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9842. A noninvasive imaging modality for cardiac arrhythmias.
The last decade witnessed an explosion of information regarding the genetic, molecular, and mechanistic basis of heart disease. Translating this information into clinical practice requires the development of novel functional imaging modalities for diagnosis, localization, and guided intervention. A noninvasive modality for imaging cardiac arrhythmias is not yet available. Present electrocardiographic methods cannot precisely localize a ventricular tachycardia (VT) or its key reentrant circuit components. Recently, we developed a noninvasive electrocardiographic imaging modality (ECGI) that can reconstruct epicardial electrophysiological information from body surface potentials. Here, we extend its application to image reentrant arrhythmias.
9843. Angiotensin II induces leukocyte-endothelial cell interactions in vivo via AT(1) and AT(2) receptor-mediated P-selectin upregulation.
作者: L Piqueras.;P Kubes.;A Alvarez.;E O'Connor.;A C Issekutz.;J V Esplugues.;M J Sanz.
来源: Circulation. 2000年102卷17期2118-23页
Angiotensin II (Ang II) plays a critical role in the development of vascular lesions in hypertension, atherosclerosis, and several renal diseases. Because Ang II may contribute to the leukocyte recruitment associated with these pathological states, the aim of the present study was to assess the role of Ang II in leukocyte-endothelial cell interactions in vivo.
9844. Single-beat estimation of end-systolic elastance using bilinearly approximated time-varying elastance curve.
作者: T Shishido.;K Hayashi.;K Shigemi.;T Sato.;M Sugimachi.;K Sunagawa.
来源: Circulation. 2000年102卷16期1983-9页
Although left ventricular end-systolic elastance (E(es)) has often been used as an index of contractility, technical difficulties in measuring volume and in changing loading conditions have made its clinical application somewhat limited. By approximating the time-varying elastance curve by 2 linear functions (isovolumic contraction phase and ejection phase) and estimating the slope ratio of these, we developed a method to estimate E(es) on a single-beat basis from pressure values, systolic time intervals, and stroke volume.
9845. Tissue Doppler imaging consistently detects myocardial contraction and relaxation abnormalities, irrespective of cardiac hypertrophy, in a transgenic rabbit model of human hypertrophic cardiomyopathy.
作者: S F Nagueh.;H A Kopelen.;D S Lim.;W A Zoghbi.;M A Quiñones.;R Roberts.;A J Marian.
来源: Circulation. 2000年102卷12期1346-50页
Hypertrophic cardiomyopathy (HCM) is diagnosed clinically by the presence of left ventricular hypertrophy (LVH). However, LVH is absent in a significant number of genotype-positive patients. Because myocyte dysfunction and disarray are the primary abnormalities in HCM, we reasoned that tissue Doppler imaging could identify contraction and relaxation abnormalities, irrespective of hypertrophy, in a transgenic rabbit model of human HCM.
9847. Perinatal changes in myocardial metabolism in lambs.
作者: B Bartelds.;H Knoester.;G B Smid.;J Takens.;G H Visser.;L Penninga.;F R van der Leij.;G C Beaufort-Krol.;W G Zijlstra.;H S Heymans.;J R Kuipers.
来源: Circulation. 2000年102卷8期926-31页
Lactate accounts for a third of myocardial oxygen consumption before and in the first 2 weeks after birth. It is unknown how the remainder of myocardial oxygen is consumed. Glucose is thought to be important before birth, whereas long-chain fatty acids (LC-FA) are the prime substrate for the adult. However, the ability of the myocardium of the newborn to use LC-FA has been doubted.
9849. Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro.
作者: C L de Korte.;G Pasterkamp.;A F van der Steen.;H A Woutman.;N Bom.
来源: Circulation. 2000年102卷6期617-23页
The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial wall. The aim of this study was to investigate the capability of intravascular elastography to characterize different plaque components.
9850. Coronary artery fly-through using electron beam computed tomography.
作者: P M van Ooijen.;M Oudkerk.;R J van Geuns.;B J Rensing.;P J de Feyter.
来源: Circulation. 2000年102卷1期E6-10页
Virtual reality techniques have recently been introduced into clinical medicine. This study examines the possibility of coronary artery fly-through using a dataset obtained by noninvasive coronary angiography with contrast-enhanced electron-beam computed tomography.
9851. American College of Cardiology/American Heart Association Expert Consensus document on electron-beam computed tomography for the diagnosis and prognosis of coronary artery disease.
