaluated with large multi-center studies. With further technique enhancements and more clinical experience, coronary MRA is likely to become the dominant noninvasive modality in clinical cardiology. (orig.) [de

Celecoxib decreases growth and angiogenesis and promotes apoptosis in a tumor cell line resistant to chemotherapy

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Carlos Rosas

2014-01-01

Full Text Available BACKGROUND: During the last few years it has been shown in several laboratories that Celecoxib (Cx, a non-steroidal anti-inflammatory agent (NSAID normally used for pain and arthritis, mediates antitumor and antiangiogenic effects. However, the effects of this drug on a tumor cell line resistant to chemotherapeutical drugs used in cancer have not been described. Herein we evaluate the angiogenic and antitumor effects of Cx in the development of a drug-resistant mammary adenocarcinoma tumor (TA3-MTXR. RESULTS: Cx reduces angiogenesis in the chick embryonic chorioallantoic membrane assay (CAM, inhibits the growth and microvascular density of the murine TA3-MTXR tumor, reduces microvascular density of tumor metastases, promotes apoptosis and reduces vascular endothelial growth factor (VEGF production and cell proliferation in the tumor. CONCLUSION: The antiangiogenic and antitumor Cx effects correlate with its activity on other tumor cell lines, suggesting that Prostaglandins (PGs and VEGF production are involved. These results open the possibility of using Celecoxib combined with other experimental therapies, ideally aiming to get synergic effects.

Balloon Occlusion Types in the Treatment of Coronary Perforation during Percutaneous Coronary Intervention

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Xiangfei Wang

2014-01-01

Full Text Available Coronary artery perforation is an uncommon complication in patients with coronary heart disease undergoing percutaneous coronary intervention. However, pericardial tamponade following coronary artery perforation may be lethal, and prompt treatment is crucial in managing such patients. Balloon occlusion and the reversal of anticoagulant activity are the common methods used to prevent cardiac tamponade by reducing the amount of bleeding. Herein, we discuss the pros and cons of currently used occlusion types for coronary perforation. Optimal balloon occlusion methods should reduce the amount of bleeding and ameliorate subsequent myocardial ischemia injury, even during cardiac surgery.

The pleiotropic effects of simvastatin on retinal microvascular endothelium has important implications for ischaemic retinopathies.

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Reinhold J Medina

Full Text Available BACKGROUND: Current guidelines encourage the use of statins to reduce the risk of cardiovascular disease in diabetic patients; however the impact of these drugs on diabetic retinopathy is not well defined. Moreover, pleiotropic effects of statins on the highly specialised retinal microvascular endothelium remain largely unknown. The objective of this study was to investigate the effects of clinically relevant concentrations of simvastatin on retinal endothelium in vitro and in vivo. METHODS AND FINDINGS: Retinal microvascular endothelial cells (RMECs were treated with 0.01-10 microM simvastatin and a biphasic dose-related response was observed. Low concentrations enhanced microvascular repair with 0.1 microM simvastatin significantly increasing proliferation (p<0.05, and 0.01 microM simvastatin significantly promoting migration (p<0.05, sprouting (p<0.001, and tubulogenesis (p<0.001. High concentration of simvastatin (10 microM had the opposite effect, significantly inhibiting proliferation (p<0.01, migration (p<0.01, sprouting (p<0.001, and tubulogenesis (p<0.05. Furthermore, simvastatin concentrations higher than 1 microM induced cell death. The mouse model of oxygen-induced retinopathy was used to investigate the possible effects of simvastatin treatment on ischaemic retinopathy. Low dose simvastatin (0.2 mg/Kg promoted retinal microvascular repair in response to ischaemia by promoting intra-retinal re-vascularisation (p<0.01. By contrast, high dose simvastatin(20 mg/Kg significantly prevented re-vascularisation (p<0.01 and concomitantly increased pathological neovascularisation (p<0.01. We also demonstrated that the pro-vascular repair mechanism of simvastatin involves VEGF stimulation, Akt phosphorylation, and nitric oxide production; and the anti-vascular repair mechanism is driven by marked intracellular cholesterol depletion and related disorganisation of key intracellular structures. CONCLUSIONS: A beneficial effect of low

Microbial Translocation in HIV Infection is Associated with Dyslipidemia, Insulin Resistance, and Risk of Myocardial Infarction

DEFF Research Database (Denmark)

Pedersen, Karin Kaereby; Pedersen, Maria; Trøseid, Marius

2013-01-01

Microbial translocation has been suggested to be a driver of immune activation and inflammation. We hypothesized that microbial translocation may be related to dyslipidemia, insulin resistance, and the risk of coronary heart disease in HIV-infected individuals.......Microbial translocation has been suggested to be a driver of immune activation and inflammation. We hypothesized that microbial translocation may be related to dyslipidemia, insulin resistance, and the risk of coronary heart disease in HIV-infected individuals....

Compromised cortical bone compartment in type 2 diabetes mellitus patients with microvascular disease

DEFF Research Database (Denmark)

Shanbhogue, Vikram Vinod; Hansen, Stinus; Nielsen, Morten Frost Munk

2016-01-01

OBJECTIVE AND DESIGN: Patients with type 2 diabetes mellitus (T2D) have an increased fracture risk despite a normal or elevated bone mineral density (BMD). The aim of this cross-sectional in vivo study was to assess parameters of peripheral bone microarchitecture, estimated bone strength and bone...... remodeling in T2D patients with and without diabetic microvascular disease (MVD+ and MVD- respectively) and to compare them with healthy controls. METHODS: Fifty-one T2D patients (MVD+ group: n=25) were recruited from Funen Diabetic Database and matched for age, sex and height with 51 healthy subjects. High...... deficits are not a characteristic of all T2D patients but of a subgroup characterized by the presence of microvascular complications. Whether this influences fracture rates in these patients needs further investigation....

Restrictive use of perioperative blood transfusion does not increase complication rates in microvascular breast reconstruction.

Science.gov (United States)

O'Neill, Anne C; Barandun, Marina; Cha, Jieun; Zhong, Toni; Hofer, Stefan O P

2016-08-01

With increasing appreciation of the possible adverse effects of peri-operative blood transfusion, restrictive policies regarding use of blood products have been adopted in many surgical specialties. Although microvascular breast reconstruction has become a routine procedure, high peri-operative transfusion rates continue to be reported in the literature. In this study we examine the impact of our restrictive approach on blood transfusion rates and postoperative complications in patients undergoing microvascular blood transfusion. A retrospective review of patients undergoing microvascular breast reconstruction with abdominal flaps at a single institution was performed. Patient age and body mass index as well as type, timing and laterality of reconstruction was recorded. Pre-operative and post-operative hemoglobin and hematocrit were recorded. Peri-operative blood transfusion rates were calculated. Post-operative complication rates were compared between patients with higher and lower post-operative hemoglobin levels. Five hundred and twelve patients were included in this study. The peri-operative transfusion rate was 0.98% in this series. There was no significant difference between transfusion rates in unilateral and bilateral reconstructions (0.68 vs 1.36% p = 0.08) or immediate and delayed reconstructions (1.02 vs 0.51% p = 0.72 and 1.01 vs 1.60% p = 0.09 for unilateral and bilateral respectively). Lower post-operative hemoglobin levels were not associated with increased flap related, surgical or medical complications rates. A restrictive approach to peri-operative blood transfusion can be safely adopted in microvascular breast reconstruction without compromising flap viability or overall complication rates. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Presence of diabetic microvascular complications does not incrementally increase risk of ischemic stroke in diabetic patients with atrial fibrillation

Science.gov (United States)

Chou, Annie Y.; Liu, Chia-Jen; Chao, Tze-Fan; Wang, Kang-Ling; Tuan, Ta-Chuan; Chen, Tzeng-Ji; Chen, Shih-Ann

2016-01-01

Abstract Conventional stroke risk prediction tools used in atrial fibrillation (AF) incorporate the presence of diabetes mellitus (DM) as a risk factor. However, it is unknown whether this risk is homogenous or dependent on the presence of diabetic microvascular complications, such as diabetic retinopathy, nephropathy, and neuropathy. The present study examined the risk of ischemic stroke in diabetic patients with and without microvascular complications. The present study used the National Health Insurance Research Database in Taiwan with detailed healthcare data on all-comers to the Taiwanese medical system from January 1, 1996 to December 31, 2011. AF and DM were identified when listed as discharge diagnoses or confirmed more than twice in the outpatient department. Patients on antithrombotic agents were excluded. The clinical endpoint was ischemic stroke. Among the 50,180 AF patients with DM, the majority had no microvascular complications (72.7%), while 2.6% had diabetic retinopathy, 8.4% had diabetic nephropathy, and 16.1% had diabetic neuropathy. Ischemic stroke occurred in 6003 patients, with a 4.74% annual risk of ischemic stroke. When compared with DM patients without microvascular complications, those with diabetic retinopathy, nephropathy, or neuropathy had higher incidences of ischemic stroke (4.65 vs 5.07, 4.77, or 5.20 per 100 person-years, respectively). However, after adjusting for confounding factors, the differences were no longer significant. In a large nationwide AF cohort with DM, risk of ischemic stroke was similar between patients with and without microvascular complications, suggesting that risk stratification of these patients does not require inclusion of diabetic retinopathy, nephropathy, and neuropathy. PMID:27399075

Congenital coronary artery fistula

International Nuclear Information System (INIS)

Oh, Yeon Hee; Kim, Hong; Zeon, Seoc Kil; Suh, Soo Jhi

1986-01-01

Congenital coronary artery fistula (CCAF) is communication of a coronary artery or its main branch with one of the atria or ventricles, the coronary sinus, the superior vena cava, or the pulmonary artery. In Korean peoples, only 4 cases of the CCAF were reported as rare as worldwide and authors want to report another case of CCAF, confirmed by operation. 10-year-old girl shows a fistula between sinus node artery of the right coronary artery and right atrium on root aortogram with left-to-right shunt and Qp/Qs=1.58, in which simple ligation of the sinus node artery from right coronary artery was performed. All of the 5 Korean CCAF (4 were previously reported and 1 of authors) were originated from right coronary artery, and of which 4 were opening into right ventricle and 1 of authors were into right atrium. Associated cardiac anomaly was noted in only 1 case as single coronary artery. Ages were from 9 months of age to 10 years old and no adult left case were found. 3 were female and 2 were male patients.

Non-invasive assessment of coronary calcification

International Nuclear Information System (INIS)

Vliegenthart, Rozemarijn; Oei, Hok-Hay S.; Hofman, Albert; Oudkerk, Matthijs; Witteman, Jackqueline C. M.

2004-01-01

Electron-beam tomography (EBT) and multi-detector computed tomography (MDCT) enable the noninvasive assessment of coronary calcification. The amount of coronary calcification, as detected by EBT, has a close relation with the amount of coronary atherosclerosis, which is the substrate for the occurrence of myocardial infarction and sudden cardiac death. Calcification of the coronary arteries can be seen as a cumulative measure of life-time exposure to cardiovascular risk factors. Several studies have shown that the amount of coronary calcification is associated with the risk of coronary heart disease. Therefore, coronary calcification is a promising method for non-invasive detection of asymptomatic subjects at high risk of developing coronary heart disease. Whether measurement of coronary calcification also increases the predictive power of coronary events based on cardiovascular risk factors is topic of current research

[Pregnancy and coronary artery dissection].

Science.gov (United States)

Martínez-Quintana, Efrén; Rodríguez-González, Fayna

2015-01-01

Acute myocardial infarction during pregnancy is associated with high maternal and fetal mortality. Coronary atherosclerosis is the most common cause due to an increase in the age of the patients and the association with cardiovascular risk factors such as smoking, hypertension, diabetes mellitus, preeclampsia, and the existence of family history of coronary disease. However, thrombosis, coronary dissection or coronary vasospasms are other causes that may justify it. We report the case of a 33 weeks pregnant first-time mother, without cardiovascular risk factors, who presented an acute coronary event in the context of atherosclerotic disease and coronary dissection after percutaneous coronary intervention. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

[Microvascular injury effects and possibility of early anastomosis in the maxillofacial region following high velocity missile wound: an experimental study in dogs].

Science.gov (United States)

Yan, Y

1990-02-01

In order to provide the basis of microvascular anastomosis for reconstruction of maxillofacial defects from firearm injury by using vascularized free tissue transplantation, we studied the mechanism and pathology of microvascular injuries and the possibility of their early anastomosis. The dogs' face were wounded by 0.7 g or 1.03 g steel spheres whose muzzle velocity were 1300 m/s or 1500 m/s. The injury effects of microvascular angiograms were recorded through high speed X-ray camera at the impacting moment the specimens of small vessel were collected for light and electron microscopy at different times after wound. Some dogs were used for performing microvascular anastomosis in the wound region at different times after wound. We found that there were temporary cavity effects in maxillofacial firearm wounds, in and around which small vessel blunt injuries were found, which spread 3 cm from the wound edge. Microvascular anastomosis 3 days after the wound could get higher shortterm patency rate. These results support the conclusion that if we use microsurgical methods to repair defects in maxillofacial firearm wound region, the pedicles of the flap should be laid beyond 3 cm from the wound edge, and the reconstructive operation should be done 3 days after the wound.

Single coronary artery; extremely rare coronary anomaly successfully treated surgically in young adult male.

