Search Results
Results 451 - 500 of 772
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Ha J W - - 1994
The functional significance of the collateral circulation was evaluated in 125 patients with total coronary occlusion. Patients were classified into two groups. Group 1:patients with angina pectoris (AP), Group 2:patients with a first transmural myocardial infarction (MI) within 3 months of the symptom onset. Clinical variables, resting and exercise electrocardiogram ...
Fujita M - - 1994
AIM: To assess the direct effects of nitroglycerin on coronary and collateral circulation, 31 consecutive patients with low exercise capacity resulting from chronic effort angina but who had not suffered previous myocardial infarction were investigated. METHODS: Rapid atrial pacing was used to induce myocardial ischemia, with the same pacing rate ...
Takeishi Y - - 1994
The aim of the present study was to elucidate the characteristics of patients in whom transient myocardial ischemia was evoked during adenosine infusion. Thallium-201 (Tl-201) myocardial imaging and two-dimensional echocardiography during adenosine infusion were performed simultaneously in 61 consecutive patients enrolled for the diagnosis of coronary artery disease. Transient reduction ...
Akutsu Y - - 1994
We measured regional myocardial blood flow (RMBF) by positron emission tomography (PET) with 13N-ammonia at rest and during low-grade exercise using a bicycle ergometer fixed at 25 watts for 6.5 min. The ischemic area with severe coronary artery stenosis was evaluated in terms of quantitative RMBF. The study was performed ...
Sasayama S - - 1994
Although a functional role of coronary collaterals has been continuously debated, we observed the following facts in our studies during intracoronary thrombolytic therapy: (a) Myocardial ischemia is important for the development of collateral circulation, (b) collaterals can perfuse the infarcted myocardium, and (c) the presence of collaterals prevents the left ...
Cohen M V - - 1994
Although fibroblast growth factor has been identified in normal and ischemic myocardium, temporal changes in mitogenic activity due to fibroblast growth factors in ischemic tissue have not been well established, nor has correlation been made with the known early increases in coronary collateral flow. This study sought to measure fibroblast ...
Van Pampus E C - - 1994
Both bone marrow and circulating megakaryocytes may produce platelets. Changes in number and properties of the circulating megakaryocytes in cardiac diseases may provide information about thrombopoiesis in these disease states. Circulating megakaryocytes were obtained by retrograde aspiration through wedged pulmonary artery catheters from patients without cardiac abnormalities, patients with cardiac ...
Dabizzi P - - 1994
BACKGROUND: Several studies have indicated that ischemia induced by dipyridamole is frequently associated with angina or ischemic ST-segment depression and that it occurs mainly in patients with three-vessel disease, those with collateral vessels, or those with both. METHODS: In order to analyze the diagnostic relationships among them, we studied 227 ...
Nii T - - 1994
Patients with coronary artery disease reportedly have an impaired left ventricular filling. To evaluate the effects of coronary collaterals on diastolic function in patients with effort-induced angina, resting radionuclide ventriculography was performed in 14 patients with severe isolated (> or = 90% diameter) stenosis of the left anterior descending coronary ...
Shivalkar B - - 1994
OBJECTIVES: The purpose of this study was to evaluate functional variables and morphologic correlates of chronically hypoperfused myocardium before and after revascularization. BACKGROUND: Neonates with congenital anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA syndrome) develop some myocardial necrosis shortly after birth. The survivors of this ...
Cohen M V - - 1994
OBJECTIVE: The aim was to develop a method for installing a pneumatic occluder on the coronary artery of a rabbit, and to see whether repetitive coronary occlusions could induce collateral development as in dogs. METHODS: A superficial branch of the left coronary artery was encircled with a balloon occluder, and ...
Crystal G J - - 1994
The findings presented in this article pertain strictly to the specific conditions of the studies and should be extrapolated to human patients with caution for several reasons. First, the experimental model of a single acute coronary stenosis is a rare clinical occurrence, and it ignores the influence of the well-developed ...
Miyakoda H - - 1994
To assess the perfusion reserve of coronary collateral circulation, we analyzed exercise-stress tomographic thallium-201 myocardial images in 12 patients who had total occlusion in the right coronary artery (RCA) or left circumflex coronary artery (LCX) with well-developed collateral circulation and 90% stenosis in the left anterior descending coronary artery (LAD). ...
