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Estahbanaty Gilda - - 2007
This study assessed the effects of a course of enhanced external counterpulsation (EECP) therapy on systolic and diastolic cardiac function using echocardiography to measure left ventricular ejection fraction (LVEF), end-systolic volume (ESV), end-diastolic volume (EDV), systolic wave (Sm), early diastolic wave (Ea), Vp, E/Ea, E/Vp, and diastolic function grade in ...
Aubert Xavier L - - 2007
A lumped model of the arterial circulation is applied to the study of the dependencies between blood pressure and systolic time-intervals (PEP, LVET). The left ventricle is handled as a pressure source directly coupled with the varying vascular conditions. Four factors are individually considered: peripheral resistance, LV contractility, end diastolic ...
Watson Linley E - - 2007
Fatalities due to anthrax are associated with severe hypotension suggesting that the toxins generated from Bacillus anthracis, lethal toxin (LeTx) and edema toxin (EdTx), have cardiovascular effects. Here, we demonstrate the effects of these toxins and characterize their effects by echocardiography. LeTx leads to a significant reduction in ejection fraction, ...
Swamy Gokul - - 2007
Left ventricular ejection fraction (EF) is perhaps the most clinically significant index of global ventricular function. EF is measured in clinical practice using imaging methods such as non-invasive echocardiography. However, imaging methods generally require a skilled operator and expensive equipment. Thus, EF is not sufficiently monitored. To this end, we ...
Marwick Thomas H - - 2007
Left ventricular dysfunction associated with metabolic disorders has a number of features that might shed light on the integrity of heart failure with normal ejection fraction. First, although these patients may be dyspneic and have a normal ejection fraction, their diastolic dysfunction is not isolated. Both experimental models and sensitive ...
Söderqvist Emil - - 2006
The aim of this study was to establish whether analysis of the left ventricular pressure waveform provides indicative information about cardiac load and contractility and to develop an algorithm for computer-based assessment of changes in these variables. In eight healthy standard breed anaesthetized open-chest pigs, a high frequency response guide-wire ...
Dorri F - - 2006
Local wall stress is the pivotal determinant of the heart muscle's systolic function. Under in vivo conditions, however, such stresses cannot be measured systematically and quantitatively. In contrast, imaging techniques based on magnetic resonance (MR) allow the determination of the deformation pattern of the left ventricle (LV) in vivo with ...
Amà R - - 2006
BACKGROUND AND OBJECTIVE: The haemodynamic effects of acute pulmonary hypertension can be largely attributed to ventricular interdependence during diastole. However, there is evidence that the two ventricles also interact during systole. The aim of the present study was to examine the effects of acute pulmonary hypertension on both components of ...
Xu Kai Y - - 2006
OBJECTIVE: We have recently identified an activation site on (Na+ + K+)-ATPase and found that binding of antibody SSA412 to this specific site of the enzyme markedly augments (Na+ + K+)-ATPase catalytic activity. Demonstration of whether activation of (Na+ + K+)-ATPase affects heart function in animal in vivo was the ...
Suzuki Kazuyuki - - 2006
This study investigated whether a small volume of 7.2% hypertonic saline solution (HSS) could affect M-mode echocardiographic indices in dogs. HSS induced significant increase in heart rate, stroke volume and cardiac index, when the fluid infusion was completed (P<0.05). In the HSS group, the left ventricular end-diastolic volume index, as ...
Broscheit Jens A - - 2007
OBJECTIVE: Critical myocardial oxygen imbalance as indicated by elevated interstitial lactate levels may occur in cases of rapidly elevated end-diastolic myocardial wall tension during elevated myocardial contractility in the intact myocardium. Simultaneous administration of beta-adrenergic receptor agonist and antagonist reliably allows for investigating the myocardial response. DESIGN: Experimental using an ...
Shim Eun Bo - - 2006
We developed a comprehensive cell model that simulates the sequential cellular events from membrane excitation to contraction in the human ventricle. By combining this ventricular cell model with a lumped circulation model, we examined how blood pressure dynamics in the ventricle and aorta are related to the cellular processes. To ...
Monnet Xavier - - 2006
PURPOSE OF REVIEW: Cardiac preload is frequently altered during hemodynamic failure and is a major focus of therapeutic management. The aim of this review was to summarize the invasive indicators of preload and the invasive predictors of preload responsiveness. RECENT FINDINGS: The static assessment of preload is based on the ...
