Abstract:
:In the standard accepted concept, contractility is the intrinsic ability of heart muscle to generate force and to shorten, independently of changes in the preload or afterload with fixed heart rates. At molecular level the crux of the contractile process lies in the changing concentrations of Ca2+ ions in the myocardial cytosol. Ca2+ ions enter through the calcium channel that opens in response to the wave of depolarization that travels along the sarcolemma. These Ca2+ ions "trigger" the release of more calcium from the sarcoplasmic reticulum (SR) and thereby initiate a contraction-relaxation cycle. In the past, several attempts were made to transfer the pure physiological concept of contractility, expressed in the isolated myocardial fiber by the maximal velocity of contraction of unloaded muscle fiber (Vmax), to the in vivo beating heart. Suga and Sagawa achieved this aim by measuring pressure/volume loops in the intact heart: during a positive inotropic intervention, the pressure volume loop reflects a smaller end-systolic volume and a higher end-systolic pressure, so that the slope of the pressure volume relationship moves upward and to the left. The pressure volume relationship is the most reliable index for assessing myocardial contractility in the intact circulation and is almost insensitive to changes in preload and after load. This is widely used in animal studies and occasionally clinically. The limit of the pressure volume relationship is that it fails to take into account the frequency-dependent regulation of contractility: the frequency-dependent control of transmembrane Ca2+ entry via voltage-gated Ca2+ channels provides cardiac cells with a highly sophisticated short-term system for the regulation of intracellular Ca2+ homeostasis. An increased stimulation rate increases the force of contraction: the explanation is repetitive Ca2+ entry with each depolarization and, hence, an accumulation of cytosolic calcium. As the heart fails, there is a change in the gene expression from the normal adult pattern to that of fetal life with an inversion of the normal positive slope of the force-frequency relation: systolic calcium release and diastolic calcium reuptake process is lowered at the basal state and, instead of accelerating for increasing heart rates, slows down. Since the force-frequency relation uncovers initial alteration of contractility, as an intermediate step between normal and abnormal contractility at rest, a practical index to measure it is mandatory. Measuring end-systolic elastance for increasing heart rates is impractical: increasing heart rates with atrial pacing has to be adjunct to the left ventricular conductance catheter, to the left ventricular pressure catheter, to the vena cava balloon, and to afterload changes. Furthermore, a noninvasive index is needed. Noninvasive measurement of the pressure/volume ratio for increasing heart rates during stress in the echo lab could be the practical answer to this new clinical demand in the current years of a dramatic increase in the number of heart failure patients.
journal_name
Cardiovasc Ultrasoundjournal_title
Cardiovascular ultrasoundauthors
Bombardini Tdoi
10.1186/1476-7120-3-27keywords:
subject
Has Abstractpub_date
2005-09-08 00:00:00pages
27issn
1476-7120pii
1476-7120-3-27journal_volume
3pub_type
杂志文章,评审abstract:BACKGROUND:Though hemodialysis (HD) acutely improves cardiac function, the impact of background diseases like coronary artery disease (CAD) and Type 2 diabetes (DM) in the setting of end-stage renal disease (ESRD) is not known. Tissue velocity echocardiography (TVE) offers a fast choice to follow changes in myocardial ...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-4-9
更新日期:2006-02-02 00:00:00
abstract:BACKGROUND:Takotsubo cardiomyopathy is an acute cardiac syndrome characterized by transient LV regional wall motion abnormalities (with peculiar apical ballooning appearance), chest pain or dyspnea, ST-segment elevation and minor elevations of cardiac enzyme levels CASE PRESENTATION:A 68-year-old woman was admitted to...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-5-18
更新日期:2007-04-06 00:00:00
abstract:INTRODUCTION:In vivo and in vitro evidence suggests that adenosine and its agonists play key roles in the process of ischemic preconditioning. The effects of low-dose adenosine infusion on ischemic preconditioning have not been thoroughly studied in humans. AIMS:We hypothesised that a low-dose adenosine infusion could...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章,随机对照试验
doi:10.1186/1476-7120-7-52
更新日期:2009-11-05 00:00:00
abstract:BACKGROUND:In studies where cross-sectional images of coronary arteries obtained with different imaging modalities are compared, the importance of correct co-localization and matching of images along the coronary artery longitudinal axis is obvious. However, it appears neglected that correct spatial orientation of the ...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-10-12
更新日期:2012-03-22 00:00:00
abstract::A 63-year-old man was admitted to our hospital with a complaint of right lateroabdominal pain. He was diagnosed with metastatic colon cancer, and then developed multiple brain embolic infarctions 7 days after admission. Transesophageal echocardiography showed that mobile, echo-dense masses were attached to the anterio...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-9-8