LENUS (Irish Health Repository)

Shah, A R

2010-05-01

Single coronary artery arising from aortic root, is a rare congenital anomaly. A 30-year-old male presented with acute myocardial infarction (MI) complaining of chest pain and raised troponin levels. Emergency angiography showed no coronary lesions but both left and right coronary arteries arising from single ostium. Patient was operated electively and perioperative findings confirmed the diagnosis of single coronary artery, as left coronary artery after taking origin from right sinus of valsalva runs through the septum, before dividing into left anterior descending and circumflex branches. The single coronary ostium opened with a slit like incision over the course of left main coronary, making the size of ostium three to four times bigger than the native one. In addition left internal mammary artery was harvested and grafted to the left anterior descending branch distally. Patient made successful recovery. Four months follow up dobutamine stress echo showed no inducible ischemia.

Pressure-flow characteristics and nutritional capacity of coronary veins in dogs

International Nuclear Information System (INIS)

Cohen, M.V.; Matsuki, T.; Downey, J.M.

1988-01-01

To examine the hemodynamic interdependence of coronary arteries and veins, great cardiac vein (GCV) and left anterior descending (LAD) coronary artery flows of dogs were measured. Although they were not different under base-line conditions, 42.9 +/- 4.1 and 34.9 +/- 5.2 ml/min, respectively, LAD occlusion caused only a 56% decrease in GCV flow, whereas peak GCV flow during reactive hyperemia consistently underestimated peak LAD flow by nearly 40%. The measured hemodynamic data were very closely predicted by a simple model that assumed the presence of a low-resistance venous collateral anastomotic pathway between the GCV and veins outside the LAD territory. The resistance of the venous collaterals averaged 9.9 +/- 3.0% of LAD resistance. Therefore, GCV flow does not solely represent LAD collateral flow when the LAD is occluded, nor is it a reliable indicator of changes in LAD perfusion patterns. Nutritional myocardial perfusion assessed with 133 Xe washout decreased from 0.86 +/- 0.16 to 0.13 +/- 0.02 ml.min-1.g-1 after LAD occlusion, whereas retroperfusion of the GCV with arterial blood enhanced washout by 85% to 0.23 +/- 0.03 ml.min-1.g-1 (P less than 0.005). Retroperfusion was inefficient, however, since only 10% of the isotope injected into the GCV gained access to the myocardium

PLACENTAL GROWTH FACTOR AND CORONARY NEOANGIOGENESIS IN CORONARY HEART DISEASE

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M. V. Tulikov

2013-01-01

Full Text Available Neoangiogenesis in coronary heart disease is a protective reaction aimed to improve ischemic myocardial perfusion, by increasing the number and size of arterial collaterals. Placental growth factor (PlGF is one of the key peptides regulating angiogenic processes in atherosclerosis. In particular, a number of investigators have shown that injection of recombinant PlGF into the system or regional blood flow can stimulate neoangiogenesis. On the other hand, there is evidence confirming the involvement of PlGF in the progression of atherosclerosis and in the development of acute coronary syndrome. In this connection, the problem of investigating the efficiency and safety of possible use of PlGF preparations, as well as its place in the diagnosis of coronary heart disease and acute coronary syndrome remains urgent

[Development of an automated processing method to detect coronary motion for coronary magnetic resonance angiography].

Science.gov (United States)

Asou, Hiroya; Imada, N; Sato, T

2010-06-20

On coronary MR angiography (CMRA), cardiac motions worsen the image quality. To improve the image quality, detection of cardiac especially for individual coronary motion is very important. Usually, scan delay and duration were determined manually by the operator. We developed a new evaluation method to calculate static time of individual coronary artery. At first, coronary cine MRI was taken at the level of about 3 cm below the aortic valve (80 images/R-R). Chronological change of the signals were evaluated with Fourier transformation of each pixel of the images were done. Noise reduction with subtraction process and extraction process were done. To extract higher motion such as coronary arteries, morphological filter process and labeling process were added. Using these imaging processes, individual coronary motion was extracted and individual coronary static time was calculated automatically. We compared the images with ordinary manual method and new automated method in 10 healthy volunteers. Coronary static times were calculated with our method. Calculated coronary static time was shorter than that of ordinary manual method. And scan time became about 10% longer than that of ordinary method. Image qualities were improved in our method. Our automated detection method for coronary static time with chronological Fourier transformation has a potential to improve the image quality of CMRA and easy processing.

Mandibular reconstruction with composite microvascular tissue transfer

International Nuclear Information System (INIS)

Coleman, J.J. III; Wooden, W.A.

1990-01-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons [lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)]. Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure

Mandibular reconstruction with composite microvascular tissue transfer

Energy Technology Data Exchange (ETDEWEB)

Coleman, J.J. III; Wooden, W.A. (Emory Univ. School of Medicine, Atlanta, GA (USA))

1990-10-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons (lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)). Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure.

Congenital coronary-pulmonary artery fistula originating from right and left coronary artery

Directory of Open Access Journals (Sweden)

Ali Kemal Gür

2013-12-01

Full Text Available Coronary artery fistula (CAF is a rare congenital anomalywith an incidence of 1 in 50 000 live births. The fistula wasobserved at the right coronary artery in 53%, the left coronaryartery in 42% and both coronary artery in 5% of thecases. Echocardiography examination in a 46 year-oldwoman with the symptoms of chest pain, palpitation anddyspnea revealed a severe mitral valve insufficiency anda moderate to severe tricuspid valve insufficiency. A CAForiginating from the proximal part of the left anterior descendingartery (LAD and another fistula originating fromosteal part of the right coronary artery (RCA were detectedby coronary angiography. Both fistulas were draininginto the main pulmonary artery. The coronary artery fistulaclosed under cardiopulmonary by-pass. Mitral insufficiencyoriginated from the posterior leaflet was diagnosedintra-operative exploration, and thereafter it was repairedwith mitral annuloplasty including a quadrangular resectionand use of a 32 No St Jude mitral ring. Tricuspid valvewas repaired with Calangos Ring annuloplasty. Followingsix day hospital stay, the woman was discharged free ofany symptom.Key words: Dyspnea, double arteriovenous fistula, mitral and tricuspid insufficiency

Resistant and Refractory Hypertension: Antihypertensive Treatment Resistance vs Treatment Failure

Science.gov (United States)

Siddiqui, Mohammed; Dudenbostel, Tanja; Calhoun, David A.

2017-01-01

Resistant or difficult to treat hypertension is defined as high blood pressure that remains uncontrolled with 3 or more different antihypertensive medications, including a diuretic. Recent definitions also include controlled blood pressure with use of 4 or more medications as also being resistant to treatment. Recently, refractory hypertension, an extreme phenotype of antihypertensive treatment failure has been defined as hypertension uncontrolled with use of 5 or more antihypertensive agents, including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist. Patients with resistant vs refractory hypertension share similar characteristics and comorbidities, including obesity, African American race, female sex, diabetes, coronary heart disease, chronic kidney disease, and obstructive sleep apnea. Patients with refractory vs resistant hypertension tend to be younger and are more likely to have been diagnosed with congestive heart failure. Refractory hypertension might also differ from resistant hypertension in terms of underlying cause. Preliminary evidence suggests that refractory hypertension is more likely to be neurogenic in etiology (ie, heightened sympathetic tone), vs a volume-dependent hypertension that is more characteristic of resistant hypertension in general. PMID:26514749

Selective coronary scintigraphy

International Nuclear Information System (INIS)

Gambini, D.-J.

1975-01-01

Isotopic techniques occupy a leading place amongst examinations practicable on coronary patients because of their reliability and the safety and simplicity of their use. The present work reviews the possible applications of selective coronary scintigraphy in pathology. After a brief discussion on scintigraphy, isotopic techniques for myocardium research, coronarography and other methods to study local myocardium perfusion the theoretical bases for the use of the exploration are studied, the techniques and methods employed are reported and the results discussed. Coronary scintigraphy consists of selective injection in the two coronary arteries previously catheterized during a coronarography, of two different populations of microspheres labelled with two physically short-lived indicators: 15μ 99m Tc-labelled serumalbumin microspheres, 10 to 15μ In-labelled siderophiline microspheres. Various studies have shown the complete harmlessness of the exploration when certain precautions are taken regarding the size and number of the spheres. The microspheres disperse into the downstream arterial territory proportionally to the number of capillaries present in the different parts of the irrigated region, and are temporarily stopped in the precapillaries. The preparation of the different images needed to interpret the Face and OAG examination for the left coronary, then for the right coronary, is carried out at the end of the coronarography and lasts about 45 minutes. It is also possible by selective injection in the aorta-coronary bridges to judge their functional condition by observation of the regions they irrigate. 56 patients of the Necker hospital cardiological clinic have been examined [fr

Physiologic assessment of coronary artery fistula

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Gupta, N.C.; Beauvais, J. (Creighton Univ., Omaha, NE (USA))

1991-01-01

Coronary artery fistula is an uncommon clinical entity. The most common coronary artery fistula is from the right coronary artery to the right side of the heart, and it is less frequent to the pulmonary artery. The effect of a coronary artery fistula may be physiologically significant because of the steal phenomenon resulting in coronary ischemia. Based on published reports, it is recommended that patients with congenital coronary artery fistulas be considered candidates for elective surgical correction to prevent complications including development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and coronary aneurysm formation with rupture or embolization. A patient is presented in whom treadmill-exercise thallium imaging was effective in determining the degree of coronary steal from a coronary artery fistula, leading to successful corrective surgery.

Physiologic assessment of coronary artery fistula

International Nuclear Information System (INIS)

Gupta, N.C.; Beauvais, J.

1991-01-01

Coronary artery fistula is an uncommon clinical entity. The most common coronary artery fistula is from the right coronary artery to the right side of the heart, and it is less frequent to the pulmonary artery. The effect of a coronary artery fistula may be physiologically significant because of the steal phenomenon resulting in coronary ischemia. Based on published reports, it is recommended that patients with congenital coronary artery fistulas be considered candidates for elective surgical correction to prevent complications including development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and coronary aneurysm formation with rupture or embolization. A patient is presented in whom treadmill-exercise thallium imaging was effective in determining the degree of coronary steal from a coronary artery fistula, leading to successful corrective surgery

Coronary plaque quantification and fractional flow reserve by coronary computed tomography angiography identify ischaemia-causing lesions

DEFF Research Database (Denmark)

Gaur, Sara; Øvrehus, Kristian Altern; Dey, Damini

2016-01-01

AIMS: Coronary plaque characteristics are associated with ischaemia. Differences in plaque volumes and composition may explain the discordance between coronary stenosis severity and ischaemia. We evaluated the association between coronary stenosis severity, plaque characteristics, coronary computed...... tomography angiography (CTA)-derived fractional flow reserve (FFRCT), and lesion-specific ischaemia identified by FFR in a substudy of the NXT trial (Analysis of Coronary Blood Flow Using CT Angiography: Next Steps). METHODS AND RESULTS: Coronary CTA stenosis, plaque volumes, FFRCT, and FFR were assessed...

Functional Response of Tumor Vasculature to PaCO2: Determination of Total and Microvascular Blood Volume by MRI

Directory of Open Access Journals (Sweden)

Scott D. Packard

2003-07-01

Full Text Available In order to identify differences in functional activity, we compared the reactivity of glioma vasculature and the native cerebral vasculature to both dilate and constrict in response to altered PaCO2. Gliomas were generated by unilateral implantation of U87MGdEGFR human glioma tumor cells into the striatum of adult female athymic rats. Relative changes in total and microvascular cerebral blood volume were determined by steady state contrast agent-enhanced magnetic resonance imaging for transitions from normocarbia to hypercarbia and hypocarbia. Although hypercarbia induced a significant increase in both total and microvascular blood volume in normal brain and glioma, reactivity of glioma vasculature was significantly blunted in comparison to normal striatum; glioma total CBV increased by 0.6±0.1%/mm Hg CO2 whereas normal striatum increased by 1.5±0.2%/mm Hg CO2, (P < .0001, group t-test. Reactivity of microvascular blood volume was also significantly blunted. In contrast, hypocarbia decreased both total and microvascular blood volumes more in glioma than in normal striatum. These results indicate that cerebral blood vessels derived by tumor-directed angiogenesis do retain reactivity to CO2. Furthermore, reduced reactivity of tumor vessels to a single physiological perturbation, such as hypercarbia, should not be construed as a generalized reduction of functional activity of the tumor vascular bed.

Coronary heart disease

Science.gov (United States)

Heart disease, Coronary heart disease, Coronary artery disease; Arteriosclerotic heart disease; CHD; CAD ... buildup of plaque in the arteries to your heart. This may also be called hardening of the ...

Ghrelin stimulates angiogenesis in human microvascular endothelial cells: Implications beyond GH release

International Nuclear Information System (INIS)

Li Aihua; Cheng Guangli; Zhu Genghui; Tarnawski, Andrzej S.