Wansapura Janaka - - 2006
Standard methods of longitudinal relaxation (T1) measurements in the heart produce only one T1 map of the myocardium, usually at the end diastole (ED). In this article, we investigated the feasibility of using a dual flip angle fast gradient echo technique in the steady state to generate a movie of ...
Pai Moonsun - - 2006
The electrocardiogram-gated single photon emission computed tomography (SPECT) measurement of left ventricular end-diastolic volume, end-systolic volume and ejection fraction may contain substantial errors. We evaluated whether patient-related factors affect the accuracy of left ventricular volume and ejection fraction measured by gated Tl-201 SPECT. A total of 518 patients without perfusion ...
Dohi Kaoru - - 2006
Our objective was to test the hypothesis that novel angle-corrected radial strain imaging can quantify left ventricular dyssynchrony associated with contractile impairment and improved with biventricular pacing. Eight open-chest dogs were studied by novel angle-corrected color-coded radial strain imaging and high-fidelity pressure-conductance catheters recording pressure-volume loops. Heart rate was controlled ...
Riordan Matt M - - 2006
Previous studies in healthy humans have established that the (approximately 850 ml) volume enclosed by the pericardial sac is nearly constant over the cardiac cycle, exhibiting a transient approximately 5% decrease (approximately 40 ml) from end diastole to end systole. This volume decrease manifests as a "crescent" at the ventricular ...
García Edgar H - - 2006
BACKGROUND: Tissue Doppler imaging (TDI) is useful in the evaluation of systolic and diastolic function. It allows assessment of ventricular dynamics in its longitudinal axis. We sought to investigate the difference in systolic and diastolic longitudinal function in patients with chronic heart failure (CHF) with normal and reduced ejection fraction. ...
Hofer C K - - 2006
The new Volumetric Ejection Fraction monitoring system (VoLEF), when combined with the Pulse Contour Cardiac Output monitoring system (PiCCO) system, allows measurement of left and right heart end-diastolic volumes by thermodilution. The aim of this study was to evaluate whether the left heart end-diastolic volume index determined by the VoLEF ...
Aghajani Ebrahim - - 2006
Our previous studies indicate that left ventricular end-systolic pressure-volume relations (ESPVRs) or elastance (Ees) are not reduced in studies where expected reductions of contractility should be found (i.e., heart failure, stunning, and endotoxemia). The present study was done to assess whether this phenomenon is due to a particular load sensitivity ...
Shmuylovich Leonid - - 2006
Maximum elastance is an experimentally validated, load-independent systolic function index stemming from the time-varying elastance paradigm that decoupled extrinsic load from (intrinsic) contractility. Although Doppler echocardiography is the preferred method of diastolic function (DF) assessment, all echo-derived indexes are load dependent, and no invasive or noninvasive load-independent index of filling ...
Rodriguez Ignacio - - 2006
In coronary circulation the flow in epicardial arteries and veins is observed to be pulsatile and out of phase with each other. Theoretical considerations predict that this phenomenon extends to all levels of the vascular tree and leads to a cyclic fluctuation of regional tissue volume. Intramyocardial tissue volume change ...
How Ole-Jakob - - 2006
Altered cardiac metabolism and function (diabetic cardiomyopathy) has been observed in diabetes. We hypothesize that cardiac efficiency, the ratio of cardiac work (pressure-volume area [PVA]) and myocardial oxygen consumption (MVo(2)), is reduced in diabetic hearts. Experiments used ex vivo working hearts from control db/+, db/db (type 2 diabetes), and db/+ ...
Hirota Masanori - - 2006
BACKGROUND: Cardiac function of non-heart-beating donors (NHBDs) is uncertain due to severe myocardial damage. We developed an isolated myocardial perfusion system to resuscitate NHBD hearts and attempted to predict functional recovery of 60-minute warm ischemic hearts by analyzing systolic and diastolic functions. METHODS: Hypoxic cardiac arrest was induced in 8 ...
Klotz Stefan - - 2006
Whereas end-systolic and end-diastolic pressure-volume relations (ESPVR, EDPVR) characterize left ventricular (LV) pump properties, clinical utility of these relations has been hampered by the need for invasive measurements over a range of pressure and volumes. We propose a single-beat approach to estimate the whole EDPVR from one measured volume-pressure (Vm ...
