Abstract:
BACKGROUND:Resting cardiac function does not necessarily affect exercise capacity. However, to determine whether it affects early dynamics of oxygen uptake (VO2) during exercise, we measured VO2 during a constant work rate and during incremental exercise testing in patients with a history of myocardial infarction. VO2 kinetics and exercise capacity were compared between patients with relatively high left ventricular ejection fractions (LVEF > or = 35%, group 1) and those with lower ejection fractions (LVEF < 35%, group 2). METHODS AND RESULTS:Forty patients with a history of prior myocardial infarction (age, 57 +/- 10 years) were monitored during 6 minutes of moderate constant work rate testing (40 +/- 8 W) and during symptom-limited incremental exercise testing with a cycle ergometer. VO2 was calculated from respired gas analysis on a breath-by-breath basis. Cardiac output determinations were made with a computerized cadmium telluride detector every 10 seconds during exercise. The VO2 time constant during constant work rate exercise was slower in group 2 (58.0 +/- 7.6 seconds) compared with group 1 (45.8 +/- 10.5 seconds, P = .0002), indicating slower kinetics in group 2. The time constant for the rise in cardiac output during exercise was also slower in patients with lower EFs (63.0 +/- 12.8 versus 50.0 +/- 12.2 seconds). However, there were no differences in exercise capacity parameters, such as the VO2 or cardiac output at peak exercise, obtained during incremental exercise testing among the two groups. CONCLUSIONS:The prolonged time constant of VO2, which is primarily determined during early parts of exercise, reflects delayed cardiac output response in patients with severely impaired LV function. The time constant of VO2 during submaximal constant work rate exercise can be used as a sensitive and discriminant measure of impaired cardiac reserve in these patients.
journal_name
Circulationjournal_title
Circulationauthors
Koike A,Hiroe M,Adachi H,Yajima T,Yamauchi Y,Nogami A,Ito H,Miyahara Y,Korenaga M,Marumo Fdoi
10.1161/01.cir.90.5.2324subject
Has Abstractpub_date
1994-11-01 00:00:00pages
2324-32issue
5eissn
0009-7322issn
1524-4539journal_volume
90pub_type
杂志文章相关文献
CIRCULATION文献大全abstract::The two-dimensional echocardiographic features of three patients with congenital aneurysms of the left atrium are described. The aneurysm arose from the left atrial appendage in two patients and from the posterior left atrial wall in one. The aneurysms were characterized by their origin from an otherwise normal left a...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.66.5.1065
更新日期:1982-11-01 00:00:00
abstract::A transvenous lead system for implantable defibrillators would obviate a surgical thoracotomy and reduce the morbidity and mortality associated with implantation. We evaluated the clinical performance of a new nonthoracotomy lead system that included a defibrillation lead in the coronary sinus. At the time of defibril...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.85.1.196
更新日期:1992-01-01 00:00:00
abstract:BACKGROUND:The specific role of apoptosis in human atherosclerosis remains unknown. During apoptotic cell death, phosphatidylserine exposure on the cell surface confers a high tissue-factor (TF)-dependent procoagulant activity. METHODS AND RESULTS:In this study, we examined the role of apoptotic cell death in the prom...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.99.3.348
更新日期:1999-01-26 00:00:00
abstract:BACKGROUND:Passive ventricular constraint provides external cardiac support to reduce left ventricular (LV) wall stress and myocardial stretch, which are primary determinants of LV remodeling. Altered wall strain results in cytokine and reactive oxygen species production, which, in turn, stimulates apoptosis and extrac...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/CIRCULATIONAHA.105.001578
更新日期:2006-07-04 00:00:00
abstract::Systemic, renal and splanchnic hemodynamics, intravascular volume, circulating catecholamine levels and plasma renin activity were compared in 39 patients with borderline hypertension and 28 normotensive subjects, who were less than 5% (n = 42, lean patients) or more than 40% overweight (n = 25, obese patients). Lean ...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.66.1.55
更新日期:1982-07-01 00:00:00
abstract::Syncope and sudden death occurs in certain purebred Pug dogs which have been found to have intermittent sinus pauses and paroxysmal second degree heart block on electrocardiographic (ECG) study. We have established a colony of such dogs to study this problem and here report the results of histological examination of t...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.52.6.1152
更新日期:1975-12-01 00:00:00
abstract:BACKGROUND:Although implantable cardioverter-defibrillator (ICD) therapy reduces mortality in moderately symptomatic heart failure patients with an ejection fraction journal_title:Circulation pub_type: 杂志文章,随机对照试验 doi:10.1161/CIRCULATIONAHA.108.816884 更新日期:2009-09-08 00:00:00
abstract::In seven patients who underwent Fontan procedures but in whom no valves were inserted, dynamics of right heart flow were evaluated with the use of a catheter-tipped velocity transducer, pulsed Doppler echocardiography, and angiocardiography. Right atrial (RA) contraction caused a forward flow to the pulmonary artery (...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.69.2.306
更新日期:1984-02-01 00:00:00
abstract::Correlates of high-density lipoprotein (HDL) cholesterol levels were studied in 4756 white males and females ages 20-59 years examined during a population survey conducted by 10 North American Lipid Research Clinics. Multivariable analysis was used to assess the relation of social, demographic, physical and behavioral...
