Search Results
Results 301 - 350 of 772
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He Z X - - 2001
BACKGROUND: Previous studies that investigated the effects of coronary collateral circulation on myocardial perfusion were compromised by inclusion of patients with multivessel coronary artery disease, incomplete occlusion, prior myocardial infarction, or a combination of these. In this study we ascertained the relationship between angiographic collateral circulation and myocardial perfusion only ...
Belardinelli R - - 2001
AIMS: There is evidence that oral dipyridamole, a nucleoside uptake blocker that increases myocardial adenosine levels, lessens myocardial ischaemia by inducing coronary collateral growth in animal models of ischaemic heart disease. However, whether dipyridamole can exert a similar effect in humans with coronary artery disease is controversial. METHODS AND RESULTS: ...
Cafri C - - 2001
ST elevation in the anterior leads may be due to isolated right ventricular infarction associated with occlusion of a nondominant or codominant right coronary artery. The authors report a case of isolated right ventricular infarction from a dominant right coronary artery's proximal occlusion in the presence of collateral circulation provided ...
Pagni S - - 2001
The occurrence of a flow "steal phenomenon" from a large branch of the internal mammary artery (IMA) is rare and its pathogenesis is still controversial. We describe a case of a patent large anomalous left IMA branch which produced recurrent angina 3 years post MIDCAB. Transcatheter coil obliteration of the ...
Araujo L I - - 2001
BACKGROUND: The aim of this study was to determine the relationship between vasodilatation-induced ischemia and poststress glucose uptake. Coronary vasodilators may induce myocardial ischemia due to coronary steal through collateral circulation or transmural blood flow redistribution with diminished subendocardial perfusion. Myocardial ischemia can be demonstrated by increased glucose uptake as ...
Nagata K - - 2001
A 74-year-old Japanese male was referred to our hospital because of an abnormal electrocardiogram. The electrocardiogram revealed tall P waves in leads II, III, and aV(F). Echocardiography disclosed hypokinesis extending from the anteroseptal region to the apex. Iodine-123 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (123-BMIPP) scintigraphy revealed reduced uptake from the anteroseptal region to ...
Ido A - - 2001
On the hypothesis that coronary sinus occlusion (CSO) may reduce myocardial ischemia, we examined the effects of CSO on coronary collateral blood flow and on the distribution of regional myocardial blood flow (RMBF) in dogs. Thirty-eight anesthetized dogs underwent occlusion of the left anterior descending coronary artery with or without ...
Iwatate M - - 2001
The effects of gene transfer of the secreted form of fibroblast growth factor-2 (FGF-2) were tested using an adenovirus vector in the microembolized rabbit heart. Japanese white rabbits underwent an intracoronary injection of 25-microm microspheres followed by recombinant adenovirus vectors encoding a secreted form of FGF-2 (FGF group), LacZ (LacZ ...
Unger E F - - 2001
During the last decade, there has been great interest in the potential use of biologic agents and mechanical techniques to enhance myocardial collateral development. Available experimental methods to detect the effects of interventions designed to improve collateral function include assessment of vascular cell proliferation, quantification of vessel number and size, ...
Koliakos G - - 2001
In an attempt to evaluate the clinical significance of reverse redistribution in Tl201 cardiac SPET, Tl201 SPET examinations included in the data base of our department have been retrospectively reviewed. PATIENTS: Six hundred ninety eight patients demonstrated the pattern of reverse redistribution. For 237 of these patients' cardiac catheterization data ...
Wang N - - 2001
Sheng-mei-san (SMS), a traditional Chinese formulation comprising Radix Ginseng, Radix Ophiopogonis and Fructus Schisandrae, has long been used for more than 700 years for patients with coronary heart disease. We attempted to clarify 1) whether SMS reduces myocardial infarct size, and 2) whether the infarct size-reducing effect of SMS is ...
Zhu H - - 2000
OBJECTIVES: To observe the effect of basic fibroblast growth factor (bFGF) slow-release microcapsules on angiogenesis in infarcted myocardial regions. METHODS: Myocardial infarction was induced in 24 New Zealand rabbits by ligating the root of left anterior descending coronary artery. Group I (n = 8) served as control, group II (n ...
