Abstract:
OBJECTIVES:The aim of the present study was to investigate dynamic changes in the mitral regurgitant orifice using electromagnetic flow probes and flowmeters and the color Doppler flow convergence method. BACKGROUND:Methods for determining mitral regurgitant orifice areas have been described using flow convergence imaging with a hemispheric isovelocity surface assumption. However, the shape of flow convergence isovelocity surfaces depends on many factors that change during regurgitation. METHODS:In seven sheep with surgically created mitral regurgitation, 18 hemodynamic states were studied. The aliasing distances of flow convergence were measured at 10 sequential points using two ranges of aliasing velocities (0.20 to 0.32 and 0.56 to 0.72 m/s), and instantaneous flow rates were calculated using the hemispheric assumption. Instantaneous regurgitant areas were determined from the regurgitant flow rates obtained from both electromagnetic flowmeters and flow convergence divided by the corresponding continuous wave velocities. RESULTS:The regurgitant orifice sizes obtained using the electromagnetic flow method usually increased to maximal size in early to midsystole and then decreased in late systole. Patterns of dynamic changes in orifice area obtained by flow convergence were not the same as those delineated by the electromagnetic flow method. Time-averaged regurgitant orifice areas obtained by flow convergence using lower aliasing velocities overestimated the areas obtained by the electromagnetic flow method ([mean +/- SD] 0.27 +/- 0.14 vs. 0.12 +/- 0.06 cm2, p < 0.001), whereas flow convergence, using higher aliasing velocities, estimated the reference areas more reliably (0.15 +/- 0.06 cm2). CONCLUSIONS:The electromagnetic flow method studies uniformly demonstrated dynamic change in mitral regurgitant orifice area and suggested limitations of the flow convergence method.
journal_name
J Am Coll Cardioljournal_title
Journal of the American College of Cardiologyauthors
Shiota T,Jones M,Teien DE,Yamada I,Passafini A,Ge S,Sahn DJdoi
10.1016/0735-1097(95)80033-dsubject
Has Abstractpub_date
1995-08-01 00:00:00pages
528-36issue
2eissn
0735-1097issn
1558-3597pii
0735-1097(95)80033-Djournal_volume
26pub_type
杂志文章abstract:BACKGROUND:Interstitial fibrosis is an important component of diastolic, and systolic, dysfunction in heart failure (HF) and depends on activation and differentiation of fibroblasts into myofibroblasts (MyoFb). Recent clinical evidence suggests that in late-stage HF, fibrosis is not reversible. OBJECTIVES:The study ai...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2019.02.049
更新日期:2019-05-14 00:00:00
abstract::The mechanism of the antianginal actions of nilvadipine was investigated in 11 patients with effort angina pectoris. Hemodynamic data were obtained by angina-limited supine multistage bicycle ergometer exercise testing before and after a single 6 mg dose of nilvadipine. Compared with chest pain during control exercise...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(87)80277-2
更新日期:1987-10-01 00:00:00
abstract::This study presents follow-up data on 95 patients with transposition of the great arteries who underwent a Mustard intraatrial baffle operation. The patients were followed up serially by means of scalar electrocardiograms and 24 hour Holter monitoring studies. The latter study was effective in documenting abnormal rhy...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(86)80270-4
更新日期:1986-01-01 00:00:00
abstract:OBJECTIVES:We sought to determine whether nitroglycerin (NTG) withdrawal contributes to worsening of endothelial dysfunction and development of the rebound phenomenon during intermittent transdermal NTG therapy. BACKGROUND:Intermittent transdermal NTG therapy is recommended to avoid the development of tolerance. Howev...
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(00)01140-2
更新日期:2001-02-01 00:00:00
abstract::Anisoylated plasminogen streptokinase activator complex (APSAC) is a new thrombolytic agent that is of interest because of its ease of administration as an intravenous bolus injection. This report describes the first double-blind, placebo-controlled evaluation of intravenous APSAC for coronary recanalization in acute ...
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(87)80181-x
更新日期:1987-07-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to determine the predictors of major bleeding and the impact of major bleeding on outcomes, including mortality, in acute coronary syndromes (ACS). BACKGROUND:Whether major bleeding independently predicts mortality in patients with ACS undergoing an early invasive strategy is u...
