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At least 55 records · Page 3Linked to original sources
PubMed2001

[Significance of soluble thrombomodulin in the coronary circulation of patients with coronary artery disease].

OBJECTIVES: The relationship between plasma levels of soluble thrombomodulin, a probable marker for endothelial damage, and the severity of coronary atherosclerosis was investigated. METHODS: Plasma soluble thrombomodulin levels were evaluated in 160 patients(mean age 62 +/- 11 years) who underwent coronary angiography. Blood samples were obtained from the peripheral vein, ostium of the left coronary artery and coronary sinus. The levels of plasma thrombomodulin were measured by enzyme-linked immunosorbent assay. The change of thrombomodulin level in the coronary circulation (delta TM) was calculated as the coronary sino-arterial difference. Patients were classified into four groups according to the number of diseased vessels, and the severity of coronary atherosclerosis was evaluated with the modified Gensini score. RESULTS: Coronary sinus levels of thrombomodulin were significantly higher in the two or more vessel disease(VD) groups than in the no or one VD groups(p < 0.05). delta TM were significantly higher in the 2VD than in the 0VD groups(p < 0.05), and higher in the 3VD than in the 0VD or 1VD groups(p < 0.05). delta TM showed positive correlation with Gensini score for left coronary arteries(r = 0.347, p < 0.0001). CONCLUSIONS: The increment of thrombomodulin across the coronary circulation was significantly correlated with the severity of coronary atherosclerosis, suggesting a close association between the progression of coronary atherosclerotic stenosis and damage to the endothelial surface.

Aged↗
PubMed2000

Decrease of nitric oxide end-products during coronary circulation reflects elevated basal coronary artery tone in patients with vasospastic angina.

The aim of this study was to investigate the role of nitric oxide (NO) in the coronary circulation and its relation to basal coronary artery tone in patients with vasospastic angina (VSA). We evaluated the level of nitric oxide end-products (NOx; nitrite + nitrate) in coronary circulation blood using an HPLC-Griess system for nine patients with VSA and nine control patients. All of the patients with VSA experienced focal spasm in the proximal to middle segments of the left anterior descending coronary artery (LAD) in response to intracoronary injection of ergonovine maleate. The luminal diameter of the coronary artery was measured in each patient by quantitative coronary arteriography. Blood samples for NOx measurement were obtained from the coronary sinus (NOxV) and the ostium of the left coronary artery (NOxA). The NOx difference, calculated from the coronary venous-arterial difference in NOx, was close to zero for the control patients whereas it was clearly negative for the patients with VSA. In addition, the NOx difference in the patients with VSA showed a negative correlation with basal coronary artery tone (r = -0.91, p < 0.01) and a positive correlation with the dose of ergonovine required for spasm provocation (r = 0.77, p < 0.05). These results indicate that increased basal coronary artery tone and higher susceptibility to ergonovine in patients with VSA would be a consequence of coronary endothelial dysfunction as is indicated by NOx.

Adult↗
PubMed1993

[Doppler microprobe for evaluation of coronary circulation after successful coronary angioplasty].

The influence of angiographically successful coronary angioplasty (PTCA) in 27 patients (mean age 64 +/- 8 years) was assessed by means of 0.018" intracoronary Doppler guidewire. Averaged peak flow velocity (APV) and diastolic-systolic velocity ratio (DSVR) were recorded in resting conditions (bas) and during papaverine induced hyperemia before and after PTCA. Coronary flow reserve (CFR) was calculated as ratio of hyperemic and resting APV. The parameters mentioned above were estimated proximally and distally to coronary stenosis to be dilated. Mean value of APVbas for distal part of the vessels was significantly lower (about 46-57%) then for the two proximal segments. PTCA caused significant increase of APVbas as for proximal (about 21-69%) as for distal segments (about 62-77%). That procedure caused significant increase of CFR only for right coronary artery (RCA). Mean values of DSVRbas in proximal position for left descendens (LAD) and left circumflex (LCx) arteries before PTCA were significantly higher than DSVbas for distal position but did not differ for RCA. PTCA caused significant increase of DSVRbas in distal position only for LAD and LCx. Our results showed that angiographically successful PTCA causes significant increase of APVbas for right and left coronary arteries and normalization of DSVRbas in distal segments of LAD and LCx.