Kyriakides Z S - - 2000
BACKGROUND: Myocardial ischemia and reperfusion are associated with increased production of endothelin (ET)-1. METHODS AND RESULTS: We examined the effects of BQ-123, a selective ET(A) receptor antagonist, in 80 patients. All patients were randomly allocated to an intracoronary infusion of saline or BQ-123 (6 micromol/L over 20 minutes). The reference ...
Patel S R - - 2000
BACKGROUND: The development of mature coronary collateral vessels in patients with obstructive coronary artery disease (CAD) decreases the ischemic myocardial burden. Chronic bradycardia has been shown to stimulate formation of collateral vessels in experimental models. OBJECTIVE: To test our hypothesis that CAD patients with bradycardia would have better developed collateral ...
Imasaka K - - 2000
BACKGROUND: In beating heart coronary artery bypass grafting (CABG) the effect of ischemic insult during coronary occlusion could not be evaluated immediately. Using transesophageal echocardiography, myocardial performance can be evaluated with analysis of integrated backscatter. METHODS: In 15 beating heart CABGs, cyclic variation (CV) of integrated backscatter of the anterior ...
Mills J D - - 2000
OBJECTIVES: We sought to characterize collateral development in an experimental model of chronic myocardial ischemia by using myocardial contrast echocardiography (MCE). BACKGROUND: Coronary collaterals maintain myocyte viability during myocardial ischemia. The natural history and determinants of collateral development are difficult to study serially in vivo. METHODS: The left anterior descending ...
Hutter P A - - 2000
BACKGROUND: Abnormal coronary artery anatomy is reported to have a significant influence on the outcome of the arterial switch operation. This study examines the impact of coronary anatomy and the occurrence of late coronary obstruction on left ventricular (LV) function and long-term outcome. METHODS: Coronary artery anatomy, of 170 patients ...
Laham RJ - - 2000
Therapeutic angiogenesis is a potential new treatment strategy that promises to grow new blood vessels to the ischemic myocardium in patients with ischemic heart disease. Despite its investigation in more than 550 patients with ischemic heart disease, the concept of clinical therapeutic angiogenesis remains a theoretic one with more questions ...
Yoneda T - - 2000
The strong association between severe coronary stenosis and collateral growth continues to be a paradigm in this field of investigation. The present study was based on the hypothesis that angiogenic growth factors are produced by ischemic cardiac tissue, are diffusible and more concentrated in pericardial fluid, and accelerate the growth ...
Kaufmann P A - - 2000
Coronary vasomotion has an important role in the regulation of myocardial perfusion. During dynamic exercise, normal coronary arteries dilate, whereas stenotic arteries constrict. This exercise-induced vasoconstriction has been associated with the occurrence of myocardial ischemia and has been believed to be the result of endothelial dysfunction, with a reduced release ...
Preumont N - - 2000
BACKGROUND: The evaluation of the coronary reserve provides valuable information on the status of coronary vessels. Therefore, we studied with positron emission tomography (PET) and 13N-ammonia the myocardial blood flow (MBF) reserve in heart transplant recipients free of allograft rejection and with angiographically normal coronary arteries early after heart transplantation ...
Stoll H P - - 2000
BACKGROUND: The rubidium 81/krypton 81m method was suggested for assessment of myocardial blood flow (MBF) three decades ago. This study investigates the novel concept of using 81Rb-/81mKr-labeled coronary guide wires with wire-attached 81Rb activity and diffusable 81mKr gas for assessment of lesion-specific impairment of MBF by evaluation of the 81Rb/81mKr ...
Operschall C - - 2000
Chronic cardiac ischemia has mainly been studied in large species such as pigs or dogs. Little research has been performed using small species such as rabbits. In the present study, 1-3 wk after implantation of a novel device (ameroid) on the circumflex coronary artery of New Zealand White rabbits, vessel ...
Van Langenhove G - - 2000
A 65-year old patient was referred to our institution for a diagnostic catheterization. 23 years before, a direct surgical myocardial procedure using the Vineberg technique was performed. Currently, the angiogram shows patent left and right internal mammary arteries implanted directly into the myocardium and connecting with the native circulation through ...
Lee C W - - 2000
OBJECTIVES: We evaluated the relation between pressure-derived fractional collateral flow (PDCF) and left ventricular (LV) recovery after reperfused acute myocardial infarction (AMI). BACKGROUND: The functional significance of collateral flow remains uncertain in AMI. METHODS: The PDCF was measured in 70 patients with first AMI (pain onset <12 h) treated with ...
