Search Results
Results 401 - 450 of 772
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Sanchis J - - 1997
The aim of this study was to evaluate the relation between the infarction artery status and left ventricular volumes, independently of regional ventricular dysfunction, at 4-6 weeks after a first myocardial infarction. The study group consisted of 100 patients, of whom 80 received thrombolytic treatment. Coronary and contrast left ventricular ...
Shou M - - 1997
OBJECTIVES: We sought to evaluate the potential of basic fibroblast growth factor (bFGF) to enhance coronary collateral perfusion in dogs with chronic single-vessel coronary occlusion. A secondary goal was to examine whether the salutary effects of bFGF treatment, previously proved effective in the short term, would be maintained in the ...
Elhendy A - - 1997
The aim of this study was to assess the influence of the severity of coronary artery stenosis and the grade of collateral circulation on myocardial viability in patients with chronic left ventricular (LV) dysfunction undergoing coronary artery bypass grafting. Forty patients (age 59 +/- 8 years) with old myocardial infarction ...
Piek J J - - 1997
OBJECTIVES: We sought to determine the predictive value of factors influencing coronary collateral vascular responses in humans. BACKGROUND: There is limited information on the factors responsible for coronary collateral vascular development, despite the protective effect of collateral vessels in ischemic syndromes. METHODS: Angiography of the contralateral artery was performed during ...
Lindner J R - - 1997
Vasodilation of microvessels distal to a stenosis results in an increase in myocardial blood volume (MBV). The purpose of this study was to examine the changes in MBV induced by graded coronary artery stenoses by using myocardial contrast echocardiography (MCE). Accordingly, 21 dogs underwent progressive stenosis of a coronary artery ...
Seiler C - - 1997
A steal phenomenon was detected by intravascular Doppler guidewire in a patient with a well collateralised coronary vascular area supplied by a reopened left circumflex coronary artery. This phenomenon accounted for the fall in blood flow velocity reserve during hyperaemic conditions to 50% of the baseline value. The collaterals must ...
Gliozheni E - - 1996
In patients with a major coronary vessel occluded, the presence of good coronary collateral circulation increases vulnerability to myocardial ischemia induced by pharmacologic coronary vasodilation. The presence of good collaterals results in a greater frequency, severity, and extent of dipyridamole-induced regional left ventricular dysfunction, consistent with the hypothesis of angiographically ...
Skyba D M - - 1996
OBJECTIVES: We sought to 1) study the effects of FS-069 on cardiac and systemic hemodynamic function, myocardial blood flow, left ventricular wall thickening and pulmonary gas exchange when injected intravenously; and 2) compare the myocardial kinetics and microvascular rheology of FS-069 and Albunex when injected directly into a coronary artery. ...
Ghaleh B - - 1996
BACKGROUND: Myocardial blood flow distribution is known to be heterogeneous. It is also known that not all of the area at risk (AAR) infarcts with coronary artery occlusion (CAO) and coronary artery reperfusion (CAR). The goal of the present study was to determine whether the proportion of AAR that is ...
Shen Y T - - 1996
Inotropic reserve, demonstrated with administration of sympathomimetic amines, is characteristic of hibernating myocardium. The goal of this study was to determine whether inotropic reserve was present following chronic coronary artery constriction in the pig, which is one potential model of hibernating myocardium. The effects of isoproterenol were examined in five ...
Sato M - - 1996
Controlled coronary sinus occlusion was shown to retard necrosis of ischemic myocardium. To elucidate this mechanism, regional myocardial blood flow measurement was performed with and without coronary sinus pressure elevation to 30 mmHg (CS30). Colored microspheres were injected into left and right coronary arteries after coronary perfusion of the left ...
Burks J M - - 1996
Anomalous right coronary artery from the left coronary sinus was associated with inferior wall ischemia. There were extensive left-to-right collaterals. This is the first documentation of collateral circulation in this anomaly, extending its pathophysiologic spectrum to include this response to ischemia that is well-known in atherosclerotic disease.
Annane D - - 1996
BACKGROUND: In myotonic dystrophy (DM), striated muscle is involved in relation to the size of the DNA mutation. Smooth muscle may be similarly impaired at the level of the urinary and digestive apparatus and possibly at the level of small vessels, since microangiopathy has been described in the iris and ...
