References of "Ghuysen, Alexandre"
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See detailRight ventricular operational mode and changes in mechanical efficiency in acute pulmonary embolism
Ghuysen, Alexandre ULg; Lambermont, Bernard ULg; Kolh, Philippe ULg et al

in 4th European Congress On Emergency Medicine (2006)

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See detailHaemodynamic Management Using a Minimal Cardiac Model,” Young Researchers Meeting on Haemodynamic Management
Starfinger, C.; Hann, C. E.; Chase, J. G. et al

in Pulsion Medical Systems AG (2006)

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See detailCan CT pulmonary angiography allow assessment of severity and prognosis in patients presenting with pulmonary embolism? What the radiologist needs to know
Ghaye, Benoît ULg; Ghuysen, Alexandre ULg; Bruyere, P. J. et al

in Radiographics (2006), 26(1, Jan-Feb), 23-3939-40

Computed tomographic (CT) pulmonary angiography has been established as a first-line diagnostic technique in patients suspected of having pulmonary embolism. Risk stratification is important in patients ... [more ▼]

Computed tomographic (CT) pulmonary angiography has been established as a first-line diagnostic technique in patients suspected of having pulmonary embolism. Risk stratification is important in patients with pulmonary embolism because optimal management, monitoring, and therapeutic strategies depend on the prognosis. Acute right-sided heart failure is known to be responsible for circulatory collapse and death in patients with severe pulmonary embolism. Acute right-sided heart failure can be assessed at CT pulmonary angiography by measuring the dimensions of right-sided heart cavities or upstream venous structures, such as the superior vena cava or azygos vein. The magnitude of pulmonary embolism can be calculated at CT pulmonary angiography by applying angiographic scores adapted for CT (Miller and Walsh scores) or dedicated CT scores (Qanadli and Mastora scores). The advent of CT pulmonary angiography performed with electrocardiographic gating permits new advances in assessment of acute right-sided heart failure, such as measurement of the ventricular ejection fraction. Although such findings may be useful for assessment of treatment effectiveness, their effect on prognosis in patients with severe pulmonary embolism is debated in the literature. (C) RSNA, 2006. [less ▲]

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See detailEffects of BM-573, a thromboxane A(2) modulator on systemic hemodynamics perturbations induced by U-46619 in the pig
Tchana-Sato, Vincent ULg; Dogné, Jean-Michel ULg; Lambermont, Bernard ULg et al

in Prostaglandins & Other Lipid Mediators (2005), 78(1-4), 82-95

The aim of our study was to evaluate the effects of thromboxane A(2) (TXA(2)) agonist, U-46619, on systemic circulatory parameters in the pigs before and after administration of a novel TXA(2) receptor ... [more ▼]

The aim of our study was to evaluate the effects of thromboxane A(2) (TXA(2)) agonist, U-46619, on systemic circulatory parameters in the pigs before and after administration of a novel TXA(2) receptor antagonist and synthase inhibitor (BM-573). Twelve anesthetized pigs were randomly assigned in two groups: in Ago group (n=6), the animals received six consecutive injections of U-46619 at 30 min interval, while in Anta group (n = 6) they received an increasing dosage regimen of BM-573 10 min before each U-46619 injection. The effects of each dose of BM-573 on ex vivo platelet aggregation induced by arachidonic acid, collagen or ADP were also evaluated. Vascular properties such as characteristic impedance, peripheral resistance, compliance, arterial elastance were estimated using a windkessel model. Intravenous injections of 0.500 mg/ml of BM-573 and higher doses resulted in a complete inhibition of platelet aggregation induced by arachidonic acid. In the same conditions, BM-573 completely blocked the increase of arterial elastance, and stabilized both mean aortic blood pressure and mean systemic blood flow. In conclusion, BM-573 could therefore be a promising therapeutic approach in pathophysiological states where TXA(2) plays it main role in the increase of vascular resistance like in pathologies such as systemic hypertension. (c) 2005 Published by Elsevier Inc. [less ▲]

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See detailComputed tomographic pulmonary angiography and prognostic significance in patients with acute pulmonary embolism
Ghuysen, Alexandre ULg; Ghaye, Benoît ULg; Willems, V. et al

in Thorax (2005), 60(11), 956-961

Background: Patients with acute pulmonary embolism (APE) present with a broad spectrum of prognoses. Computed tomographic pulmonary angiography (CTPA) has progressively been established as a first line ... [more ▼]

