Search results for "cardiac output"
showing 10 items of 95 documents
Non-invasive determination of cardiac output by transesophageal Doppler ultrasound-clinical application and validation
2003
The authors describe the development and validation of a device using transesophageal (TE) Doppler ultrasound to provide continuous and noninvasive monitoring of cardiac output (CO) and related parameters. In intubated and artificially ventilated patients who underwent pulmonary artery catherization for hemodynamic monitoring, CO was determined by the esophageal Doppler ultrasound probe and compared to the results obtained simultaneously by means of thermodilution. A very close correlation was found between the results (r=0.99), with a standard estimate of error less than 5% as well as good reproducibility (r=0.96 and r=0.98). >
Central obesity and hypertension: Pathophysiologic role of renal haemodynamics and function
1995
OBJECTIVE: To investigate the role of alterations in renal haemodynamics and function and in plasma renin activity on obesity-induced hypertension. DESIGN: Renal haemodynamics and function, salt-regulating hormones and structural cardiac parameters were evaluated in 20 lean normotensives and in 64 obese subjects with central or peripheral fat distribution, 43 of them were normotensives and 21 of them were hypertensives. Obesity and central fat distribution were defined according to sex-specific 85th percentile respectively of Body Mass Index (BMI) and Waist to Hip Ratio (WHR). MEASUREMENTS: Serum immunoreactive insulin (IRI), plasma renin activity (PRA), plasma aldosterone (PA), microalbumi…
Subclinical impairment of lung function is related to mild cardiac dysfunction and manifest heart failure in the general population.
2016
Lung function impairment has previously been related to heart failure, although no overt cardiovascular or structural heart disease is present. The extent to which pulmonary function is related to subclinical left ventricular impairment in the general population remains to be investigated.15010 individuals from the general population (mean age 55±11years, 50.5% men) in the Gutenberg Health Study underwent spirometry, transthoracic echocardiography and biomarker measurement. Forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) in percent of the predicted value and FEV1/FVC ratio were associated with echocardiographic measures of cardiac structure, systolic and diastolic func…
Ventricular paired pacing to control intractable junctional tachycardia following open heart surgery in a child.
1989
A 5-month-old girl presented postoperatively with an atrioventricular (A-V) junctional tachycardia at a rate of 245/min following surgical repair of tetralogy of Fallot. The systolic blood pressure dropped to 60 mmHg with this rapid heart rate, and the infant became shocked. Drugs and overdrive pacing were ineffective in suppressing the A-V junctional tachycardia and in improving cardiac output. Ventricular paired pacing was used successfully to halve the mechanically effective ventricular rate and to restore cardiac output. When ventricular paired pacing was stopped after 12 h, the spontaneous rhythm was an atrial rhythm with 1-1 A-V conduction. The patient was discharged in sinus rhythm o…
Síndrome compartimental abdominal y síndrome de distrés intestinal agudo
2013
Seriously ill patients frequently present intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) as complications, and the associated mortality is very high. This review offers an update on the most controversial aspects of these entities: factors favoring their appearance, the most common causes, prognosis, and methods of measuring intra-abdominal pressure (IAP), physiopathological consequences in relation to the different organs and systems, and the currently accepted treatment measures (medical and/or surgical). Simultaneously to the strictly physical mechanisms of injury, such as direct compression of intra-abdominal organs and vessels, the transmission of IAP to ot…
A Nonlinear Circulatory Model for Artificial Heart Studies
1983
Animals with total artificial heart replacement (TAH) have survived for up to 9 months with manually controlled driving systems. A certain physiological control is provided by the animals intact peripheral regulation resulting in pathological venous hemodynamics, expressing the needs for a technical automatic control system, replacing the natural sympathetic stimulation and Starlings Law of the heart. A nonlinear dynamic mathematical model of the human cardiovascular system (CVSM) containing the systemic and pulmonary components was outlined and verified, which is employable to analyse the hemodynamic behaviour under normal and abnormal states. By modifying this model, assuming that cardiac…
Pathophysiology of Cerebral Ischemia
1991
The weight of the brain amounts to only 2% of total body weight, but it receives 15% of the cardiac output and uses 20% of the oxygen consumed by the body. The energy supply is provided almost exclusively by glucose metabolism. The substrate for this is stored in the brain in the form of glucose or glycogen and is sufficient to cover the energy requirements for only about 1 min. Consequently, there is a delicate equilibrium between oxygen and nutrient supply from the blood and the energy requirements of the brain. Disturbances in neurologic function appear after a few seconds of ischemia, although they are not necessarily persistent at first.
A mathematical model of cardiovascular dynamics for the diagnosis and prognosis of hemorrhagic shock
2020
Abstract A variety of mathematical models of the cardiovascular system have been suggested over several years in order to describe the time-course of a series of physiological variables (i.e. heart rate, cardiac output, arterial pressure) relevant for the compensation mechanisms to perturbations, such as severe haemorrhage. The current study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. The present work proposes a first version of a differential-algebraic equations model, the model dynamical ODE model for haemorrhage (dODEg). The model consists of 10 differential and 14 algebraic e…
Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs.
2019
Hemorrhagic shock ranks among the main reasons for severe injury-related death. The loss of circulatory volume and oxygen carriers can lead to an insufficient oxygen supply and irreversible organ failure. The brain exerts only limited compensation capacities and is particularly at high risk of severe hypoxic damage.This article demonstrates the reproducible induction of life-threatening hemorrhagic shock in a porcine model by means of calculated blood withdrawal. We titrate shock induction guided by near-infrared spectroscopy and extended hemodynamic monitoring to display systemic circulatory failure, as well as cerebral microcirculatory oxygen depletion. In comparison to similar models tha…
The influence of dopamine on hemodynamics, microcirculation and renal function in patients with hypnotic drug intoxication
1976
The effect of dopamine on hemodynamics (CO, AoPm, TPR, SV, SW, CVP, PAPm, PAEDP), microcirculation (MBF, PS-product) and renal function (VU, CKI, CNa, CK, Cosm, TcH2O) was studied in 8 patients with hypnotic drug poisoning. With increasing doses of dopamine, cardiac output and heart rate increased and the peripheral resistance decreased. An augmentation of stroke volume and left ventricular stroke work was observed in the low dose range only (200--400 mug/min). With increasing doses, central venous pressure as well as mean pulmonary artery pressure and enddiastolic pulmonary artery pressure decreased. No vasoconstriction was found in muscle tissue vessels even with large doses of dopamine. …