更新日期:2011-02-28 00:00:00
abstract:BACKGROUND:The morning hours are associated with increased cardiovascular (CV) risk, and vascular endothelial function (VEF) is a strong predictor of CV disease. A diurnal rhythm in VEF has been established but the morning variation in VEF is not well-documented. Thus, we tested if VEF is impaired across the vulnerable...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/s12947-015-0036-1
更新日期:2015-10-05 00:00:00
abstract:BACKGROUND:Calcification is an independent predictor of mortality in calcific aortic valve disease (CAVD). The aim of this study was to evaluate the use of non-invasive, non-ionizing echocardiographic calibrated integrated backscatter (cIB) for monitoring progression and subsequent regression of aortic valvular calcifi...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-11-4
更新日期:2013-01-26 00:00:00
abstract:BACKGROUND:The effect of aggressive medical therapy on quantitative coronary plaque burden is not generally known, especially in ethnic Chinese. AIMS:We reasoned that Cardiac CT could conveniently quantify early coronary atherosclerosis in our patient population, and hypothesized that serial observation could differen...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-8-5
更新日期:2010-03-12 00:00:00
abstract:BACKGROUND:Left ventricular diastolic dysfunction, with secondary atrial pressure elevation, is a well-known concept. On the contrary, effect of left atrial compliance on pulmonary pressure is rarely considered. CASE PRESENTATION:We report the echocardiographic case of a 9-year-old child who presented severe rheumatic...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-4-31
更新日期:2006-08-10 00:00:00
abstract:BACKGROUND:The aim of this study was to define the independent determinants of left atrial appendage (LAA) thrombus among various echocardiographic parameters measured by Velocity Vector Imaging (VVI) in patients with nonvalvular atrial fibrillation (AF) receiving warfarin, particularly in patients with a low CHADS2 sc...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-10-50
更新日期:2012-12-27 00:00:00
abstract::Echocardiography is one of the most important diagnostic testing in cardiology. The presence of a breast implant overlying heart can cause significant impairment of the echocardiographic acoustic window. Breast implants are increasing in popularity in the USA and the Federal Drug and Food Administration (FDA) just app...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章,评审
doi:10.1186/1476-7120-5-9
更新日期:2007-02-23 00:00:00
abstract::Miniaturization has evolved in the creation of a pocket-size imaging device which can be utilized as an ultrasound stethoscope. This study assessed the additional diagnostic power of pocket size device by both experts operators and trainees in comparison with physical examination and its appropriateness of use in comp...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-8-51
更新日期:2010-11-26 00:00:00
abstract:BACKGROUND:Shear Wave Elastography (SWE) imaging is a novel ultrasound technique for quantifying tissue elasticity. Studies have demonstrated that SWE is able to differentiate between diseased and normal tissue in a wide range clinical applications. However its applicability to atherosclerotic carotid disease has not b...
journal_title:Cardiovascular ultrasound
pub_type: 临床试验,杂志文章
doi:10.1186/1476-7120-12-49
更新日期:2014-12-08 00:00:00
abstract::Supravalvular mitral stenosis is a rare condition characterized by an abnormal ridge, with one or two orifices, covering and obstructing the mitral valve. Preoperative diagnosis is difficult with transtoracic echo (TTE), angiography and magnetic resonance imaging (MRI). In this case, a 36-year-old male, was admitted t...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-3-19
更新日期:2005-08-11 00:00:00
abstract::Originally described by Brock and Teare, today hypertrophic cardiomyopathy is clinically defined as left (or right) ventricular hypertrophy without a known cardiac or systemic cause, such as systemic hypertension, Fabry's disease or aortic stenosis.Also appreciated today is the enormous genotypic and phenotypic hetero...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-7-31
更新日期:2009-07-03 00:00:00
abstract:BACKGROUND:While echocardiographic grading of left ventricular (LV) diastolic dysfunction (DD) is used every day, the relationship between echocardiographic DD grade and hemodynamic abnormalities is uncertain. METHODS:We identified 460 consecutive patients who underwent transthoracic echocardiography within 24 h of el...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/s12947-015-0023-6
更新日期:2015-06-24 00:00:00
abstract::Pulmonary embolism is a common cardiovascular emergency, but it is still often misdiagnosed due to its unspecific clinical symptoms. Elevated troponin concentrations are associated with greater morbidity and mortality in patients with pulmonary embolism. Right ventricular ischemia due to increased right ventricular af...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-8-50
更新日期:2010-11-24 00:00:00
abstract::Echocardiography has the ability to noninvasively explore hemodynamic variables during pharmacologic or exercise stress test in patients with heart failure. In this review, we detail some important potential applications of stress echocardiography in patients with heart failure. In patients with coronary artery diseas...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章,评审
doi:10.1186/1476-7120-2-11
更新日期:2004-07-30 00:00:00
abstract:BACKGROUND:The percentage of hypertrophic cardiomyopathy (HCM) patients who are in high risk for Sudden Death (SD) constitutes only a minority of all HCM population but the incidence of SD in this subset is high (at least 5% annually). The identification of this small but important proportion of high risk HCM patients ...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-7-37
更新日期:2009-07-26 00:00:00
abstract:BACKGROUND:Cardiac shock wave therapy (CSWT) improves cardiac function in patients with severe coronary artery disease (CAD). We aimed to evaluate the clinical outcomes of a new CSWT treatment regimen. METHODS:The 55 patients with severe CAD were randomly divided into 3 treatment groups. The control group (n = 14) rec...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章,随机对照试验
doi:10.1186/1476-7120-10-35
更新日期:2012-08-17 00:00:00
abstract:BACKGROUND:Atrial septal defect (ASD) accounts for 10% of all congenital heart lesions and represent the third most congenital cardiac defect seen in adults. Atrial natriuretic peptide (ANP) is an important regulator of the sodium and volume homeostasis. This study was designed to investigate the changes in plasma ANP ...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-6-35
更新日期:2008-07-07 00:00:00
abstract:BACKGROUND:Left ventricular free wall rupture occurs in up to 10% of the in-hospital deaths following myocardial infarction. It is mainly associated with posterolateral myocardial infarction and its antemortem diagnosis is rarely made. Contrast echocardiography has been increasingly used for the evaluation of myocardia...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-4-7
更新日期:2006-01-26 00:00:00
abstract:BACKGROUND:Myocardial contractility can be investigated using longitudinal peak strain. It can be calculated using the Doppler-derived TDI method and the non-Doppler method based on tissue tracking on B-mode images. Both are validated and show good reproducibility, but no comparative analysis of their results has yet b...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-5-7
更新日期:2007-02-07 00:00:00
abstract:BACKGROUND:In the last recent years a new percutaneous procedure, the MitraClip, has been validated for the treatment of mitral regurgitation. MitraClip procedure is a promising alternative for patients unsuitable for surgery as it reduces the risk of death related to surgery ensuring a similar result. Few data are pre...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-11-13
更新日期:2013-05-04 00:00:00
abstract:OBJECTIVE:Left ventricular wall stress has been investigated in a variety of populations, but the effect of food intake has not been evaluated. We assessed whether left ventricular wall stress is affected by food intake in healthy subjects. METHODS:Twenty-three healthy subjects aged 25.6 ± 4.5 years were investigated....
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-12-2
更新日期:2014-01-28 00:00:00
abstract::Persistent left superior vena cava is rare but important congenital vascular anomaly. It results when the left superior cardinal vein caudal to the innominate vein fails to regress. It is most commonly observed in isolation but can be associated with other cardiovascular abnormalities including atrial septal defect, b...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章,评审
doi:10.1186/1476-7120-6-50
更新日期:2008-10-10 00:00:00
abstract:OBJECTIVE:Correlate the anatomic features of atrioventricular septal defect with echocardiographic images. MATERIALS AND METHODS:Sixty specimen hearts were studied by sequential segmental analysis. Echocardiograms were performed on 34 patients. Specimen hearts with findings equivalent to those of echocardiographic ima...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-6-33
更新日期:2008-06-24 00:00:00
abstract:INTRODUCTION:Serial monitoring of patients participating in clinical trials of carotid artery therapy requires noninvasive precision methods that are inexpensive, safe and widely available. Noninvasive ultrasonic duplex Doppler velocimetry provides a precision method that can be used for recruitment qualification, pre-...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-8-39
更新日期:2010-09-07 00:00:00
abstract::Global and regional left ventricular (LV) systolic dysfunction is a marker of coronary artery disease (CAD), which is conventionally assessed using two-dimensional echocardiography. Tissue Doppler imaging (TDI) has emerged as an adjunct tool in the diagnosis of regional wall motion abnormalities from CAD. We performed...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章,meta分析,评审
doi:10.1186/1476-7120-10-47
更新日期:2012-11-30 00:00:00
abstract::In this case report we describe a rare case of right atrium myxoma that coexisted with antiphospholipid syndrome in a young woman. We describe the unusual findings and diagnostic challenges combined with a review of the literature. ...
journal_title:Cardiovascular ultrasound
pub_type: 杂志文章
doi:10.1186/1476-7120-7-47
更新日期:2009-10-11 00:00:00