mean circulatory filling pressure

The present work investigated the dynamic changes in stressed volume (Vs) and other determinants of venous return using a porcine model of hyperdynamic septic shock. Septicemia was induced in 10 anesthetized swine, and fluid challenges were started after the diagnosis of sepsis-induced arterial hypotension and/or tissue hypoperfusion. Norepinephrine infusion targeting a mean arterial pressure (MAP) of 65 mmHg was started after three consecutive fluid challenges. After septic shock was confirmed, norepinephrine infusion was discontinued, and the animals were left untreated until cardiac arrest occurred...

The absence of an accepted gold standard to estimate volume status is an obstacle for optimal management of left ventricular assist devices (LVADs). The applicability of the analogue mean systemic filling pressure (Pmsa) as a surrogate of the mean circulatory pressure to estimate volume status for patients with LVADs has not been investigated. Variability of flows generated by the Impella CP, a temporary LVAD, should have no physiological impact on fluid status. This translational interventional ovine study demonstrated that Pmsa did not change with variable circulatory flows induced by a continuous flow LVAD (the average dynamic increase in Pmsa of 0...

BACKGROUND: Mean circulatory filling pressure (Pmcf) provides information on stressed volume and is crucial for maintaining venous return. This study investigated the Pmcf and other determinants of venous return in dysrhythmic and asphyxial circulatory shock and arrest. METHODS: Twenty Landrace/Large-White piglets were allocated into two groups of 10 animals each. In the dysrhythmic group, ventricular fibrillation was induced with a 9 V cadmium battery, while in the asphyxia group, cardiac arrest was induced by stopping and disconnecting the ventilator and clamping the tracheal tube at the end of exhalation...

OBJECTIVES: To describe hemodynamic effects of iVAC2L mechanical circulatory support (MCS). BACKGROUND: MCS is increasingly used in the context of high-risk percutaneous coronary intervention (PCI). The effect of the pulsatile iVAC2L MCS on left ventricular loading conditions and myocardial oxygen consumption (MVO2 ) is unknown. METHODS: This prospective single-arm two-center study included 29 patients who underwent high-risk PCI with iVAC2L MCS using simultaneous invasive pulmonary pressure monitoring and left ventricular pressure-volume analysis...

Veins are important in the control of venous return, cardiac output, and cardiovascular homeostasis. However, the effector systems modulating venous function remain to be fully elucidated. We demonstrated that activation of bradykinin-sensitive pericardial afferents elicited systemic venoconstriction. The hypothalamic paraventricular nucleus (PVN) is an important site modulating autonomic outflow to the venous compartment. We tested the hypothesis that the PVN region is involved in the venoconstrictor response to pericardial injection of bradykinin...

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is typically caused by mutations in sarcomeric genes leading to cardiomyocyte disarray, replacement fibrosis, impaired contractility, and elevated filling pressures. These varying tissue properties are associated with certain strain patterns that may allow to establish a diagnosis by means of non-invasive imaging without the necessity of harmful myocardial biopsies or contrast agent application. With a numerical study, we aim to answer: how the variability in each of these mechanisms contributes to altered mechanics of the left ventricle (LV) and if the deformation obtained in in-silico experiments is comparable to values reported from clinical measurements...

The objective of this study is to identify the preload and afterload sensitivity of the ReinHeart TAH 2.0. For adequate left-right flow balance, the concept of a reduced right stroke volume (by about 10%) and active adaption of the right diastole duration are evaluated concerning the controllability of the flow balance. This study used an active mock circulation loop to test a wide range of preload and afterload conditions. Preload sensitivity was tested at atrial pressures (APs) between 4 and 20 mm Hg. Left afterload was varied in a range of 60-140 mm Hg mean aortic pressure (MAP), right afterload was simulated between 15 and 40 mm Hg...

We present the case of a 1-year-old boy who developed protein-losing enteropathy (PLE) within 2 months of a fenestrated Fontan procedure. His fenestration rapidly closed despite bilateral pulmonary stenosis (BPS). Subsequent to PLE onset, both fenestration and the bilateral pulmonary artery were reconstructed, and the patient's PLE had been in remission, with additive use of medications, for more than 2 years. Notably, although fenestration closed again and central venous pressure (CVP) reduction was minimal, the surrogates of venous return resistance were markedly suppressed as shown by increased blood volume, reduced estimated mean circulatory filling pressure, and suppressed CVP augmentation against a contrast agent...

Mean systemic filling pressure (Pms) is a promising parameter in determining intravascular fluid status. Pms derived from venous return curves during inspiratory holds with incremental airway pressures (Pms-Insp) estimates Pms reliably but is labor-intensive. A computerized algorithm to calculate Pms (Pmsa) at the bedside has been proposed. In previous studies Pmsa and Pms-Insp correlated well but with considerable bias. This observational study was performed to validate Pmsa with Pms-Insp in cardiac surgery patients...

This study tested the hypothesis that early left ventricular (LV) relaxation is impaired in older obese heart failure with preserved ejection fraction (HFpEF) patients, and related to decreased peak exercise oxygen uptake (peak VO2 ). LV strain and strain rate were measured by feature tracking of magentic resonance cine images in 79 older obese HFpEF patients (mean age: 66 years; mean BMI: 38 kg/m2 ) and 54 healthy control participants. LV diastolic strain rates were indexed to cardiac preload as estimated by echocardiography derived diastolic filling pressures (E/e'), and correlated to peak VO2 ...

