Left atrial contraction strain during a Valsalva manoeuvre: A study in healthy humans.

Background: Cardiac mechanics are influenced by loading conditions as well as sympathetic tone. Left atrial (LA) contractile function assessed by two-dimensional (2D) strain has been described in the setting of controlled preload alterations; however, studies show conflicting findings about change or direction of change. We hypothesized that the controlled preload reduction and the sympathetic nervous system activation that occurs during a standardized Valsalva manoeuvre would bring about a change in LA contraction strain.

Pre-operative point-of-care assessment of left ventricular diastolic dysfunction, an observational study.

Background: Left ventricular (LV) diastolic dysfunction is an acknowledged peri-operative risk factor that should be identified before surgery. This study aimed to evaluate a simplified echocardiographic method using e' and E/e' for identification and grading of diastolic dysfunction pre-operatively.

Methods: Ninety six ambulatory surgical patients were consecutively included to this prospective observational study.

Left atrial contraction strain and controlled preload alterations, a study in healthy individuals.

Background: In order to assess left atrial contractile function in disturbed circulatory conditions, it is necessary to have a clear understanding of how it behaves in a normal resting state with changes in loading conditions. However, currently the understanding of this relationship is incomplete. We hypothesize that in healthy individuals, left atrial contraction strain and its peak strain rate are increased or decreased by increasing or decreasing preload, respectively.

Can Doppler echocardiography estimate raised pulmonary capillary wedge pressure provoked by passive leg lifting in suspected heart failure?

Aims: Non-invasive estimation of left ventricular filling pressure (LVFP) during stress is important for explaining exertional symptoms in patients with heart failure (HF). The aim of this study was to evaluate ability of Doppler echocardiographic measures of elevated LVFP with passive leg lifting (PLL) in patients with suspected HF.

Methods: Twenty-nine patients with clinical signs of HF who underwent simultaneous Doppler echocardiography and right heart catheterization (RHC) at rest and during PLL were consecutively investigated.

Perioperative fluid guidance with transthoracic echocardiography and pulse-contour device in morbidly obese patients.

Background: In bariatric surgery, non- or mini-invasive modalities for cardiovascular monitoring are addressed to meet individual variability in hydration needs. The aim of the study was to compare conventional monitoring to an individualized goal-directed therapy (IGDT) regarding the need of perioperative fluids and cardiovascular stability.

Methods: Fifty morbidly obese patients were consecutively scheduled for laparoscopic bariatric surgery (ClinicalTrials.

Morbid obesity and optimization of preoperative fluid therapy.

Background: Preoperative venous return (VR) optimization and adequate blood volume is essential in management of morbidly obese patients (MO) in order to avoid perioperative circulatory instability. In this study, all subjects underwent a preoperative 3-week preparation by rapid-weight-loss-diet (RWL) as part of their treatment program for bariatric surgery.

Methods: This is a prospective, observational study of 34 morbidly obese patients consecutively scheduled for bariatric surgery at Sunderby County Hospital, Luleå, Sweden.

Rapid weight loss is associated with preoperative hypovolemia in morbidly obese patients.

Background: In morbidly obese patients (MO), adequate levels of venous return (VR) and left ventricular filling pressures (LVFP) are crucial in order to augment perioperative safety. Rapid weight loss (RWL) preparation with very low calorie diet is commonly used aiming to facilitate bariatric surgery. However, the impact of RWL on VR and LVFP is poorly studied.

Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load.

Background: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV) contractility.

Methods: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography.

Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model.

Background: Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function. Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility, though their load-sensitivity has been studied in different settings, but still remains a matter of controversy. We sought to characterize the effects of acute load change (both preload and afterload) and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility.