Long-term head-down-tilt bed rest (HDT) causes cardiovascular deconditioning, attributed to reflex dysfunctions, plasma volume reduction, or cardiac impairments. Our objective with the present study was to evaluate the functional importance and relative contribution of these during rest and exercise in supine and upright postures. We studied six subjects before (baseline), during [days 60 (D60)...

We hypothesized that 10 days of training would enhance cardiac output (CO) and stroke volume (SV) during peak exercise and increase the inotropic response to beta-adrenergic stimulation. Ten subjects [age 26 +/- 2 (SE) yr] trained on a cycle ergometer for 10 days. At peak exercise, training increased O2 uptake, CO, and SV (P < 0.001). Left ventricular (LV) size and function at rest were assesse...

Using Bluetooth wireless technology, we developed an implantable telemetry system for measurement of the left ventricular pressure-volume relation in conscious, freely moving rats. The telemetry system consisted of a pressure-conductance catheter (1.8-Fr) connected to a small (14-g) fully implantable signal transmitter. To make the system fully telemetric, calibrations such as blood resistivity...

BACKGROUND This study evaluated the ability of a non-invasive cardiac output monitoring device (NICOM) to predict fluid responsiveness in paediatric patients undergoing cardiac surgery. METHODS Children aged <5 yr undergoing congenital heart surgery were included. Once the sternum had been closed after repair of the congenital heart defect, 10 ml kg(-1) colloid solution was administered for v...

Background Atrial fibrillation (AF) is a common sustained cardiac arrhythmia associated with increased risks of heart failure, left ventricle (LV) dysfunction, and known to cause an increase in left atrium (LA) volume with decrease in atrial contractility. Cine magnetic resonance images (MRI) were used to measure changes in LA and LV function in a chronic AF goat model. Ejection fraction (EF), ...

BACKGROUND In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP) is presented, that measures the average stroke volume (SV) for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition) with six independent electrode...

BACKGROUND Although cardiac output (CO) plays the vital role of delivering nutrients to body tissues, few data are available concerning the relations of stroke volume (SV) and CO to body composition in large population samples. METHODS AND RESULTS Doppler and 2D echocardiography and bioelectric impedance in 2744 Strong Heart Study participants were used to calculate SV and CO and to relate th...

OBJECTIVE To investigate cardiovascular responses to orthostatic stress in patients with cerebrovascular accidents (CVA). METHODS Twelve male patients with CVA, 11 healthy elderly and 12 healthy young males participated in the present study. The CVA patients had suffered stroke with hemiplegia at least 11 months prior to the study, their medical conditions were stable, and no subjects were ta...

Women have a greater incidence of orthostatic intolerance than men. We hypothesized that this difference is related to hemodynamic effects on regulation of cardiac filling rather than to reduced responsiveness of vascular resistance during orthostatic stress. We constructed Frank-Starling curves from pulmonary capillary wedge pressure (PCWP), stroke volume (SV), and stroke index (SI) during low...

It is difficult to define all cardiac risk factors in the course of burn treatment. The adequate function of the circulatory system is the main factor in successful therapy. The aim of this study was to define, using a transoesophageal Doppler system, the cardiac circulatory risk factors of death in burn patients. One hundred and forty-seven burn patients were divided into two groups defined as...