ZieliƄski K W - - 1994
Comparative results of morphometric investigations describing the microvasculature of the human left ventricle heart wall muscle have been presented. The control group consisted of 11 autopsied cases of the atherosclerotically non damaged hearts and the second group consisted of 13 autopsied cases of the hearts with double or triple vessel ...
Ross J J - - 1993
Left ventricular dysfunction and dilation after reperfusion relate to the amount of infarcted and dysfunctional myocardium and will continue to be important determinants of morbidity and mortality. There is marked heterogeneity in the anatomic and pathophysiologic presentation of patients with acute myocardial infarction prior to thrombolysis, and many of these ...
Battler A - - 1993
OBJECTIVES: This study was performed to examine the effect of intracoronary exogenous basic fibroblast growth factor (bFGF) on angiogenesis in infarcted myocardial regions. BACKGROUND: Exogenous bFGF is a potent promoter of angiogenesis. Little information is available on its effect on myocardial angiogenesis. METHODS: Myocardial infarction was induced in 10 pigs ...
Igawa A - - 1993
This study assesses the effects of early and late reperfusion of the infarct-related coronary artery and collateral circulation developed after infarction on left ventricular morphology and function in 22 patients with a first acute anterior myocardial infarction and without long-standing preinfarction angina. The patients were categorized into 4 groups: group ...
Iwamoto T - - 1993
OBJECTIVE: The aim was to examine whether an absolute reduction in energy supply is required for preconditioning against myocardial infarction, and whether an episode of increased adrenergic activity with or without supply-demand imbalance is capable of triggering cardioprotection. METHODS: 41 anaesthetised dogs were subjected to 60 min left circumflex artery ...
Bajaj S - - 1993
BACKGROUND: The concept that coronary collateral (CC) circulation can develop in cardiac transplant recipients (CTR) is controversial. Indeed, a decreased occurrence of CC in CTR has been previously reported. METHODS AND RESULTS: We reviewed 102 coronary angiograms in 73 CTR to evaluate the presence and significance of CC in denervated ...
Clements I P - - 1993
BACKGROUND: In acute myocardial infarction, residual flow to the infarct zone either through antegrade flow in the infarct-related coronary artery or collateral flow from the non-infarct-related arteries is often present before reperfusion therapy. The purpose of this study was to assess the influence of antegrade flow in the infarct-related artery ...
Shalev Y - - 1993
Acute myocardial infarction during pregnancy is considered to be associated with approximately 50% mortality of both mother and fetus. However, there are not enough data regarding the role of acute myocardial ischemia. We present a 36-year-old, pregnant, white female who was admitted twice at 18 and 20 weeks of gestation ...
Charney R - - 1993
The role of coronary collateral circulation in limiting ischemia and infarction has been studied prospectively. Transient occlusion of a coronary artery angioplasty has provided evidence that collateral circulation decreases wall motion abnormalities, ST segment changes, and lactate production. Patients who have collateral flow also have a better outcome after coronary ...
Lim Y J - - 1993
Myocardial contrast echocardiography was used to characterize changes in the regional and transmural myocardial blood flow distribution that were provoked by rapid atrial pacing stress in patients with coronary artery diseases. In patients with coronary organic stenosis, a decrease in the myocardial contrast-enhancement in the subendocardial half after rapid atrial ...
Schuler J G - - 1993
Hepatic infarction is an unusual event. A patient is described who had a hepatic infarct after a sigmoid resection. She was found to have occluded superior mesenteric and celiac arteries, with visceral circulation dependent on the inferior mesenteric artery. Disruption of the collateral circulation was presumed to have caused the ...
Van Blankenstein J H - - 1993
By its nature, vaporization of atherosclerotic plaques by laser irradiation or spark erosion may produce a substantial amount of gas. To evaluate the effect of gas embolism possibly caused by vaporization techniques, air bubbles with diameters of 75, 150, or 300 microns, each in a volume of 2 microliters/kg, were ...
