Search Results
Results 301 - 350 of 2719
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Notomi Yuichi - - 2008
Left ventricular (LV) untwisting starts early during the isovolumic relaxation phase and proceeds throughout the early filling phase, releasing elastic energy stored by the preceding systolic deformation. Data relating untwisting, relaxation, and intraventricular pressure gradients (IVPG), which represent another manifestation of elastic recoil, are sparse. To understand the interaction between ...
Geske Jeffrey B - - 2007
BACKGROUND: Diastolic dysfunction is a major pathophysiological abnormality in hypertrophic cardiomyopathy (HCM). Doppler echocardiographic parameters correlate with left ventricular (LV) filling pressures in other diseases, but it is unclear whether these findings apply to patients with HCM, who have multiple complex interrelated events leading to diastolic dysfunction. This study compares ...
Levine Benjamin D - - 2008
Maximal oxygen uptake (.VO(2,max)) is a physiological characteristic bounded by the parametric limits of the Fick equation: (left ventricular (LV) end-diastolic volume--LV end-systolic volume) x heart rate x arterio-venous oxygen difference. 'Classical' views of .VO(2,max) emphasize its critical dependence on convective oxygen transport to working skeletal muscle, and recent data ...
Chen Ling - - 2008
Obstructive sleep apnea (OSA) increases cardiovascular morbidity and mortality. We have reported that chronic intermittent hypoxia (CIH), a direct consequence during OSA, leads to left ventricular (LV) remodeling and dysfunction in rats. The present study is to determine LV myocardial cellular injury that is possibly associated with LV global dysfunction. ...
Pingitore Alessandro - - 2008
Prolonged breath hold (BH) represents a valid model for studying the cardiac adaptation to acute hypoxemia in humans. Cardiac magnetic resonance (CMR) allows a three-dimensional, high-resolution, noninvasive, and nonionizing anatomical and functional evaluation of the heart. The aim of the study was to assess the adaptation of the cardiovascular system ...
Xu Qi - - 2008
The effect of endogenous relaxin on the development of cardiac hypertrophy, dysfunction, and fibrosis remains completely unknown. We addressed this question by subjecting relaxin-1 deficient (Rln1-/-) and littermate control (Rln1+/+) mice of both genders to chronic transverse aortic constriction (TAC). The extent of left ventricular (LV) remodeling and dysfunction were ...
Hori Yasutomo - - 2007
OBJECTIVE: To investigate the relationship between the myocardial performance index (MPI) determined by use of pulsed Doppler (PD) echocardiography and tissue Doppler imaging (TDI) in the response to volume overload-related changes in left ventricle (LV) performance. ANIMALS: 7 male Beagles. PROCEDURES: Dogs were anesthetized and intubated. A 6-F fluid-filled catheter ...
Strand Arne - - 2007
We have previously demonstrated that neurohormonal activity can predict left ventricular (LV) mass in men who developed hypertension over 20 years. The aim of the study was to investigate early markers of cardiac and hemorheological changes at baseline in these men, i.e., before a rise in blood pressure. Fifty-six middle-aged ...
Mizuguchi Yukio - - 2007
BACKGROUND: It is well known that left ventricular (LV) diastolic function declines in the elderly, especially in patients with cardiovascular risk factors. However, few data are available on the early detection of relationship between arterial stiffness and LV diastolic dysfunction. METHODS AND RESULTS: The common carotid artery intima-media thickness (IMT) ...
Chiladakis John A - - 2007
INTRODUCTION: Conventional, atrial-synchronised, right ventricular apical pacing (VP) may compromise ventricular function by causing ventricular desynchronisation. The aim of this study was to evaluate the long-term effects of VP on left and right ventricular systolic and diastolic function. METHODS: We studied 21 clinically stable dual-chamber pacemaker recipients (mean age 68 ...
Goto Koji - - 2007
STUDY OBJECTIVE: To examine the effect of landiolol (normal dose) on hemodynamics and left ventricular (LV) function. DESIGN: Prospective, observational, repeated-measures study. SETTING: University hospital. PATIENTS: 56 adult patients who were diagnosed with angina pectoris and who underwent elective off-pump coronary artery bypass surgery. INTERVENTIONS: Patients were divided into two ...
Mornos Cristian - - 2008
N-terminal pro-brain natriuretic peptide (NTproBNP) correlates with left ventricular (LV) filling pressure. The ratio between early diastolic transmitral velocity and early mitral annular diastolic velocity (E/Ea) reflects LV filling pressure in a variety of cardiac diseases. However this relationship was not validated in some categories of patients. Our aim was ...
