Abstract:
OBJECTIVES:The purpose of this review is to assemble the widely dispersed information about cardiac alternans and to categorize the types and mechanisms of alternans, their clinical manifestations and possible therapeutic implications. BACKGROUND:The phenomena of mechanical and electrical alternans have been of continuing interest to both physiologists and clinicians. Recent studies have enhanced this interest because of the reported association of alternans with experimental myocardial ischemia and cardiac arrhythmias. METHODS:The review formulates concepts based on extensive review of published studies and personal observations. RESULTS:Cardiac alternans has been subdivided into the following four categories: 1) mechanical, 2) electrical, 3) in association with myocardial ischemia, and 4) in association with cardiac motion. Mechanical alternans can be explained by hemodynamic or inotropic alterations, or both. Mechanical alternans in the ventricular muscle is accompanied by alternans of action potential shape. In the Purkinje fibers, action potential duration alternates without change in shape and is determined by the duration of the preceding diastolic interval. However, in ventricular muscle fiber, alternans can occur in the presence of constant diastolic intervals. T wave alternans reflects changes in action potential duration and is frequently associated with a long QT interval. Electrocardiographic manifestations of conduction alternans occur at many different sites within the conducting system and myocardium. During myocardial ischemia, additional mechanisms of repolarization alternans have been proposed. Alternans occurring in the presence of a large pericardial effusion is attributed to swinging motion of the heart maintaining two-beat periodicity. CONCLUSIONS:Since its origin as "pulsus alternans" described by Traube in 1872, the definition of alternans has evolved into a term encompassing multiple physiologic and pathologic phenomena that, although united by the term cardiac alternans, diverge widely with respect to etiology, mechanism and clinical significance.
journal_name
J Am Coll Cardioljournal_title
Journal of the American College of Cardiologyauthors
Surawicz B,Fisch Cdoi
10.1016/0735-1097(92)90122-4subject
Has Abstractpub_date
1992-08-01 00:00:00pages
483-99issue
2eissn
0735-1097issn
1558-3597pii
0735-1097(92)90122-4journal_volume
20pub_type
杂志文章,评审abstract::Cardiac resynchronization therapy (CRT) is used to treat a subset of heart failure patients with discoordinate wall motion. Defining appropriate patients is important, and, although electrical delay (wide QRS) is commonly used, recent data show that measures of mechanical dyssynchrony improve the sensitivity and speci...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,评审
doi:10.1016/j.jacc.2007.09.027
更新日期:2008-01-01 00:00:00
abstract::The sequential univalent reduction of oxygen gives rise to very reactive intermediate products including superoxide anion radical, hydrogen peroxide and free hydroxyl radicals. Normally, the tissue concentration of these intermediate products of oxygen is severely limited; however, if oxygen free radicals are produced...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(85)80278-3
更新日期:1985-07-01 00:00:00
abstract:OBJECTIVES:To determine the effect of angiotensin-converting enzyme (ACE) inhibition on brachial flow-mediated vasodilation. BACKGROUND:Quinapril, an ACE inhibitor with high affinity, has been shown to improve coronary endothelial dysfunction in patients with coronary artery disease. The effectiveness of different vas...
journal_title:Journal of the American College of Cardiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/s0735-1097(99)00537-9
更新日期:2000-01-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to assess the prognostic significance of preinfarction angina after a first Q wave myocardial infarction. Patients with anterior or inferior myocardial infarction were compared. BACKGROUND:The effect of preinfarction angina on prognosis after anterior and inferior myocardial in...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(95)80002-x
更新日期:1995-08-01 00:00:00
abstract:OBJECTIVES:The purpose of this analysis was to define the factors that predict 3-year graft patency. BACKGROUND:The success of coronary artery bypass graft surgery (CABG) is dependent on vein graft patency after the operation. It has been well established by a series of Department of Veterans Affairs Cooperative Trial...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(97)82539-9
更新日期:1997-06-01 00:00:00
abstract:OBJECTIVES:To test the hypothesis that post-shock dispersion of repolarization (PSDR) is higher in T wave shocks that induce ventricular fibrillation (VF) than in those that do not, as well as in implantable cardioverter defibrillator (ICD) defibrillation shocks which fail to terminate VF when compared with those that ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(99)00579-3
更新日期:2000-02-01 00:00:00
abstract::Glycoprotein (GP) IIb/IIIa inhibitors are beneficial in unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI). In large trials, the GP IIb/IIIa inhibitors tirofiban and eptifibatide were each found to reduce the risk of death or myocardial infarction (MI) in these patients at 30 days. These agents...