Lim Y T - - 1996
Over a period of 27 months, 32 patients aged 40 and below were admitted for acute myocardial infarction. Twenty-nine had coronary angiography with a mean of 15.7 +/- 10.0 days following infarction. Fourteen patients had single vessel, 10 multi-vessel and 5 had only minor coronary disease. Disease in the left ...
Tyagi S C - - 1996
Although heart attack is caused by occlusion of a major coronary artery, some patients have occlusion without heart attack because these patients have sufficient collateral circulation to provide an alternate pathway for blood supply to the myocardium at ischemic risk. The growth of new capillary vessels (angiogenesis) and enlargement of ...
Hariawala M D - - 1996
Several recent studies have demonstrated the potential for improving myocardial perfusion by the continuous administration of angiogenic growth factors. Studies in our laboratory have shown that a single intraarterial or intravenous bolus of the endothelial cell specific mitogen vascular endothelial growth factor (VEGF) can significantly improve perfusion in a rabbit ...
Nakae I - - 1996
OBJECTIVES: The purpose of this study was to test the hypothesis that the incidence of restenosis after primary percutaneous transluminal coronary angioplasty for acute myocardial infarction is largely influenced by the preexistent coronary collateral circulation to the infarct-related coronary artery. BACKGROUND: The occurrence of restenosis after coronary angioplasty is the ...
Sharma M P - - 1996
A prospective case controlled study was conducted to evaluate the value of real time ultrasound in establishing the diagnosis and the etiology of portal hypertension. Patients attending the outpatient department of a tertiary care centre were included. There were 324 consecutive patients with portal hypertension due to cirrhosis (n = ...
Kodama K - - 1996
OBJECTIVES: We sought to evaluate the effect of collateral channels that develop late after a first anterior myocardial infarction on left ventricular dilation and function. BACKGROUND: Collateral channels in an infarct-related artery may develop long after occlusion of the artery. Well visualized collateral channels that appear immediately after a myocardial ...
Cheng D C - - 1996
PURPOSE: This study compared the effects of nifedipine and metoprolol on collateral-dependent myocardial blood flow in a swine model of chronic coronary obstruction and acute ischaemia during isoflurane anaesthesia. METHODS: Collateral coronary circulation was induced in 15 three-week-old piglets by banding of the proximal left anterior descending coronary artery (LAD). ...
Li D S - - 1996
1. We evaluated the use of non-radioactive fluorescent-labelled microspheres (FM) for the measurement of regional myocardial blood flow (RMBF) in an ischaemic sheep model. 2. Injection of FM directly into the coronary artery was compared with left atrial injection. There was a good correlation in the measurement of RMBF between ...
Ing F F - - 1996
Coexisting aortopulmonary collaterals in patients diagnosed with a patent ductus arteriosus (PDA) are rare findings. Percutaneous transcatheter closure of PDA and requisite aortography offer an unique opportunity to identify and treat these systemic arterial anomailes, which would be missed by echocardiographic evaluation alone. The significance of these collaterals is unclear, ...
Kinoshita Y - - 1996
Using myocardial contrast echocardiography (MCE), coronary arteriography, and thallium-201 myocardial imaging (TMI), we examined the characteristics and the role of collateral vessels in 35 patients with coronary artery lesions after Kawasaki disease. The male/female ratio was 25:10. The patients' ages are examination ranged from 1.0 to 20.3 years (mean, 10.8 ...
Fujita M - - 1995
Although myocardial ischemia in patients with coronary artery disease should be eliminated with medical and surgical treatment, it paradoxically contributes to the preservation of compromised myocardium through various mechanisms. First, ischemic vasodilation of coronary and collateral vessels resulting from the activation of the ATP-sensitive K+ channel maximizes a blood supply ...
Geldof M J - - 1995
Diameter stenosis and flow reserve are indices of morphological and functional severity of coronary artery stenosis. Flow reserve can be determined at coronary arterial or at myocardial level. In the presence of functional collateral circulation, coronary flow reserve and myocardial perfusion reserve may differ. We studied coronary flow, coronary flow ...