Cohen M V - - 1993
To investigate the possible effect of heparin on coronary-collateral growth, dogs were instrumented chronically with a left circumflex (LCF) flow probe, an ameroid constrictor, a balloon occluder, and left and right atrial and aortic catheters. Collateral blood flow was measured at least weekly or when the coronary artery was occluded. ...
Yoshida N - - 1993
OBJECTIVES: The purpose of the present study was to elucidate the relation between the extent of perfusion of the ischemia-related coronary artery and the degree of visualization of the collateral circulation to the ischemic area. BACKGROUND: Because it is difficult to accurately assess coronary stenosis severity with standard angiographic techniques, ...
Morales A R - - 1993
To establish whether an intramural left anterior descending coronary artery (LADA) is a simple anatomic or a singularly pathologic variant we studied 39 hearts, each with an intramural course of the LADA and no coronary artery disease, valvular derangement, cardiomyopathy, or congenital anomaly. Seventeen of the 39 hearts had no ...
Bernotat-Danielowski S - - 1993
OBJECTIVE: The collateral circulation plays a critical role in the prognosis of ischaemic heart disease, with a clear correlation between neovascularisation, infarction, and tissue recovery. The aim of the study was to address the question of whether endogenous acidic and basic fibroblast growth factors (FGF) participate in ischaemia induced collateral ...
Carroll S M - - 1993
BACKGROUND: Coronary collaterals develop in response to an ischemic stimulus. However, collateral growth is not sufficient to result in the complete recovery of coronary reserves. Using a porcine model of gradual coronary artery occlusion, we investigated the effect of continuous heparin infusion on coronary collateral development. METHODS AND RESULTS: We ...
Sofikitis N - - 1993
OBJECTIVE: To evaluate the importance of retrograde adrenal metabolite flow for testicular function in a varicocelized animal model. MATERIALS AND METHODS: Partial occlusion of the left renal vein and ligation of the collateral vein between the left testicular and left common iliac veins was carried out on 14 Wistar rats ...
Vanoverschelde J L - - 1993
BACKGROUND: Even in the absence of a previous myocardial infarction, patients with coronary artery disease often present with chronic regional wall motion abnormalities that are reversible spontaneously or after coronary revascularization. In these patients, regional dysfunction has been proposed to result either from prolonged postischemic dysfunction (myocardial "stunning") or from ...
Ejiri M - - 1993
To elucidate whether the presence of significant stenoses in donor coronary arteries compromises collateral flow reserve, coronary arteriography was performed in 22 patients with stable effort angina who had a complete obstruction in one of the major coronary arteries. The patients were divided into two groups according to the absence ...
Banerjee A K - - 1993
The importance of coronary collateral circulation in relation to the left ventricular function, aneurysm formation and size was investigated in 100 patients with previous 'Q' wave myocardial infarction who underwent coronary angiography. Aneurysms were present in 20% of patients. The majority of these (80%) patients had severe or total occlusion ...
Cohen M V - - 1993
OBJECTIVE: The aim was to test the effect of propranolol, a beta adrenergic receptor blocking drug which diminishes myocardial ischaemia, on coronary collateral development. METHODS: Dogs were chronically instrumented with a left circumflex coronary artery Doppler flow probe, ameroid constrictor, pneumatic occluder, and left atrial and aortic catheters. Haemodynamic studies ...
Koh K K - - 1993
OBJECTIVES: This study was performed to determine whether there are differences in the operative, histopathologic, angiographic and clinical findings of isolated ostial stenosis between Oriental and western patients. BACKGROUND: Angiographic, clinical and histologic findings in isolated ostial stenosis have been reported in western but not in Oriental patients. METHODS: Six ...
Yamakado T - - 1993
Clinical and experimental observations have suggested that newly developed collaterals usually remain even after successful revascularization. We present a patient in whom coronary collateral regression was angiographically demonstrated within about 1 month after percutaneous transluminal coronary angioplasty, which led to the development of acute myocardial infarction. This case suggests that ...
Mayer N - - 1993
To examine the effects of propofol on the function of normal, collateral-dependent, and acutely ischemic myocardium, nine mongrel dogs were chronically instrumented with hydraulic occluders and ameroid constrictors were inserted around the left coronary artery, pressure transducers in the left ventricle, and heparin-filled catheters in the descending aorta and the ...
