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Swamy Gokul - - 2009
We developed a technique to monitor left ventricular ejection fraction (EF) by model-based analysis of the aortic pressure waveform. First, the aortic pressure waveform is represented with a lumped parameter circulatory model. Then, the model is fitted to each beat of the waveform to estimate its lumped parameters to within ...
Bak Zoltan - - 2009
BACKGROUND: The Parkland formula (2-4 mL/kg/burned area of total body surface area %) with urine output and mean arterial pressure (MAP) as endpoints for the fluid resuscitation in burns is recommended all over the world. There has recently been a discussion on whether central circulatory endpoints should be used instead, ...
Shmuylovich Leonid - - 2009
Diastolic heart failure (DHF) is present in over 50% of hospitalized heart failure patients, and diastolic dysfunction is known to play a critical pathophysiologic role. Measurement of left-ventricular pressure (LVP) via catheterization is the gold standard for diastolic function (DF) evaluation, but current methods fail to fully capitalize on the ...
Z?calo Yanina - - 2009
The cardiac resynchronization therapy (CRT)effects on the arterial load components, the mechanisms (i.e.haemodynamic changes-dependence) involved in the load reduction and the factors (i.e. basal load conditions) associated with the load changes after CRT, are to be evaluated. Aims: a)to analyze the potential changes in the arterial load components(peripheral resistances, arterial ...
Zocalo Yanina - - 2009
The cardiac resynchronization therapy (CRT) effects on the arterial load components, the mechanisms (i.e. haemodynamic changes-dependence) involved in the load reduction and the factors (i.e. basal load conditions) associated with the load changes after CRT, are to be evaluated. Aims: a) to analyze the potential changes in the arterial load ...
Kind Taco - - 2009
The time-varying elastance concept provides a comprehensive description of the intrinsic mechanical properties of the left ventricle that are assumed to be load independent. Based on pressure-volume measurements obtained with combined pressure conductance catheterization in six open-chest anesthetized sheep, we show that the time to reach end systole (defined as ...
Watanabe Manabu - - 2008
PURPOSE: The transitional changes of the ventricular function at different time points after total cavopulmonary connection (TCPC) were examined. METHODS: A total of 29 patients were divided into a primary TCPC group and a staged TCPC group. In both groups, phase I was defined as within 2 months after TCPC ...
Nicolas-Robin Armelle - - 2008
BACKGROUND: As a result of donor heart shortage, resorting to marginal heart donors is being promoted. Dobutamine is usually used to support these potential donors and has been proposed to identify the reversible part of the brain death-induced myocardial dysfunction before potential organ donation. But dobutamine impairs the oxygen supply-demand ...
Senzaki Hideaki - - 2008
Despite successful repair, patients with coarctation of the aorta (COA) often show persistent hypertension at rest and/or during exercise. Previous studies indicated that the hypertension is mainly due to abnormalities in the arterial bed and its regulatory systems. We hypothesized that ventricular systolic stiffness also contributes to the hypertensive state ...
Sagiv M - - 2008
AIM: The study investigated lactic acid and left ventricular function in response to two different sprint cycling schedules varying in their time schedule, in 15 healthy national level cyclists (23+/-1 years). METHODS: During one testing session subjects performed four strenuous bouts in a schedule of increasing time order: 1, 2, ...
Menzies-Gow N J - - 2008
Eight normal thoroughbred horses were examined by echocardiography before and 10 minutes after they had been sedated by the intravenous administration of 0.03 mg/kg acepromazine. There were significant (P<0.025) increases in the diameters of the pulmonary artery and the aorta, measured at end-systole, and in the thickness of the interventricular ...
Goetz Christian - - 2008
The feasibility of blood-pool pinhole ECG gated SPECT was investigated in healthy mice to assess right and left ventricular function analysis. Anaesthetized (isoflurane 1-1.5%) adult CD1 mice (n=11) were analyzed after intravenous administration of 0.2 ml of 550 MBq of (99m)Tc human albumin. For blood-pool gated SPECT imaging, 48 ventral ...
Zhao Hong-wei - - 2008
BACKGROUND: Right ventricular function plays an important role in the hemodynamic derangement during off-pump coronary artery bypass (OPCAB) surgery. Pressure-volume loops have been shown to provide load-independent information of cardiac function. Therefore, the aim of this study was to investigate the feasibility of construction of right ventricular pressure-volume loops with ...