2007-01-01

Ghrelin, a peptide hormone isolated from the stomach, releases growth hormone and stimulates appetite. Ghrelin is also expressed in pancreas, kidneys, cardiovascular system and in endothelial cells. The precise role of ghrelin in endothelial cell functions remains unknown. We examined the expression of ghrelin and its receptor (GHSR1) mRNAs and proteins in human microvascular endothelial cells (HMVEC) and determined whether ghrelin affects in these cells proliferation, migration and in vitro angiogenesis; and whether MAPK/ERK2 signaling is important for the latter action. We found that ghrelin and GHSR1 are constitutively expressed in HMVEC. Treatment of HMVEC with exogenous ghrelin significantly increased in these cells proliferation, migration, in vitro angiogenesis and ERK2 phosphorylation. MEK/ERK2 inhibitor, PD 98059 abolished ghrelin-induced in vitro angiogenesis. This is First demonstration that ghrelin and its receptor are expressed in human microvascular endothelial cells and that ghrelin stimulates HMVEC proliferation, migration, and angiogenesis through activation of ERK2 signaling

Coronary artery anatomy and variants

Energy Technology Data Exchange (ETDEWEB)

Malago, Roberto; Pezzato, Andrea; Barbiani, Camilla; Alfonsi, Ugolino; Nicoli, Lisa; Caliari, Giuliana; Pozzi Mucelli, Roberto [Policlinico G.B. Rossi, University of Verona, Department of Radiology, Verona (Italy)

2011-12-15

Variants and congenital anomalies of the coronary arteries are usually asymptomatic, but may present with severe chest pain or cardiac arrest. The introduction of multidetector CT coronary angiography (MDCT-CA) allows the detection of significant coronary artery stenosis. Improved performance with isotropic spatial resolution and higher temporal resolution provides a valid alternative to conventional coronary angiography (CCA) in many patients. MDCT-CA is now considered the ideal tool for three-dimensional visualization of the complex and tortuous anatomy of the coronary arteries. With multiplanar and volume-rendered reconstructions, MDCT-CA may even outperform CCA in determining the relative position of vessels, thus providing a better view of the coronary vascular anatomy. The purpose of this review is to describe the normal anatomy of the coronary arteries and their main variants based on MDCT-CA with appropriate reconstructions. (orig.)

Coronary artery anomalies in Turner Syndrome.

Science.gov (United States)

Viuff, Mette H; Trolle, Christian; Wen, Jan; Jensen, Jesper M; Nørgaard, Bjarne L; Gutmark, Ephraim J; Gutmark-Little, Iris; Mortensen, Kristian H; Gravholt, Claus Højbjerg; Andersen, Niels H

Congenital heart disease, primarily involving the left-sided structures, is often seen in patients with Turner Syndrome. Moreover, a few case reports have indicated that coronary anomalies may be more prevalent in Turner Syndrome than in the normal population. We therefore set out to systematically investigate coronary arterial anatomy by computed tomographic coronary angiography (coronary CTA) in Turner Syndrome patients. Fifty consecutive women with Turner Syndrome (mean age 47 years [17-71]) underwent coronary CTA. Patients were compared with 25 gender-matched controls. Coronary anomaly was more frequent in patients with Turner Syndrome than in healthy controls [20% vs. 4% (p = 0.043)]. Nine out of ten abnormal cases had an anomalous left coronary artery anatomy (absent left main trunk, n = 7; circumflex artery originating from the right aortic sinus, n = 2). One case had a tubular origin of the right coronary artery above the aortic sinus. There was no correlation between the presence of coronary arterial anomalies and karyotype, bicuspid aortic valve, or other congenital heart defects. Coronary anomalies are highly prevalent in Turner Syndrome. The left coronary artery is predominantly affected, with an absent left main coronary artery being the most common anomaly. No hemodynamically relevant coronary anomalies were found. Copyright © 2016 Society of Cardiovascular Computed Tomography. All rights reserved.

Coronary stent on coronary CT angiography: Assessment with model-based iterative reconstruction technique

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Lee, Eun Chae; Kim, Yeo Koon; Chun, Eun Ju; Choi, Sang IL [Dept. of of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2016-05-15

To assess the performance of model-based iterative reconstruction (MBIR) technique for evaluation of coronary artery stents on coronary CT angiography (CCTA). Twenty-two patients with coronary stent implantation who underwent CCTA were retrospectively enrolled for comparison of image quality between filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR) and MBIR. In each data set, image noise was measured as the standard deviation of the measured attenuation units within circular regions of interest in the ascending aorta (AA) and left main coronary artery (LM). To objectively assess the noise and blooming artifacts in coronary stent, we additionally measured the standard deviation of the measured attenuation and intra-luminal stent diameters of total 35 stents with dedicated software. All image noise measured in the AA (all p < 0.001), LM (p < 0.001, p = 0.001) and coronary stent (all p < 0.001) were significantly lower with MBIR in comparison to those with FBP or ASIR. Intraluminal stent diameter was significantly higher with MBIR, as compared with ASIR or FBP (p < 0.001, p = 0.001). MBIR can reduce image noise and blooming artifact from the stent, leading to better in-stent assessment in patients with coronary artery stent.

Large coronary intramural hematomas

DEFF Research Database (Denmark)

Antonsen, Lisbeth; Thayssen, Per; Jensen, Lisette Okkels

2015-01-01

Isolated spontaneous coronary intramural hematoma is a unique subset of spontaneous coronary artery dissection that is characterized by a hemorrhage limited to the medial-adventitial layers, causing subsequent hematoma formation without visible intimal flaps. It is an infrequent and serious...... diagnostics and treatment strategy. Coronary intramural hematomas can also occur iatrogenically, as a complication to percutaneous coronary intervention (PCI). Coronary angiography (CAG) has limited diagnostic value in the absence of intimal dissections, and lesions are often angiographically ambiguous....... Intravascular ultrasound (IVUS) is an important diagnostic tool in establishing the correct diagnosis, as it provides a complete vessel wall assessment, and enables morphometric information regarding the magnitude and severity of the underlying hematoma. Due to the rarity of this clinical scenario...

Multislice CT coronary angiography: effect of sublingual nitroglycerine on the diameter of coronary arteries

International Nuclear Information System (INIS)

Dewey, M.; Hamm, B.; Hoffmann, H.

2006-01-01

Purpose: to investigate the influence of sublingual glycerol trinitrate (1.2 mg, Nitrate [nitroglycerine], Nitrolingual N spray) on the coronary artery diameter on multislice computed tomography (MSCT) coronary angiography. Materials and methods: out of our database of patients who underwent MSCT (slice thickness of 0.5 mm, Aquilion, Toshiba) coronary angiography between July 2003 and November 2005 (950 patients) we retrospectively identified patients with follow-up examinations who received Nitrate for one examination while another examination was performed without Nitrate (10 patients). Another 10 patients who underwent two MSCT examinations with sublingual Nitrate administration were randomly selected from this database to serve as control group. For the resulting 40 MSCT examinations, blinded MSCT datasets were prepared, which were randomly evaluated by a reader blinded to the patient information and whether or not Nitrate had been given. The proximal coronary artery diameters were measured for the left main coronary artery (LMA), the left anterior descending coronary artery (LAD), the left circumflex coronary artery (LCX), and the right coronary artery (RCA) in all 40 datasets, resulting in altogether 160 measurements. Results: the proximal diameters of all four coronary arteries were significantly larger on the MSCT coronary angiograms obtained after sublingual administration of Nitrate compared with the examinations in the same 10 patients without Nitrate (p < 0.001). The average diameters without and with Nitrate for the LMA, LAD, LCX, and RCA were 4.3 ± 1.1 vs. 4.8 ± 0.9 mm (12% increase, p < 0.005), 3.0 ± 0.6 vs. 3.5 ± 0.5 mm (17% increase, p < 0.001), 2.7 ± 0.6 vs. 3.2 ± 0.7 mm (19% increase, p < 0.005), and 2.9 ± 0.9 vs. 3.5 ± 0.7 mm (21% increase, p < 0.005), respectively. In the control group of 10 patients who underwent two MSCT coronary angiographies after sublingual Nitrate, no significant difference in the proximal diameter of all four

Breath-hold two-dimensional MR angiography of coronary arteries. Comparison with conventional coronary angiography in ten cases

International Nuclear Information System (INIS)

Li Liwei; Zhang Wanshi; Liu Chaozhong; Lu Xiaoyan; Xu Jiaxing

1997-01-01

Purpose: To assess the diagnostic value of two-dimensional coronary magnetic resonance (MR) angiography in patients evaluated for ischemic heart disease. Materials and methods: Ten patients who underwent selective cardiac catheterization with coronary MR angiography were evaluated with two-dimensional coronary MR angiography. Coronary MR angiography was performed with breath-hold fat-suppressed ECG-gated Turbo-FLASH with K-space segmentation using a 1.5 T imager. Results: The left main coronary artery, proximal left anterior descending artery, circumflex artery and right coronary artery were demonstrated in all cases. Continuous segments (mean) of left anterior descending, circumflex and right coronary arteries visualized on MRA were 6.72 +- 3.16 cm, 3.67 +- 4.81 cm and 7.93 +- 3.12 cm respectively. The overall sensitivity for detection of hemodynamically significant coronary artery lesion (≥50%) was 62.5% respectively. Conclusion: Breath-hold two-dimensional coronary MR angiography was useful in showing relatively long segments of the main coronary arteries and also has potential in depicting hemodynamically significant coronary artery lesions

Encouraging effects of a short-term, adapted Nordic diet intervention on skin microvascular function and skin oxygen tension in younger and older adults.

Science.gov (United States)

Rogerson, David; McNeill, Scott; Könönen, Heidi; Klonizakis, Markos

2018-05-01

The microvascular benefits of regional diets appear in the literature; however, little is known about Nordic-type diets. We investigated the effects of a short-term, adapted, Nordic diet on microvascular function in younger and older individuals at rest and during activity. Thirteen young (mean age: 28 y; standard deviation: 5 y) and 15 older (mean age: 68 y; standard deviation: 6 y) participants consumed a modified Nordic diet for 4 wk. Laser Doppler flowmetry and transcutaneous oxygen monitoring were used to assess cutaneous microvascular function and oxygen tension pre- and postintervention; blood pressure, body mass, body fat percentage, ratings of perceived exertion, and peak heart rate during activity were examined concurrently. Axon-mediated vasodilation improved in older participants (1.17 [0.30] to 1.30 [0.30]; P Nordic diet might improve microvascular health. Copyright © 2017 Elsevier Inc. All rights reserved.

Short-term endurance training after coronary artery bypass grafting improves insulin resistance parameters in patients with hypertension.

Science.gov (United States)

Borowicz-Bieńkowska, Sławomira; Przywarska, Izabela; Dylewicz, Piotr; Pilaczyńska-Szcześniak, Łucja; Rychlewski, Tadeusz; Wilk, Małgorzata; Rózańska, Anna

2004-05-01

It has been shown that short-term exercise training improves insulin resistance parameters in patients with ischaemic heart disease. The effects of such a rehabilitation programme in patients with hypertension have not been well established. To assess whether short-term endurance training after coronary artery bypass grafting (CABG) may improve metabolic parameters and reduce blood pressure in patients with hypertension. The study group consisted of 30 male patients (15 with hypertension and 15 normotensive) aged 55+/-2.1 years who underwent CABG 1 to 6 months before the initiation of a 3-week endurance training. Glucose, insulin and C-peptide blood levels as well as binding and degradation of 125I-insulin by erythrocyte receptors were assessed before and after the training programme. The effects of training on blood pressure values were also evaluated. A significant improvement (phypertension. This was accompanied by a significant (phypertension, both the exercise systolic and diastolic pressures decreased significantly (pendurance training was especially effective in patients with hypertension in whom beneficial changes in some metabolic risk factors of ischaemic heart disease as well as the reduction in the blood pressure values were observed.

Current status of hybrid coronary revascularization.

Science.gov (United States)

Jaik, Nikhil P; Umakanthan, Ramanan; Leacche, Marzia; Solenkova, Natalia; Balaguer, Jorge M; Hoff, Steven J; Ball, Stephen K; Zhao, David X; Byrne, John G

2011-10-01

Hybrid coronary revascularization combines coronary artery bypass surgery with percutaneous coronary intervention techniques to treat coronary artery disease. The potential benefits of such a technique are to offer the patients the best available treatments for coronary artery disease while minimizing the risks of the surgery. Hybrid coronary revascularization has resulted in the establishment of new 'hybrid operating suites', which incorporate and integrate the capabilities of a cardiac surgery operating room with that of an interventional cardiology laboratory. Hybrid coronary revascularization has greatly augmented teamwork and cooperation between both fields and has demonstrated encouraging as well as good initial outcomes.

Comparison of cardiovascular risk factors and biochemical profile in patients with cardiac syndrome X and obstructive coronary artery disease: A propensity score-matched study

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Ali Vasheghani-Farahani

2013-09-01

Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 BACKGROUND: This study was designed to compare the frequency of conventional cardiovascular disease risk factors and clinical biochemistry profile in patients with cardiac syndrome X (CSX and obstructive coronary artery disease (CAD. METHODS: A cross-sectional study was conducted on patients with typical angina and positive exercise tolerance test undergoing coronary angiography in our center. 342 consecutive patients with CSX were enrolled into this study and were matched regarding age and sex with 342 patients with acute coronary syndrome (ACS and also 342 patients with chronic stable angina (SA. Cardiovascular risk factors as well as biochemistry profile of the patients were recorded. RESULTS: Mean age of the studied patients was 53.0 years and 41.5% were male. There was no significant difference between the CSX patients and CAD patients regarding body mass index (BMI. Frequency of diabetes mellitus, hyperlipidemia, smoking, family history of premature CAD and hypertension was significantly lower in patients with CSX than ACS and SA patients. Patients with CSX had significantly higher levels of high-density lipoprotein cholesterol (HDL-cholesterol than comparators while the levels of low-density lipoprotein cholesterol (LDL-cholesterol, total cholesterol, triglyceride and fasting blood sugar (FBS were significantly lower in patients with CSX than CAD patients. CONCLUSION: The present study demonstrated that CSX patients had substantially lower frequency of all conventional CVD risk factors than patients with obstructive CAD. This might aid in developing novel scoring systems or appropriateness criteria for angiographic evaluation of patients with typical angina and positive exercise test in order to reduce the rate of negative results.   Keywords: Cardiac Syndrome X, Microvascular Dysfunction

Association Between Early Q Waves and Reperfusion Success in Patients With ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

DEFF Research Database (Denmark)

Topal, Divan Gabriel; Lønborg, Jacob; Ahtarovski, Kiril Aleksov

2017-01-01

BACKGROUND: Pathological early Q waves (QW) are associated with adverse outcomes in patients with ST-segment-elevation myocardial infarction (STEMI). Primary percutaneous coronary intervention (PCI) may therefore be less beneficial in patients with QW than in patients without QW. Myocardial salvage......: The ECG was assessed before primary PCI for the presence of QW (early) in 515 STEMI patients. The patients underwent a cardiac magnetic resonance imaging scan at day 1 (interquartile range [IQR], 1-1) and again at day 92 (IQR, 89-96). Early QW was observed in 108 (21%) patients and was related to smaller...... index and microvascular obstruction (MVO) are markers for reperfusion success. Thus, to clarify the benefit from primary PCI in STEMI patients with QW, we examined the association between baseline QW and myocardial salvage index and MVO in STEMI patients treated with primary PCI. METHODS AND RESULTS...

