BACKGROUND In patients with severe sepsis, depression of cardiac performance is common and is often associated with left ventricular (LV) dilatation to maintain stroke volume. Although it is essential to optimize cardiac preload to maintain tissue perfusion in patients with severe sepsis, the optimal preload remains unknown. This study aimed to evaluate the reliability of global end-diastolic v...

We studied the effect of an isolated increase in preload on isovolumetric relaxation in the intact dog heart and isometric relaxation in isolated cardiac muscle (dog and rat) preparations. In eight anesthetized dogs, 8 to 12 ml of blood was infused into the left ventricle during a single diastole. The exponential time constant (T) of isovolumetric relaxation was measured in single-beat experime...

As a key parameter, stiffness determines the dynamic characteristics of both bearing and spindle unit. However, interactions between speed, initial preload, cutting force caused by thermal expansion unit components alter during running process. Aiming to carry out real-time online monitoring their effect on machine tool stiffness, fiber Bragg grating (FBG) sensors network was proposed. Further,...

We studied the effect of an isolated increase in preload on isovolumetric relaxation in the intact dog heart and isometric relaxation in isolated cardiac muscle (dog and rat) preparations. In eight anesthetized dogs, 8 to 12 ml of blood was infused into the left ventricle during a single diastole. The exponential time constant (T) of isovolumetric relaxation was measured in single-beat experime...

It was considered that the relationship between dp/dt and simultaneously developed pressure during the course of isovolumic contraction might afford a more accurate measure of contractility than the maximum rate of intraventricular pressure rise (peak dp/dt). In six cat papillary muscles contracting isometrically from any given preload, the ratio of the rate of tension development (dT/dt) to si...

Anaesthesia was induced in 58 women (ASA I or II) undergoing elective gynaecological procedures, using propofol 2.5 mg kg-1 and fentanyl 1.5 micrograms kg-1. Patients were allocated to receive 20 ml kg-1 of crystalloid fluid preload over 20 min or to receive no fluids before induction of anaesthesia. A significant decrease in systolic arterial pressure (< 75% of baseline value) occurred in both...

Left ventricular ejection fraction (EF) depends on ventricular contractility, afterload, and preload. Preload is related to end-diastolic volume (EDV) and pressure; the relationship between these 2 parameters (the end-diastolic pressurevolume relationship, EDPVR) indexes the degree of ventricular remodeling. Although EF is known to correlate with mortality in the subset of heart failure patient...

Introduction: Non-invasive measurement of regional cardiac function is critical for the evaluation and development of pharmacologic, stem cell, and mechanical therapies to prevent adverse ventricular remodeling (1,2). Current methods require catheterization, have limited spatial resolution or field-of-view. Tyberg placed strain gauges directly on the epicardium to measure work (3). Current imag...

This paper presents a novel test rig, developed to analyse the behaviour of rolling element bearings subjected to highly varying loads. The design is optimised to measure the bearing behaviour, free from dynamics of the surrounding structure. A test bearing is mounted in a floating housing supported by flexible air springs, providing a preload force on the bearing. This allows measuring the rig...

Glyceryl trinitrate (GTN) is a potent vasodilator. It causes venodilatation which reduces venous return to the heart and thus reduces preload and also causes arterial vasodilatation which reduces left ventricular afterload. In angina pectoris these effects reduce myocardial wall tension and thereby reduce myocardial oxygen consumption and arterial vasodilatation increases myocardial oxygen deli...