journal_title:Circulation
pub_type: 杂志文章
doi:
更新日期:1980-11-01 00:00:00
abstract::A reduced rate of diastolic closure of the anterior mitral leaflet has been shown to occur in mitral stenosis, primary pulmonary hypertension, and in cases with reduced left ventricular compliance. Posterior notion of the posterior mitral leaflet in diastole has been the distinguishing feature to rule out the diagnosi...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.51.3.511
更新日期:1975-03-01 00:00:00
abstract:BACKGROUND:An inverse association between height and risk of coronary heart disease (CHD) has been reported in several case-control and cohort studies, but the reasons for the association remain uncertain. We evaluated this association among 22,071 male physicians, a population homogeneous for high educational attainme...
journal_title:Circulation
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1161/01.cir.88.4.1437
更新日期:1993-10-01 00:00:00
abstract:BACKGROUND:Radiofrequency catheter ablation is the treatment of choice for patients with paroxysmal supraventricular tachycardias refractory to medical therapy. However, in symptomatic patients with inappropriate sinus tachycardia resistant to drug therapy, catheter ablation of the His' bundle with permanent pacemaker ...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.92.10.2919
更新日期:1995-11-15 00:00:00
abstract:BACKGROUND:Chronic heart failure remains a major cause of mortality and morbidity. The role of antithrombotic therapy in patients with chronic heart failure has long been debated. The objective of this study was to determine the optimal antithrombotic agent for heart failure patients with reduced ejection fractions who...
journal_title:Circulation
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1161/CIRCULATIONAHA.108.801753
更新日期:2009-03-31 00:00:00
abstract:BACKGROUND:The causes of metabolic syndrome (MS), which may be a precursor of coronary disease, are uncertain. We hypothesize that disturbances in neuroendocrine and cardiac autonomic activity (CAA) contribute to development of MS. We examine reversibility and the power of psychosocial and behavioral factors to explain...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.0000038364.26310.bd
更新日期:2002-11-19 00:00:00
abstract:BACKGROUND:Little is known about the behavior with regard to restenosis of multiple lesions within the same patient treated with intracoronary stenting. Our objective was to test the hypothesis that there is an intrapatient dependence of restenosis between lesions. METHODS AND RESULTS:Quantitative analysis was carried...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.97.24.2396
更新日期:1998-06-23 00:00:00
abstract:BACKGROUND:The number of CD4(+)CD28(null) (CD28(null)) T cells, a unique subset of T lymphocytes with proinflammatory and cell-lytic phenotype, increases markedly in patients with acute coronary syndrome (ACS). ACS patients harboring high numbers of CD28(null) T cells have increased risk of recurrent severe acute coron...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/CIRCULATIONAHA.114.013710
更新日期:2015-02-24 00:00:00
abstract:BACKGROUND:By the formation of cGMP, nitric oxide (NO)-sensitive guanylyl cyclase (GC) acts as the effector for the signaling molecule NO and mediates the relaxation of vascular smooth muscle and the inhibition of platelet aggregation. The compounds YC-1 and BAY 41-2272 are regarded as NO-independent activators and sen...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.CIR.0000126286.47618.BD
更新日期:2004-04-13 00:00:00
abstract:BACKGROUND:Fetal tachycardia may cause hydrops fetalis and lead to fetal death. No unanimity of opinion exists regarding the optimum treatment. This study evaluates our experience with transplacental sotalol therapy to treat fetal tachycardias in terms of safety and efficacy. METHODS AND RESULTS:The charts of 21 patie...
