Norepinephrine and dobutamine improve cardiac index equally by supporting opposite sides of the heart in an experimental model of chronic pulmonary hypertension.

Background: Pulmonary hypertension is a significant risk factor in patients undergoing surgery. The combined effects of general anaesthesia and positive pressure ventilation can aggravate this condition and cause increased pulmonary blood pressures, reduced systemic blood pressures and ventricular contractility. Although perioperative use of inotropic support or vasopressors is almost mandatory for these patients, preference is disputed.

Unloading using Impella CP during profound cardiogenic shock caused by left ventricular failure in a large animal model: impact on the right ventricle.

Background And Aim: This study aimed to assess right ventricular (RV) function during cardiogenic shock due to acute left ventricular (LV) failure, including during LV unloading with Impella CP and an added moderate dose of norepinephrine.

Methods: Cardiogenic shock was induced by injecting microspheres in the left main coronary artery in 18 adult Danish Landrace pigs. Conductance catheters were placed in both ventricles and pressure-volume loops were recorded simultaneously.

Effects of 6-mercaptopurine in pressure overload induced right heart failure.

Background: Several antineoplastic drugs have been proposed as new compounds for pulmonary arterial hypertension treatment but many have cardiotoxic side effects. The chemotherapeutic agent 6-mercaptopurine may have an effect in treatment of pulmonary arterial hypertension but at the same time, its effects on the afterload adaption of the right ventricle is unpredictable due to interaction with multiple downstream signalling pathways in the cardiomyocytes. We investigated the direct cardiac effects of 6-mercaptopurine in rats with isolated right heart failure caused by pulmonary trunk banding (PTB).

Magnetic resonance hyperpolarization imaging detects early myocardial dysfunction in a porcine model of right ventricular heart failure.

Aims: Early detection of heart failure is important for timely treatment. During the development of heart failure, adaptive intracellular metabolic processes that evolve prior to macro-anatomic remodelling, could provide an early signal of impending failure. We hypothesized that metabolic imaging with hyperpolarized magnetic resonance would detect the early development of heart failure before conventional echocardiography could reveal cardiac dysfunction.

Effects of combined angiotensin II receptor antagonism and neprilysin inhibition in experimental pulmonary hypertension and right ventricular failure.

Background: Combined angiotensin II receptor antagonism and neprilysin inhibition by LCZ696 reduces morbidity and mortality in heart failure patients and works by reducing RAAS activity and increasing cGMP levels. This study aims to evaluate the effects of LCZ696 in rats with pulmonary hypertension and right ventricular (RV) failure.

Methods: Pulmonary hypertension was induced in rats (n = 34) by combined exposure to the vascular endothelial growth factor-receptor antagonist SU5416 and hypoxia (SuHx).

Impella CP or VA-ECMO in profound cardiogenic shock: left ventricular unloading and organ perfusion in a large animal model.

Aims: The aim of this study was to evaluate the Impella CP over veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and their impact on left ventricular unloading and end-organ perfusion.

Methods And Results: Cardiogenic shock (CS) was induced by injecting microspheres into the left coronary artery in fourteen adult female swine. Impella CP or VA-ECMO was initiated in the presence of CS and evaluated after 60 minutes.

Fluid loading and norepinephrine infusion mask the left ventricular preload decrease induced by pleural effusion.

Background: Pleural effusion (PLE) may lead to low blood pressure and reduced cardiac output. Low blood pressure and reduced cardiac output are often treated with fluid loading and vasopressors. This study aimed to determine the impact of fluid loading and norepinephrine infusion on physiologic determinants of cardiac function obtained by ultrasonography during PLE.

Citric Acid Cycle Metabolites Predict the Severity of Myocardial Stunning and Mortality in Newborn Pigs.

Objectives: Myocardial infarction and chronic heart failure induce specific metabolic changes in the neonatal myocardium that are closely correlated to outcome. The aim of this study was to examine the metabolic responses to noninfarct heart failure and inotropic treatments in the newborn heart, which so far are undetermined.

Design: A total of 28 newborn pigs were instrumented with a microdialysis catheter in the right ventricle, and intercellular citric acid cycle intermediates and adenosine metabolite concentrations were determined at 20-minute intervals.

Rotigaptide protects the myocardium and arterial vasculature from ischaemia reperfusion injury.

