The jugular venous pulse (JVP) provides valuable information about cardiac haemodynamics and filling pressures and is an indirect estimate of the central venous pressure (CVP). Recently it has been proven that JVP can be obtained by measuring the cross-sectional area (CSA) of the IJV on each sonogram of an ultrasound B-mode sonogram sequence. It has also been proven that during its pulsation th...

According to the concept of Guyton, cardiac output is largely controlled by venous return, which is determined by the difference between mean systemic venous pressure and right atrial pressure. In the analysis of the venous return curve, other authors have suggested that right atrial pressure is the dependent variable and venous return is the independent variable (right atrial pressure decrease...

Changes in cardiac filling pressure (central venous pressure) were measured following carotid occlusion and infusions of catecholamines in awake dogs while cardiac output was held constant. After carotid occlusion in dogs with vagi blocked, central venous pressure increased about 0.8 mm Hg (an estimated decrease in vascular capacity of 2.4 ml/kg). Carotid occlusion before vagal block or followi...

The effect on elastic stockings on ambulatory venous pressure was investigated in 22 limbs with deep venous insufficiency. The failure of some elastic stockings to reduce the ambulatory venous pressure in some limbs is due to the lack of graduated compression, which is caused by ankle-calf disproportion--narrow ankles and wide calves. This can be recognised by using the pressure-girth profile a...

Venous return is a major determinant of cardiac output. Adjustments within the venous system are critical for maintaining venous pressure during loss in circulating volume. This article reviews two factors that are thought to enable the venous system to compensate during acute hemorrhage: 1) changes in venous elastance and 2) mobilization of unstressed blood volume into stressed blood volume. W...

STUDY OBJECTIVE Among adult emergency department (ED) patients undergoing central venous catheterization, we determine whether a greater than or equal to 50% decrease in inferior vena cava diameter is associated with a central venous pressure of less than 8 mm Hg. METHODS Adult patients undergoing central venous catheterization were enrolled in a prospective, observational study. Inferior ven...

BACKGROUND Peripheral venous pressure (PVP) has been shown to correlate with central venous pressure (CVP) in a number of reports. Few studies, however, have explored the relationship between tissue pressure (TP) and PVP/CVP correlation. METHODS PVP and CVP were simultaneously recorded in a bench-top model of the venous circulation of the upper limb and in a single human volunteer after under...

Sine, triangular and square wave alternating currents were used to anaesthetize young buffalo calves. Central venous pressure, systolic and diastolic blood pressure and circulatory rate were monitored before, during and after application of currents. The square and triangular wave current produced a significant (P less than 0.01) increase in central venous pressure, mean systolic and diastolic ...

The effects of treadmill exercise on components of the cardiovascular (venous return, heart rate, arterial blood pressure) and respiratory systems (minute ventilation, tidal volume, breathing frequency, oxygen consumption, carbon dioxide production) and intra-abdominal pressure were investigated in the Savannah monitor lizard, Varanus exanthematicus B., at 35 degrees C. Compared with resting co...

Limb venous compliance decreases with advancing age, even in healthy humans. To test the hypothesis that adrenergic mechanisms contribute to age-associated reductions in limb venous compliance, we measured calf venous compliance before and during acute systemic α- and β-adrenergic blockade in eight young (27 ± 1 yr old, mean ± SE) and eight older healthy men (67 ± 2 yr old). Calf venous complia...