journal_title:Circulation
pub_type: 杂志文章,多中心研究
doi:10.1161/01.cir.101.23.2721
更新日期:2000-06-13 00:00:00
abstract:BACKGROUND:Endothelin (ET), a coronary vasoconstrictor, mediates its activity through the specific receptors ET-A and ET-B, which may demonstrate different activity under pathophysiological conditions. Thoracic inferior vena cava constriction (TIVCC) is an experimental model of congestive heart failure that is characte...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.93.4.646
更新日期:1996-02-15 00:00:00
abstract:BACKGROUND:Angiotensin-converting enzyme (ACE) inhibition potentiates the tissue-type plasminogen activator (t-PA) response to exogenous bradykinin. This study tested the hypothesis that ACE inhibition increases endothelial t-PA release through endogenous bradykinin. METHODS AND RESULTS:We measured the effect of intra...
journal_title:Circulation
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1161/01.cir.0000046268.59922.a4
更新日期:2003-02-04 00:00:00
abstract:BACKGROUND:The role of angiotensin as a vasoconstrictor is well established. Lately, several other actions of this hormone on vascular smooth muscle (VSM) cells have been recognized including the induction of hypertrophy and/or DNA synthesis. Platelet-derived growth factor (PDGF), a mitogen recently shown to increase p...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.90.1.362
更新日期:1994-07-01 00:00:00
abstract:BACKGROUND:Chronic thromboembolic pulmonary hypertension (CTEPH) is a disorder characterized by pulmonary arterial hypertension as a consequence of organized thrombotic material in the central pulmonary arteries. Incomplete resolution of acute pulmonary emboli is believed to be pathogenically important; however, the me...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.86.4.1241
更新日期:1992-10-01 00:00:00
abstract:BACKGROUND:Chronic inhibition of endothelial nitric oxide (NO) synthesis by the administration of N:(omega)-nitro-L-arginine methyl ester (L-NAME) to rats induces early vascular inflammatory changes (monocyte infiltration into coronary vessels and monocyte chemoattractant protein-1 [MCP-1] expression) as well as subseq...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.102.18.2243
更新日期:2000-10-31 00:00:00
abstract:BACKGROUND:The cross-talk between vascular endothelial growth factor (VEGF)-A, angiopoietin (Ang), and VE-cadherin coregulates endothelial cell (EC) survival. Cardiac expression of VEGF-A but not its receptor KDR is blunted in dilated cardiomyopathy (DCM). Whether VE-cadherin/Ang function is affected in DCM is unknown....
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.CIR.0000091085.12422.19
更新日期:2003-09-30 00:00:00
abstract:BACKGROUND:Patients with congenital heart disease (CHD) and heterotaxy show high postsurgical morbidity/mortality, with some developing respiratory complications. Although this finding is often attributed to the CHD, airway clearance and left-right patterning both require motile cilia function. Thus, airway ciliary dys...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/CIRCULATIONAHA.111.079780
更新日期:2012-05-08 00:00:00
abstract::Background: In ISCHEMIA, an initial invasive strategy did not significantly reduce rates of cardiovascular events or all-cause mortality compared with a conservative strategy in patients with stable ischemic heart disease and moderate/severe myocardial ischemia. The most frequent component of composite cardiovascular ...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/CIRCULATIONAHA.120.047987
更新日期:2020-12-03 00:00:00
abstract:BACKGROUND:Thrombin plays a role in mediating ischemic injury and cardiac arrhythmias, but the mechanisms involved are poorly understood. Because voltage-gated sodium channels (VGSCs) have not previously been considered, putative effects of thrombin on VGSC function were investigated in human isolated cardiomyocytes. ...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.0000034510.64828.96
更新日期:2002-10-15 00:00:00
abstract::Conventional wall motion analysis of contrast ventriculograms assesses only that part of the wall that is tangential to the x-ray beam. To assess regional left ventricular function in three dimensions, a new computerized method based on densitometric analysis of digital subtraction left ventriculograms was developed a...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.77.2.457
更新日期:1988-02-01 00:00:00
abstract::Diffuse coronary artery disease is frequently untreatable by coronary artery bypass or angioplasty. Many such "no-option" patients have been subjects for trials of angiogenesis using growth factor manipulation or laser injury. We think these novel revascularization strategies are limited by insufficient inflow to puta...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/01.cir.103.21.2539
更新日期:2001-05-29 00:00:00
abstract:BACKGROUND:Prosthetic valve thrombosis during pregnancy is life-threatening for mother and fetus, and the treatment of this complication is unclear. Cardiac surgery in pregnancy is associated with very high maternal and fetal mortality and morbidity. Thrombolytic therapy has rarely been used in these patients. The aim ...
journal_title:Circulation
pub_type: 杂志文章
doi:10.1161/CIRCULATIONAHA.113.001145
更新日期:2013-07-30 00:00:00