Kliger Chad - - 2006
The incidence and prevalence of heart failure are increasing as the population ages. Epidemiologic studies demonstrate that more than half of heart failure patients have a normal ejection fraction. The pathophysiology of this disorder is not completely understood. It is primarily attributed to left ventricular diastolic dysfunction (a leftward- and ...
Preisman S - - 2005
BACKGROUND: Prediction of the response of the left ventricular stroke volume to fluid administration remains an unsolved clinical problem. We compared the predictive performance of various haemodynamic parameters in the perioperative period in patients undergoing coronary artery bypass surgery. These parameters included static indicators of cardiac preload and functional parameters, ...
Claessens T E - - 2006
The linear time-varying elastance theory is frequently used to describe the change in ventricular stiffness during the cardiac cycle. The concept assumes that all isochrones (i.e., curves that connect pressure-volume data occurring at the same time) are linear and have a common volume intercept. Of specific interest is the steepest ...
Connelly K A - - 2006
Transgenic animal models have provided a vital insight into the pathogenesis of cardiovascular disease, but functional cardiac assessment is often limited by high heart rates and small heart size. We hypothesized that in the presence of concentric left ventricular (LV) hypertrophy (LVH), load-sensitive measures of contractility may be misinterpreted as ...
Bal M P - - 2005
AIMS: Left ventricular (LV) pressure-volume relations provide relatively load-independent indexes of systolic and diastolic LV function, but few data are available on pressure-volume relations during growth and development in the normal adult heart. Furthermore, to quantify intrinsic ventricular function the indexes should be normalized for heart weight. However, in many ...
Cider Asa - - 2006
The effects of immersion and training of patients with chronic heart failure (CHF) in warm water has not been thoroughly investigated. The aim of this study was to assess the acute hemodynamic response of immersion and peripheral muscle training in elderly patients with CHF. Thirteen CHF patients and 13 healthy ...
Borlaug Barry A - - 2005
BACKGROUND: Sildenafil inhibits phosphodiesterase 5 (PDE5A) to elevate intracellular cGMP and to induce vasodilation. This effect has led to its use for treating erectile dysfunction. Although its influence on rest heart function has appeared minimal, recent animal studies suggest that sildenafil can have potent effects on hearts stimulated by beta-adrenergic ...
Khalil Magdy M - - 2005
AIM: To compare the currently available gated SPECT software programs, quantitative gated SPECT (QGS), Emory Cardiac Toolbox (ECTb), Left Ventricular Global Thickening Fraction (LVGTF), and the recently developed Layer of Maximum Count (LMC) method with equilibrium Gated Blood Pool (GBP) scintigraphy in calculating the ejection fraction in patients with small ...
Mohri Satoshi - - 2005
We have reported that the contractility index (E(max)) and the total mechanical energy (PVA) of arrhythmic beats of the left ventricle (LV) distribute normally in canine hearts under electrically induced atrial fibrillation (AF). Here, E(max) is the ventricular elastance as the slope of the end-systolic (ES) pressure-volume (P-V) relation (ESPVR), ...
Yotti Raquel - - 2005
BACKGROUND: Ejection intraventricular pressure gradients are caused by the systolic force developed by the left ventricle (LV). By postprocessing color Doppler M-mode (CDMM) images, we can measure noninvasively the ejection intraventricular pressure difference (EIVPD) between the LV apex and the outflow tract. This study was designed to assess the value ...
Amado Luciano C - - 2005
We hypothesized that chronic xanthine oxidase inhibition (XOI) would have favorable effects on both ventricular and vascular performance in evolving heart failure (HF), thereby preserving ventricular-vascular coupling. In HF, XOI reduces oxidative stress and improves both vascular and myocardial function. Dogs were randomized to receive either allopurinol (100 mg/day p.o.) ...
Moyssakis Ioannis - - 2005
The independence of the slope of the left ventricular (LV) end-systolic stress/end systolic diameter (ESS/ESD) relation of preload (PL) after normalization for end-diastolic diameter (EDD), and the reliability of both the original and the normalized slope as contractility and prognostic indices, were assessed. We studied echocardiographically, hemodynamically, and with carotid ...
Royse Colin F - - 2005
Ropivacaine and levobupivacaine were developed to reduce the risk of fatal accidental overdose reported with bupivacaine. The myocardial depressant potential of these drugs in sublethal dosage is unknown. Pressure volume loops can be used to separate myocardial from vascular effects. We acquired dose-response curves to incremental infusions in seven anesthetized, ...