作者: R A O'Rourke.;B H Brundage.;V F Froelicher.;P Greenland.;S M Grundy.;R Hachamovitch.;G M Pohost.;L J Shaw.;W S Weintraub.;W L Winters.;J S Forrester.;P S Douglas.;D P Faxon.;J D Fisher.;G Gregoratos.;J S Hochman.;A M Hutter.;S Kaul.;M J Wolk.
来源: Circulation. 2000年102卷1期126-40页 9852. Time course and mechanism of myocardial catecholamine release during transient ischemia in vivo.
作者: T W Lameris.;S de Zeeuw.;G Alberts.;F Boomsma.;D J Duncker.;P D Verdouw.;A J Veld.;A H van Den Meiracker.
来源: Circulation. 2000年101卷22期2645-50页
Elevated concentrations of norepinephrine (NE) have been observed in ischemic myocardium. We investigated the magnitude and mechanism of catecholamine release in the myocardial interstitial fluid (MIF) during ischemia and reperfusion in vivo through the use of microdialysis.
9853. Myofilament calcium regulation in human myocardium.
作者: R J Hajjar.;R H Schwinger.;U Schmidt.;C S Kim.;D Lebeche.;A A Doye.;J K Gwathmey.
来源: Circulation. 2000年101卷14期1679-85页
We investigated whether decreased myofilament calcium contractile activation may, in part, contribute to heart failure.
9854. Monoclonal anti-CD18 antibody prevents transcellular biosynthesis of cysteinyl leukotrienes in vitro and in vivo and protects against leukotriene-dependent increase in coronary vascular resistance and myocardial stiffness.
作者: A Sala.;G Rossoni.;F Berti.;C Buccellati.;A Bonazzi.;J Maclouf.;G Folco.
来源: Circulation. 2000年101卷12期1436-40页
Cysteinyl leukotrienes (cys-LT) can constrict small and large vessels and increase vascular permeability. Formation of cys-LT arising from polymorphonuclear leukocytes (PMNL) and endothelial cell cooperation (transcellular synthesis) led to the hypothesis that PMNL-endothelial cell adhesion may represent a key step toward the formation of vasoactive cys-LT.
9855. Troglitazone improves recovery of left ventricular function after regional ischemia in pigs.
This study determined whether treatment of normal (nondiabetic) pigs with the insulin-sensitizing agent troglitazone improves recovery of left ventricular (LV) function after acute ischemia and whether such effects are associated with altered myocardial substrate metabolism.
9857. Akt promotes survival of cardiomyocytes in vitro and protects against ischemia-reperfusion injury in mouse heart.
IGF-1 has been shown to protect myocardium against death in animal models of infarct and ischemia-reperfusion injury. In the present study, we investigated the role of the IGF-1-regulated protein kinase Akt in cardiac myocyte survival in vitro and in vivo.
9858. Restoration of contractile function in isolated cardiomyocytes from failing human hearts by gene transfer of SERCA2a.
作者: del MonteF.;S E Harding.;U Schmidt.;T Matsui.;Z B Kang.;G W Dec.;J K Gwathmey.;A Rosenzweig.;R J Hajjar.
来源: Circulation. 1999年100卷23期2308-11页
Failing human myocardium is characterized by abnormal relaxation, a deficient sarcoplasmic reticulum (SR) Ca(2+) uptake, and a negative frequency response, which have all been related to a deficiency in the SR Ca(2+) ATPase (SERCA2a) pump.
9859. Reference chart derived from post-stent-implantation intravascular ultrasound predictors of 6-month expected restenosis on quantitative coronary angiography.
Intravascular ultrasound (IVUS)-guided stent implantation and the availability of a reference chart to predict the expected in-stent restenosis rate based on operator-dependent IVUS parameters may interactively facilitate optimal stent placement. The use of IVUS guidance protects against undue risks of dissection or rupture.
9860. Preserved endothelium-dependent vasodilation in coronary segments previously treated with balloon angioplasty and intracoronary irradiation.
作者: M Sabaté.;I P Kay.;W J van Der Giessen.;A Cequier.;J M Ligthart.;J A Gómez-Hospital.;S G Carlier.;V L Coen.;J P Marijnissen.;A J Wardeh.;P C Levendag.;P W Serruys.
来源: Circulation. 1999年100卷15期1623-9页
Abnormal endothelium-dependent coronary vasomotion has been reported after balloon angioplasty (BA), as well as after intracoronary radiation. However, the long-term effect on coronary vasomotion is not known. The aim of this study was to evaluate the long-term vasomotion of coronary segments treated with BA and brachytherapy.
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