Milrinone infusion: A therapeutic option in coronary vasospasm after primary percutaneous transluminal coronary angioplasty

Directory of Open Access Journals (Sweden)

Singh Amarpal

2009-01-01

Full Text Available A 42-year-old male presented to the emergency department with acute chest pain. The electrocardiogram revealed inferior wall myocardial infarction. Emergency coronary angiography revealed total occlusion of the distal right coronary artery with thrombus. Patient was taken up for primary percutaneous coronary angioplasty with stenting of distal right coronary artery. Six hours following the procedure, the patient developed re-elevation of ST-segment in inferior leads of electrocardiogram and subsequent haemodynamic instability. Repeat coronary angiography revealed patent stent and coronary artery spasm in proximal part, which was relieved by intracoronary injection of nitroglycerine. After an hour, the patient re-developed symptoms of chest pain along with bradycardia, hypotension and ST segment elevation. Intravenous infusion of nitroglycerine did not improve the condition but produced persistent hypotension. Infusion of milrinone was then started. Over time, normalisation of electrocardiogram occurred. The patient was discharged in stable condition. This case suggests that milrinone may be effective in alleviating coronary artery spasm when the use of other agents fails

A Case of Cardiac Cephalalgia Showing Reversible Coronary Vasospasm on Coronary Angiogram

Science.gov (United States)

Yang, YoungSoon; Jin, Dong Gyu; Jang, Il Mi; Jang, YoungHee; Na, Hae Ri; Kim, SanYun

2010-01-01

Background Under certain conditions, exertional headaches may reflect coronary ischemia. Case Report A 44-year-old woman developed intermittent exercise-induced headaches with chest tightness over a period of 10 months. Cardiac catheterization followed by acetylcholine provocation demonstrated a right coronary artery spasm with chest tightness, headache, and ischemic effect of continuous electrocardiography changes. The patient's headache disappeared following intra-arterial nitroglycerine injection. Conclusions A coronary angiogram with provocation study revealed variant angina and cardiac cephalalgia, as per the International Classification of Headache Disorders (code 10.6). We report herein a patient with cardiac cephalalgia that manifested as reversible coronary vasospasm following an acetylcholine provocation test. PMID:20607049

Impact of coronary dominance on in-hospital outcomes after percutaneous coronary intervention in patients with acute coronary syndrome.

Directory of Open Access Journals (Sweden)

Toshiki Kuno

Full Text Available OBJECTIVE: This study evaluated the manner in which coronary dominance affects in-hospital outcomes of acute coronary syndrome (ACS patients undergoing percutaneous coronary intervention (PCI. BACKGROUND: Previous studies have shown that left dominant coronary anatomies are associated with worse prognoses in patients with coronary artery disease. METHODS: Data were analyzed from 4873 ACS patients undergoing PCI between September 2008 and April 2013 at 14 hospitals participating in the Japanese Cardiovascular Database Registry. The patients were grouped based on diagnostic coronary angiograms performed prior to PCI; those with right- or co-dominant anatomy (RD group and those with left-dominant anatomy (LD group. RESULTS: The average patient age was 67.6±11.8 years and both patient groups had similar ages, coronary risk factors, comorbidities, and prior histories. The numbers of patients presenting with symptoms of heart failure, cardiogenic shock, or cardiopulmonary arrest were significantly higher in the LD group than in the RD group (heart failure: 650 RD patients [14.7%] vs. 87 LD patients [18.8%], P = 0.025; cardiogenic shock: 322 RD patients [7.3%] vs. 48 LD patients [10.3%], P = 0.021; and cardiopulmonary arrest: 197 RD patients [4.5%] vs. 36 LD patients [7.8%], P = 0.003. In-hospital mortality was significantly higher among LD patients than among RD patients (182 RD patients [4.1%] vs. 36 LD patients [7.8%], P = 0.001. Multivariate logistic regression analysis revealed that LD anatomy was an independent predictor for in-hospital mortality (odds ratio, 1.75; 95% confidence interval, 1.06-2.89; P = 0.030. CONCLUSION: Among ACS patients who underwent PCI, LD patients had significantly worse in-hospital outcomes compared with RD patients, and LD anatomy was an independent predictor of in-hospital mortality.

[Endarterectomy of the coronary arteries].

Science.gov (United States)

Fischer, V; Simkovic, I; Holoman, M; Verchvodko, P; Janotík, P; Galbánek, J; Hulman, M; Kostelnicák, J; Jurco, R; Slezák, J

1992-02-01

The authors analyze 50 patients with endarterectomy of the coronary arteries during the periods of 1972-1974 and 1988-1990. The results of endarterectomy of the right and left coronary artery provide evidence of its justification in indicated cases whereby contrary to some departments the results of endarterectomy of the left coronary artery are comparable with endarterectomy of the right coronary artery.

An unusual neonatal presentation of anomalous origin of the left coronary artery arising from the pulmonary artery.

Science.gov (United States)

Garty, Y; Guri, A; Shinwell, E S; Matitiau, A

2008-01-01

We describe a previously unreported neonatal presentation of an anomalous origin of the left coronary artery arising from the pulmonary artery. This is a full-term female infant after normal pregnancy and delivery. The baby was diagnosed at 2 days of age due to weak femoral pulses noted on the routine nursery discharge examination. The cardiac examination revealed weak pulses everywhere and mild tachypnea and tachycardia. An electrocardiogram showed clear signs of ischemia. Echocardiography demonstrated an anomalous origin of the left coronary artery arising from the pulmonary artery with bidirectional blood flow. There was a severely depressed left ventricular function and mild mitral valve regurgitation. At 4 days of age, the infant underwent complete successful surgical repair with reimplantation of the anomalous coronary artery to the aorta. She recovered slowly but well. Fifteen months later she is doing well with no cardiac residua. A neonatal presentation is very unusual due to protective high pulmonary resistance after birth, with gradual decline in pressure and gradual onset of heart failure. This case may be related to an unusually rapid drop in pulmonary vascular resistance causing very early cardiac ischemia. (c) 2007 S. Karger AG, Basel.

Optimal time for predicting left ventricular remodeling after successful primary coronary angioplasty in acute myocardial infarction using serial myocardial contrast echocardiography and magnetic resonance imaging

International Nuclear Information System (INIS)

Sakuma, Tadamichi; Okada, Takenori; Hayashi, Yasuhiko; Otsuka, Masaya; Hirai, Yuukou

2002-01-01

The objective of this study was to determine the optimal time to assess microvascular integrity within the risk area for myocardial infarction in order to predict unfavorable left ventricular remodeling (LVR) after successful primary coronary angioplasty. Fifty-three patients who underwent myocardial contrast echocardiography (MCE) just before recanalization, shortly after and 1 day (Day 2) and 3 weeks after recanalization were studied. The no- and low-reflow ratio (LR ratio) was analyzed at each stage. The wall-tinning ratio within the risk area was determined using magnetic resonance imaging performed 3-4 weeks after the recanalization. Thirteen of the 53 patients showed LVR 3-8 months after recanalization. The optimal time to predict LVR was found to be Day 2 based on the receiver operating characteristic curves. The LR ratio on Day 2 (χ 2 =7.39, p=0.007) and the collateral circulation before recanalization (χ 2 =4.57, p=0.03) were chosen as independent variables for predicting LVR. Patients with greater than 0.43 in the LR ratio on Day 2 showed a lower wall-thinning ratio (58±19% vs 72±20%, p=0.05). This study shows that the optimal time to estimate the microvascular integrity for predicting LVR is 1 day after recanalization, which is neither shortly after recanalization nor during the convalescent stage. (author)

Detection of coronary calcium with electron beam tomography in coronary artery disease

International Nuclear Information System (INIS)

Haberl, R.; Knez, A.; Becker, A.; Becker, C.; Bruening, R.; Reiser, M.; Maass, A.; Steinbeck, G.

1998-01-01

Purpose: Coronary calcium is a powerful indicator of arteriosclerosis and can be detected very precisely with electron beam tomography. The method can be applied in patients with known coronary artery disease or in asymptomatic patients at risk of arteriosclerotic disease. Results: At the University of Munich we performed an EBT scan of the heart in 1100 patients within the last year. In 567 patients coronary angiography was performed also (±3 days). Confirming previous reports in the literature, we found a correlation of the calcium score with the age and gender of the patients. Severe coronary artery disease (stenoses ≥ 75%) was associated with significantly more calcium than less severe CAD. The calcium score did not discriminate between one-, two- and three-vessel disease. The site of calcification does not correlate with the localization of stenoses. Thirty-three percent of the patients with significant coronary artery disease showed a normal age-adjusted calcium score; a total of 8.1% of patients with severe stenoses did not reveal any coronary calcification (score =0). With asymptomatic patients there are only a few studies available. Soft plaques cannot be detected with EBT, but in most patients soft plaques occur together with hard plaques. Our results show that spiral CT of the newest generation may also be used for calcium screening. There was an excellent correlation of the calcium scores of EBT and spiral CT at all levels of calcification. Discussion: Coronary calcium is a sensitive marker of coronary artery disease. In the clinical setting EBT is indicated in patients with known coronary artery disease (to evaluate prognosis), in patients who are unable to perform a stress test, and in patients with atypical chest pain. However, lack of calcification may be associated with severe stenoses in a minority of patients. The clinical value in asymptomatic patients needs to be defined: Randomized studies are necessary. We see a possible indication in

Multiple giant coronary aneurysms arising from coronary istula to the pulmonary artery revealed in aorta CT angiography

Energy Technology Data Exchange (ETDEWEB)

Kang, Eun Ju; Lee, Ki Nam [Dept. of Radiology, Dong A University Hospital, Dong-A University College of Medicine, Busan (Korea, Republic of); Lee, Jong Min [Dept. of Radiology, Kyungpook National University Hospital, Kyungpook National University College of Medicine, Daegu (Korea, Republic of)

2015-12-15

Coronary fistula is a rare coronary abnormality through which blood drains into the cardiac chamber, great vessel or other vessels. In addition, giant aneurysm arising from coronary fistula is rare pathologic manifestation. Herein, we presented a rare case of multiple giant coronary artery aneurysms arising from coronary to pulmonary artery fistula in a 79-year-old woman presenting with sudden loss of consciousness. The aneurysms were detected using thoracic computed tomography angiography and consequently confirmed by invasive coronary angiography.

Remodelling of the microarchitecture of resistance arteries in cardiovascular diseases

DEFF Research Database (Denmark)

Bloksgaard, Maria; Brewer, Jonathan R.; Leurgans, Thomas

Small resistance artery structure is an independent predictor of cardiovascular events in essential hypertension [1, 2] and diabetes (types I and II) [3, 4]. In particular, the media-to-lumen ratio (M:L) is predictive of cardiovascular events. The exact nature of this resistance artery remodeling...... in comparison to other well-studied microvascular beds (e.g. rat mesentery). In the future we aim to compare the microarchitecture of small resistance arteries from parietal pericardial biopsies between patients with and without (treated) hypertension, diabetes and/or ischemic heart disease. 1. Buus, N.H., et...... al., Small artery structure during antihypertensive therapy is an independent predictor of cardiovascular events in essential hypertension. J Hypertens, 2013. 31(4): p. 791-7. 2. Mathiassen, O.N., et al., Small artery structure is an independent predictor of cardiovascular events in essential...

Role of endothelial function in coronary slow-flow phenomenon with angiographically normal coronaries

Directory of Open Access Journals (Sweden)

Srikanth Nathani

2016-01-01

Conclusion: Coronary slow flow phenomenon is a marker of atherosclerosis (as documented by carotid intima media thickness and our study has also shown that endothelial function is significantly impaired in patients with coronary slow flow (as documented by impaired endothelial dependent vasodilatation than that of patients with normal epicardial coronaries with normal flow.

Determining the proportion of coronary segments assessable on 16-slice CT coronary angiography: a brief report

International Nuclear Information System (INIS)

Soon, K. H.; Cox, N.; Eccleston, D.; Lim, Y.; Chaitowitz, I.; Bell, K. W.; Kelly, A-M.

