نتایج جستجو برای: systolic shortening
تعداد نتایج: 71184 فیلتر نتایج به سال:
The present study was designed to investigate the anisotropy of systolic chord shortening hi the lateral, inferior, septal, and anterior regions of the human left ventricle. At the time of surgery, 12 miniature radiopaque markers were implanted into the left ventricular midwall of the donor heart in 15 cardiac transplant recipients. Postoperative biplane cineradiograms were computeranalyzed to ...
BACKGROUND Long-standing aortic stenosis causes significant left ventricular (LV) dysfunction, which may progress irreversibly. In many cases, LV function can be salvaged by aortic valve surgery, although debate exists regarding the best valve prosthesis to use. METHODS AND RESULTS We studied 33 patients retrospectively who had significant aortic stenosis and impaired LV systolic function, as...
With aging, structural and functional changes occur in the myocardium without obvious impairment of systolic left ventricular (LV) function. Transmural differences in myocardial vulnerability for these changes may result in increase of transmural inhomogeneity in contractile myofiber function. Subendocardial fibrosis and impairment of subendocardial perfusion due to hypertension might change th...
Despite normal indices of left ventricular (LV) chamber function, patients with LV hypertrophy (LVH) due to hypertension are thought to have depressed midwall systolic shortening compared with normotensives. The aims of the present study were (1) to confirm this observation and (2) to assess the effects of antihypertensive therapy that cause regression of LVH on LV systolic function assessed at...
BACKGROUND We describe a method for 3-/4D reconstruction of tissue Doppler data from three standard apical planes, post processing to derived data of strain rate/strain and parametric colour imaging of the data. The data can be displayed as M-mode arrays from all six walls, Bull's eye projection and a 3D surface figure that can be scrolled and rotated. Numerical data and waveforms can be re-ext...
Background—Normal left ventricular myocardium demonstrates distinct spikes in the velocity trace before and after left ventricular ejection. We tested the hypothesis that the preejection and postejection velocity spikes reflect early systolic shortening and late systolic lengthening that are interrupted by mitral and aortic valve closure, respectively. Methods and Results—In 11 anesthetized dog...
This study is written in a way to stress the importance of introducing the active force generated by the myocardium in the formalism describing the pressure-volume relation (PVR) in the left ventricle. Various clinical applications of the end-systolic pressure-volume relation (ESPVR) are also discussed. Attention is given to the calculation of the ejection fraction (EF) and the myocardial longi...
BACKGROUND Normal left ventricular myocardium demonstrates distinct spikes in the velocity trace before and after left ventricular ejection. We tested the hypothesis that the preejection and postejection velocity spikes reflect early systolic shortening and late systolic lengthening that are interrupted by mitral and aortic valve closure, respectively. METHODS AND RESULTS In 11 anesthetized d...
Myocardial post-systolic shortening is characterized by a large variability in both duration and magnitude. Although typically occurring in a setting of ischemic heart disease, this regionally asynchronous myocardial contraction is considered a normal finding in approximately one-third of myocardial segments in healthy subjects, as long as the magnitude is low and the systolic strain is preserv...
BACKGROUND Recent in-vitro observations suggest that left ventricular (LV) contraction is powered by 'stretch activation', an intrinsic mechanism by which the stretching of an activated cardiomyocyte causes delayed force redevelopment. We hypothesized that mechanical dyssynchrony is related to prolonged early systolic stretch that delays the timing of peak segmental shortening. METHODS AND RE...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید