Sökning: "left ventricular contractility"
Visar resultat 1 - 5 av 17 avhandlingar innehållade orden left ventricular contractility.
1. Strain echocardiography in cardiac surgery - studies on the effects of loading conditions and inotropic agents on myocardial contraction and relaxation
Sammanfattning : Background: Although reductions in myocardial contractility and relaxation are key compo-nents in heart failure (HF), assessment of them is difficult, as clinical measurements deal with a net effect of myocardial contractility, heart filling (preload), outflow impedance (afterload) and heart rate (HR). Echocardiographic (echo) deformation parameters, like strain (myocardial shortening) and strain rate (the speed of deformation, SR), have been proposed to more accu-rately measure myocardial function, but incongruent previous studies have raised concerns that they may be load-dependent. LÄS MER
2. Left ventricular function's relation to load, experimental studies in a porcine model
Sammanfattning : Background: Loading conditions are recognized to influence ventricular function according to the Starling relationship for length/stretch and force. Many modern echocardiographic parameters which have been announced as describing ventricular function and contractile status, may be confounded by uncontrolled and unmeasured load. LÄS MER
3. Cardiac Resynchronization Therapy Optimization : Comparison and Evaluation of Non-invasive Methods
Sammanfattning : The general purpose of this thesis was to investigate new cardiac resynchronization therapy (CRT) optimization techniques and to assess their reliability when compared to invasive measurements of left ventricular contractility (LV dP/dtmax).We first assessed whether cardiac output (CO) measured by trans-thoracic impedance cardiography could correctly identify the optimal interventricular (VV) pacing interval while using invasive measurements of LV dP/dtmax as reference. LÄS MER
4. Levosimendan in early experimental sepsis: effects on the heart and hepatosplanchnic circulation
Sammanfattning : Sepsis-related cardiovascular dysfunction associated with fluid-unresponsive tissue hypoperfusion might require inotropic treatment. This cardiovascular dysfunction seems to involve calcium desensitization and adrenergic unresponsiveness. LÄS MER
5. Echocardiographic assessment of ventricular size and function in heart transplant patients
Sammanfattning : AbstractThe overall aims of this thesis were to use echocardiography to non-invasively, delineate early structural andfunctional changes following orthotopic heart transplantation (OHT), and to define reference values in the contextof gender and bridging with mechanical circulatory support.Several factors might affect myocardial function in OHT patients rendering the use of normal values fortransthoracic echocardiography derived from healthy subjects unsatisfactory. LÄS MER