Abstract:
:Ventricular repolarization was analyzed by measuring epicardial potential distributions in intact dogs with single or multiple ectopic foci and a minimum at the terminal site(s) of excitation. During the latter half of the T wave the distributions became more complex, and two maxima evolved from the initial one at each ectopic site. The measured epicardial potentials were simulated by means of a model of ST-T wave events that is suitable for study of single and multiple ectopic beats with fusion, a a model we call 'SI model.' Intracellular potentials around the ventricles during repolarization were calculated from measured excitation sequences and known action potential shapes. The extracellular potentials around the ventricles were computed from the intracellular ones by a simplified ventricular geometry. The satisfactory agreement between the theoretical and measured extracellular potential distribution shows that the complex changes which occur throughout the ST-T wave are predicted well on the basis of changes in the intracellular potential distributions. In contrast to the well known lability of the T wave from beat, the results show that for any single beat the events of repolarization proceed in an entirely repeatable and deterministic fashion. The results present a way to directly represent cardiac extracellular events during the ST-T wave, a method analogous to the use of isochromes during QRS, and they imply that in the future it will by possible to achieve a more precise quantitative understanding of the events of the ST-T wave than thus far has been possible for QRS.
journal_name
Circ Resjournal_title
Circulation researchauthors
Spach MS,Barr RCdoi
10.1161/01.res.39.4.475subject
Has Abstractpub_date
1976-10-01 00:00:00pages
475-87issue
4eissn
0009-7330issn
1524-4571journal_volume
39pub_type
杂志文章abstract::Experiments were designed to determine the contribution of endothelial cells to the heterogeneous behavior of the arterial and venous wall. Rings of canine femoral, pulmonary, saphenous, and splenic arteries and veins, with and without endothelium, were mounted for isometric tension recording in Krebs-Ringer bicarbona...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.51.4.439
更新日期:1982-10-01 00:00:00
abstract::We examined whether albumin-derived advanced glycosylation end products (AGEs) downregulate the expression of endothelial nitric oxide synthase (NOS). Significant reductions in NOS activity and cGMP levels in bovine aortic endothelial cells were observed when exposed to different concentrations of albumin-derived AGEs...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.86.3.e50
更新日期:2000-02-18 00:00:00
abstract::Originally identified as moderate biological modifiers, microRNAs have recently emerged as powerful regulators of diverse cellular processes with especially important roles in disease and tissue remodeling. The rapid pace of studies on microRNA regulation and function necessitates the development of suitable technique...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.110.227496
更新日期:2011-01-21 00:00:00
abstract::The purpose of this study was to determine whether a cyclic adenosine 3',5'-monophosphate-dependent process can be involved in the regulation of vascular smooth muscle alpha 1-adrenergic receptor responsiveness. Experiments were performed in cultured rabbit aortic smooth muscle cells which were characterized previousl...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.58.2.292
更新日期:1986-02-01 00:00:00
abstract::We determined whether local bradykinin production modulates cardiac adrenergic activity. Depolarization of guinea pig heart sympathetic nerve endings (synaptosomes) with 1 to 100 mmol/L K+ caused the release of endogenous norepinephrine (10% to 50% above basal level). This release was exocytotic, because it depended o...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.81.5.774
更新日期:1997-11-01 00:00:00
abstract::The direct-current magnetocardiogram, which shows the T-Q (baseline) shift, is used to clarify the cause of S-T depression induced by stress testing in the human heart. Measurements are made of the amount of baseline shift associated with the S-T depression. Results are presented of a well-documented patient, with typ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.53.2.274
更新日期:1983-08-01 00:00:00
abstract::The synthesis of an angiotensin II (A II) antagonist, sarcosyl1-cysteinyl(S-methyl)8-angiotensin II [Sar1-Cys(Me)8-A II], showing partial organ selectivity and properties of a noncompetitive antagonist, is described. The compound was found to be an extremely potent antagonist on vascular smooth muscle both in vitro (p...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.46.5.720
更新日期:1980-05-01 00:00:00
abstract::To determine the effects of aging on the human myocardium, 67 hearts were obtained from individuals who died from causes other than cardiovascular disease. The age interval examined was 17-90 years. Regression analysis demonstrated that the aging process was characterized by a loss of 38 million and 14 million myocyte...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.6.1560
更新日期:1991-06-01 00:00:00
abstract::Tissue factor (TF) is a low-molecular-weight glycoprotein that initiates the extrinsic clotting cascade and is considered a major regulator of arterial thrombogenicity. TF pathway inhibitor (TFPI) is a major physiological inhibitor of TF-initiated coagulation. The aim of this study was to define the complex interplay ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh1301.092508
更新日期:2001-07-06 00:00:00
abstract::To study whether atrial fibrillation might produce local changes in the atrium which could facilitate the tendency of this arrhythmia to become chronic and self-perpetuating, we compared the effect of atrial fibrillation, atrial pacing, and acute volume loading on the perfusion and oxygen consumption of the atrium in ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.51.2.205
更新日期:1982-08-01 00:00:00
abstract::Angiotensin II and its metabolites, [des-Asp-1]-angiotensin II (angiotensin III), [des-(Asp-1,Arg-2)]angiotensin II, and [des-(Asp-1,Arg-2,val-3)]angiotensin II, were measured in arterial and venous plasma from normal rats. Paper chromatography was used to separate the peptides which were measured with a radioimmunoas...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.38.6.122
更新日期:1976-06-01 00:00:00
abstract::Desmosomes and gap junctions are distinct structural components of the cardiac intercalated disc. Here, we asked whether the presence of plakophilin (PKP)2, a component of the desmosome, is essential for the proper function and distribution of the gap junction protein connexin (Cx)43. We used RNA silencing technology ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.107.154252
更新日期:2007-09-28 00:00:00
abstract::Available data demonstrate that oxygen free radicals and derived reactive species of oxygen are produced during myocardial ischemia as well as upon reperfusion of the ischemic tissue. The present study was designed to determine if polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), with its extended plasma ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.64.4.665
更新日期:1989-04-01 00:00:00
abstract::We investigated whether the heart, like other mammalian organs, possesses internal clocks, and, if so, whether pressure overload-induced hypertrophy alters the clock mechanism. Clock genes are intrinsically maintained, as shown by rhythmic changes even in single cells. Clocks are believed to confer a selective advanta...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh1101.091190
更新日期:2001-06-08 00:00:00
abstract::Rationale: The overuse of antibiotics has been an important clinical issue, and antibiotic exposure is linked to alterations in gut microbiota, which has been related to risks of various chronic diseases such as cardiovascular disease and cancer. Also, duration of antibiotic exposure may be a risk factor of premature ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.119.315279
更新日期:2020-01-31 00:00:00
abstract::Although the molecular effectors of apoptotic cell death have been largely annotated over the past 30 years, leading to a strong biological understanding of this process and its importance in cell biology, cell death through necrosis has only recently been accepted as a similarly regulated process with definable molec...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.116.305421
更新日期:2015-05-22 00:00:00
abstract::The purpose of this study was to examine by freeze-fracture the ultrastructure of intercellular junctions between mouse pulmonary endothelial and epithelial cells, and to relate this fine structure to that deduced from previous physiological and ultrastructural studies using tracer techniques. Junctions between capill...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.38.5.404
更新日期:1976-05-01 00:00:00
abstract:RATIONALE:Although the fibroblast growth factor (FGF) signaling axis plays important roles in heart development, the molecular mechanism by which the FGF regulates cardiogenesis is not fully understood. OBJECTIVE:To investigate the mechanism by which FGF signaling regulates cardiac progenitor cell differentiation. ME...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.255950
更新日期:2012-02-17 00:00:00
abstract::p21ras is a potent regulator of myogenic cell growth and differentiation. It has been implicated as playing a major role in the genesis of cardiac hypertrophy. We examined the effect of Ras overexpression on human atrial natriuretic peptide (hANP) gene expression, a marker of hypertrophy, in neonatal rat ventricular m...