With each heartbeat, the right ventricle (RV) inputs blood into the pulmonary vascular (PV) compartment, which conducts blood through the lungs at low pressure and concurrently fills the left atrium (LA) for output to the systemic circulation. This overall hemodynamic function of the integrated RV-PV-LA unit is determined by complex interactions between the components that vary over the cardiac cycle but are often assessed in terms of mean pressure and flow. Exercise challenges these hemodynamic interactions as cardiac filling increases, stroke volume augments, and cycle length decreases, with PV pressures ultimately increasing in association with cardiac output...

BACKGROUND: The upstream pressure for venous return (VR) is considered to be a combined conceptual blood pressure of the systemic vessels: the mean systemic filling pressure (MSFP). The relevance of estimating the MSFP during dynamic changes of the circulation at the bedside is controversial. Herein, we studied the effect of high ventilatory pressures on the relationship between VR and central venous pressure (CVP). METHODS: In 9 healthy pigs under anaesthesia and mechanically ventilated, MSFP was estimated from extrapolated VR versus CVP relationships during inspiratory hold maneuvers (IHMs) with different levels of ventilatory pressure (Pvent)...

AIMS: Heart failure with preserved ejection fraction (HFpEF) is characterized by complex pathophysiology including an impaired diastolic reserve. We recently showed that milrinone favourably modifies filling pressures at rest and during exertion in HFpEF patients; however, the responsible mechanism is uncertain. The objective of this study was to develop a clearer understanding of the acutely modifiable physiologic parameters that may be targeted in HFpEF. METHODS AND RESULTS: We conducted computer modelling simulations based on invasive haemodynamic assessments, by right heart catheterization, in HFpEF patients at baseline and in response to milrinone...

Potentially, mean circulatory filling pressure (Pmcf) could aid hemodynamic management in patients admitted to the intensive care unit (ICU). However, data regarding the normal range for Pmcf do not exist challenging its clinical use. We aimed to define the range for Pmcf for ICU patients and also calculated in what percentage of cases equilibrium between arterial blood pressure (ABP) and central venous pressure (CVP) was reached. In patients in whom no equilibrium was reached, we corrected for arterial-to-venous compliance differences...

This article describes the modified arterial reservoir in detail. The modified arterial reservoir makes explicit the wave nature of both reservoir ( Pres ) and excess pressure ( Pxs ). The mathematical derivation and methods for estimating Pres in the absence of flow velocity data are described. There is also discussion of zero-flow pressure ( Pzf ), the pressure at which flow through the circulation ceases; its relationship to asymptotic pressure ( P∞ ) estimated by the reservoir model; and the physiological interpretation of Pzf ...

Our understanding of reflex regulation of veins lags behind that of the arterial system. While the cardiac sympathetic afferent reflex (CSAR) exerts control over sympathetic outflow, its effect on venous tone is not known. We tested the hypothesis that activation of pericardial bradykinin sensitive afferents elicits systemic venoconstriction. Male and female Sprague Dawley rats were chronically instrumented for measurement of arterial pressure and mean circulatory filling pressure, an index of venous tone, and with an indwelling pericardial catheter...

Splanchnic circulation constitutes a major portion of the vasculature capacitance and plays an important role in maintaining blood perfusion. Because patients with asplenia syndrome lack this vascular bed as a blood reservoir, they may have a unique blood volume and distribution, which may be related to their vulnerability to the haemodynamic changes often observed in clinical practice. During cardiac catheterisation, the mean circulatory filling pressure was calculated with the Valsalva manoeuvre in 19 patients with Fontan circulation, including 5 patients with asplenia syndrome...

The high cost of ventricular assist devices results in poor cost-effectiveness when used as a short-term bridging solution, thus a low-cost alternative is desirable. The present study aimed to develop an intraventricular balloon pump (IVBP) for short-term circulatory support, and to evaluate the effect of balloon actuation timing on the degree of cardiac support provided to a simulated in vitro severe heart failure (SHF) patient. A silicone IVBP was designed to avoid contact with internal left ventricular (LV) features (ie, papillary muscles, chordae, aortic, and mitral valves) based on LV computed tomography data of 10 SHF patients with dilated cardiomyopathy...

BACKGROUND: The distending intravascular pressure at no flow conditions reflects the stressed volume. While this haemodynamic variable is recognised as clinically important, there is a paucity of reports of its range and responsiveness to volume expansion in patients without cardiovascular disease and no reports of correlations to echocardiographic assessments of left ventricular filling. METHODS: Twenty-seven awake (13 male), spontaneously breathing patients without any history of cardiopulmonary, vascular or renal disease were studied prior to induction of anaesthesia...

Venous return, i.e., the blood flowing back to the heart, is driven by the pressure difference between mean systemic filling pressure and right atrial pressure (RAP). Besides cardiac function, it is the major determinant of cardiac output. Mean systemic filling pressure is a function of the vascular volume. The concept of venous return has a central role for heart lung interactions and the explanation of shock states. Mechanical ventilation during anaesthesia and critical illness may severely affect venous return by different mechanisms...