Search results for "Cardiac"
showing 10 items of 1495 documents
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. …
Hemodynamic monitoring and management in patients undergoing high risk surgery: a survey among North American and European anesthesiologists
2011
Abstract Introduction Several studies have demonstrated that perioperative hemodynamic optimization has the ability to improve postoperative outcome in high-risk surgical patients. All of these studies aimed at optimizing cardiac output and/or oxygen delivery in the perioperative period. We conducted a survey with the American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology (ESA) to assess current hemodynamic management practices in patients undergoing high-risk surgery in Europe and in the United States. Methods A survey including 33 specific questions was emailed to 2,500 randomly selected active members of the ASA and to active ESA members. Results Overall,…
The Role of Cardiac Pacing in Heart Block Complicating Acute Myocardial Infarction
1983
The organization of the Coronary Care Unit and the use of electrocardiographic monitoring have allowed a re-evaluation of the incidence of the atrioventricular conduction disturbances in acute myocardial infarction.
Are double potentials markers of a specific zone of the atrioventricular junction in the isolated rabbit heart?
1997
A study is made of the characteristics of the atrial potentials recorded in the Koch triangle and its proximity, their variations on modifying the site of cardiac pacing, and their usefulness as markers of a distinct zone of the AV junction. In 12 isolated and perfused rabbit heart preparations an analysis was made of the endocardial atrial electrograms recorded with a multiple electrode positioned in the AV junction. The electrograms were obtained during spontaneous rhythm and on pacing at the crista terminalis (CT), interatrial septum (IAS), left atrium, and right ventricle. Double potentials were frequently obtained. On pacing at the CT, high-low double potentials (DP [H-L]) were more fr…