Adult↗
PubMed2004

Increased platelet-derived microparticles in the coronary circulation of percutaneous transluminal coronary angioplasty patients.

Platelet-derived microparticles that are produced during platelet activation are capable of adhesion and aggregation. Endothelial trauma that occurs during percutaneous transluminal coronary angioplasty (PTCA) may support platelet-derived microparticle adhesion and contribute to development of restenosis. We have previously reported an increase in platelet-derived microparticles in peripheral arterial blood with angioplasty. This finding raised concerns regarding the role of platelet-derived microparticles in restenosis, and therefore the aim of this study was to monitor levels in the coronary circulation. The study population consisted of 19 angioplasty patients. Paired coronary artery and sinus samples were obtained following heparinization, following contrast administration, and subsequent to all vessel manipulation. Platelet-derived microparticles were identified with an anti-CD61 (glycoprotein IIIa) fluorescence-conjugated antibody using flow cytometry. There was a significant decrease in arterial platelet-derived microparticles from heparinization to contrast administration (P = 0.001), followed by a significant increase to the end of angioplasty (P = 0.004). However, there was no significant change throughout the venous samples. These results indicate that the higher level of platelet-derived microparticles after angioplasty in arterial blood remained in the coronary circulation. Interestingly, levels of thrombin-antithrombin complexes did not rise during PTCA. This may have implications for the development of coronary restenosis post-PTCA, although this remains to be determined.

Angioplasty, Balloon, Coronary↗
PubMed2002

Hemodynamic analysis of coronary circulation in angulated coronary stenosis following stenting.

The present study in angulated coronary stenosis used human in vivo hemodynamic parameters and computed simulation, both qualitatively and qualitatively, to evaluate the influence of flow velocity and wall shear stress (WSS) on coronary atherosclerosis, the changes of hemodynamic indices following coronary stenting, and their effect on evolving in-stent restenosis. Initial and follow-up coronary angiographies in patients with angulated coronary stenosis were performed (n=60). The optimal degree of coronary stenting for angulated coronary stenosis had two models, the less than 50% angle changed group (model 1, n=33) and the more than 50% angle changed group (model 2, n=27). This angle change was based on the percentage change of vascular angle between pre- and post-intracoronary stenting. The flow-velocity wave obtained from in vivo intracoronary Doppler study data was used for in vitro numerical simulation. Spatial and temporal patterns of the flow-velocity vector and recirculation area were drawn throughout the selected segment of coronary models. WSS of pre- and post-intracoronary stenting was calculated from three-dimensional computer simulation. As results, follow-up coronary angiogram demonstrated significant difference in the percentage of diameter stenosis between the two groups (group 1: 40.3 +/- 30.2 vs. group 2: 25.5 +/- 22.5%, p < 0.05). Negative shear area on 3D simulation, which is consistent with the re-circulation area of flow vector, was noted on the inner wall of the post-stenotic area before stenting. The negative WSS disappeared after stenting. High spatial and temporal WSS before stenting fell within the range of physiologic WSS after stenting. This finding was more prominent in model 2 (p < 0.01). The present study suggests that hemodynamic forces exerted by pulsatile coronary circulation, termed WSS, might affect the evolution of atherosclerosis within the angulated vascular curvature. Moreover, geometric characteristics, such as the angular difference between pre- and post- intracoronary stenting might define optimal rheologic properties for vascular repair after stenting.

Adult↗
PubMed1977

[Coronary circulation in abnormal left coronary artery arizing from the pulmonary artery trunk, before and after correction].

Two patients, both of them young girls, aged 14 and 15, had this condition and were studied by haemodynamic methods preoperatively and during the seventh postoperative month. In both cases, the retrograde perfusion of the left coronary vascular tree was shown up well, demonstrating the "coronary steal" and a left-right shunt of 2 volumes. In both cases also, the postoperative coronary arteriogram showed a return of the left coronary circulation to normal, disappearance of the large anastomatic vessels, and above all a return to normal dimensions of the right coronary artery, previously extremely tortuous and dilated. The 30 or so cases of total correction published in the world literature have been reviewed in the light of these two new cases.