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.2007.02.027
更新日期:2007-03-27 00:00:00
abstract:OBJECTIVES:This study was designed to evaluate the efficacy of local versus systemic treatment of thrombosis with various antithrombotic drugs. BACKGROUND:Local use of low dose antithrombotic drugs has been proposed as being effective and safe. METHODS:Heparin (30 U/kg), an antithrombin agent (argatroban, 0.05 mg/kg ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(95)00324-X
更新日期:1995-11-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to compare treatment effects of drug-eluting stents (DES) or coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease according to the complexity of atherosclerotic disease burden. BACKGROUND:Limited information is available on the relationships between t...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,多中心研究
doi:10.1016/j.jacc.2011.01.033
更新日期:2011-05-24 00:00:00
abstract:OBJECTIVES:This study was designed to investigate the appropriateness and complications of the use of spironolactone for heart failure (HF) in clinical practice. BACKGROUND:Spironolactone was reported by one prospective randomized trial to decrease morbidity and mortality in patients with New York Heart Association (N...
journal_title:Journal of the American College of Cardiology
pub_type: 临床试验,评论,杂志文章,随机对照试验
doi:10.1016/s0735-1097(02)02694-3
更新日期:2003-01-15 00:00:00
abstract:OBJECTIVES:The purpose of this study was to determine the spatial distribution of myocardial function (myofiber shortening and work) within the left ventricular (LV) wall during ventricular pacing. BACKGROUND:Asynchronous electrical activation, as induced by ventricular pacing, causes various abnormalities in LV funct...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(99)00068-6
更新日期:1999-05-01 00:00:00
abstract::This article deals with the question of whether or not the risk factor concept, a principal aspect of preventive cardiology, has contributed to patient care in coronary heart disease. The risk factors considered are plasma cholesterol, high blood pressure, smoking, diabetes and marked obesity. With the exception of pl...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(83)80006-0
更新日期:1983-01-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to assess the ability of plasma B-type natriuretic peptide (BNP) to diagnose significant cardiovascular disease (CVD) in the pediatric population. BACKGROUND:BNP has been shown to be reliable in detecting ventricular dysfunction and heart failure in adults. Timely and accurate ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2009.06.020
更新日期:2009-10-06 00:00:00
abstract:BACKGROUND:Early pathogenesis of diabetic cardiomyopathy (DMCM) may involve lipotoxicity of cardiomyocytes in the context of hyperglycemia. There are many preclinical studies of DMCM pathogenesis, but the human evidence is still poorly understood. OBJECTIVES:By using a nondiabetic mellitus (non-DM) heart transplanted ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2020.01.018
更新日期:2020-03-24 00:00:00
abstract:OBJECTIVES:This study was done to test the hypothesis that a forced diuresis with maintenance of intravascular volume after contrast exposure would reduce the rate of contrast-induced renal injury. BACKGROUND:We have previously shown a graded relationship with the degree of postprocedure renal failure and the probabil...
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(98)00574-9
更新日期:1999-02-01 00:00:00
abstract:BACKGROUND:Myocarditis is an uncommon, but potentially fatal, toxicity of immune checkpoint inhibitors (ICI). Myocarditis after ICI has not been well characterized. OBJECTIVES:The authors sought to understand the presentation and clinical course of ICI-associated myocarditis. METHODS:After observation of sporadic ICI...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章,多中心研究
doi:10.1016/j.jacc.2018.02.037
更新日期:2018-04-24 00:00:00
abstract:OBJECTIVES:We studied the acute effects of cardiac resynchronization therapy (CRT) on functional mitral regurgitation in heart failure (HF) patients with left bundle branch block (LBBB). BACKGROUND:Both an decrease [corrected] in left ventricular (LV) closing force and mitral valve tethering have been implicated as me...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(02)02937-6
更新日期:2003-03-05 00:00:00
abstract::To evaluate the risks of and optimal method for valve dilation in aortic stenosis, balloons of different sizes were used to dilate the normal aortic root in 16 lambs and then stenotic valves in 15 children. In the lambs, inflated balloon to aortic anulus diameter ratios ranged from 0.9 to 1.5. These hearts were examin...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(87)80237-1
更新日期:1987-04-01 00:00:00
abstract:BACKGROUND:The risk of sudden cardiac death (SCD) is high early after myocardial infarction (MI). Current knowledge and guidelines mainly rely on results from older clinical trials and registry studies. Left ventricular ejection fraction (LVEF) alone has not been proven a reliable predictor of SCD. OBJECTIVES:This stu...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2020.10.033