journal_title:Circulation research
pub_type: 杂志文章
doi:
更新日期:1997-04-01 00:00:00
abstract::To investigate the spread of contraction in the rabbit ear artery, changes in segment diameter were measured after local stimulation. No spread of contraction was produced by direct current or local application of norepinephrine (NE). Repetitive electrical stimulation caused contraction which spread far from the point...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.49.3.600
更新日期:1981-09-01 00:00:00
abstract::Postnatal development of the mammalian heart is associated with changes in the population of isoforms of the thin filament proteins. We correlated the change in thin filament proteins, which occur in rabbit hearts between 5 days and 22 days of age, with changes in Ca2+ dependence of myofibrillar ATPase activity, force...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.66.5.1204
更新日期:1990-05-01 00:00:00
abstract::We have previously demonstrated that urokinase-type plasminogen activator (uPA) is highly expressed in the aneurysmal segment of the abdominal aorta (AAA) in apolipoprotein E-deficient (apoE-/-) mice treated with angiotensin II (Ang II). In the present study, we tested the hypothesis that uPA is essential for AAA form...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000061571.49375.E1
更新日期:2003-03-21 00:00:00
abstract::To isolate specific markers of both differentiated and proliferating vascular smooth muscle cells (VSMCs), we used the technique of differential cDNA screening using RNA from cultured rat aortic VSMCs. The tissue specificity of expression of all of the cDNAs isolated was determined by Northern analysis. We isolated se...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.73.1.193
更新日期:1993-07-01 00:00:00
abstract::Cardiomyocyte hypertrophy is transcriptionally controlled and inhibited by glycogen synthase kinase 3beta (GSK3beta). Myocardin is a muscle-specific transcription factor with yet unknown relation to hypertrophy. Therefore, we investigated whether myocardin is sufficient to induce cardiomyocyte hypertrophy and whether ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000184684.88750.FE
更新日期:2005-09-30 00:00:00
abstract:RATIONALE:Lymphatic vasculature constitutes a second vascular system essential for immune surveillance and tissue fluid homeostasis. Maturation of the hierarchical vascular structure, with a highly branched network of capillaries and ducts, is crucial for its function. Environmental cues mediate the remodeling process,...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.116.308825
更新日期:2017-04-14 00:00:00
abstract::The major goal of this study was to determine the interactions of VLDL surface and core lipids with the artery wall. We first demonstrated in vitro that surface lipid in VLDL could be traced using the phospholipid-like fluorescent probe 1,1'-dioctadecyl-3,3, 3',3'-tetramethyl-indocarbocyanine (DiI). The core of VLDL p...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.86.7.768
更新日期:2000-04-14 00:00:00
abstract::The identification of nitric oxide ((*)NO) as an endogenously produced free radical mediator of endothelial-dependent relaxation and host defense has fundamentally changed concepts of cell signal transduction. Ligand-receptor oriented paradigms of cell signaling were originally centered on the concept of a high affini...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.109.202077
更新日期:2009-09-11 00:00:00
abstract::Matrix metalloproteinases (MMPs) and, in particular, MMP-9 are important for smooth muscle cell (SMC) migration into the intima. In this study, we sought to determine whether MMP-9 is critical for SMC migration and for the formation of a neointima by using mice in which the gene was deleted (MMP-9(-/-) mice). A denudi...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000040420.17366.2e
更新日期:2002-11-01 00:00:00
abstract::The transcriptional regulation of cardiovascular development requires precise spatiotemporal control of gene expression, and heterozygous mutations of transcription factors have frequently been implicated in human cardiovascular malformations. A novel mechanism involving posttranscriptional regulation by small, noncod...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.108.192872
更新日期:2009-03-27 00:00:00
abstract::Endothelin-1 (ET-1) and endothelin-3 (ET-3) produced positive inotropic effects on electrically stimulated left atria and increased the frequency of spontaneously beating right atria of adult rats. The potency of the inotropic effect of ET-1 was greater than that of ET-3, but the potencies of the chronotropic effects ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.69.4.918
更新日期:1991-10-01 00:00:00