Background: Patients with acute pulmonary embolism (APE) present with a broad spectrum of prognoses. Computed tomographic pulmonary angiography (CTPA) has progressively been established as a first line test in the APE diagnostic algorithm, but estimation of short term prognosis by this method remains to be explored. Methods: Eighty two patients admitted with APE were divided into three groups according to their clinical presentation: pulmonary infarction (n=21), prominent dyspnoea (n=29), and circulatory failure (n=32). CTPA studies included assessment of both pulmonary obstruction index and right heart overload. Haemodynamic evaluation was based on systolic aortic blood pressure, heart rate, and systolic pulmonary arterial pressure obtained non-invasively by echocardiography at the time of diagnosis of pulmonary embolism. Results: The mortality rate was 0%, 13.8% and 25% in the three groups, respectively. Neither the pulmonary obstruction index nor the pulmonary artery pressure could predict patient outcome. In contrast, a significant correlation with mortality was found using the systolic blood pressure (p<0.001) and heart rate (p<0.05), as well as from imaging parameters including right to left ventricle minor axis ratio (p<0.005), proximal superior vena cava diameter (p<0.001), azygos vein diameter (p<0.001), and presence of contrast regurgitation into the inferior vena cava (p=0.001). Analysis from logistic regression aimed at testing for mortality prediction revealed true reclassification of 89% using radiological variables. Conclusion: These results suggest that CTPA quantification of right ventricular strain is an accurate predictor of in-hospital death related to pulmonary embolism. [less ▲]

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See detailCharacterisation of an original model of myocardial infarction provoked by coronary artery thrombosis induced by ferric chloride in pig
Dogné, Jean-Michel ULg; Rolin, S.; Tchana-Sato, Vincent ULg et al

in European Heart Journal (2005, September), 26(Suppl. 1), 455-456

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See detailEffects of dobutamine on left ventriculoarterial coupling and mechanical efficiency in acutely ischemic pigs
Kolh, Philippe ULg; Lambermont, Bernard ULg; Ghuysen, Alexandre ULg et al

in Journal of Cardiovascular Pharmacology (2005), 45(2), 144-152

This study investigated the effects of dobutamine on left ventriculoarterial (VA) coupling and mechanical efficiency in acutely ischemic pigs. Experiments were performed in 12 pigs in which vascular ... [more ▼]

This study investigated the effects of dobutamine on left ventriculoarterial (VA) coupling and mechanical efficiency in acutely ischemic pigs. Experiments were performed in 12 pigs in which vascular properties, including peripheral resistance (R-2), compliance (C), and arterial elastance (E-a), were estimated with a windkessel model, and left ventricular (LV) function by the slope (E-es) of the end-systolic pressure-volume relationship (ESPVR) and stroke work (SW). VA coupling was defined as E-es/E-a, and mechanical efficiency as SW/pressure-volume area (PVA). In all animals, the left anterior descending coronary artery was ligated after basal measures. The animals were then randomly divided into 2 groups: group CTRL (n = 6) was followed for 180 minutes without other intervention, whereas group DOBU (n = 6) was infused with dobutamine (5 mug(.)kg(-1.)min(-1)) starting after T60 measures. Coronary occlusion induced a rightward shift of ESPVR and a decrease in E-es from 3.67 +/- 0.33 to 1.92 +/- 0.20 mm Hg(.)mL(-1), while E-a changed from 3.33 +/- 0.56 to 4.65 +/- 0.29 mm Hg(.)mL(-1), R-2 from 1.72 +/- 0.30 to 2.38 +/- 0.16 mm Hg(.)s(.)mL(-1), and C from 0.78 +/- 0.16 to 0.46 +/- 0.08 mL(.)mm Hg-1. This altered VA coupling from 1.22 +/- 0.11 to 0.44 +/- 0.07. SW decreased from 4056 +/- 223 to 2372 +/- 122 mm Hg(.)mL, and PVA and SW/PVA decreased from 5575 +/- 514 to 4830 +/- 3.17 mm Hg(.)mL, and from 0.76 +/- 0.04 to 0.49 +/- 0.03, respectively. In group DOBU, dobutamine restored E-es and the position of ESPVR to baseline values, while E-a decreased to 3.39 +/- 0.34 mm Hg(.)mL(-1) because of an R-2 decrease to 1.60 +/- 0.24 mm Hg(.)s(.)mL(-1). VA coupling was restored. SW and PVA increased to 3833 +/- 180 mm Hg(.)mL and to 7498 +/- 442 mm Hg(.)mL, respectively, while SW/PVA was unchanged. In ischemic pigs, dobutamine restored VA coupling through an increase in LV contractility and decrease in arterial elastance as a result of peripheral vasodilatation. However, myocardial oxygen consumption was increased, and mechanical efficiency impaired. [less ▲]

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See detailElectrical mapping of spontaneous ventricular fibrillation in acutely ischemic pigs.
Desaive, Thomas ULg; Janssen, Nathalie; Péters, Fabrise et al

in Proceedings of the 5th Belgian Day on Biomedical Engineering, 2005, Brussels (2005)

