Distinct morphologies of arterial waveforms reveal preload-, contractility-, and afterload-deficient hemodynamic instability: An in silico simulation study.

Hemodynamic instability is frequently present in critically ill patients, primarily caused by a decreased preload, contractility, and/or afterload. We hypothesized that peripheral arterial blood pressure waveforms allow to differentiate between these underlying causes. In this in-silico experimental study, a computational cardiovascular model was used to simulate hemodynamic instability by decreasing blood volume, left ventricular contractility or systemic vascular resistance, and additionally adaptive and compensatory mechanisms.

Long-term Extracorporeal Membrane Oxygenation Bridge to Lung Transplantation After COVID-19.

This report describes a patient with severe acute respiratory syndrome coronavirus 2 infection and irreversible lung destruction who underwent successful lung transplantation after 138 days of bridging with extracorporeal membrane oxygenation support. The case exemplifies that lung transplantation may be a possibility after very long-term coronavirus disease 2019 care, even if the patient is initially an unsuitable candidate.

Right-Left Ventricular Interaction in Left-Sided Heart Failure With and Without Venoarterial Extracorporeal Membrane Oxygenation Support-A Simulation Study.

Left ventricular (LV) dilatation is commonly seen with LV failure and is often aggravated during venoarterial extracorporeal membrane oxygenation (VA ECMO). In this context, the intricate interaction between left and right heart function is considered to be of pivotal importance, yet mechanistically not well understood. We hypothesize that a preserved or enhanced right heart contractility causes increased LV loading both with and without VA ECMO.

Hydraulic force is a novel mechanism of diastolic function that may contribute to decreased diastolic filling in HFpEF and facilitate filling in HFrEF.

A hydraulic force generated by blood moving the atrioventricular plane is a novel mechanism of diastolic function. The direction and magnitude of the force is dependent on the geometrical relationship between the left atrium and ventricle and is measured as the short-axis atrioventricular area difference (AVAD). In short, the net hydraulic force acts from a larger area toward a smaller one.

A Missense Variant in Associated with Canine Succinic Semialdehyde Dehydrogenase Deficiency (SSADHD) in the Saluki Dog.

Dogs provide highly valuable models of human disease due to the similarity in phenotype presentation and the ease of genetic analysis. Seven Saluki puppies were investigated for neurological abnormalities including seizures and altered behavior. Magnetic resonance imaging showed a diffuse, marked reduction in cerebral cortical thickness, and symmetrical T2 hyperintensity in specific brain regions.

The hemodynamic effect of different left ventricular unloading techniques during veno-arterial extracorporeal life support: a systematic review and meta-analysis.

Background: Pulmonary edema and left ventricular thrombosis may arise during veno-arterial extracorporeal life support due to an increase in cardiac load. This mechanical stress can be reduced through different left ventricular unloading techniques. We set out to quantitatively summarize the hemodynamic effects of available methods in patients treated with veno-arterial extracorporeal life support.

Extended use of extra corporeal membrane oxygenation as bridge to lung transplantation in two patients.

Background: We have previously reported our outcome after extra-corporeal membrane oxygenation as bridge-to-lung transplantation, which initially was considered controversial, but over time have gained acceptance and now is performed in most high-volume institutions.

Case Presentation: We now report two "extreme" extra-corporeal membrane oxygenation (ECMO) bridge-to-lung transplantation cases, on ECMO > 200 days prior to lung transplantation. One patient survived long-term and the other one did not, and clinical cause and morbidity is outlined in this case-report.

Differential hypoxemia during venoarterial extracorporeal membrane oxygenation.

Venoarterial extracorporeal membrane oxygenation, indicated for severe cardio-respiratory failure, may result in anatomic regional differences in oxygen saturation. This depends on cannulation, hemodynamic state, and severity of respiratory failure. Differential hypoxemia, often discrete, may cause clinical problems in peripheral femoro-femoral venoarterial extracorporeal membrane oxygenation, when the upper body is perfused with low saturated blood from the heart and the lower body with well-oxygenated extracorporeal membrane oxygenation blood.

Cardiac remodeling in aortic and mitral valve disease: a simulation study with clinical validation.

Remodeling is an important long-term determinant of cardiac function throughout the progression of heart disease. Numerous biomolecular pathways for mechanosensing and transduction are involved. However, we hypothesize that biomechanical factors alone can explain changes in myocardial volume and chamber size in valve disease.

Left ventricular unloading during veno-arterial ECMO: a review of percutaneous and surgical unloading interventions.

Short-term mechanical support by veno-arterial extracorporeal membrane oxygenation (VA ECMO) is more and more applied in patients with severe cardiogenic shock. A major shortcoming of VA ECMO is its variable, but inherent increase of left ventricular (LV) mechanical load, which may aggravate pulmonary edema and hamper cardiac recovery. In order to mitigate these negative sequelae of VA ECMO, different adjunct LV unloading interventions have gained a broad interest in recent years.