Ferrazzi Paolo - - 2007
OBJECTIVES: We hypothesize that the implantation of an endoventricular elastic ring at the left ventricle (LV) equatorial site will positively affect the cardiac mechanics in an experimental model of acute LV dysfunction. BACKGROUND: Changes in the elastic properties of LV occur in the dilated and failing heart, contributing to overall ...
Vazeou A - - 2008
Left ventricular (LV) function was assessed in 42 patients (mean age +/- SD, 18.45 +/- 3.76 years; 17 males) with type I diabetes mellitus (T1DM; mean duration 9.89 years) and in 43 healthy controls (mean age +/- SD, 18.27 +/- 3.36 years; 18 males). Systolic, diastolic cardiac function and LV ...
Birner Christoph M - - 2007
Activation of BNP and IL-6 are hallmarks of left ventricular (LV) dysfunction and congestive heart failure (CHF). To assess the relative activation of BNP and IL-6 in clinical and experimental heart failure, we performed a human study in which plasma N-terminal proBNP (NT-proBNP) and IL-6 were measured in a large ...
Becker Michael - - 2007
We sought to define the impact of echocardiographically defined left ventricular (LV) lead position on the efficacy of cardiac resynchronization therapy (CRT) in a serial study using 3-dimensional echocardiography. Fifty-eight consecutive patients (53+/-9 years of age; 37 men) with heart failure were included in the study. Echocardiograms were obtained before ...
Saraiva R M - - 2007
The severity of left ventricular (LV) dysfunction in rats with myocardial infarction (MI) varies widely. Because homogeneity in baseline parameters is essential for experimental investigations, a study was conducted to establish whether Doppler echocardiography (DE) could accurately identify animals with high LV end-diastolic pressure as a marker of LV dysfunction ...
Clemente Carolina F M Z - - 2007
Hypertrophy is a critical event in the onset of failure in chronically overloaded hearts. Focal adhesion kinase (FAK) has attracted particular attention as a mediator of hypertrophy induced by increased load. Here, we demonstrate increased expression and phosphorylation of FAK in the hypertrophic left ventricles (LVs) of aortic-banded mice. We ...
Yoshida Kentaro - - 2007
AIMS: This study examined the impact of cardiac resynchronization therapy (CRT) by triangle ventricular pacing (Tri-V) on left ventricular (LV) function and dyssynchrony. METHODS AND RESULTS: Twenty-one patients with NYHA class III or IV heart failure were studied. For Tri-V, two right ventricular (RV) leads were connected to the CRT ...
Bodyak Natalya - - 2007
Observations in hemodialysis patients suggest a survival advantage associated with activated vitamin D therapy. Left ventricular (LV) structural and functional abnormalities are strongly linked with hemodialysis mortality. Here, we investigated whether paricalcitol (PC, 19-nor-1,25(OH)(2)D(2)), an activated vitamin D compound, attenuates the development of LV abnormalities in the Dahl salt-sensitive (DSS) ...
Jöbsis Paul D - - 2007
Much attention has been focused on the passive mechanical properties of the myocardium, which determines left ventricular (LV) diastolic mechanics, but the significance of the visceral pericardium (VP) has not been extensively studied. A unique en face three-dimensional volumetric view of the porcine VP was obtained using two-photon excitation fluorescence ...
Firstenberg Michael S - - 2008
BACKGROUND: Early diastolic intraventricular pressure gradient (IVPG), as derived by color M-mode echocardiography, has been proposed to correlate with left ventricular (LV) elastic recoil. However, any relationship to quantifiable indices of LV contractility is poorly defined. METHODS: To relate IVPG with invasive and noninvasive indices of contractility, 6 closed-chest dogs ...
Yoshioka Jun - - 2007
Biomechanical overload induces cardiac hypertrophy and heart failure, and reactive oxygen species (ROS) play a role in both processes. Thioredoxin-Interacting Protein (Txnip) is encoded by a mechanically-regulated gene that controls cell growth and apoptosis in part through interaction with the endogenous dithiol antioxidant thioredoxin. Here we show that Txnip is ...
Baltabaeva Aigul - - 2008
AIM: In the early stages of hypertension (HTN), when global left ventricular (LV) function is still unaffected, localized geometrical changes suggest changes in regional function. We investigated regional geometry and systolic deformation (using strain/strain rate (S/SR) imaging) in HTN. METHODS AND RESULTS: We studied 74 untreated mild to moderate HTNs ...