Hecker Tracy - - 2008
High-dose dobutamine used in dobutamine stress echocardiography (DSE) has hemodynamically based side effects due to a variable combination of beta1 (inotropic) and beta2 (vasodilator) effects. Of concern is the development of an "empty ventricle syndrome" associated with intracavitary or outflow tract obstruction and resultant symptomatic hypotension. This study was undertaken ...
Westermann Dirk - - 2008
BACKGROUND: Increased left ventricular stiffness is a distinct finding in patients who have heart failure with normal ejection fraction (HFNEF). To elucidate how diastolic dysfunction contributes to heart failure symptomatology during exercise, we conducted a study using an invasive pressure-volume loop approach and measured cardiac function at rest and during ...
Cirillo Marco - - 2008
OBJECTIVES: To verify whether the use of a small, oval-shaped patch limits the trend toward re-dilatation compared to endoventricular circular patch plasty and leads to different geometrical and functional results in surgical anterior restoration. METHODS: Thirty-seven patients with ischemic cardiomyopathy after anterior myocardial infarction end-systolic volume index of > or ...
Toschi N - - 2008
Mechanical interplay between the adjacent ventricles is one of the principal modulators of physiopathological heart function, and the underlying mechanisms of interaction are only partially understood, hence hampering clinically useful interpretation of imaging data. In order to characterize the influence of chamber geometry on ventricular coupling, the ventricles and septum ...
Soriano Brian D - - 2008
BACKGROUND: Quantitative assessment of ventricular volumes and mass in pediatric patients with single-ventricle physiology would aid clinical management, but it is difficult to obtain with 2-dimensional echocardiography. The purpose of the present study was to compare matrix-array 3-dimensional echocardiography (3DE) measurements of single-ventricle volumes, mass, and ejection fraction with those ...
Do─čan H - - 2008
The objective of the study was to assess the effect of heart rate, filling condition and slice thickness on the accuracy of volumetric analysis based on multidetector-row computed tomography (MDCT) of a cardiac phantom. Retrospective electrocardiogram-gated MDCT of a pulsating phantom was performed under different conditions. End-diastolic volume (EDV) and ...
Rocca Giorgio Della - - 2008
Cardiac preload is traditionally considered to be represented by its filling pressures, but more recently, estimations of end diastolic volume of the left or right ventricle have been shown to better reflect preload. One method of determining volumes is the evaluation of the continuous right ventricular end diastolic volume index ...
Minczykowski Andrzej - - 2008
PURPOSE: Sonographic myocardial tissue characterization with integrated backscatter (IBS) is affected by both structural and functional properties of the myocardium. The aim of the present study was to investigate the effect of preload reduction by hemodialysis (HD) on IBS measurements. METHODS: Fifty-two patients on maintenance HD underwent echocardiography before and ...
Loiselle D S - - 2008
In this brief review, we have focussed largely on the well-established, but essentially phenomenological, linear relationship between the energy expenditure of the heart (commonly assessed as the oxygen consumed per beat, oxygen consumption (VO2)) and the pressure-volume-area (PVA, the sum of pressure-volume work and a specified 'potential energy' term). We ...
Freudenberger Ronald - - 2008
BACKGROUND: Postextrasystolic potentiation (PESP) is a property of cardiac tissue whereby two closely timed depolarizations cause the subsequent contraction to be of increased magnitude. METHODS AND RESULTS: Ten subjects were studied in a single-blind study to evaluate the safety and performance of an atrioventricular coupled pacing (A-VCP) algorithm to produce ...
Inage Tomohito - - 2008
AIMS: The aim of this study was to assess chronic invasive haemodynamic effects of cardiac resynchronization therapy (CRT) in patients with severe heart failure. METHODS AND RESULTS: Seventeen patients with New York Heart Association (NYHA) class III or IV and QRS duration >120 ms on optimal treatments underwent CRT. Haemodynamic ...
Sagiv Moran - - 2008
PURPOSE: We evaluated left ventricular contractility during upright isometric exercise, in heart transplant recipients (HTRs) and in healthy controls, using ejection fraction and end-systolic pressure/volume ratio indexes. METHODS: Fifteen healthy men (40 +/- 13 years) and 10 HTRs (42 +/- 12 years) underwent dead lift (DL) test at 30% of ...