Grosu Aurelia - - 2005
AIMS: Left ventricular end-systolic pressure-volume relationship (PVR) provides a robust, relatively load-insensitive evaluation of contractility and can be assessed non-invasively during exercise echo. Dobutamine might provide an exercise-independent alternative approach to assess inotropic reserve. The feasibility of a non-invasive estimation of PVR during dobutamine stress in the echo lab and ...
Crepaz Roberto - - 2005
BACKGROUND: In pediatric age echocardiographic evaluation of left ventricular systolic function is usually based on indexes obtained by measurements at the endocardial level. In the presence of ventricular hypertrophy this may lead to an overestimation of systolic function. The aim of this study was to assess the developmental changes of ...
Vinereanu Dragos - - 2005
To investigate regional systolic function of the left ventricle, to test the hypothesis that "pure" diastolic dysfunction (impaired global diastolic filling, with a preserved ejection fraction > or = 50%) is associated with longitudinal systolic dysfunction. One hundred thirty subjects (31 patients with asymptomatic diastolic dysfunction, 30 with diastolic heart ...
Burkhoff Daniel - - 2005
Assessment of left ventricular systolic and diastolic pump properties is fundamental to advancing the understanding of cardiovascular pathophysiology and therapeutics, especially for heart failure. The use of end-systolic and end-diastolic pressure-volume relationships derived from measurements of instantaneous left ventricular pressure-volume loops emerged in the 1970s as a comprehensive approach for ...
Blagonravov M L - - 2005
In rabbits, arterial hypertension was characterized by progressive elevation of systolic and diastolic blood pressure. The contractile function of the left ventricle augmented, but its potential working capacity decreased. Opposite changes were observed in the right ventricle. It was hypothesized that the compensatory mechanisms in the right ventricle during arterial ...
Icardo Josè M - - 2005
This morphodynamic study provides an insight on how the architecture of the heart ventricle of the gilthead seabream (Sparus auratus) is designed to accomplish the functional performance typical of an active teleost species. Using an in vitro working heart preparation, mechanical performance was analyzed under loading (i.e., preload and afterload) ...
Siniscalchi A - - 2005
OBJECTIVE: The objective of this study was to compare the accuracy of 2 variables: pulmonary artery occlusion pressure (PAOP) and right ventricular end diastolic volume index (RVEDVI) as predictors of the hemodynamic response to fluid challenge as well as definition of the overall correlation between RVEDVI and change in PAOP, ...
Kerckhoffs R C P - - 2005
Intraventricular synchrony of cardiac activation is important for efficient pump function. Ventricular pacing restores the beating frequency but induces more asynchronous depolarization and more inhomogeneous contraction than in the normal heart. We investigated whether the increased inhomogeneity in the left ventricle can be described by a relatively simple mathematical model ...
Pinsky Michael R - - 2005
PURPOSE OF REVIEW: To summarize the relevant peer-reviewed publications over the past year that addressed issues of when to give (or not give) fluid to the critically ill patient. RECENT FINDINGS: Clinical data from several studies underscore the inability of measures of ventricular filling to assess either preload or preload ...
Constantinesco André - - 2005
Quantitative functional normal data should be a prerequisite before applying SPECT in murine models of cardiac disease. Therefore, we investigated the capability of in vivo pinhole gated SPECT for establishment of a reference database for left ventricular myocardial perfusion, volumes, and motion in normal mice. METHODS: A small-animal dedicated pinhole ...
Castella Manuel - - 2005
OBJECTIVE: To mechanically test the intact cardiac structure to determine the sequence of contraction within the myocardial mass to try to explain ejection and suction. METHODS: In 24 pigs (30-85 kg), segment shortening at the site of sonomicrometer crystals was continuously recorded. The ECG evaluated rhythm, and Millar pressure transducers ...
Maurer Mathew S - - 2005
BACKGROUND: Although heart failure with a normal ejection fraction (HFNEF) is a clinically heterogeneous syndrome, a single pathophysiologic mechanism, diastolic dysfunction, is often ascribed to explain this condition. In view of the clinical heterogeneity of these patients, we hypothesized that subgroups of HFNEF patients may have different underlying pathophysiologic mechanisms. ...
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