Jansen Annemieke - - 2008
AIMS: Left ventricular (LV) ejection fraction is an important determinant of prognosis in heart failure. We evaluated the accuracy of a novel algorithm for LV ejection fraction quantification based on indicator dilution curve (IDC) principles using ultrasound contrast as indicator, and compared the results with contrast enhanced biplane LV ejection ...
Shinke Toshiro - - 2007
BACKGROUND: Excessive oxidative stress is considered one of the mechanisms of a decrease in contractile force without concomitant reduction in oxygen cost in failing myocardium. We hypothesized that the antioxidant vitamin C may help reverse hyporesponsiveness to beta-adrenergic stimulation and improve myocardial efficiency in patients with heart failure (HF) after ...
Dokainish Hisham - - 2007
Tissue Doppler imaging is an echocardiographic technique that directly measures myocardial velocities. Diastolic tissue Doppler velocities reflect myocardial relaxation, and in combination with conventional Doppler measurements, ratios (transmitral early diastolic velocity/mitral annular early diastolic velocity [E/Ea]) have been developed to noninvasively estimate left ventricular (LV) filling pressure. Consequently, mitral E/Ea ...
Hamada Mareomi - - 2007
BACKGROUND: Cibenzoline is able to improve left ventricular (LV) diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM), but the exact mechanism remains to be determined. METHODS AND RESULTS: The present study was designed to elucidate the effect of intravenous administration of 1.4 mg/kg of cibenzoline on aortic and LV pressures, ...
Kneffel Zsuzsanna - - 2007
The relationship between relative aerobic power (rel.VO(2)max) as a generally accepted indicator of endurance capacity and certain characteristics of the athlete's heart, such as body-size related (relative) left ventricular (LV) diastolic wall thickness (WTd), internal diameter (LVIDd), muscle mass (MM), WTd/IDd, heart rate (HR), fractional shortening (FS) and E/A ratio, ...
Remmelink Maurice - - 2007
OBJECTIVES: We studied the effects of LV unloading by the Impella on coronary hemodynamics by simultaneously measuring intracoronary pressure and flow and the derived parameters fractional flow reserve (FFR), coronary flow velocity reserve (CFVR), and coronary microvascular resistance (MR). BACKGROUND: Patients with compromised left ventricular (LV) function undergoing high-risk percutaneous ...
Baker G Hamilton - - 2008
INTRODUCTION: We used 3-dimensional (3D) echocardiography to identify and quantify left ventricular (LV) dyssynchrony in children with LV dysfunction compared with control subjects. METHODS: The 3D echocardiography LV full volumes were acquired in 18 children, 9 with LV dysfunction and 9 control subjects. The LV was subdivided into 16 segments ...
Hydock David S - - 2007
Reducing testosterone and estrogen levels with a luteinizing hormone-releasing hormone agonist such as Zoladex (i.e., chemical gonadectomy) is a common treatment for many prostate and breast cancer patients, respectively. There are reports of surgical gonadectomy inducing cardiac dysfunction, and exercise has been shown to be cardioprotective under these circumstances. Minimal ...
Ciobotaru Vlad - - 2008
We investigated the effects of long-term heart rate reduction (HRR) on pressure overload-induced heart failure. Pressure overload of the left ventricle was induced in 21-day-old rats by banding the ascending aorta. HRR was induced for 3 months with ivabradine (n = 44), a selective I(f) current inhibitor, at 10 mg/kg/day, ...
Byrne Melissa J - - 2007
OBJECTIVES: We compared mechanical dyssynchrony and the impact of cardiac resynchronization therapy (CRT) in failing hearts with a pure right (RBBB) versus left bundle branch block (LBBB). BACKGROUND: Cardiac resynchronization therapy is effective for treating failing hearts with conduction delay and discoordinate contraction. Most data pertain to LBBB delays. With ...
Mullens Wilfried - - 2008
BACKGROUND: Heart failure is associated with a reduction in left ventricular (LV) contractility as evidenced by a blunted force-frequency response (FFR) and downregulation of contractility regulating genes. OBJECTIVE: This study sought to investigate whether cardiac resynchronization therapy (CRT) is capable of reversing the blunted FFR and the downregulation of contractility ...
Johnson Lauren - - 2007
The goal of the present study was to assess the effects of left ventricular (LV) pacing sites (apex vs. free wall) on radial synchrony and global LV performance in a canine model of contraction dyssynchrony. Ultrasound tissue Doppler imaging and hemodynamic (LV pressure-volume) data were collected in seven anesthetized, opened-chest ...