2007-01-01

Computed tomography coronary angiography (CT-CA) is becoming a popular non-invasive coronary imaging method. We aimed to determine the proportion of coronary segments assessable on a 16-slice CT in comparison with conventional selective coronary angiography (SCA). We identified all patients who had both 16-slice CT-CA and recent SCA (less than 12 months) from March 2004 to July 2005. Two CT reporters blinded to SCA independently classified coronary segment assessability on CT-CA. A cardiologist blinded to CT findings classified assess-ability of coronary segments on SCA. Data were analysed using descriptive statistics and proportion of agreement. Ninety-five study pairs were included in the analysis. Of those, 1161 coronary segments were deemed assessable on SCA and 1103 segments (95%) were also assessable on CT-CA. Nonassessable segments on CT-CA were predominantly in the distal segments and branches of coronary arteries. Reasons for nonassessability were small calibre (48.3%), motion artefacts (20.7%) and poorly reconstructed segments (22.4%). The 16-slice CT was able to assess a high proportion of but not all coronary segments. Nonassessable segments were predominantly distal segments or branches of coronary arteries. Motion artefacts due to heart-rate changes, small calibre and poorly reconstructed images were main causes of nonassessability on 16-slice CT-CA

Relationship of Hypertension to Coronary Atherosclerosis and Cardiac Events in Patients With Coronary Computed Tomographic Angiography.

Science.gov (United States)

Nakanishi, Rine; Baskaran, Lohendran; Gransar, Heidi; Budoff, Matthew J; Achenbach, Stephan; Al-Mallah, Mouaz; Cademartiri, Filippo; Callister, Tracy Q; Chang, Hyuk-Jae; Chinnaiyan, Kavitha; Chow, Benjamin J W; DeLago, Augustin; Hadamitzky, Martin; Hausleiter, Joerg; Cury, Ricardo; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Kaufmann, Philipp A; Maffei, Erica; Raff, Gilbert; Shaw, Leslee J; Villines, Todd C; Dunning, Allison; Marques, Hugo; Pontone, Gianluca; Andreini, Daniele; Rubinshtein, Ronen; Bax, Jeroen; Jones, Erica; Hindoyan, Niree; Gomez, Millie; Lin, Fay Y; Min, James K; Berman, Daniel S

2017-08-01

Hypertension is an atherosclerosis factor and is associated with cardiovascular risk. We investigated the relationship between hypertension and the presence, extent, and severity of coronary atherosclerosis in coronary computed tomographic angiography and cardiac events risk. Of 17 181 patients enrolled in the CONFIRM registry (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter Registry) who underwent ≥64-detector row coronary computed tomographic angiography, we identified 14 803 patients without known coronary artery disease. Of these, 1434 hypertensive patients were matched to 1434 patients without hypertension. Major adverse cardiac events risk of hypertension and non-hypertensive patients was evaluated with Cox proportional hazards models. The prognostic associations between hypertension and no-hypertension with increasing degree of coronary stenosis severity (nonobstructive or obstructive ≥50%) and extent of coronary artery disease (segment involvement score of 1-5, >5) was also assessed. Hypertension patients less commonly had no coronary atherosclerosis and more commonly had nonobstructive and 1-, 2-, and 3-vessel disease than the no-hypertension group. During a mean follow-up of 5.2±1.2 years, 180 patients experienced cardiac events, with 104 (2.0%) occurring in the hypertension group and 76 (1.5%) occurring in the no-hypertension group (hazard ratios, 1.4; 95% confidence intervals, 1.0-1.9). Compared with no-hypertension patients without coronary atherosclerosis, hypertension patients with no coronary atherosclerosis and obstructive coronary disease tended to have higher risk of cardiac events. Similar trends were observed with respect to extent of coronary artery disease. Compared with no-hypertension patients, hypertensive patients have increased presence, extent, and severity of coronary atherosclerosis and tend to have an increase in major adverse cardiac events. © 2017 American Heart Association, Inc.

Coronary CT angiography

Energy Technology Data Exchange (ETDEWEB)

Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

2009-07-01

Coronary CT angiography has attained increasing scientific attention at academic institutions and has become a highly accurate diagnostic modality. Extending this knowledge into a practice setting is the purpose of 'Coronary CT Angiography'. This book will assist you in integrating cardiac CT into your daily practice, while also giving an overview of the current technical status and applications. The specific features of scanners from all four main vendors are also presented providing an objective overview of noninvasive coronary angiography using CT. (orig.)

Coffee consumption and coronary calcification: The Rotterdam coronary calcification study

NARCIS (Netherlands)

G.J. van Woudenbergh (Geertruida); R. Vliegenthart (Rozemarijn); F.J.A. van Rooij (Frank); A. Hofman (Albert); M. Oudkerk (Matthijs); J.C.M. Witteman (Jacqueline); J.M. Geleijnse (Marianne)

2008-01-01

textabstractBACKGROUND - The role of coffee in the cardiovascular system is not yet clear. We examined the relation of coffee intake with coronary calcification in a population-based cohort. METHODS AND RESULTS - The study involved 1570 older men and women without coronary heart disease who

Evaluation of Coronary Artery Stenosis by Quantitative Flow Ratio During Invasive Coronary Angiography

DEFF Research Database (Denmark)

Westra, Jelmer; Tu, Shengxian; Winther, Simon

2018-01-01

BACKGROUND: Quantitative flow ratio (QFR) is a novel diagnostic modality for functional testing of coronary artery stenosis without the use of pressure wires and induction of hyperemia. QFR is based on computation of standard invasive coronary angiographic imaging. The purpose of WIFI II (Wire...... patients with suspected coronary artery disease on coronary computed tomographic angiography for diagnostic invasive coronary angiography. Fractional flow reserve (FFR) was measured in all segments with 30% to 90% diameter stenosis. Blinded observers calculated QFR (Medis Medical Imaging bv......, The Netherlands) for comparison with FFR. FFR was measured in 292 lesions from 191 patients. Ten (5%) and 9 patients (5%) were excluded because of FFR and angiographic core laboratory criteria, respectively. QFR was successfully computed in 240 out of 255 lesions (94%) with a mean diameter stenosis of 50...

Relation of coronary vasoreactivity and coronary calcification in asymptomatic subjects with a family history of premature coronary artery disease

International Nuclear Information System (INIS)

Pirich, Christian; Leber, Alexander; Knez, Andreas; Bengel, Frank M.; Nekolla, Stephan G.; Schwaiger, Markus; Haberl, Ralph

2004-01-01

Electron-beam computed tomography (EBCT) allows non-invasive imaging of coronary calcification and has been promoted as a screening tool for coronary artery disease (CAD) in asymptomatic high-risk subjects. This study assessed the relation of coronary calcifications to alterations in coronary vascular reactivity by means of positron emission tomography (PET) in asymptomatic subjects with a familial history of premature CAD. Twenty-one subjects (mean age 51±10 years) underwent EBCT imaging for coronary calcifications expressed as the coronary calcium score (CCS according to Agatston) and rest/adenosine-stress nitrogen-13 ammonia PET with quantification of myocardial blood flow (MBF) and coronary flow reserve (CFR). The mean CCS was 237±256 (median 146, range 0-915). The CCS was 100 units in 13. As defined by age-related thresholds, 15 subjects had an increased CCS (>75th percentile). Overall mean resting and stress MBF and CFR were 71±16 ml 100 g -1 min -1 , 218±54 ml 100 g -1 min -1 and 3.20±0.77, respectively. Three subjects with CCS ranging from 114 to 451 units had an abnormal CFR (<2.5). There was no relation between CCS and resting or stress MBF or CFR (r=0.17, 0.18 and 0.10, respectively). In asymptomatic subjects a pathological CCS was five times more prevalent than an abnormal CFR. The absence of any close relationship between CCS and CFR reflects the fact that quantitative myocardial perfusion imaging with PET characterises the dynamic process of vascular reactivity while EBCT is a measure of more stable calcified lesions in the arterial wall whose presence is closely related to age. (orig.)

Is heart rate variability a feasible method to determine anaerobic threshold in progressive resistance exercise in coronary artery disease?

Science.gov (United States)

Sperling, Milena P R; Simões, Rodrigo P; Caruso, Flávia C R; Mendes, Renata G; Arena, Ross; Borghi-Silva, Audrey

2016-01-01

Recent studies have shown that the magnitude of the metabolic and autonomic responses during progressive resistance exercise (PRE) is associated with the determination of the anaerobic threshold (AT). AT is an important parameter to determine intensity in dynamic exercise. To investigate the metabolic and cardiac autonomic responses during dynamic resistance exercise in patients with Coronary Artery Disease (CAD). Twenty men (age = 63±7 years) with CAD [Left Ventricular Ejection Fraction (LVEF) = 60±10%] underwent a PRE protocol on a leg press until maximal exertion. The protocol began at 10% of One Repetition Maximum Test (1-RM), with subsequent increases of 10% until maximal exhaustion. Heart Rate Variability (HRV) indices from Poincaré plots (SD1, SD2, SD1/SD2) and time domain (rMSSD and RMSM), and blood lactate were determined at rest and during PRE. Significant alterations in HRV and blood lactate were observed starting at 30% of 1-RM (p<0.05). Bland-Altman plots revealed a consistent agreement between blood lactate threshold (LT) and rMSSD threshold (rMSSDT) and between LT and SD1 threshold (SD1T). Relative values of 1-RM in all LT, rMSSDT and SD1T did not differ (29%±5 vs 28%±5 vs 29%±5 Kg, respectively). HRV during PRE could be a feasible noninvasive method of determining AT in CAD patients to plan intensities during cardiac rehabilitation.

Rest period duration of the coronary arteries: Implications for magnetic resonance coronary angiography

International Nuclear Information System (INIS)

Shechter, Guy; Resar, Jon R.; McVeigh, Elliot R.

2005-01-01

Magnetic resonance (MR) and computed tomography coronary imaging is susceptible to artifacts caused by motion of the heart. The presence of rest periods during the cardiac and respiratory cycles suggests that images free of motion artifacts could be acquired. In this paper, we studied the rest period (RP) duration of the coronary arteries during a cardiac contraction and a tidal respiratory cycle. We also studied whether three MR motion correction methods could be used to increase the respiratory RP duration. Free breathing x-ray coronary angiograms were acquired in ten patients. The three-dimensional (3D) structure of the coronary arteries was reconstructed from a biplane acquisition using stereo reconstruction methods. The 3D motion of the arterial model was then recovered using an automatic motion tracking algorithm. The motion field was then decomposed into separate cardiac and respiratory components using a cardiac respiratory parametric model. For the proximal-to-middle segments of the right coronary artery (RCA), a cardiac RP (<1 mm 3D displacement) of 76±34 ms was measured at end systole (ES), and 65±42 ms in mid-diastole (MD). The cardiac RP was 80±25 ms at ES and 112±42 ms at MD for the proximal 5 cm of the left coronary tree. At end expiration, the respiratory RP (in percent of the respiratory period) was 26±8% for the RCA and 27±17% for the left coronary tree. Left coronary respiratory RP (<0.5 mm 3D displacement) increased with translation (32% of the respiratory period), rigid body (51%), and affine (79%) motion correction. The RCA respiratory RP using translational (27%) and rigid body (33%) motion correction were not statistically different from each other. Measurements of the cardiac and respiratory rest periods will improve our understanding of the temporal and spatial resolution constraints for coronary imaging

Indications for coronary angiography

International Nuclear Information System (INIS)

Kaltenbach, M.; Vallbracht, C.

1985-01-01

Today selective coronary angiography, introduced by Sones in 1957, is used as clinical routine for diagnosing morphological changes in the coronary arteries. Hitherto, more recent techniques such as digital subtraction angiography cannot provide comparable information. Strict criteria for its indication depending on possible therapeutic consequences, have to be applied, although the risk is low with a letality of 0.01 to 0.05 percent. Radionuclear investigations can be used as additional tool in selected cases. The careful indication for coronary angiography usually implies the possible need for coronary bypass graft surgery of balloon angioplasty. (orig./MG) [de

Circulating IGF-1 deficiency exacerbates hypertension-induced microvascular rarefaction in the mouse hippocampus and retrosplenial cortex: implications for cerebromicrovascular and brain aging.

Science.gov (United States)

Tarantini, Stefano; Tucsek, Zsuzsanna; Valcarcel-Ares, M Noa; Toth, Peter; Gautam, Tripti; Giles, Cory B; Ballabh, Praveen; Wei, Jeanne Y; Wren, Jonathan D; Ashpole, Nicole M; Sonntag, William E; Ungvari, Zoltan; Csiszar, Anna

2016-08-01

Strong epidemiological and experimental evidence indicate that both age and hypertension lead to significant functional and structural impairment of the cerebral microcirculation, predisposing to the development of vascular cognitive impairment (VCI) and Alzheimer's disease. Preclinical studies establish a causal link between cognitive decline and microvascular rarefaction in the hippocampus, an area of brain important for learning and memory. Age-related decline in circulating IGF-1 levels results in functional impairment of the cerebral microvessels; however, the mechanistic role of IGF-1 deficiency in impaired hippocampal microvascularization remains elusive. The present study was designed to characterize the additive/synergistic effects of IGF-1 deficiency and hypertension on microvascular density and expression of genes involved in angiogenesis and microvascular regression in the hippocampus. To achieve that goal, we induced hypertension in control and IGF-1 deficient mice (Igf1 f/f  + TBG-Cre-AAV8) by chronic infusion of angiotensin II. We found that circulating IGF-1 deficiency is associated with decreased microvascular density and exacerbates hypertension-induced microvascular rarefaction both in the hippocampus and the neocortex. The anti-angiogenic hippocampal gene expression signature observed in hypertensive IGF-1 deficient mice in the present study provides important clues for subsequent studies to elucidate mechanisms by which hypertension may contribute to the pathogenesis and clinical manifestation of VCI. In conclusion, adult-onset, isolated endocrine IGF-1 deficiency exerts deleterious effects on the cerebral microcirculation, leading to a significant decline in cortical and hippocampal capillarity and exacerbating hypertension-induced cerebromicrovascular rarefaction. The morphological impairment of the cerebral microvasculature induced by IGF-1 deficiency and hypertension reported here, in combination with neurovascular uncoupling, increased

Optimal timing of coronary invasive strategy in non-ST-segment elevation acute coronary syndromes

DEFF Research Database (Denmark)

Navarese, Eliano P; Gurbel, Paul A; Andreotti, Felicita

2013-01-01

The optimal timing of coronary intervention in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACSs) is a matter of debate. Conflicting results among published studies partly relate to different risk profiles of the studied populations.......The optimal timing of coronary intervention in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACSs) is a matter of debate. Conflicting results among published studies partly relate to different risk profiles of the studied populations....