Echocardiography in extracorporeal life support: A key player in procedural guidance, tailoring and monitoring.

Extracorporeal life support (ECLS) is a mainstay of current practice in severe respiratory, circulatory or cardiac failure refractory to conventional management. The inherent complexity of different ECLS modes and their influence on the native pulmonary and cardiovascular system require patient-specific tailoring to optimize outcome. Echocardiography plays a key role throughout the ECLS care, including patient selection, adequate placement of cannulas, monitoring, weaning and follow-up after decannulation.

Left Ventricular Unloading During Veno-Arterial ECMO: A Simulation Study.

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is widely used in cardiogenic shock. It provides systemic perfusion, but left ventricular (LV) unloading is suboptimal. Using a closed-loop, real-time computer model of the human cardiovascular system, cardiogenic shock supported by peripheral VA ECMO was simulated, and effects of various adjunct LV unloading interventions were quantified.

Hydraulic forces contribute to left ventricular diastolic filling.

Myocardial active relaxation and restoring forces are known determinants of left ventricular (LV) diastolic function. We hypothesize the existence of an additional mechanism involved in LV filling, namely, a hydraulic force contributing to the longitudinal motion of the atrioventricular (AV) plane. A prerequisite for the presence of a net hydraulic force during diastole is that the atrial short-axis area (ASA) is smaller than the ventricular short-axis area (VSA).

Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study.

During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesise that the heart contributes to the age-related blood pressure progression as well.

Venous Cannula Positioning in Arterial Deoxygenation During Veno-Arterial Extracorporeal Membrane Oxygenation-A Simulation Study and Case Report.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is indicated in reversible life-threatening circulatory failure with or without respiratory failure. Arterial desaturation in the upper body is frequently seen in patients with peripheral arterial cannulation and severe respiratory failure. The importance of venous cannula positioning was explored in a computer simulation model and a clinical case was described.

EVALUATION OF QUANTITATIVE THYROID SCINTIGRAPHY FOR DIAGNOSIS AND STAGING OF DISEASE SEVERITY IN CATS WITH HYPERTHYROIDISM: COMPARISON OF THE PERCENT THYROIDAL UPTAKE OF PERTECHNETATE TO THYROID-TO-SALIVARY RATIO AND THYROID-TO-BACKGROUND RATIOS.

Thyroid scintigraphy is commonly used for evaluation of cats with hyperthyroidism, with the thyroid-to-salivary ratio (T/S) being the most common method to quantify the degree of thyroid activity and disease. Calculation of thyroid-to-background ratios (T/B) or percent thyroidal uptake of (99m) TcO(-) 4 (TcTU) has only been reported in a few studies. The purpose of this prospective, cross-sectional study was to evaluate a number of quantitative scintigraphic indices as diagnostic tests for hyperthyroidism, including the T/S, three different T/B, TcTU, and estimated thyroid volume.

Individualized real-time clinical decision support to monitor cardiac loading during venoarterial ECMO.

Veno-arterial extracoporeal membrane oxygenation (VA ECMO) is increasingly used for acute and refractory cardiogenic shock. Yet, in clinical practice, monitoring of cardiac loading conditions during VA ECMO can be cumbersome. To this end, we illustrate the validity and clinical applicability of a real-time cardiovascular computer simulation, which allows to integrate hemodynamics, cardiac dimensions and the corresponding degree of VA ECMO support and ventricular loading in individual patients over time.

Prevalence and degree of thyroid pathology in hyperthyroid cats increases with disease duration: a cross-sectional analysis of 2096 cats referred for radioiodine therapy.

Objectives: Hyperthyroidism is common in cats, but there are no reports that evaluate its severity or underlying thyroid tumor disease based on disease duration (ie, time from original diagnosis). The objective of this study was to compare serum thyroxine (T4) concentrations and thyroid scintigraphic characteristics of cats referred for radioiodine treatment based on disease duration.

Methods: This was a cross-sectional study of 2096 cats with hyperthyroidism.

Recirculation during veno-venous extra-corporeal membrane oxygenation--a simulation study.

Purpose: Veno-venous ECMO is indicated in reversible life-threatening respiratory failure without life-threatening circulatory failure. Recirculation of oxygenated blood in the ECMO circuit decreases efficiency of patient oxygen delivery but is difficult to measure. We seek to identify and quantify some of the factors responsible for recirculation in a simulation model and compare with clinical data.

Exogenous thyrotoxicosis in dogs attributable to consumption of all-meat commercial dog food or treats containing excessive thyroid hormone: 14 cases (2008-2013).

Objective: To describe findings in dogs with exogenous thyrotoxicosis attributable to consumption of commercially available dog foods or treats containing high concentrations of thyroid hormone.

Design: Retrospective and prospective case series.

Animals: 14 dogs.