Aim: Ischaemia-reperfusion injury (IRI) causes impaired endothelial function and is a major component of the adverse effects of reperfusion following myocardial infarction. Rotigaptide increases gap junction conductance via connexin-43. We tested the hypothesis that rotigaptide reduces experimental myocardial infarction size and ameliorates endothelial IRI in humans.

Effects of milrinone and epinephrine or dopamine on biventricular function and hemodynamics in right heart failure after pulmonary regurgitation.

Right ventricular failure (RVF) secondary to pulmonary regurgitation (PR) impairs right ventricular (RV) function and interrupts the interventricular relationship. There are few recommendations for the medical management of severe RVF after prolonged PR. PR was induced in 16 Danish landrace pigs by plication of the pulmonary valve leaflets.

Effects of milrinone and epinephrine or dopamine on biventricular function and hemodynamics in an animal model with right ventricular failure after pulmonary artery banding.

Right ventricular (RV) failure due to chronic pressure overload is a main determinant of outcome in congenital heart disease. Medical management is challenging because not only contractility but also the interventricular relationship is important for increasing cardiac output. This study evaluated the effect of milrinone alone and in combination with epinephrine or dopamine on hemodynamics, ventricular performance, and the interventricular relationship.

Inotropic therapy for right ventricular failure in newborn piglets: effect on contractility, hemodynamics, and interventricular interaction.

Objectives: To investigate the effect of right ventricular stunning on interventricular relationships in newborn piglets and to determine the effect of three commonly used inotropic treatment strategies.

Design: Randomized, placebo-controlled animal study.

Setting: Aarhus University Hospital, animal laboratory.

Negative inotropic and hypotensive effects of the superoxide dismutase mimetic tempol in pigs.

Through interference with free radicals, the nitroxide tempol potentially increases bioavailability of nitric oxide (NO) and along with modulation of potassium channels reduces blood pressure (BP). We studied whether tempol in pigs lowers BP by mechanisms sensitive to inhibition of NO synthase or large conductance calcium-activated potassium channels (BKCa). The cardiovascular effects of intravenous tempol (25-50mg/kg) were examined in anesthetized pigs with myocardial function being evaluated by echocardiography.

Small-volume 7.5% NaCl adenosine, lidocaine, and Mg2+ has multiple benefits during hypotensive and blood resuscitation in the pig following severe blood loss: rat to pig translation.

Objectives: Currently, there is no effective small-volume fluid for traumatic hemorrhagic shock. Our objective was to translate small-volume 7.5% NaCl adenosine, lidocaine, and Mg hypotensive fluid resuscitation from the rat to the pig.

Remote ischemic preconditioning with--but not without--metabolic support protects the neonatal porcine heart against ischemia-reperfusion injury.

Background: While remote ischemic preconditioning (rIPC) protects the mature heart against ischemia-reperfusion (IR) injury, the effect on the neonatal heart is not known. The neonatal heart relies almost solely on carbohydrate metabolism, which is modified by rIPC in the mature heart. We hypothesized that rIPC combined with metabolic support with glucose-insulin (GI) infusion improves cardiac function and reduces infarct size after IR injury in neonatal piglets in-vivo.

Adenocaine and Mg(2+) reduce fluid requirement to maintain hypotensive resuscitation and improve cardiac and renal function in a porcine model of severe hemorrhagic shock*.

Objectives: Hypotensive resuscitation is gaining clinical acceptance in the treatment of hemorrhagic shock. Our aims were to investigate: 1) the effect of 7.5% NaCl with adenocaine (adenosine and lidocaine, AL) and AL with Mg (ALM) on fluid requirement to maintain a minimum mean arterial pressure of 50 mm Hg, and 2) the effect of a second bolus of 0.

Age-dependent effects of milrinone and levosimendan on ventricular function and haemodynamics in newborn and mature pigs.

Inodilators are used in the treatment of low cardiac output, mainly after cardiac surgery. At present, there is little knowledge of the effect of inodilators in the newborn heart. Immediately after birth and in the neonatal period, the metabolism and physiology of the heart undergo major changes.

A novel porcine model for right ventricular dilatation by external suture plication of the pulmonary valve leaflets--practical and reproducible.

The right ventricle (RV) tolerates acute pulmonary valvular regurgitation fairly well, however, in the long-term dilatation and failure often ensues. There is little known of the structural and functional myocardial alterations following this pathophysiology, and therefore animal models are sought. We aimed to develop an animal experimental model for RV dilatation emphasizing feasibility, reproducibility and human compatibility.