journal_title:Journal of the American College of Cardiology
pub_type: 临床试验,杂志文章,随机对照试验,评审
doi:10.1016/s0735-1097(02)03018-8
更新日期:2003-02-19 00:00:00
abstract:OBJECTIVES:The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism. BACKGROUND:The value of echocardiography in predicting embolism in pati...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(00)01206-7
更新日期:2001-03-15 00:00:00
abstract:OBJECTIVE:This study sought to test the efficacy of phosphodiesterase type 5A (PDE5A) inhibition for treating advanced hypertrophy/remodeling caused by pressure overload, and to elucidate cellular and molecular mechanisms for this response. BACKGROUND:Sildenafil (SIL) inhibits cyclic guanosine monophosphate-specific P...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2008.08.069
更新日期:2009-01-13 00:00:00
abstract:OBJECTIVES:This study sought to develop quality indicators (QIs) for outpatient management of adult congenital heart disease (ACHD) patients. BACKGROUND:There are no published QIs to promote quality measurement and improvement for ACHD patients. METHODS:Working groups of ACHD experts reviewed published data and Unite...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2013.07.099
更新日期:2013-12-10 00:00:00
abstract:OBJECTIVES:This study sought to investigate the prevalence and mechanisms underlying right ventricular (RV) dyssynchrony in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) using tissue Doppler echocardiography (TDE). BACKGROUND:An ARVD/C is characterized by fibrofatty replacement of RV myocardium an...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2009.04.038
更新日期:2009-07-28 00:00:00
abstract:OBJECTIVES:This study evaluates the hemodynamic, bioenergetic and cytoprotective effects of urocortin (Ucn) in the isolated rat heart exposed to ischemia (I)/reperfusion (R). BACKGROUND:We have previously demonstrated that administration of exogenous Ucn reduces infarct size in ischemic-reperfused rat hearts. METHODS...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(02)01930-7
更新日期:2002-07-03 00:00:00
abstract::All patients with stable ischemic heart disease (SIHD) should be managed with guideline-directed medical therapy (GDMT), which reduces progression of atherosclerosis and prevents coronary thrombosis. Revascularization is also indicated in patients with SIHD and progressive or refractory symptoms, despite medical manag...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,评审
doi:10.1016/j.jacc.2015.09.056
更新日期:2016-01-05 00:00:00
abstract:BACKGROUND:The recommended doses for direct oral anticoagulants (DOACs) to prevent stroke and systemic embolism (SE) in patients with atrial fibrillation (AF) are described in specific regulatory authority approvals. OBJECTIVES:The impact of DOAC dosing, according to the recommended guidance on all-cause mortality, st...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2020.07.045
更新日期:2020-09-22 00:00:00
abstract:OBJECTIVES:This study sought to determine the relation between coronary calcification detected with ultrafast computed tomography and lumen narrowing defined with angiography and evaluated whether this relation is influenced by age and gender. BACKGROUND:Ultrafast computed tomography has been shown to be a sensitive m...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(94)00342-n
更新日期:1995-01-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to characterize the relationship between pericardial fat and atrial fibrillation (AF). BACKGROUND:Obesity is an important risk factor for AF. Pericardial fat has been hypothesized to exert local pathogenic effects on nearby cardiac structures above and beyond that of systemic adipo...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2010.11.045
更新日期:2011-04-26 00:00:00
abstract:OBJECTIVES:The purpose of this study was to determine the spectrum of left ventricular hypertrophy and ventricular morphology in adults with hypertrophic cardiomyopathy due to mutations of the beta-myosin heavy-chain gene. BACKGROUND:Although echocardiography is an important test in diagnosing hypertrophic cardiomyopa...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(93)90055-6
更新日期:1993-08-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to determine the characteristics and outcomes of patients with acute myocardial infarction (MI) complicated by cardiogenic shock due to predominant right ventricular (RV) infarction. BACKGROUND:Although RV infarction has been shown to have favorable long-term outcomes, the infl...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(03)00120-7
更新日期:2003-04-16 00:00:00
abstract:OBJECTIVES:To explain the discrepancy between the symptomatic status of patients and the hemodynamically calculated mitral valve area during long-term follow-up after mitral balloon valvulotomy, mitral valve orifice variability after dobutamine infusion was investigated in two groups of patients. BACKGROUND:A signific...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(93)90597-t
更新日期:1993-11-15 00:00:00
abstract:BACKGROUND:Cholesterol reduction with proprotein convertase subtilisin-kexin type 9 inhibitors reduces ischemic events; however, the cost-effectiveness in statin-treated patients with recent acute coronary syndrome remains uncertain. OBJECTIVES:This study sought to determine whether further cholesterol reduction with ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.jacc.2020.03.029
更新日期:2020-05-12 00:00:00
abstract::The relation between coronary patency after infusion of recombinant tissue-type plasminogen activator (rt-PA) and clinical and laboratory findings was assessed in patients with acute myocardial infarction. This study focused primarily on information available early in the hospitalization phase. Data were available for...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(88)90196-9
更新日期:1988-04-01 00:00:00
abstract:OBJECTIVES:The study sought to determine the effects of lipid-lowering with pravastatin on the systemic fibrinolytic profile and on thrombus formation under dynamic flow conditions. BACKGROUND:Lowering cholesterol (C) decreases clinical events in coronary artery disease (CAD) patients, but an analysis of the effects o...