更新日期:2020-12-22 00:00:00
abstract:OBJECTIVES:The aim of this study was to assess the efficacy of radiofrequency catheter ablation (RFCA) in the treatment of hypertrophic obstructive cardiomyopathy in children. BACKGROUND:Hypertrophic obstructive cardiomyopathy is an uncommon cause of left ventricular outflow tract obstruction in children. In symptomat...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/j.jacc.2011.09.020
更新日期:2011-12-06 00:00:00
abstract::To evaluate the effectiveness and cost of low osmolarity, nonionic contrast agents for cardiac angiography, 443 patients were randomized to receive either iopamidol or diatrizoate. All adverse events that occurred within 24 h of the procedure were recorded prospectively by study personnel and classified according to 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/s0735-1097(10)80335-3
更新日期:1990-10-01 00:00:00
abstract::To be of clinical value in the treatment of heart failure, a drug must permit patients either to feel better or to live longer, or both. Yet, because the assessment of both quality and quantity of life is difficult, many investigators have proposed using alternate measures (namely, surrogate end points) that may indic...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(93)90487-l
更新日期:1993-10-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to examine the interaction between cigarette smoking and the clinical efficacy of clopidogrel in ST-segment elevation myocardial infarction (STEMI). BACKGROUND:Cigarette smoking induces cytochrome P450 (CYP)1A2, which converts clopidogrel into its active metabolite, and prior studi...
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.2008.12.044
更新日期:2009-04-14 00:00:00
abstract:OBJECTIVES:This study sought to determine the incidence and extent of dobutamine-induced contractile reserve in myocardial regions characterized by classical and new positron emission tomographic (PET) patterns in patients with chronic ischemic left ventricular dysfunction. BACKGROUND:PET is considered the most accura...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(97)00373-2
更新日期:1997-12-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to compare metabolic risk factors in men with anginal chest pain and a normal or abnormal coronary angiogram with those in healthy men. BACKGROUND:Risk factors for coronary heart disease, including lipoprotein abnormalities, hypertension and adiposity, may be metabolically interlin...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(94)90423-5
更新日期:1994-02-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to investigate whether omega-3 polyunsaturated fatty acids (PUFAs) are able to modify platelet responsiveness to dual antiplatelet therapy in stable coronary artery disease patients undergoing percutaneous coronary intervention (PCI). BACKGROUND:Although previous studies have s...
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.2009.11.080
更新日期:2010-04-20 00:00:00
abstract:OBJECTIVES:This study aimed to determine whether angiographically visualized collateral vessels in patients with chronic coronary artery disease imply the presence of viable myocardium in asynergic regions subtended by completely occluded coronary arteries. BACKGROUND:Patients with chronic coronary artery disease who ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(94)90630-0
更新日期:1994-03-15 00:00:00
abstract:OBJECTIVES:The objective of this study was to show elevations in septal shear stress in response to morphologic abnormalities that have been associated with discrete subaortic stenosis (SAS) in children. Combined with the published data, this critical connection supports a four-stage etiology of SAS that is advanced in...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/s0735-1097(97)00048-x
更新日期:1997-07-01 00:00:00
abstract::Between January 1983 and October 1989, 290 patients underwent an arterial switch operation for transposition of the great arteries; 30 (10.3%) of the patients had abnormalities of the left ventricular outflow tract or mitral valve, or both. These abnormalities included isolated pulmonary valve stenosis (n = 9), septal...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(90)90391-2
更新日期:1990-11-01 00:00:00
abstract::The results of recatheterization were assessed in a select group of 95 patients enrolled in the Mansfield Scientific Aortic Valvuloplasty Registry to determine whether any procedural or patient-related variables at baseline predicted either initial immediate or follow-up (6.2 +/- 3.3 months) results. At the follow-up ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(91)90853-2
更新日期:1991-04-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to determine whether residual stenoses after excimer laser angioplasty and atherectomy were due to inefficient tissue ablation/removal or to undersized devices. BACKGROUND:Significant residual stenoses are commonly observed after use of laser and atherectomy devices. It is not ...
journal_title:Journal of the American College of Cardiology
pub_type: 杂志文章
doi:10.1016/0735-1097(93)90587-q
更新日期:1993-11-15 00:00:00