Optically measured microvascular blood flow contrast of malignant breast tumors.

Directory of Open Access Journals (Sweden)

Regine Choe

Full Text Available Microvascular blood flow contrast is an important hemodynamic and metabolic parameter with potential to enhance in vivo breast cancer detection and therapy monitoring. Here we report on non-invasive line-scan measurements of malignant breast tumors with a hand-held optical probe in the remission geometry. The probe employs diffuse correlation spectroscopy (DCS, a near-infrared optical method that quantifies deep tissue microvascular blood flow. Tumor-to-normal perfusion ratios are derived from thirty-two human subjects. Mean (95% confidence interval tumor-to-normal ratio using surrounding normal tissue was 2.25 (1.92-2.63; tumor-to-normal ratio using normal tissues at the corresponding tumor location in the contralateral breast was 2.27 (1.94-2.66, and using normal tissue in the contralateral breast was 2.27 (1.90-2.70. Thus, the mean tumor-to-normal ratios were significantly different from unity irrespective of the normal tissue chosen, implying that tumors have significantly higher blood flow than normal tissues. Therefore, the study demonstrates existence of breast cancer contrast in blood flow measured by DCS. The new, optically accessible cancer contrast holds potential for cancer detection and therapy monitoring applications, and it is likely to be especially useful when combined with diffuse optical spectroscopy/tomography.

Coffee consumption and coronary calcification - The Rotterdam Coronary Calcification Study

NARCIS (Netherlands)

van Woudenbergh, Geertruida J.; Vliegenthart, Rozemarijn; van Rooij, Frank J. A.; Hofman, Albert; Oudkerk, Matthijs; Witteman, Jacqueline C. M.; Geleijnse, Johanna M.

Background-The role of coffee in the cardiovascular system is not yet clear. We examined the relation of coffee intake with coronary calcification in a population-based cohort. Methods and Results-The study involved 1570 older men and women without coronary heart disease who participated in the

Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation.

Science.gov (United States)

Gagnon, Louis; Smith, Amy F; Boas, David A; Devor, Anna; Secomb, Timothy W; Sakadžić, Sava

2016-01-01

Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These "bottom-up" models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

The effect of nitroglycerin on microvascular perfusion and oxygenation during gastric tube reconstruction

NARCIS (Netherlands)

Buise, Marc P.; Ince, Can; Tilanus, Hugo W.; Klein, Jan; Gommers, Diederik; van Bommel, Jasper

2005-01-01

Esophagectomy followed by gastric tube reconstruction is the surgical treatment of choice for patients with esophageal cancer. Complications of the cervical anastomosis are associated with impaired microvascular blood flow (MBF) and ischemia in the gastric fundus. The aim of the present study was to

GLP-1-based therapies have no microvascular effects in type 2 diabetes mellitus

NARCIS (Netherlands)

Smits, Mark M.; Tonneijck, Lennart; Muskiet, Marcel H.A.; Hoekstra, Trynke; Kramer, Mark H.H.; Diamant, Michaela; Serné, Erik H.; Van Raalte, Daniël H.

2016-01-01

Objective - To assess the effects of glucagon-like peptide (GLP)-1-based therapies (ie, GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) on microvascular function in patients with type 2 diabetes mellitus. Approach and Results - We studied 57 patients with type 2 diabetes mellitus

Preservation of intestinal microvascular Po2 during normovolemic hemodilution in a rat model

NARCIS (Netherlands)

van Bommel, J.; Siegemund, M.; Henny, C. P.; van den Heuvel, D. A.; Trouwborst, A.; Ince, C.

2000-01-01

The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2).

Palmitate-induced inflammatory pathways in human adipose microvascular endothelial cells promote monocyte adhesion and impair insulin transcytosis.

Science.gov (United States)

Pillon, Nicolas J; Azizi, Paymon M; Li, Yujin E; Liu, Jun; Wang, Changsen; Chan, Kenny L; Hopperton, Kathryn E; Bazinet, Richard P; Heit, Bryan; Bilan, Philip J; Lee, Warren L; Klip, Amira

2015-07-01

Obesity is associated with inflammation and immune cell recruitment to adipose tissue, muscle and intima of atherosclerotic blood vessels. Obesity and hyperlipidemia are also associated with tissue insulin resistance and can compromise insulin delivery to muscle. The muscle/fat microvascular endothelium mediates insulin delivery and facilitates monocyte transmigration, yet its contribution to the consequences of hyperlipidemia is poorly understood. Using primary endothelial cells from human adipose tissue microvasculature (HAMEC), we investigated the effects of physiological levels of fatty acids on endothelial inflammation and function. Expression of cytokines and adhesion molecules was measured by RT-qPCR. Signaling pathways were evaluated by pharmacological manipulation and immunoblotting. Surface expression of adhesion molecules was determined by immunohistochemistry. THP1 monocyte interaction with HAMEC was measured by cell adhesion and migration across transwells. Insulin transcytosis was measured by total internal reflection fluorescence microscopy. Palmitate, but not palmitoleate, elevated the expression of IL-6, IL-8, TLR2 (Toll-like receptor 2), and intercellular adhesion molecule 1 (ICAM-1). HAMEC had markedly low fatty acid uptake and oxidation, and CD36 inhibition did not reverse the palmitate-induced expression of adhesion molecules, suggesting that inflammation did not arise from palmitate uptake/metabolism. Instead, inhibition of TLR4 to NF-κB signaling blunted palmitate-induced ICAM-1 expression. Importantly, palmitate-induced surface expression of ICAM-1 promoted monocyte binding and transmigration. Conversely, palmitate reduced insulin transcytosis, an effect reversed by TLR4 inhibition. In summary, palmitate activates inflammatory pathways in primary microvascular endothelial cells, impairing insulin transport and increasing monocyte transmigration. This behavior may contribute in vivo to reduced tissue insulin action and enhanced tissue

Effect of Thrombus Composition and Viscosity on Sonoreperfusion Efficacy in a Model of Micro-Vascular Obstruction.

Science.gov (United States)

Black, John J; Yu, Francois T H; Schnatz, Rick G; Chen, Xucai; Villanueva, Flordeliza S; Pacella, John J

2016-09-01

Distal embolization of micro-thrombi during stenting for myocardial infarction causes micro-vascular obstruction (MVO). We have previously shown that sonoreperfusion (SRP), a microbubble (MB)-mediated ultrasound (US) therapy, resolves MVO from venous micro-thrombi in vitro in saline. However, blood is more viscous than saline, and arterial thrombi that embolize during stenting are mechanically distinct from venous clot. Therefore, we tested the hypothesis that MVO created with arterial micro-thrombi are more resistant to SRP therapy compared with venous micro-thrombi, and higher viscosity further increases the US requirement for effective SRP in an in vitro model of MVO. Lipid MBs suspended in plasma with adjusted viscosity (1.1 cP or 4.0 cP) were passed through tubing bearing a mesh with 40-μm pores to simulate a micro-vascular cross-section; upstream pressure reflected thrombus burden. To simulate MVO, the mesh was occluded with either arterial or venous micro-thrombi to increase upstream pressure to 40 mmHg ± 5 mmHg. Therapeutic long-tone-burst US was delivered to the occluded area for 20 min. MB activity was recorded with a passive cavitation detector. MVO caused by arterial micro-thrombi at either blood or plasma viscosity resulted in less effective SRP therapy compared to venous thrombi. Higher viscosity further reduced the effectiveness of SRP therapy. The passive cavitation detector showed a decrease in inertial cavitation when viscosity was increased, while stable cavitation was affected in a more complex manner. Overall, these data suggest that arterial thrombi may require higher acoustic pressure US than venous thrombi to achieve similar SRP efficacy; increased viscosity decreases SRP efficacy; and both inertial and stable cavitation are implicated in observed SRP efficacy. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Subclinical Coronary Plaque Burden in Asymptomatic Relatives of Patients With Documented Premature Coronary Artery Disease

DEFF Research Database (Denmark)

Christiansen, Morten Krogh; Jensen, Jesper Møller; Bøtker, Hans Erik

Introduction: A family history of premature coronary artery disease (CAD) is a well-known risk factor for adverse coronary events with age of onset being inversely related to the degree of heritability. Hypothesis: We hypothesized that asymptomatic first degree relatives, of patients with premature...... CAD, suffer a high burden of subclinical coronary atherosclerosis. Methods: First degree relatives, aged 30-65 years, of patients with a documented coronary revascularization procedure before the age of 40 years, were invited to participate in the study. Participants were matched by age, sex...... and absence of a family history, with patients referred for coronary CT angiography (CTA) because of atypical angina or non-anginal chest pain. A pooled blinded analysis was performed. The main outcome measure was the number of plaque-affected coronary segments. Results: 88 relatives and 88 symptomatic...

Coffee Consumption and Coronary Calcification: The Rotterdam Coronary Calcification Study

NARCIS (Netherlands)

Woudenbergh, van G.J.; Vliegenthart, R.; Rooij, van F.J.A.; Hofman, A.; Oudkerk, M.; Witteman, J.C.M.; Geleijnse, J.M.

2008-01-01

Background¿ The role of coffee in the cardiovascular system is not yet clear. We examined the relation of coffee intake with coronary calcification in a population-based cohort. Methods and Results¿ The study involved 1570 older men and women without coronary heart disease who participated in the

The Angio-Seal™ femoral closure device allows immediate ambulation after coronary angiography and percutaneous coronary intervention

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Hvelplund, Anders; Jeger, Raban; Osterwalder, Remo

2011-01-01

To test the safety of immediate mobilisation of patients undergoing coronary angiography and percutaneous coronary intervention (PCI) closed with Angio-Seal™ -a femoral vascular closure device.......To test the safety of immediate mobilisation of patients undergoing coronary angiography and percutaneous coronary intervention (PCI) closed with Angio-Seal™ -a femoral vascular closure device....

Optimization of coronary attenuation in coronary computed tomography angiography using diluted contrast material.

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Kawaguchi, Naoto; Kurata, Akira; Kido, Teruhito; Nishiyama, Yoshiko; Kido, Tomoyuki; Miyagawa, Masao; Ogimoto, Akiyoshi; Mochizuki, Teruhito

2014-01-01

The purpose of this study was to evaluate a personalized protocol with diluted contrast material (CM) for coronary computed tomography angiography (CTA). One hundred patients with suspected coronary artery disease underwent retrospective electrocardiogram-gated coronary CTA on a 256-slice multidetector-row CT scanner. In the diluted CM protocol (n=50), the optimal scan timing and CM dilution rate were determined by the timing bolus scan, with 20% CM dilution (5ml/s during 10s) being considered suitable to achieve the target arterial attenuation of 350 Hounsfield units (HU). In the body weight (BW)-adjusted protocol (n=50, 222mg iodine/kg), only the optimal scan timing was determined by the timing bolus scan. The injection rate and volume in the timing bolus scan and real scan were identical between the 2 protocols. We compared the means and variations in coronary attenuation between the 2 protocols. Coronary attenuation (mean±SD) in the diluted CM and BW-adjusted protocols was 346.1±23.9 HU and 298.8±45.2 HU, respectively. The diluted CM protocol provided significantly higher coronary attenuation and lower variance than did the BW-adjusted protocol (P<0.05, in each). The diluted CM protocol facilitates more uniform attenuation on coronary CTA in comparison with the BW-adjusted protocol.  

Morphometry of the coronary ostia and the structure of coronary arteries in the shorthair domestic cat.

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Karolina Barszcz

Full Text Available The aim of this study was to measure the area of the coronary ostia, assess their localization in the coronary sinuses and to determine the morphology of the stem of the left and right coronary arteries in the domestic shorthair cat. The study was conducted on 100 hearts of domestic shorthair cats of both sexes, aged 2-18 years, with an average body weight of 4.05 kg. A morphometric analysis of the coronary ostia was carried out on 52 hearts. The remaining 48 hearts were injected with a casting material in order to carry out a morphological assessment of the left and right coronary arteries. In all the studied animals, the surface of the left coronary artery ostium was larger than the surface of the right coronary artery ostium. There were four types of the left main coronary artery: type I (23 animals, 49%-double-branched left main stem (giving off the left circumflex branch and the interventricular paraconal branch, which in turn gave off the septal branch, type II (12 animals, 26%-double-branched left main stem (giving off the left circumflex branch and the interventricular paraconal branch without the septal branch, type III (11 animals, 23%-triple-branched left main stem (giving off the left circumflex branch, interventricular branch and the septal branch, type IV (1 animal, 2%-double-branched left main stem (giving off the interventricular paraconal branch and the left circumflex branch, which in turn gave off the septal branch. The left coronary artery ostium is greater than the right one. There is considerable diversity in the branches of proximal segment of the left coronary artery, while the right coronary artery is more conservative. These results can be useful in defining the optimal strategies in the endovascular procedures involving the coronary arteries or the aortic valve in the domestic shorthair cat.