Stanley W C - - 2000
This review examines the in vivo techniques that are available for evaluation of the metabolic effects and efficacy of agents intended for the treatment of myocardial ischemia. Energy substrate metabolism is complex, and requires simultaneous measurement of a variety of processes in order to obtain a thorough understanding of the ...
Levy Andrew P - - 2000
Despite tremendous advances in the management of coronary artery disease, there is a growing population of patients who remain symptomatic with residual myocardial ischemia. Therapeutic angiogenesis, designed to promote the development of endogenous conduits forming collateral blood vessels that serve to bypass coronary artery stenotic lesions, may constitute an alternative ...
Miwa K - - 2000
OBJECTIVES: We sought to determine whether exercise-induced U-wave alterations are observed in association with well-developed and well-functioning collateral vessels. BACKGROUND: Although exercise-induced electrocardiographic (ECG) U-wave alterations including negative and prominent U waves have been established as a marker of significant or critical narrowing of a major coronary artery, the relation ...
Sand N P - - 2000
OBJECTIVES: The present study evaluated the impact of recruitable collaterals on regional myocardial perfusion measured by 99mtechnetium (Tc)-sestamibi single-photon emission computerized tomography (SPECT) during temporary coronary occlusion and related these estimates to the coronary wedge pressure and electrocardiographic (ECG) ST-segment changes. BACKGROUND: Clinical variables (angina and ECG changes) and intracoronary ...
Fukai M - - 2000
Angiographical demonstration of coronary collateral circulation may suggest the presence of residual viable myocardium. The development of coronary collaterals was judged according to Rentrop's classification in 37 patients with old anteroseptal myocardial infarction and 13 control patients with chest pain syndrome. The subjects with myocardial infarction were divided into 2 ...
Kornowski R - - 2000
The use of recombinant genes or growth factors to enhance myocardial collateral blood vessel function may represent a new approach to the treatment of cardiovascular disease. Proof of concept has been demonstrated in animal models of myocardial ischemia, and clinical trials are underway. Currently, it is unknown which is the ...
Laham R J - - 2000
Therapeutic angiogenesis is a novel approach to the treatment of myocardial ischemia based on the use of proangiogenic growth factors to induce the growth of new blood vessels to supply the myocardium at risk. This study was designed to assess the safety and efficacy of a single intrapericardial injection of ...
Gonçalves L M - - 2000
In models of hind-limb ischemia and progressive coronary artery occlusion, angiogenic growth factor proteins and genes expressing growth factors have been shown to induce the development of collateral vessels and remodeling of existing collaterals. The therapeutic potential of growth factors in the setting of acute myocardial infarction may be related ...
Freedom R M - - 2000
A patient with pulmonary atresia and intact ventricular septum was found to have a right ventricular-dependent coronary circulation. In this infant both coronary arteries lacked their normal proximal connection with the aorta, perhaps the most egregious form of this prejudicial coronary circulation. Even more interesting was a direct collateral vessel ...
Nakae I - - 2000
The purpose of this study was to evaluate whether age influences collateral development in patients with coronary artery disease. The extent of collateral development to the area perfused by the infarct-related artery was graded, depending on the degree of opacification of the occluded infarct-related artery. We evaluated the extent of ...
Kersten J R - - 2000
We tested the hypothesis that levosimendan, a new positive inotropic drug that activates adenosine triphosphate-regulated potassium (K(ATP)) channels in vitro, decreases myocardial infarct size in vivo. Myocardial infarct size was measured after a 60-min left anterior descending coronary artery occlusion and 3 h of reperfusion in dogs receiving either IV ...
Tio R A - - 1999
Both VEGF protein and VEGF DNA in combination with an adenoviral vector have been shown to enhance collateral formation in a porcine model of chronic myocardial ischemia. We sought to determine whether direct intramyocardial injection of naked DNA encoding for VEGF could similarly improve myocardial perfusion. Initially, 23 nonischemic pigs ...