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See detailEffects of reperfusion on left ventricular hemodynamics and ventriculo-arterial coupling in acutely ischemic pigs
Lanoye, Lieve; KOLH, Philippe ULg; Rolin, Stéphanie et al

in Computer Methods in Biomechanics & Biomedical Engineering (2005), 8(suppl. 1), 169-170

Rapid restoration of coronary blood flow following a period of myocardial ischemia (due to coronary occlusion) is mandatory to preserve the cardiac muscle. Reperfusion, however, not necessarily restores ... [more ▼]

Rapid restoration of coronary blood flow following a period of myocardial ischemia (due to coronary occlusion) is mandatory to preserve the cardiac muscle. Reperfusion, however, not necessarily restores cardiac function, and cellular damage of the cardiac muscle cells following reperfusion (reperfusion injury) is well documented. The aim of this study was to investigate the effects of reperfusion on left ventricular (LV) hemodynamics and on left ventriculo-arterial (VA) coupling in acutely ischemic pigs. [less ▲]

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See detailCharacterization of an original model of myocardial infarction provoked by coronary artery thrombosis induced by ferric chloride in pig
Dogné, Jean-Michel ULg; Rolin, Stéphanie; Petein, Michel et al

in Thrombosis Research (2005), 116(5), 431-442

Background: Great advances have been made in the prevention of thrombotic disorders by developments of new pharmacological and surgical treatments. Animal models of arterial thrombosis have largely ... [more ▼]

Background: Great advances have been made in the prevention of thrombotic disorders by developments of new pharmacological and surgical treatments. Animal models of arterial thrombosis have largely contributed to the discovery and to the validation of original treatments. The purpose of the present work was to develop and validate an original model of acute myocardial infarction provoked in pig by thrombosis of the left anterior descending (LAD) coronary artery induced by topical application of ferric chloride solution. Methods and results: Myocardial infarction, resulting from an occlusive and adherent mixed thrombus formed in the LAD coronary artery, was examined at macroscopic level using dual staining technique (Evans blue dye; triphenyltetrazolium chloride) and at microscopic level using conventional histological analyses and immunohistochemical detection of desmin. Biochemical markers (troponin T and ATP), platelet reactivity and standard hemodynamic parameters (such as stroke volume, ejection fraction, stroke work and cardiac output) have also been evaluated. From these analyses, it was demonstrated that each pig developed a transmural area of irreversible damage mainly located in the anteroseptal region of the left ventricle. The more progressive development of coronary artery occlusion, as compared to an abrupt Ligation, was accompanied by a correspondingly progressive impairment in hemodynamics. Conclusion: We conclude that this original porcine model of myocardial infarction is quite close to clinical pathophysiological conditions, such as thrombus formation occurring after atherosclerotic plaque rupture. This certainly constitutes a further argument in favour of this model to assess pharmaceutical or mechanical support of an acutely ischemic heart. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailClosed-loop model of the cardiovascular system including ventricular interaction and valve dynamics: application to pulmonary embolism
Desaive, Thomas ULg; Dutron, S.; Lambermont, Bernard ULg et al

in 12th International Conference on Biomedical Engineering (2005)

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See detailPharmacological profile and therapeutic potential of BM-573, a combined thromboxane receptor antagonist and synthase inhibitor.
Ghuysen, Alexandre ULg; Dogné, Jean-Michel; Chiap, Patrice ULg et al

in Cardiovascular Drug Reviews (2005), 23(1), 1-14

BM-573 (N-terbutyl-N'-[2-(4'-methylphenylamino)-5-nitro-benzenesulfonyl]urea), a torsemide derivative, is a novel non-carboxylic dual TXA2 synthase inhibitor and receptor antagonist. The pharmacological ... [more ▼]

BM-573 (N-terbutyl-N'-[2-(4'-methylphenylamino)-5-nitro-benzenesulfonyl]urea), a torsemide derivative, is a novel non-carboxylic dual TXA2 synthase inhibitor and receptor antagonist. The pharmacological profile of the drug is characterized by a higher affinity for the thromboxane receptor than that of SQ-29548, one of the most powerful antagonists described to date, by a complete prevention of human platelet aggregation induced by arachidonic acid at a lower dose than either torsemide or sulotroban, and by a significantly prolonged closure time measured by the platelet function analyser (PFA-100). Moreover, at the concentrations of 1 and 10 microM, BM-573 completely prevented production of TXB2 by human platelets activated by 0.6 mM of arachidonic acid. BM-573 prevents rat fundus contraction induced by U-46619 but not by prostacyclin or other prostaglandins. Despite possessing a chemical structure very similar to that of a diuretic torsemide, BM-573 has no diuretic activity. BM-573 does not prolong bleeding time and, unlike some of the other sulfonylureas, has no effect on blood glucose levels. In vivo, BM-573 appears to have antiplatelet and antithrombotic activities since it reduced thrombus weight and prolonged the time to abdominal aorta occlusion induced by ferric chloride. BM-573 also relaxed rat aorta and guinea pig trachea precontracted with U-46619. In pigs, BM-573 completely antagonized pulmonary hypertensive effects of U-46619 and reduced the early phase of pulmonary hypertension in models of endotoxic shock and pulmonary embolism. Finally, BM-573 protected pigs from myocardial infarction induced by coronary thrombosis. These results suggest that BM-573 should be viewed as a promising therapeutic agent in the treatment of pulmonary hypertension and syndromes associated with platelet activation. [less ▲]

