Five young normal subjects (NS) and six middle-aged patients with chronic, lowoutput, congestive heart failure (HFP) were studied before and after 10 minutes of exposure to hypovolemia induced by negative pressure (30 mm Hg) applied to the lower body. ECG, respirometer, and catheters placed in the subclavian artery and superior vena cava permitted measurements of heart rate (HR), respiration ra...

BACKGROUND Transcatheter embolisation is widely used to close pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Data on the direct cardiovascular haemodynamic changes induced by this treatment are scarce. OBJECTIVES We investigated the direct haemodynamic effects of transcatheter embolisation of PAVMs, using non-invasive finger pressu...

Changes in stroke volume variation (SVV) and pulse pressure variation (PPV) in response to fluid infusion were experimentally evaluated during vecuronium infusion and sevoflurane anesthesia in 5 adult, mechanically ventilated, euvolemic, beagle dogs. Sequential increases in central venous pressure (CVP; 3-7[baseline], 8-12, 13-17, 18-22 and 23-27 mmHg) were produced by infusing lactated Ringer'...

Purpose: The current cardiac magnetic resonance (CMR) based approach to assessment of right ventricular (RV) volumes is time-consuming and not optimized for routine clinical use. This study tested a new CMR based 3-Dimensional (3D) method of RV volume estimation that employed automated tracking to reduce analysis time. Methods: Twenty RV-shaped latex models of different sizes (25-225 ml) were s...

UNLABELLED Recently, devices have become available that allow non-invasive measurement of stroke volume and cardiac output through ambulatory thorax impedance recording. If such recordings have adequate temporal stability, they offer great potential to further our understanding of how repeated or chronic cardiovascular activation in response to naturalistic events may contribute to cardiovascul...

BACKGROUND Arterial blood pressure is dependent on interactions between the heart and arteries. Resistive and pulsatile components of arterial load can be assessed by systemic vascular resistance (SVR, a microvascular property) and the ratio of stroke volume to pulse pressure (a surrogate of total arterial compliance, TAC), respectively. The relationship between arterial function and cardiovasc...

Stroke volume was determined from the pulmonary artery pressure record by application of the pulse contour method. Pulmonary artery pressure records were obtained in 17 patients using a high fidelity catheter-tip pressure transducer and simultaneous measurements of cardiac output were obtained from indicator dilution curves. The formula used was SV = KP sa (i plus T s/Td) where Psa is the plani...

Key points † Controlled application of lower body negative pressure simulated hypovolaemia and resuscitation in human subjects. † Thoracic electrical bioimpedance, and arterial blood pressure (ABP) analysis by the Long Time Interval method, were the most discriminatory measurements. † The Modelflow method of ABP analysis effectively tracked hypovolaemia, but underestimated resuscitation. † Puls...

AIM Recent findings have challenged the belief that the cardiac output (CO) and oxygen consumption (VO(2) ) relationship is linear from rest to maximal exercise. The purpose of this study was to determine the CO and stroke volume (SV) response to a range of exercise intensities, 40-100% of VO(2max), during cycling. METHODS Ten well-trained cyclists performed a series of discontinuous exercise...