Suzuki Kazuyuki - - 2008
We studied the effect of a small volume of 7.2% hypertonic saline solution (HSS) or HSS with 6% dextran 70 (HSD) on hemodynamic status, especially on cardiac contractility, in anesthetized dogs using the left ventricular end-systolic volume index (ESVI) and ejection fraction (EF), which can be obtained in noninvasive echocardiography. ...
Fukuta Hidekatsu - - 2008
Heart failure is defined as the pathologic state in which the heart is unable to pump blood at a rate required by the metabolizing tissues or can do so only with an elevated filling pressure. Heart failure in adults most frequently results from the inability of the left ventricle to ...
Osranek Martin - - 2008
Patients with hypertension exhibit impaired energetic coupling between the ventricle and the arterial system, leading to reduced cardiac mechanic efficiency and exercise capacity. We tested whether blood pressure normalization with current antihypertensive therapy can improve arterioventricular coupling. Eighteen hypertensive patients without other cardiovascular disease were examined before and after antihypertensive ...
Hanft Laurin M - - 2008
The Frank-Starling relationship provides beat-to-beat regulation of ventricular function by matching ventricular input and output. This review addresses the subcellular mechanisms by which the ventricle adjusts its output (i.e. stroke volume) by changes in end-diastolic volume. The subcellular processes are placed in the context of the four phases of the ...
Renner J - - 2008
BACKGROUND AND OBJECTIVES: The myocardial performance index is a non-geometric, heart rate-independent echocardiography-derived index of left ventricular performance combining systolic and diastolic function. There is an ongoing debate whether the myocardial performance index is affected by preload or not. Moreover, a systematic evaluation of the effect of changing tidal volume ...
Riordan Matt M - - 2008
Cardiac output maintenance is so fundamental that, when regional systolic function is impaired, as during ischemia, nonischemic segments compensate by becoming hypercontractile. By analogy, diastolic compensatory mechanisms that maintain filling volume must exist but remain to be fully elucidated. Viewing filling in spatially distinct (longitudinal, radial) mechanistic terms facilitates elucidation ...
Li Xiu-Chang - - 2008
Real-time three-dimensional (3D) echocardiography (RT-3DE) provides a unique technique to evaluate left ventricular regional function in a 3D format. We aimed to explore whether the left ventricular segmental volume and systolic function is uniform and to establish normal values of volume and systolic function parameters of 16 regions in healthy ...
Stekelenburg-de Vos S - - 2007
OBJECTIVES: Fluid mechanical forces affect cardiac development. In the chicken embryo, permanent obstruction of the right lateral vitelline vein by clipping reduces the mechanical load on the embryonic myocardium, which has been shown to induce a spectrum of outflow tract anomalies. Insight into the effects of this intervention on the ...
Pearson James T - - 2007
The cellular basis of the length-dependent increases in contractile force in the beating heart has remained unclear. Our aim was to investigate whether length-dependent mediated increases in contractile force are correlated with myosin head proximity to actin filaments, and presumably the number of cross-bridges activated during a contraction. We therefore ...
Hofer Christoph K - - 2008
OBJECTIVES: The aim of this study was to compare the following approaches to assess left ventricular preload by transesophageal echocardiography (TEE): left ventricular end-diastolic volume index (LVEDVI) determined by using the method of disc summation (LVEDVI(Md)) and left ventricular end-diastolic area index (LVEDAI) were compared with LVEDVI assessed by the ...
Rex S - - 2007
BACKGROUND: In addition to their well-known ability to predict fluid responsiveness, functional pre-load parameters, such as the left ventricular stroke volume variation (SVV) and pulse pressure variation (PPV), have been proposed to allow real-time monitoring of cardiac pre-load. SVV and PPV result from complex heart-lung interactions during mechanical ventilation. It ...
Messing B - - 2007
OBJECTIVE: Quantification of fetal heart ventricle volume can aid in the evaluation of functional and anatomical aspects of congenital heart disease. The aim of this study was to establish nomograms for ventricular volume using three-dimensional (3D) inversion mode ultrasonography with the spatio-temporal image correlation (STIC) modality and to calculate ejection ...
Ahmed Syed N - - 2007
Hemodynamic assessment is a constant and common task in critically ill and injured patients. Correct interpretation of this data is vital to implement the appropriate intervention, if any. It can be difficult to properly interpret derived and measured data from a pulmonary artery catheter for optimal care of these difficult ...