Marsan Nina Ajmone - - 2008
PURPOSE: To compare left ventricular (LV) dyssynchrony assessment by phase analysis from gated myocardial perfusion SPECT (GMPS) with LV dyssynchrony assessment by tri-plane tissue Doppler imaging (TDI). Baseline LV dyssynchrony assessed with standard deviation (SD) of time-to-peak systolic velocity of 12 LV segments (Ts-SD) with TDI has proven to be ...
Hung Judy - - 2007
BACKGROUND: Recurrent ischemic mitral regurgitation (IMR) is frequent despite initial reduction by annuloplasty because continued LV remodeling increases tethering to the infarcted papillary muscle (PM). We have previously shown that PM repositioning by an external patch device can acutely reduce IMR. In this study, we tested the hypothesis that IMR ...
Fox Ervin R - - 2007
BACKGROUND: There are limited data on the prevalence and the clinical and echocardiographic correlates of pure valvular regurgitation in African Americans despite the higher rates of cardiovascular disease in this group. PURPOSE: The Jackson, Mississippi, site of the Atherosclerosis Risk in Communities study provides a unique opportunity to study mitral ...
Mitoff Peter R - - 2007
BACKGROUND: Women with systolic heart failure (HF) demonstrate better survival than men. Whether sex differences occur in hemodynamics or measures of left ventricular (LV) function is not well understood. METHODS: We retrospectively analyzed a cohort who underwent evaluation by right heart catheterization +/- micromanometer-tipped catheterization of the LV. Two groups, ...
Nakao Shinji - - 2007
BACKGROUND: Although Doppler left ventricular (LV) filling abnormalities have been extensively analyzed in patients with systolic heart failure (SHF), they have not yet been well characterized in patients with acute to chronic diastolic heart failure (DHF) in the light of plasma brain natriuretic peptide (BNP) levels. METHODS AND RESULTS: In ...
Boussuges Alain - - 2007
The present study was designed to assess the cardiac changes induced by cold water immersion compared with dry conditions during a prolonged hyperbaric and hyperoxic exposure (ambient pressure between 1.6 and 3 ATA and PiO(2) between 1.2 and 2.8 ATA). Ten healthy volunteers were studied during a 6 h compression ...
Nishijima Yoshinori - - 2007
While cardiac resynchronization therapy (CRT) has been shown to reduce morbidity and mortality in heart failure (HF) patients, the fundamental mechanisms for the efficacy of CRT are poorly understood. The lack of understanding of these basic mechanisms represents a significant barrier to our understanding of the pathogenesis of HF and ...
Alter P - - 2008
In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived ...
Lionetti Vincenzo - - 2007
Increased glucose utilization and regional differences in contractile function are well-known alterations of the failing heart and play an important pathophysiological role. We tested whether, similar to functional derangement, changes in glucose uptake develop following a regional pattern. Heart failure was induced in 13 chronically instrumented minipigs by pacing the ...
Ceyhan Ceyhun - - 2008
The utility of N-Terminal pro Brain Natriuretic Peptide (NT-proBNP) and Brain Natriuretic Peptide (BNP) for detecting left ventricular (LV) diastolic dysfunction in hypertensive patients without heart failure symptoms is unclear. In this study, we investigated the relation between NT-proBNP plasma levels and LV diastolic dysfunction in hypertensive patients without systolic ...
Tsai Chia-Ti - - 2008
BACKGROUND: To evaluate the left atrial (LA) volume, and LA systolic (contractile) and diastolic (expansion) functions in different stages of hypertension with or without atrial fibrillation (AF), as well as the effects of good blood pressure control. METHODS: A prospective observational study. Individuals including 22 normotensive controls, 23 patients with ...
Mansouri Vafa - - 2007
BACKGROUND: With left ventricular (LV) dysfunction, it is not clear how alterations in external constraint influence the index of myocardial performance (IMP). We have previously demonstrated that pericardial constraint is a factor in the production of the restrictive filling pattern. We hypothesized that altering pericardial constraint by changing intracardiac volume ...
Ballo Piercarlo - - 2007
OBJECTIVE: Previous studies evaluated the effect of obesity on left ventricular (LV) mass and systolic function in healthy subjects and in patients with coexistent chronic LV pressure overload due to hypertension, but no data exist regarding subjects with underlying volume overload. This study assessed the impact of overweight-obesity on LV ...
Fei Hongwen - - 2007
The volume-time curve change in patients with normal left ventricular (LV) diastolic function and diastolic dysfunction was evaluated by real-time three-dimensional echocardiography (RT3DE). LV diastolic dysfunction was defined by E'<A' in pulse-wave tissue Doppler for inter-ventricular septal (IVS) of mitral annulus. In 24 patients with LV diastolic dysfunction, including 12 ...
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