Hamaoka K - - 1993
BACKGROUND: Few studies have been reported on the prognosis or reversibility of ischemic myocardial lesions in Kawasaki disease. In this study, the pathophysiologic causes of reversible left ventricular dysfunction were evaluated in seven children with severe stenotic coronary lesions caused by Kawasaki disease. METHODS: The clinical process and the changes ...
Hartford C G - - 1993
Serotonin (5-hydroxytryptamine, 5-HT) mediates vasoconstriction and vasodilation in normal coronary circulation of various animal species. In the presence of coronary artery disease, serotonin may inhibit coronary collateral formation and stimulate predominantly vasoconstriction. We tested the effect of ketanserin, a selective 5-HT2 receptor antagonist and platelet aggregation inhibitor, on ischemic myocardium ...
Fujita M - - 1993
OBJECTIVES: The purpose of this study was to test the hypothesis that the diameter of the recipient coronary artery of the well developed collateral circulation in patients with acute myocardial infarction increases because of the augmented intravascular pressure caused by subsequent collateral development. BACKGROUND: It is well known that collateral ...
Sabia P J - - 1992
BACKGROUND: We hypothesized that successful reperfusion of an occluded infarct-related coronary artery even late after acute myocardial infarction would result in improved regional wall motion and that such improvement might be related to the presence of collateral blood flow within the infarct bed. METHODS: We assessed regional wall motion by ...
Leung J M - - 1992
OBJECTIVES: Our study objective was to determine whether the presence of steal-prone anatomy conferred an increased risk in the development of intraoperative myocardial ischemia. BACKGROUND: Coronary artery steal of collateral blood flow has been demonstrated for many vasodilators, including isoflurane, the most commonly used inhalational anesthetic agent in the United ...
Takeshita S - - 1992
We directly assessed the anomalous and collateral coronary flow profiles of a 58 year-old-man with Bland-White-Garland syndrome using pulsed Doppler echocardiography. Doppler recordings in this patient document the utility of pulsed Doppler echocardiography in the assessment of a cardiac shunt associated with a congenital coronary anomaly in an adult.
Flaherty J T - - 1992
In patients with acute myocardial infarction, intravenous nitroglycerin lowers left ventricular filling pressure and systemic vascular resistance. At lower infusion rates (less than 50 micrograms/min) nitroglycerin is principally a venodilator, whereas at higher infusion rates more balanced venous and arterial dilating effects are seen. Patients with left ventricular failure demonstrate ...
Yanagisawa-Miwa A - - 1992
Coronary collateral vessels reduce damage to ischemic myocardium after coronary obstruction. Factors that stimulate collateral formation are expected to have ameliorating effects on myocardial infarction. In a canine experimental myocardial infarct model, intracoronary injection of basic fibroblast growth factor (bFGF) improved cardiac systolic function and reduced infarct size. Treatment with ...
Sauer U - - 1992
The present study was conducted on 33 children (median age at initial cardiac catheterization 0.4 years [0.1 to 11.8]) with anomalous origin of the left coronary artery from the pulmonary artery, without associated hemodynamically significant cardiovascular anomalies, who were treated throughout a period of 18 years in our hospital. A ...
Watarai M - - 1992
The clinical significance of collaterals visible on angiography immediately after successful percutaneous transluminal coronary angioplasty (PTCA) was analyzed in 221 patients who underwent successful PTCA for coronary arteries receiving collaterals. Filling of the collaterals was classified as good; filling the entire epicardial segment of the stenosed site, fair; partially filling ...
Ropchan G V - - 1992
Salvage of ischemic myocardium, with the aid of a nonsynchronized coronary sinus retroperfusion system, was studied in a pig infarct model. In anesthetized open chested animals, the left anterior descending coronary artery was occluded for 4 hours and then reperfused for 1 hour before the animals were killed. In the ...
Cribier A - - 1992
OBJECTIVES: The goal of the study was to evaluate the progressive increase in ischemic threshold with multiple sequential transient coronary occlusions and to assess the role of the collateral circulation in adaptation to ischemia. BACKGROUND: It has been observed that the duration of balloon inflations during coronary angioplasty can be ...
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