Shivalkar B - - 1999
OBJECTIVE: The aim of this study was to characterize a regional myocardial flow-function relationship in collateral dependent myocardium produced by multiple coronary artery obstruction. METHODS: Ameroid constrictors were placed around the proximal right (RC) and circumflex (CX) coronary arteries and a silicon tubing cuff around the proximal LAD (left anterior ...
Carmeliet P - - 1999
Blood vessels are essential for the supply of oxygen and nutrients to the heart. An imbalance between oxygen demand and supply (ischemia), as occurs when coronary arteries become obstructed by atherosclerotic plaques, triggers a response to improve myocardial perfusion by the formation of new capillaries (angiogenesis) and by the enlargement ...
Safi J J - - 1999
Most patients with severe coronary artery disease have normal baseline myocardial blood flow. Therefore, interventions aimed at inducing therapeutic angiogenesis in these patients should cause new blood vessel growth in the heart in the absence of chronic ischemia. It was examined whether adenovirus-mediated gene transfer of recombinant, secreted acidic fibroblast ...
Miwa K - - 1999
OBJECTIVE: To determine whether the presence of well-developed collateral vessels (visualized by baseline angiography) prevents myocardial ischemia associated with electrocardiographic ST-segment deviation or anginal pain during subsequent coronary balloon occlusion. METHODS: Study patients with stable effort angina but without complete coronary obstruction were divided into two groups on the basis ...
Fujita M - - 1999
BACKGROUND: The presence or absence of collateral circulation to the infarct-related coronary artery in acute myocardial infarction (AMI) significantly impacts on infarct size and resulting left ventricular function. However, the determinants of collateral development have not been clarified. HYPOTHESIS: The purpose of this study was to elucidate the determinants of ...
Virmani R - - 1999
Transmyocardial laser revascularization (TMLR) is increasingly used for improving myocardial perfusion in patients with diffuse coronary artery disease and refractory ischemia. The efficacy of TMLR, however, is in doubt because no definite increase in blood flow or longevity has been demonstrated. Although histologic results after TMLR show some neocapillary formation, ...
Kyriakides Z S - - 1999
AIMS: To test the hypothesis that ketanserin augments coronary collateral blood flow and decreases myocardial ischemia during balloon angioplasty. METHODS AND RESULTS: Forty-four patients with single vessel disease and stable angina were studied. Collateral flow was determined during balloon inflations, based on the distal velocity time integral (13 patients) or ...
Kanter K R - - 1999
BACKGROUND: Children with chronic cyanotic heart disease often develop systemic-to-pulmonary collateral arteries that can be deleterious at the time of a Fontan procedure due to excessive pulmonary blood flow. We therefore occlude all significant collaterals during cardiac catheterization. METHODS: From June 1993 to May 1998, 93 children aged 1.5 to ...
Schultz A - - 1999
BACKGROUND: The coronary artery collateral circulation may be beneficial in protecting against myocardial ischemia and necrosis. However, there is a tremendous interindividual variability in the degree of new collateral formation in patients with coronary artery disease. The basis for this interindividual heterogeneity is not understood. In this study we test ...
Agati L - - 1999
Several perfusion techniques have definitively shown that microvascular dysfunction plays a crucial role in patients with acute myocardial infarction. In those patients, despite a rapid and sustained restoration of flow throughout a previously occluded epicardial coronary artery, microvascular damage still may be observed. Duration of ischemia and/or time to recanalization ...
Fujita M - - 1999
Heparin accelerates coronary collateral development in various animal models of myocardial ischemia. The purpose of this study was to clarify the beneficial effect of heparin on canine collateral development. Seventeen adult mongrel dogs were instrumented for measurements of a subendocardial segment length in the central area perfused by the left ...
Kersten J R - - 1999
Angiogenesis and vasculogenesis are adaptive responses of the coronary collateral circulation to myocardial ischemia. This review focuses on the concerted action of growth factors, growth factor receptors, extracellular matrix, and inflammatory cellular responses to regulate angiogenesis and vasculogenesis in response to myocardial ischemia and alterations in shear stress. Therapeutic angiogenesis ...
Leclercq F - - 1999
OBJECTIVE: To evaluate the combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after myocardial infarction. DESIGN: Myocardial contrast echocardiography was performed in patients with acute myocardial infarction shortly after successful coronary reperfusion (TIMI 3 patency) by direct angioplasty. Collateral flow was assessed before coronary angioplasty, and ...
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