Coronary heart disease risk assessment and characterization of coronary artery disease using coronary CT angiography: comparison of asymptomatic and symptomatic groups

International Nuclear Information System (INIS)

Hwang, Y.; Kim, Y.; Chung, I.-M.; Ryu, J.; Park, H.

2010-01-01

Aim: To evaluate the prevalence of coronary artery disease (CAD) in relation to risk of coronary heart disease (CHD) and assess plaque characteristics from coronary computed tomography (CT) angiography in asymptomatic and symptomatic patients. Materials and methods: Three hundred and ninety consecutive patients [asymptomatic group, n = 138; symptomatic group (atypical or non-anginal chest pain), n = 252] were retrospectively enrolled. They were subsequently classified into three CHD risk categories, based on the National Cholesterol Education Program guidelines, and 10 year risks of coronary events were calculated using Framingham risk score. CT was evaluated for stenosis, plaque composition, and coronary calcium scores. Results: CAD was observed in 42% of the asymptomatic group and 62% of the symptomatic group. In the former, the prevalence of CAD in low-, moderate- and high-risk subgroups was 21.4, 47.4 and 65%, respectively, and was 33.3, 74.4, and 72.4% in the symptomatic group. Framingham 10-year risks of coronary events were significantly higher in patients with CAD than in normal participants, and receiver operating characteristics curves showed that discriminatory power was poor in the asymptomatic group and symptomatic men, and good in symptomatic women. Of the participants in the asymptomatic group, 12% exhibited only non-calcified plaques and of the symptomatic group, 7% exhibited only non-calcified plaques. The coronary calcium score was significantly higher for significant stenosis than for non-significant stenosis in both groups. Conclusions: The prevalence of CAD was not negligible even in subgroups with low-to-moderate CHD risk. Additionally, the Framingham risk score was effective for predicting CAD only in symptomatic women. Coronary calcium scores correlated with significant stenosis; however, a sizeable percentage of both groups had only non-calcified plaques.

Coronary artery calcification in Kawasaki disease

International Nuclear Information System (INIS)

Ino, T.; Shimazaki, S.; Akimoto, K.; Park, I.; Nishimoto, K.; Yabuta, K.; Tanaka, A.

1990-01-01

To evaluate the angiographic features of coronary lesions in Kawasaki disease with coronary artery calcification, cinefluoroscopy and cineangiography were retrospectively reviewed in 116 patients who had undergone coronary angiography between 1982 and 1989. Angiographic abnormalities of coronary arteries were demonstrated in 55 of 116 patients. In 5 (9.1%) of the 55 patients, 9 with calcification were identified by cinefluoroscopy and chest X-ray. Eight of the 9 calcified lesions showed a circular or ring-shape configuration. Coronary angiography revealed a total occlusion of the right coronary artery with collateral circulation from the distal left coronary artery in 2 patients and a severe stenosis of the right coronary artery in 2 patients, in whom anticoagulant therapy had not been continued during the follow-up periods. The remaining patient in whom anticoagulant therapy had been continued had bilateral aneurysms but no significant stenosis. These results indicate that a ring-shape calcification on chest X-ray in 2 patients with a history of Kawasaki disease may suggest an involvement by coronary artery stenosis even when anticoagulant drugs had been given. Therefore, coronary angiography should be performed to evaluate the stenotic lesions if this type of calcification is found by routine radiographic examination. (orig.)

Obesity-metabolic derangement exacerbates cardiomyocyte loss distal to moderate coronary artery stenosis in pigs without affecting global cardiac function.

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Li, Zi-Lun; Ebrahimi, Behzad; Zhang, Xin; Eirin, Alfonso; Woollard, John R; Tang, Hui; Lerman, Amir; Wang, Shen-Ming; Lerman, Lilach O

2014-04-01

Obesity associated with metabolic derangements (ObM) worsens the prognosis of patients with coronary artery stenosis (CAS), but the underlying cardiac pathophysiologic mechanisms remain elusive. We tested the hypothesis that ObM exacerbates cardiomyocyte loss distal to moderate CAS. Obesity-prone pigs were randomized to four groups (n = 6 each): lean-sham, ObM-sham, lean-CAS, and ObM-CAS. Lean and ObM pigs were maintained on a 12-wk standard or atherogenic diet, respectively, and left circumflex CAS was then induced by placing local-irritant coils. Cardiac structure, function, and myocardial oxygenation were assessed 4 wk later by computed-tomography and blood oxygenation level dependent (BOLD) MRI, the microcirculation with micro-computed-tomography, and injury mechanisms by immunoblotting and histology. ObM pigs showed obesity, dyslipidemia, and insulin resistance. The degree of CAS (range, 50-70%) was similar in lean and ObM pigs, and resting myocardial perfusion and global cardiac function remained unchanged. Increased angiogenesis distal to the moderate CAS observed in lean was attenuated in ObM pigs, which also showed microvascular dysfunction and increased inflammation (M1-macrophages, TNF-α expression), oxidative stress (gp91), hypoxia (BOLD-MRI), and fibrosis (Sirius-red and trichrome). Furthermore, lean-CAS showed increased myocardial autophagy, which was blunted in ObM pigs (downregulated expression of unc-51-like kinase-1 and autophagy-related gene-12; P < 0.05 vs. lean CAS) and associated with marked apoptosis. The interaction diet xstenosis synergistically inhibited angiogenic, autophagic, and fibrogenic activities. ObM exacerbates structural and functional myocardial injury distal to moderate CAS with preserved myocardial perfusion, possibly due to impaired cardiomyocyte turnover.

Coronary Artery Disease

DEFF Research Database (Denmark)

Christiansen, Morten Krogh

2017-01-01

A family history of coronary artery disease (CAD) is an important risk factor for adverse coronary events, in particular if the disease has an early onset. The risk of CAD is influenced by genetic and environmental factors with a greater genetic contribution earlier in life. Through recent years......), and to characterize and quantify subclinical atherosclerosis in their relatives. Furthermore, the aim was to explore the impact of common genetic risk variants on the age of onset, familial clustering and disease severity. In study I, 143 patients with early- onset CAD were recruited from the Western Denmark Heart...... Registry and risk factor control was evaluated. The study revealed that risk factors are common in early-onset CAD and that a large room for risk factor improvement remains. In study II, we used coronary computed tomography angiography to compare the coronary plaque burden and characteristics between 88...

Propionyl-L-Carnitine Enhances Wound Healing and Counteracts Microvascular Endothelial Cell Dysfunction.

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Maria Giovanna Scioli

Full Text Available Impaired wound healing represents a high cost for health care systems. Endothelial dysfunction characterizes dermal microangiopathy and contributes to delayed wound healing and chronic ulcers. Endothelial dysfunction impairs cutaneous microvascular blood flow by inducing an imbalance between vasorelaxation and vasoconstriction as a consequence of reduced nitric oxide (NO production and the increase of oxidative stress and inflammation. Propionyl-L-carnitine (PLC is a natural derivative of carnitine that has been reported to ameliorate post-ischemic blood flow recovery.We investigated the effects of PLC in rat skin flap and cutaneous wound healing. A daily oral PLC treatment improved skin flap viability and associated with reactive oxygen species (ROS reduction, inducible nitric oxide synthase (iNOS and NO up-regulation, accelerated wound healing and increased capillary density, likely favoring dermal angiogenesis by up-regulation for iNOS, vascular endothelial growth factor (VEGF, placental growth factor (PlGF and reduction of NADPH-oxidase 4 (Nox4 expression. In serum-deprived human dermal microvascular endothelial cell cultures, PLC ameliorated endothelial dysfunction by increasing iNOS, PlGF, VEGF receptors 1 and 2 expression and NO level. In addition, PLC counteracted serum deprivation-induced impairment of mitochondrial β-oxidation, Nox4 and cellular adhesion molecule (CAM expression, ROS generation and leukocyte adhesion. Moreover, dermal microvascular endothelial cell dysfunction was prevented by Nox4 inhibition. Interestingly, inhibition of β-oxidation counteracted the beneficial effects of PLC on oxidative stress and endothelial dysfunction.PLC treatment improved rat skin flap viability, accelerated wound healing and dermal angiogenesis. The beneficial effects of PLC likely derived from improvement of mitochondrial β-oxidation and reduction of Nox4-mediated oxidative stress and endothelial dysfunction. Antioxidant therapy and

Microvascular volume in symptomatic Achilles tendons is associated with VISA-A score.

Science.gov (United States)

Praet, S F E; Ong, J H; Purdam, C; Welvaert, M; Lovell, G; Dixon, L; Gaida, J E; Anglim, J; Manzanero, S; Vlahovich, N; Hughes, D; Waddington, G

2018-05-15

The role of neovascularisation in tendinopathy is still poorly understood, potentially due to technical limitations of conventional power Doppler ultrasound. This study aimed to investigate the association between contrast-enhanced ultrasound (CEUS) microvascular volume (MV), Victorian Institute of Sports Assessment-Achilles (VISA-A) scores and intrinsic Achilles tendon tenderness, as well as two different Power Doppler modes. Cross-sectional study. 20 individuals with uni- or bilateral Achilles tendinopathy completed a VISA-A questionnaire, and underwent microvascular volume measurements of the Achilles tendon mid-portion using both conventional, ultrasensitive (SMI™) power Doppler ultrasound and CEUS. Intrinsic tendon tenderness was assessed with sensation detection threshold to extracorporeal shock waves (ESW). Linear Mixed Model analysis was used to determine the association between microvascular volume (MV), VISA-A, and ESW-detection threshold for both symptomatic and asymptomatic Achilles tendons. There was a significant association between VISA-A and MV (B=-5.3, 95%CI=[-8.5; -2.0], P=0.0004), and between MV and symptom duration (B=-1.7, 95%CI=[-3.2; -5.0], P=0.023). No significant associations were found between power Doppler ultrasound and CEUS-based MV or between CEUS-based MV and ESW-detection threshold. In comparison with conventional power Doppler ultrasound, SMI™ showed on average similar detection capacity for neovessels in the mid-portion of the Achilles tendon, whilst being superior for detecting neovessels within Kager's fat pad (t=3.46, 95%CI=[0.27; 1.03], P<0.005). Our results indicate that CEUS-based MV of the Achilles tendon is moderately associated with Achilles tendon symptoms. In accordance, CEUS-detected MV could be a novel target for treatment as it seems to be more sensitive than PDU and is correlated with symptoms. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Noninvasive Coronary Angiography with 64-Channel Multidetector Computed Tomography in Patients with Acute Coronary Syndrome

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Ulimoen, G. R.; Gjoennaess, E.; Atar, D.; Dahl, T.; Stranden, E.; Sandbaek, G. (Dept. of Radiology, Dept. of Vascular Diagnosis and Research, and Division of Cardiology, Aker Univ. Hospital, Oslo (Norway))

2008-12-15

Background: Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. Purpose: To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). Material and Methods: MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. Results: 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Conclusion: Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome.

Noninvasive Coronary Angiography with 64-Channel Multidetector Computed Tomography in Patients with Acute Coronary Syndrome

International Nuclear Information System (INIS)

Ulimoen, G. R.; Gjoennaess, E.; Atar, D.; Dahl, T.; Stranden, E.; Sandbaek, G.

2008-01-01

Background: Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. Purpose: To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). Material and Methods: MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. Results: 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Conclusion: Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome

Aneurysmal coronary artery disease: An overview

Science.gov (United States)

ElGuindy, Mohamed S.

Aneurysmal coronary artery disease (ACAD) comprises both coronary artery aneurysms (CAA) and coronary artery ectasia (CAE). The reported prevalence of ACAD varies widely from 0.2 to 10%, with male predominance and a predilection for the right coronary artery (RCA). Atherosclerosis is the commonest cause of ACAD in adults, while Kawasaki disease is the commonest cause in children and adolescents, as well as in the Far East. Most patients are asymptomatic, but when symptoms do exist, they are usually related to myocardial ischemia. Coronary angiography is the mainstay of diagnosis, but follow up is best achieved using noninvasive imaging that does not involve exposure to radiation. The optimal management strategy in patients with ACAD remains controversial. Medical therapy is indicated for the vast majority of patients and includes antiplatelets and/or anticoagulants. Covered stents effectively limit further expansion of the affected coronary segments. Surgical ligation, resection, and coronary artery bypass grafting are appropriate for large lesions and for associated obstructive coronary artery disease. PMID:29564347

Agranulocytosis and acute coronary syndrom in apathetic hyperthyreoidism

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Ivović Miomira

2003-01-01

pulmonary emphysema. Because the worsening of ECG changes she was transferred to Coronary unit. The diagnosis of non-Q myocardial infarction was confirmed and treatment with nitrates and beta-adrenergic antagonists was instituted. Four weeks later she became euthyroid and coronarography was performed. Subepicardial coronary arteries were normal (Figure 1. She was dismissed, and still euthyroid three months later. DISCUSSION Agranulocytosis is very rare but very serious complication of antithyroid drug therapy. It can be detected in about 0.1 -1 % patients during the first three months of treatment. Sudden appearance, heralded by sore throat and fever, prompt physicians to seek white blood cell and differential count [1-3]. Confirmation of diagnosis urges cessation of drug therapy and appropriate antibiotic treatment. Recently, it was reported that recombinant human granulocyte colony-stimulating factor (rhG-CSF is to be effective in shortening the recovery time in the neutropenic patients undergoing chemotherapy and also in patients with other types of neutropenia [5]. Tamai at al. [7] confirmed positive outcome in 34 patients treated with rhG-CSF compared to corticosteroid treatment. Hematologic laboratory abnormalities disappear 7-10 days after secession of therapy. Patients completely recover two to three weeks later. Fatal outcome was also described [1 -5]. Thyroid hormones have profound effects on cardiovascular physiology, especially on heart rate, cardiac output and systemic vascular resistance. In patients with hyperthyroidism, cardiac output is much higher than in normal persons. This is the result of direct effect of thyroid hormones on cardiac muscle contractility, heart rate and decrease in systemic vascular resistance. Excessive thyroid hormone secretion increases cardiac Na-K-activated plasma membrane ATP-ase and sarcoplasmic reticulum Ca-activated ATP-ase with resultant in increase myocardial contractility [6 9]. Sinus tachycardia is the most common rhythm

[Agranulocytosis and acute coronary syndrome in apathetic hyperthyroidism].