Takahara Akira - - 2007
Chronic atrioventricular block dogs have been established as an in vivo model of drug-induced torsades de pointes arrhythmias. We compared the cardiovascular profile of the canine model with that of sham-operated animals using echocardiographic and haemodynamic methods. In the echocardiographic study, the larger diameters of the left atria, inferior vena ...
Costa M G - - 2007
Assessing the optimal volemia in the perioperative course of liver transplantation is a challenge for the anesthesiologist. Traditional estimates of intravascular volume status, such as pulmonary artery occlusion pressure (PAOP), have been widely shown to poorly correlate with changes in cardiac output among critically ill patients. Hence, there has been ...
Langer Frank - - 2007
BACKGROUND: Increased circumferential-radial shear in the midlateral left ventricle adjacent to ischemic myocardium has been observed during acute midcircumflex ischemia in open-chest animals. Extending this work, we studied transmural strains in closed-chest animals during acute proximal-circumflex (pCX) and proximal-left anterior descending (pLAD) occlusions. METHODS: Six sheep had radiopaque markers implanted ...
Psaltopoulou T - - 2007
Subclinical hyperthyroidism (SH) is defined by suppressed TSH and normal levels of thyroid hormones. Endogenous subclinical hyperthyroidism (ESH) is probably less common than exogenous SH. Adverse effects of SH due to exogenous administration of thyroxine have been well studied, while the impact of ESH on the cardiovascular system and metabolic ...
Guadagnoli J A - - 2007
The ventricular pressure-volume (PV) relationship has been used extensively to study the mechanics and energetics in multi-chambered hearts of closed circulatory system vertebrates. In the current study we applied the use of PV loops in the assessment of cardiac mechanics and energetics in the single ventricle of a decapod crustacean ...
Della Rocca Giorgio - - 2007
PURPOSE OF REVIEW: To update the situation over the past few years on the clinical application of volumetric measures of preload in critically ill patients. RECENT FINDINGS: Cardiac filling pressures monitoring is unreliable for assessing cardiac preload in mechanically ventilated critically ill patients. The transpulmonary dilution indicator technique was shown ...
Colacino Francesco M - - 2007
The aim of this work is to investigate the dependence between left ventricular load impedance control by an apical ventricular assist device (VAD) and the consequent benefits for pathological heart recovery. A pathological left ventricle with 34% contractility has been simulated in the assisted and nonassisted conditions. By means of ...
Moscato Francesco - - 2007
For better understanding of the interaction between left ventricle and continuous cardiac assist, the effect of different working conditions and support levels on left ventricular pressure-volume (PV) loop was investigated in acute animal experiments. A MicroMed-DeBakey ventricular assist device (MicroMed Cardiovascular Inc., Houston, TX, USA) was implanted in seven healthy ...
Gopal Aasha S - - 2007
BACKGROUND: Assessment of right ventricular function by 2-dimensional echocardiography (2DECHO) is difficult because of its complex shape. Real-time 3-dimensional echocardiography (RT3DECHO) may be superior. METHODS: End-diastolic volume, end-systolic volume, stroke volume, and ejection fraction obtained by 2DECHO, RT3DECHO short-axis disk summation (DS), and RT3DECHO apical rotation were compared with cardiac ...
Barraud Damien - - 2007
OBJECTIVE: Current treatment strategies for severe septic conditions (i.e., intravenous fluids, vasopressors, and cardiac inotropes) reestablish fluid balance and improve cardiac systole but do not address diastolic dysfunction. Our study aimed to fully characterize both systolic and diastolic abnormalities of sepsis-associated heart failure and to identify treatment that would support ...
Haney M F - - 2007
BACKGROUND: This study was designed to assess the relationship of the "myocardial performance index" (MPI) to the beat-by-beat change in pre-load with static or unchanged contractile status. METHODS: Eight anesthetized juvenile pigs were studied using direct measurement of the left ventricular pressure and volume. Transient inflation of a vena cava ...
Lam Carolyn S P - - 2007
Mechanisms purported to contribute to the pathophysiology of heart failure with normal ejection fraction (HFnlEF) include diastolic dysfunction, vascular and left ventricular systolic stiffening, and volume expansion. We characterized left ventricular volume, effective arterial elastance, left ventricular end-systolic elastance, and left ventricular diastolic elastance and relaxation noninvasively in consecutive HFnlEF ...
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