Sasaki Y - - 1995
Reevaluation of repeated balloon angioplasty as a model of ischemic preconditioning and of the role of collateral circulation and high-frequency electrocardiograms in repeated inflations was carried out. There have been few studies using angioplasty as a model of ischemic preconditioning of the collateral circulation during repeated inflations or of the ...
Pearlman J D - - 1995
Coronary occlusive disease is the leading cause of death in industrial nations and affects one in four adults. Although heart attacks are caused by occlusion of a coronary artery, some patients have occlusions without infarction because they have sufficient collateral vessels providing an alternate pathway for blood supply. Vascular endothelial ...
Nishigami K - - 1995
We evaluated the effects of antecedent anginal episodes and coronary artery stenosis on left ventricular function during coronary occlusion and the role of collateral filling in 33 patients with angina pectoris who underwent angioplasty. Wall motion abnormalities were investigated by echocardiography and classified into hypokinesia and akinesia. Collateral filling during ...
Cheirif J - - 1995
OBJECTIVES: This study sought to determine whether myocardial contrast echocardiography could be used to detect and quantitate collateral blood flow capable of limiting the effects of ischemia in an experimental model of coronary thrombosis and reperfusion. BACKGROUND: Myocardial contrast echocardiography has been used to assess collateral blood flow in humans, ...
McCully R B - - 1995
This study examines the relative importance of patency of the left anterior descending (LAD) coronary artery on long-term survival when the LAD is the only significantly narrowed coronary artery. From a cardiac disease registry of 21,786 patients, 826 medically treated patients with isolated LAD disease were identified. These patients were ...
Akutsu Y - - 1995
We evaluated the regional myocardial blood flow in collateral dependent infarct-related areas to examine the functional role of coronary collaterals. Regional myocardial blood flow was measured by positron emission tomography with 13N-ammonia at rest and during low-grade exercise (bicycle ergometer fixed at 25 W for 6.5 min). The study was ...
Sellke F W - - 1995
The effect of chronic, collateral-dependent perfusion on beta-adrenergic coronary microvascular responses was examined. Ameroid constrictors were placed on the proximal left circumflex (LCx) coronary artery in 16 pigs. In 8 pigs, heparinized saline containing vascular endothelial growth factor (VEGF) was administered into the perivascular space of the proximal LCx artery ...
Kersten J R - - 1995
Coronary collateral development in response to chronic myocardial ischemia is modulated by the integrated release of a variety of growth factors. Protamine, a specific inhibitor of angiogenesis in vitro and in vivo, may attenuate coronary collateral development. The purpose of this investigation was to characterize a model of canine coronary ...
Ghezzi C - - 1995
[Bis (N-etoxy, N ethyl dithiocarbamato) nitrido] 99mTc (V) (TcN-NOET) is a new neutral lipophilic myocardial imaging agent proposed for clinical use for detecting coronary artery disease. We studied the relation between myocardial retention of TcN-NOET and myocardial blood flow (MBF) in a canine model. METHODS: A wide range of MBF ...
Schaper W - - 1995
We investigated the development of coronary collaterals in canine and porcine models using either progressive experimental coronary occlusion or microembolism of small vessels. Muscular arteries developed on the epicardial surface of canine--but not of porcine hearts, where large, thin-walled intra-myocardial capillaries developed irrespective of the type of vascular occlusion. The ...
Stone D A - - 1995
Previous studies using thallium-201 scintigraphy have suggested that angiographic coronary collaterals can protect against the development of stress-induced perfusion abnormalities, but the effect of collaterals on stress echocardiography (SECHO) has not been determined. In this study, 21 consecutive patients referred for cardiac catheterization underwent SECHO and coronary angiography. Of the ...
Kern K B - - 1995
The usefulness of intravenous beta-adrenergic receptor blockade in limiting infarct size when neither reperfusion nor collateral flow occurs is unknown. The effect of intravenous metoprolol on limiting myocardial infarct size was therefore examined in a nonreperfused porcine model. Closed-chest techniques were used to occlude the left anterior descending coronary artery, ...
Quintilio C - - 1995
Myocardial distribution of cardioplegic solution infused by combined antegrade/retrograde routes was assessed with myocardial contrast echocardiography in 18 patients with chronic stable angina and three-vessel disease undergoing elective coronary artery bypass grafting. Overall myocardial opacification was significantly greater in retrograde than in antegrade cardioplegia (77.7% +/- 13.4% versus 59.1% +/- ...