Science.gov (United States)

Ivović, Miomira; Radiojković, Biljena; Penezić, Zorana; Stojković, Mirjana; Tancić, Milina; Vujović, Svetlana; Bogdanović, Andrija; Drezgić, Milka

2003-01-01

ECG changes she was transferred to Coronary unit. The diagnosis of non-Q myocardial infarction was confirmed and treatment with nitrates and beta-adrenergic antagonists was instituted. Four weeks later she became euthyroid and coronarography was performed. Subepicardial coronary arteries were normal (Figure 1). She was dismissed, and still euthyroid three months later. Agranulocytosis is very rare but very serious complication of antithyroid drug therapy. It can be detected in about 0.1-1% patients during the first three months of treatment. Sudden appearance, heralded by sore throat and fever, prompt physicians to seek white blood cell and differential count [1-3]. Confirmation of diagnosis urges cessation of drug therapy and appropriate antibiotic treatment. Recently, it was reported that recombinant human granulocyte colony-stimulating factor (rhG-CSF) is to be effective in shortening the recovery time in the neutropenic patients undergoing chemotherapy and also in patients with other types of neutropenia [5]. Tamai at al. [7] confirmed positive outcome in 34 patients treated with rhG-CSF compared to corticosteroid treatment. Hematologic laboratory abnormalities disappear 7-10 days after session of therapy. Patients completely recover two to three weeks later. Fatal outcome was also described [1-5]. Thyroid hormones have profound effects on cardiovascular physiology, especially on heart rate, cardiac output and systemic vascular resistance. In patients with hyperthyroidism, cardiac output is much higher than in normal persons. This is the result of direct effect of thyroid hormones on cardiac muscle contractility, heart rate and decrease in systemic vascular resistance. Excessive thyroid hormone secretion increases cardiac Na-K-activated plasma membrane ATP-ase and sarcoplasmic reticulum Ca-activated ATP-ase with resultant in increase myocardial contractility [6, 9]. Sinus tachycardia is the most common rhythm disorder in hyperthyroidism, but paroxysmal tachycardia

Nuclear cardiology and coronary surgery

DEFF Research Database (Denmark)

Eckardt, R.; Andersen, L.I.; Hesse, B.

2008-01-01

Rising age, repeated percutaneous coronary revascularizations, and co-morbidity such as overweight, diabetes, and hypertension, characterize a change over the last 20-30 years in coronary patients referred to coronary artery bypass grafting (CABG). This patient group represents a great part of to...

Alternative wavelengths for sutureless laser microvascular anastomosis: a preliminary study on acute samples.

Science.gov (United States)

Bass, L S; Oz, M C; Libutti, S K; Treat, M R

1992-06-01

Attempts to improve the speed and patency of microvascular anastomosis with laser-assisted techniques have provided a modest reduction in operative time and comparable success rates. Using sutureless microvascular anastomoses, 30 end-to-end anastomoses were created in the rat carotid artery using the gallium-aluminum-arsenide diode laser (808 nm). Indocyanine green and fibrinogen were applied to enhance tissue absorption of the laser energy and strengthen the bond created. These were compared with previously reported welds using the THC:YAG laser (2150 nm). Mean welding times were 140 and 288 s, and mean bursting pressures immediately after welding were 515 and 400 mmHg for the diode and THC:YAG laser groups, respectively. Histologically, both lateral and vertical spread of thermal damage was limited. Since both lasers create welds of adequate initial strength without stay sutures and are faster and easier to use than existing systems, evaluation of long-term patency would be worthwhile.

Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

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Prisby, Rhonda D

2014-07-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (pnecrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. Copyright © 2014 Elsevier Inc. All rights reserved.

Frequency and importance of radiologically visible coronary scleroses

International Nuclear Information System (INIS)

Hoyer, B.

1981-01-01

The importance of radiologically visible coronary sceleroses for an early diagnosing of coronary heart disease was investigated. In 3 mixed collectives of patients with and without coronary heart diseases who had had a coronary angiography were examined retrospectively for coronary sclerosis (group I: standard films, group II: old X-ray findings, group III: fluoroscopy before beginning coronary angiography). In the retrospective evaluation, the sensitivity to the recognition of coronary heart disease was low. With prospective examination by means of fluoroscopy, coronary calcification could be proven in 37.66% of the patients with coronary diseases (sensitivity); the specificity (no coronary calcification in persons without coronary disease) was 99%. The duration and extent of a calcification do not show a definite influence on the severity of the disease. Several coronary scleroses in one or several vessels mostly indicate a vascular disease. Coronary scleroses are not necessarily located in the same point as coronary stenoses: in 85.5% of the patients with coronary sclerosis of the left truncus, haemodynamically important stenoses were found only in following vascular regions. Considering the high specificity of coronary scleroses in the fluoroscopic picture and the high sensitivity under favourable conditions, this method seems to be suitable as a screening method for early recognition of coronary heart diseases in the asymptomatic stage. A proven coronary sclerosis should in any case be the cause for continuing the search for a coronary heart disease. The radiation exposure during fluoroscopy of coronary sclerosis is low if the adjustment is correct, it takes little time, the patient is not put to discomfort. (orig./MG) [de

[Nailfold capillaroscopy and blood flow laser-doppler analysis of the microvascular damage in systemic sclerosis: preliminary results].

Science.gov (United States)

Secchi, M E; Sulli, A; Pizzorni, C; Cutolo, M

2009-01-01

Systemic sclerosis (SSc) is characterized by altered microvascular structure and function. Nailfold videocapillaroscopy (NVC) is the tool to evaluate capillary morphological structure and laser-Doppler Blood flowmetry (LDF) can be used to estimate cutaneous blood flow of microvessels. The aim of this study was to investigate possible relationships between capillary morphology and blood flow in SSc. Twenty-seven SSc patients and 12 healthy subjects were enrolled. SSc microvascular involvement, as evaluated by NVC, was classified in three different patterns ("Early", "Active", "Late"). LDF analysis was performed at the II, III, IV, V hand fingers in both hands and both at cutaneous temperature and at 36 degrees C. Statistical evaluation was carried out by non-parametric procedures. Blood flow was found significantly lower in SSc patients when compared with healthy subjects (p<0.05). The heating of the probe to 36 degrees C induced a significant increase in peripheral blood flow in all subjects compared to baseline (p <0.05), however, the amount of variation was significantly lower in patients with SSc, compared with healthy controls (p <0.05). The SSc patients with NVC "Late" pattern, showed lower values of peripheral blood flow than patients with NVC "Active" or "Early" patterns (p<0.05). Moreover, a negative correlation between the tissue perfusion score and the progression of the SSc microangiopathy was observed, as well as between the tissue perfusion and the duration of the Raynaud's phenomenon (p <0.03). LDF can be employed to evaluate blood perfusion in the microvascular circulation in SSc patients. The blood flow changes observed with the LDF seem to correlate with the severity of microvascular damage in SSc as detected by NVC.

DETECTION OF MICROVASCULAR COMPLICATIONS OF TYPE 2 DIABETES BY EZSCAN AND ITS COMPARISON WITH STANDARD SCREENING METHODS

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Sarita Bajaj

2016-08-01

Full Text Available BACKGROUND EZSCAN is a new, noninvasive technique to detect sudomotor dysfunction and thus neuropathy in diabetes patients at an early stage. It further predicts chances of development of other microvascular complications. In this study, we evaluated EZSCAN for detection of microvascular complications in Type 2 diabetes patients and compared accuracy of EZSCAN with standard screening methods. MATERIALS AND METHODS 104 known diabetes patients, 56 males and 48 females, were studied. All cases underwent the EZSCAN test, Nerve Conduction Study (NCS test, Vibration perception threshold test (VPT, Monofilament test, Fundus examination and Urine micral test. The results of EZSCAN were compared with standard screening methods. The data has been analysed and assessed by applying appropriate statistical tests within different groups. RESULTS Mean age of the subjects was 53.5 ± 11.4 years. For detection of diabetic neuropathy, sensitivity and specificity of EZSCAN was found to be 77.0 % and 95.3%, respectively. Odd’s ratio (OR was 68.82 with p < 0.0001. AUC in ROC curve was 0.930. Sensitivity and specificity of EZSCAN for detection of nephropathy were 67.1% and 94.1%, respectively. OR = 32.69 with p < 0.0001. AUC was 0.926. Sensitivity of EZSCAN for detection of retinopathy was 90% while specificity is 70.3%. OR = 21.27; p< 0.0001. AUC came out to be 0.920. CONCLUSION Results of EZSCAN test compared significantly to the standard screening methods for the detection of microvascular complications of diabetes and can be used as a simple, noninvasive and quick method to detect microvascular complications of diabetes.

[Evaluation of three-dimensional tumor microvascular architecture phenotype heterogeneity in non-small cell carcinoma and its significance].

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Zhou, Hui; Liu, Jinkang; Chen, Shengxi; Xiong, Zeng; Zhou, Jianhua; Tong, Shiyu; Chen, Hao; Zhou, Moling

2012-06-01

To explore the degree, mechanism and clinical significance of three-dimensional tumor microvascular architecture phenotype heterogeneity (3D-TMAPH) in non-small cell carcinoma (NSCLC). Twenty-one samples of solitary pulmonary nodules were collected integrally. To establish two-dimensional tumor microvascular architecture phenotype (2D-TMAP) and three-dimensional tumor microvascular architecture phenotype (3D-TMAP), five layers of each nodule were selected and embedded in paraffin. Test indices included the expressions of vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), EphB4, ephfinB2 and microvascular density marked by anti-CD34 (CD34-MVD). The degrees of 3D-TMAPH were evaluated by the coefficient of variation and extend of heterogeneity. Spearman rank correlation analysis was used to investigate the relationships between 2D-TMAP, 3D-TMAP and clinicopathological features. 3D-TMAPH showed that 2D-TMAP heterogeneity was expressed in the tissues of NSCLC. The heterogeneities in the malignant nodules were significantly higher than those in the active inflammatory nodules and tubercular nodules. In addition, different degrees of heterogeneity of CD34-MVD and PCNA were found in NSCLC tissues. The coefficients of variation of CD34- MVD and PCNA were positively related to the degree of differentiation (all P0.05). The level of heterogeneity of various expression indexes (ephrinB2, EphB4, VEGF) in NSCLC tissues were inconsistent, but there were no significant differences in heterogeneity in NSCLC tissues with different histological types (P>0.05). 3D-TMAPH exists widely in the microenvironment during the genesis and development of NSCLC and has a significant impact on its biological complexity.

THE PLURAL LESION CORONARY AND CYTOKINES DISBALANCE IN PATIENTS WITH CORONARY ATHEROSCLEROSIS

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Martynov AV

2012-12-01

Full Text Available The aim of the study was to examine the levels of the main pro-inflammatory and anti-inflammatory cytokines in patients with ischemic heart disease, and the study of the possible impact of persistent herpes virus infection plural lesion coronary arteries. A total of 57 patients (mean age 49,3 ± 3,7 years IHD s hemodynamically significant stenoses of the coronary vessels. Conducted virological examination, including the definition of hypertension HSV1, HSV2, HHV6, SMV, VZV and VEB immunofluorescent and cytokines ІL-1β, ІL-6 ІL-8, TNF by ELISA in serum. Found increased levels of proinflammatory cytokines ІL-1β, ІL-6 and FNPα of IHD patients who had hemodynamically significant stenoses of coronary vessels. ІL-6 level in patients with 2 or more significant coronary artery lesions exceeded the rate of patients with a damaged coronary artery in 1.67 TNFα, ІL-8 - 1.37 ІL-1β and 1.28 times respectively. In patients with plural coronary vascular damage was the most common combination of CMV, VEB and HHV6. Since CMV was detected in more than 60% of patients with injuries of two spacecraft and nearly 76% from three spacecraft, VEB was detected in 72% and 88%, respectively.

Bone Marrow Blood Vessel Ossification and “Microvascular Dead Space” in Rat and Human Long Bone

Science.gov (United States)

Prisby, Rhonda D.

2014-01-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4–6 mon; n=8) and old (22–24 mon; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner’s Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via µCT to quantify microvascular ossification. Bone marrow blood vessels from rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and “normal” vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p necrosis. The progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. PMID:24680721

A rare anomaly: Double right coronary artery

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Dursun Çayan Akkoyun