journal_title:Journal of the American College of Cardiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/s0735-1097(99)00018-2
更新日期:1999-04-01 00:00:00
abstract::Between 25,000 and 75,000 new cases of angina refractory to maximal medical therapy and standard coronary revascularization procedures are diagnosed each year. In addition, heart failure also places an enormous burden on the U.S. health care system, with an estimated economic impact ranging from $20 billion to more th...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,评审
doi:10.1016/j.jacc.2007.07.024
更新日期:2007-10-16 00:00:00
abstract:OBJECTIVES:A technique for terminating refractory ventricular fibrillation is described. BACKGROUND:Refractory ventricular fibrillation can occur in up to 0.1% of electrophysiologic studies. Animal studies have shown that rapid sequential shocks may reduce ventricular fibrillation threshold. METHODS:Five patients of ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(94)90602-5
更新日期:1994-04-01 00:00:00
abstract:BACKGROUND:Pulmonary hypertension worsens prognosis in patients with heart failure (HF) and secondary mitral regurgitation (SMR). OBJECTIVES:This study sought to determine whether baseline pulmonary hypertension influences outcomes of transcatheter mitral valve repair (TMVr) in patients with HF with SMR. METHODS:In t...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2020.09.609
更新日期:2020-12-01 00:00:00
abstract:OBJECTIVES:This study sought to determine whether circadian patterns in ventricular arrhythmias (VAs) occur in a current primary prevention defibrillator (implantable cardioverter-defibrillator [ICD]) population. BACKGROUND:Cardiovascular events, including VAs, demonstrate biorhythmic periodicity. METHODS:We tested f...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.jacc.2013.11.072
更新日期:2014-06-24 00:00:00
abstract:OBJECTIVES:This study was conducted to evaluate the sensitivity and specificity of traditional electrocardiographic (ECG) criteria for right atrial enlargement and identify improve criteria, using quantitative two-dimensional echocardiography. BACKGROUND:Traditional ECG criteria for right atrial enlargement, such as P...
journal_title:Journal of the American College of Cardiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/0735-1097(94)90763-3
更新日期:1994-03-01 00:00:00
abstract:OBJECTIVES:We sought to evaluate the mechanisms by which nonsurgical septal reduction therapy (NSRT) reduces left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) both acutely and on a long-term basis. BACKGROUND:NSRT reduces LVOT obstruction in patients with...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(00)01045-7
更新日期:2001-01-01 00:00:00
abstract:OBJECTIVES:We sought to evaluate the effectiveness of salt and fludrocortisone versus placebo in the prevention of syncope recurrence in children. BACKGROUND:Intravascular volume expansion with fludrocortisone and salt has been reported to be effective in the treatment of syncope in children. However, no pediatric pla...
journal_title:Journal of the American College of Cardiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/j.jacc.2004.11.033
更新日期:2005-02-15 00:00:00
abstract::Cholesteryl ester transfer protein (CETP) facilitates exchange of triglycerides and cholesteryl ester between high-density lipoprotein (HDL) and apolipoprotein B100-containing lipoproteins. Evidence from genetic studies that variants in the CETP gene were associated with higher blood HDL cholesterol, lower low-density...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,评审
doi:10.1016/j.jacc.2018.10.072
更新日期:2019-02-05 00:00:00