Shen Y T - - 1995
The major goal of this study was to determine whether impaired myocardial contractile function during the development of progressive coronary artery stenosis induced by ameroid constriction in conscious pigs reflected myocardial "hibernation" or "stunning." Minipigs were instrumented with a coronary ameroid constrictor and hydraulic occluder, regional wall thickness crystals, a ...
Gibson C M - - 1995
OBJECTIVES: This study attempted to determine which lesion characteristics are associated with reocclusion by 18 to 36 h. BACKGROUND: Reocclusion of the infarct-related artery after successful reperfusion is associated with significant morbidity and up to a threefold increase in mortality. METHODS: Two hundred seventy-eight patients with acute myocardial infarction were ...
Kersten J R - - 1995
Protamine has been demonstrated to inhibit angiogenesis in vitro and in vivo; however, its effect on coronary collateral development has not been examined. The present investigation tested the hypothesis that subcutaneously administered protamine inhibits canine coronary collateral development in response to chronic myocardial ischemia. Dogs underwent daily, repetitive, 2-min, left ...
Dellborg M - - 1995
Reperfusion therapy has lowered mortality in patients suffering from acute myocardial infarction. Failure to reperfuse is associated with an increased short- and long-term mortality. In a prospective study we used dynamic vectorcardiography to monitor 96 patients with acute myocardial infarction treated with reperfusion therapy to non-invasively assess coronary patency. The ...
Tomai F - - 1994
Previous studies have assessed the determinants of collateral vessel recruitment during coronary occlusion in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). However, the determinants of severity of myocardial ischemia after sudden coronary occlusion do not necessarily coincide with those responsible for collateral vessel recruitment. The aim of this study was ...
Chauhan A - - 1994
The aim of this study was to develop a method of measuring human coronary circulation impedance in a clinical setting. The authors measured coronary flow reserve (CFR) in 27 patients with chest pain and normal coronary arteries. A Judkins-style, 8F Doppler-tipped angiographic catheter was positioned in the left coronary ostium. ...
Sellke F W - - 1994
The effect of chronic, periadventitial administration of basic (b) fibroblast growth factor (FGF) on endothelial dysfunction in the collateral-dependent and normally perfused coronary microcirculation was examined. Ameroid constrictors were placed on the proximal left circumflex coronary artery (LCX) in 23 pigs. In 11 pigs, bFGF was released from calcium alginate ...
Matsuda Y - - 1994
Left ventricular ejection changes obtained from left ventricle roentgenograms were analyzed before and after coronary artery bypass grafting in 22 consecutive patients with chronic obstructive left anterior descending coronary artery disease receiving collaterals before surgical revascularization. The collateral vessels all disappeared after surgical revascularization. After operation, ejection changes of anterobasal, ...
Johnson T H - - 1994
Coronary arteries of transplanted hearts frequently develop a vasculopathy characterized by severe lumenal narrowing in the distal coronary arteries. It has been thought, on the basis of angiographic studies, that the coronary circulation of transplanted hearts with vasculopathy fails to develop collateral vessels normally. To determine the extent of the ...
Noyez L - - 1994
The importance of coronary collateral circulation for homogeneous distribution of anterograde and retrograde delivery of cardioplegia was evaluated in 36 patients undergoing myocardial revascularization. All patients had three-vessel coronary artery disease, with a stenosis of the right coronary artery of at least 80%. The patients were randomized into two groups: ...
Kassab G S - - 1994
To provide a morphometric basis for any mathematical modeling of the coronary vasculature, data on the network of coronary capillary blood vessels and the topology of the arteriolar supply and venular drainage relative to the capillaries are presented. The diameters, lengths, and branching patterns of the coronary capillary blood vessels ...
Berdjis F - - 1994
Seventeen patients with an anomalous left coronary artery from the pulmonary trunk underwent surgical treatment and were evaluated, with a mean follow-up of 9.5 years. Analysis has included clinical symptoms cardiac laboratory tests, angiographic grading of intercoronary collaterals, echocardiographic and angiographic measurement of left ventricular function, surgical methods, and the ...
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