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See detailEffect of BM-573[N-terbutyl-N '-[2-(4 '-methylphenylamino)-5-nitro-benzenesulfonyl] urea], a dual thromboxane synthase inhibitor and thromboxane receptor antagonist, in a porcine model of acute pulmonary embolism
Ghuysen, Alexandre ULg; Lambermont, Bernard ULg; Dogné, Jean-Michel ULg et al

in Journal of Pharmacology and Experimental Therapeutics (The) (2004), 310(3), 964-972

The aim of this study was to evaluate the effect of BM-573 [N-terbutyl-N'-[2-(4'-methylphenylamino)-5-nitro-benzenesulfonyl] urea], a dual thromboxane A(2) synthase inhibitor and receptor antagonist, on ... [more ▼]

The aim of this study was to evaluate the effect of BM-573 [N-terbutyl-N'-[2-(4'-methylphenylamino)-5-nitro-benzenesulfonyl] urea], a dual thromboxane A(2) synthase inhibitor and receptor antagonist, on the hemodynamic response to acute pulmonary embolism. Six anesthetized pigs were infused with placebo ( placebo group) and compared with six other pigs receiving a continuous infusion of BM-573 ( BM group). Pulmonary embolization with 0.3 g/kg autologous blood clots was carried out 30 min after the start of the infusion. Right ventricular pressure-volume loops were recorded using a conductance catheter, and end-systolic ventricular elastance was periodically assessed by varying right ventricular preload. Pulmonary vascular properties were studied by use of a four-element wind-kessel model. Hemodynamic data, including assessment of right ventricular-arterial coupling, were collected at baseline and every 30 min for 4 h. Blood samples were collected to assess gas exchange, thromboxane A(2), and prostacyclin plasma levels and to evaluate platelet aggregation. Mean pulmonary arterial pressure in the placebo group increased significantly more than in the BM group, mainly because of an additional increase in pulmonary vascular resistance. Arterial and end-systolic ventricular elastances increased also more in the placebo group, whereas right ventricular efficiency decreased. BM-573 prevented both platelet aggregation induced by U-46619 (9,11-dideoxy-11alpha, 9alpha-epoxymethanoprostaglandin F-2alpha) or by arachidonic acid, and thromboxane A(2) overproduction, whereas prostacyclin liberation was preserved. Oxygenation, however, was not significantly improved. We conclude that in this animal model of acute pulmonary embolism, infusion of BM-573 reduced pulmonary vasoconstriction. As a result, right ventricular-vascular coupling values were maintained at a maximal efficiency level. [less ▲]

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See detailComparison of the effects of propofol and pentobarbital on left ventricular adaptation to an increased afterload
Kolh, Philippe ULg; Lambermont, Bernard ULg; Ghuysen, Alexandre ULg et al

in Journal of Cardiovascular Pharmacology (2004), 44(3), 294-301

The purpose of this study was to compare the hemodynamic effects of pentobarbital and propofol and their effects on cardiovascular adaptation to an abrupt increase in left ventricular afterload ... [more ▼]

The purpose of this study was to compare the hemodynamic effects of pentobarbital and propofol and their effects on cardiovascular adaptation to an abrupt increase in left ventricular afterload. Experiments were performed in 12 open-chest pigs instrumented for measurement of aortic pressure and flow, and left ventricular pressure and volume. In one group (n = 6), anesthesia was obtained with sodium pentobarbital (3 mg x kg(-1) x h(-1)), and, in the second group B (n = 6), with propofol (10 mg x kg(-1) x h(-1)). Both groups received sufentanil (0.5 microg x kg(-1) x h(-1)) and pancuronium bromide (0.1 mg x kg(-1)). Left ventricular function was assessed by the slope of end-systolic pressure-volume relationship and stroke work. After baseline recordings, left ventricular afterload was increased by aortic banding. The cardiovascular adaptations triggered by the aortic banding, such as tachycardia, vasoconstriction, and augmentation of myocardial contractility were prevented with propofol, suggesting interference with the baroreflex. Increase in left ventricular afterload decreased mechanical efficiency, regardless of anesthetic agent. These results showed that pentobarbital at 3 mg x kg(-1) x h(-1) has less deleterious hemodynamic effects than propofol at 10 mg x kg(-1) x h(-1). [less ▲]

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