Adolescent↗
PubMed1998

Central neuroaxis blockade and coronary circulation.

The coronary circulation is subject to modulation by the autonomic nervous system. Thus, sympathetic stimulation causes coronary vasodilation in healthy humans, whereas stenotic coronary arteries react by vasoconstriction in response to sympathetic stimulation. It is for this reason that experimental studies and clinical evidence revealed beneficial effects of a blockade of cardiac sympathetic drive by thoracic epidural anaesthesia on coronary perfusion and myocardial function in normal and in ischaemic myocardium. In contrast, segmental lumbar epidural anaesthesia leads to a compensatory increase in cardiac sympathetic outflow which may jeopardize myocardial areas dependent on perfusion by stenotic coronary arteries.

Journal Article↗
PubMed2004

Plasma concentrations of monocyte chemoattractant protein 1 (MCP-1) and neopterin in the coronary circulation of patients with coronary artery disease.

BACKGROUND: The dynamics of MCP-1 and neopterin and the relation between their concentrations in coronary circulation and the severity of coronary atherosclerosis were evaluated in patients with stable coronary artery disease (CAD). METHODS AND RESULTS: Blood samples were obtained from the aortic root (Ao) and coronary sinus (CS) of 78 patients who underwent coronary angiography. Plasma MCP-1 and neopterin concentrations were measured using an enzyme-linked immunosorbent assay method and the CS-Ao differences were calculated. The severity of coronary heart disease (CHD) was evaluated in 52 patients who had no history of coronary angioplasty, using 3 coronary scoring systems: the clinical 1- to 3-vessel disease score, the American Heart Association extension score (1-15 segments), and the Gensini score. The plasma MCP-1 and neopterin concentrations increased significantly with age. The CS-Ao differences for neopterin showed weak, but significant, positive correlation with the Gensini score (r=0.347, p=0.013). There were no correlations among the MCP-1 concentrations in the Ao or CS, or in the CS-Ao difference, with the severity of CHD. CONCLUSIONS: The results indicate that neopterin is a useful marker of the severity of coronary atherosclerosis in patients with stable CAD, acting as an index of the activity of monocytes/macrophages.

Adult↗
PubMed1977

[Effect of nonachlazine and oxyfedrine on coronary circulation in dogs].

Coronary circulation was measured in the anesthetized and nonanesthetized dogs by means of ultrasonic Doppler's radiotelemetric apparatus. The ultrasonic pick-up was placed on the upper third of the descending branch of the left coronary artery. Nonachlazine considerably increased the coronary circulation in the anesthetized and nonanesthetized dogs. However, the action of the preparation lasted 2 to 3 minutes only and depended on the changes in the cardiac activity. In difference from nonachlazine, oxphedrine increased the coronary circulation to a lesser degree, but for a much longer time (20min on the average). Taking into consideration a high efficacy of these preparations under clinical conditions a conclusion was drawn that an increase of the coronary circulation was not the principal way of action for reaching the antiangina effect in the patients with ischemic heart disease.

Analgesics↗
PubMed2000

Dynamics of flow, resistance, and intramural vascular volume in canine coronary circulation.

Varying coronary volume will vary vascular resistance and thereby have an effect on coronary hemodynamics. Six ventricular septa were isolated from anesthetized dogs, dispersed in a biaxial stretch apparatus at diastolic stress, and perfused artificially with an oxygenated perfluorochemical emulsion at maximal vasodilation. Flow and thickness were measured continuously by an electromagnetic flow probe and sonomicrometer. Pressure was varied sinusoidally around 30, 50, and 70 mmHg with an amplitude of 7.5 mmHg; frequencies ranged between 0.015 and 7 Hz. Bode plots of admittance (flow/pressure) and capacitance (scaled thickness/pressure) were constructed. A two-compartment model was used in which the resistances vary with volume. Realistic values of microvascular compliance ( approximately 0.3 ml x mmHg(-1) x 100 g(-1)) were found. Values 10 times higher were then found when resistances were forced to be constant. We concluded that volume dependence of resistances have to be taken into account when dynamic or static pressure-flow relations are studied and conceal the effect of a large intramyocardial compliance on arterial hemodynamics.

Animals↗
PubMed1998

Functional assessment of collaterals in the human coronary circulation.

The coronary collateral circulation is an alternative source of blood supply to a myocardial area jeopardized by the failure of the stenotic or occluded vessel to provide enough blood flow to this region. Until recently, only qualitative or semiqualitative methods have been available for the assessment of the coronary collateral circulation in humans, such as the patient's history of walk-through angina pectoris, the registration of intracoronary ECG signs for myocardial ischaemia or angina pectoris during coronary occlusion, or coronary angiographic classification (score 0-3) of collaterals. Studies of coronary wedge pressure measurements distal of a balloon-occluded coronary artery and the recent advent of ultrathin pressure and Doppler angioplasty guidewires have made it possible to obtain pressure or flow velocity data in remote vascular areas and, thus, to calculate functional variables for coronary collateral flow. Those coronary occlusive pressure- and flow velocity-derived parameters express collateral flow as a fraction of antegrade coronary flow during vessel patency of the collateral-receiving vessel. They are both interchangeable, and they have been validated in comparison to 'traditional' methods and against each other. The possibility of accurately measuring coronary collateral flow indices in humans undergoing coronary balloon angioplasty opens areas of investigation of the pathogenesis, pathophysiology and therapeutic promotion of the collateral circulation previously reserved for exclusively experimental studies. The purpose of this article is to review several clinically available methods for the functional characterization of the coronary collateral circulation.

Angina Pectoris↗
PubMed1983

Flow-volume relations in coronary circulation and distribution of coronary flow into nutritional and non-nutritional compartments.

Simultaneous assessment of coronary flow and flow-volume relation makes it possible to evaluate the dilatatory responses of coronary vasculature. A new set up of methods for investigation of the coronary circulation was employed to study the nature of the coronary flow and volume responses to dipyridamole in dogs. The turnover rate of coronary blood, the reciprocal value of the mean transit time, can be accurately determined by computer simulation analysis of coronary dye dilution curves. After intravenous dipyridamole (0.5 mg/kg) both coronary turnover rate and electromagnetically assessed blood flow were observed to increase in parallel and to the same degree (+55%). This indicates that no increase in the coronary vascular volume and, accordingly, no significant overall coronary dilatation takes place. The effective coronary blood flow in relation to the myocardial oxygen consumption, i.e. the nutritional flow, and the myocardial oxygen consumption decreased by 25% concomitant to a corresponding fall in myocardial oxygen requirements. Thus, the increase in total coronary flow after dipyridamole is useless for myocardial metabolism, and may properly be denoted as luxury perfusion or throughput flow.

Animals↗
PubMed1992

[Specific features of the regulation of coronary circulation during reperfusion after coronary insufficiency of different degrees].

Coronary insufficiency of various degrees was reproduced in experiments with anesthetized dogs by using coronary artery catheterization by progressively limiting the regional blood flow by 30, 50, 70, and 90%, the dog chest being closed. The specific features of regulatory reactions of cardiac vessels were also studied under subsequent reperfusion. It was shown that regulation of coronary circulation became changed in most cases after markedly limited coronary blood flow, as manifested by impaired reperfusion hyperemia and its rapid cessation that prevented the "payment" of blood flow debt and a secondary increase of cardiac vascular resistance above the preocclusive level. There was a significant relationship between the detected disorders and the degree of prior limited coronary perfusion.

Animals↗
PubMed1984

Competitive blood flow in the coronary circulation simulating progression of proximal coronary artery disease after saphenous vein bypass surgery.

We report a case of competitive blood flow in the left coronary circulation after saphenous vein bypass grafting that resulted in the apparent progression of a proximal stenosis to total occlusion at coronary angiography. Repeat angiography with careful attention to catheter position and adequate injection of contrast agent demonstrated the actual anatomy and showed that there was no postoperative change in the native coronary circulation. The true incidence of progression of proximal coronary disease after saphenous vein bypass surgery is unknown, and reported figures may be falsely elevated because of unrecognized competitive flow patterns simulating obstruction.

Coronary Angiography↗