Marius Keller

• Dr. med.
• Medical Doctor at Universitätsklinikum Tübingen

Aims: Assessment of left ventricular (LV) systolic function plays a central role in cardiac imaging. Calculation of ejection fraction (EF) is the current method of choice; however, its limited intermodal comparability represents a major drawback. The assessment of myocardial mechanics by strain imaging may better reflect the complex myocardial con...

Cardiovascular pathologies are often induced by inflammation. The associated changes in the inflammatory response influence vascular endothelial biology; they complicate the extent of ischaemia and reperfusion injury, direct the migration of immune competent cells and activate platelets. The initiation and progression of inflammation is regulated b...

Background 3D right ventricular (RV) strain analysis is not routinely performed perioperatively. While 3D RV strain adds incrementally to outcome prediction in various cardiac diseases, its role in the perioperative setting is not sufficiently understood. This study investigated the association between 3D RV strain measured on RV meshes created fr...

Background: The assessment of right ventricular (RV) function in patients undergoing elective cardiac surgery is paramount for providing optimal perioperative care. The role of regional RV function assessment employing sophisticated state-of-the-art cardiac imaging modalities has not been investigated in this cohort. Hence, this study investigated...

Background: Right ventricular (RV) function can be quantified by right heart catheterization-derived pressure-volume loops. While this technique is invasive, echocardiography-based volume-strain loops (VSLs) potentially reflect a non-invasive alternative. In this study, an approach to generate VSLs from volume and multidimensional strain data of 3D...

Risk stratification for cardiac surgery is a cornerstone of perioperative management. While the prognostic impact of severe right ventricular (RV) dysfunction is well understood, the added value of the RV mechanical pattern regarding risk prediction remains unknown. We sought to prospectively validate the predictive value of 3D RV mechanics for adv...

Background Intracellular sensing of lipopolysaccharide (LPS) is essential for the immune response against gram-negative bacteria and results in activation of caspase-11 and pyroptotic cell death with fatal consequences in sepsis. We found the neuronal guidance receptor plexin C1 (PLXNC1) influences the intracellular response to LPS. Methods We emp...

Background A bilateral oblique subcostal transverse abdominis plane block may help provide perioperative analgesia and reduce opioid use in patients undergoing sublay mesh hernia repair, but its clinical value is unclear. Methods In a single-centre, prospective, placebo-controlled, double-blind study, patients scheduled for sublay mesh hernia repa...

Rationale: Pulmonary defense mechanisms are critical for host integrity during pneumonia and sepsis. This defense is fundamentally dependent on the activation of neutrophils during the innate immune response. Recent work has shown that Semaphorin 7A (Sema7A) holds significant impact on platelet function, yet its role on neutrophil function within...

Background: Veno-arterial extracorporeal membrane oxygenation (vaECMO) removal reflects a critical moment and factors of adverse outcomes are incompletely understood. Thus, we studied various patient-related factors during vaECMO removal to determine their association with outcomes. Methods: A total of 58 patients from a university hospital were in...

Background: Left atrioventricular valve (LAVV) stenosis following an atrioventricular septal defect (AVSD) repair is a rare but potentially life-threatening complication. While echocardiographic quantification of diastolic transvalvular pressure gradients is paramount in the evaluation of a newly corrected valve function, it is hypothesized that th...

In critically ill patients, hemodynamic disturbances are common and often lead to a detrimental outcome. Frequently, invasive hemodynamic monitoring is required for patients who are hemodynamically unstable. Although the pulmonary artery catheter enables a comprehensive assessment of the hemodynamic profile, this technique carries a substantial inh...

Background: Lower body perfusion (LBP) may be a strategy for maintaining organ perfusion during congenital heart disease surgery. It is hypothesized that renal and lower limb oxygen supply during LBP is superior to off-pump surgery and comparable to that of a standard cardiopulmonary bypass (CPB). Methods: in this prospective single-center study, p...

Background: Focused cardiac ultrasound (FCU) is a helpful tool to rapidly identify right ventricular (RV) causes of hemodynamic instability and facilitate the initiation of therapy. The clinical value of existing course models often remains unclear. This study investigated the effects of a one-day FCU training on the visual estimation skills of RV...

[This corrects the article DOI: 10.3389/fmed.2022.1014276.].

Background: Shock increases mortality in the critically ill and the mainstay of therapy is the administration of vasopressor agents to achieve hemodynamic targets. In the past, studies have found that the NO-pathway antagonist methylene blue improves hemodynamics. However, the optimal dosing strategy remains elusive. Therefore, we investigated the...

Background: Shock increases mortality in the critically ill and the mainstay of therapy is the administration of vasopressor agents to achieve hemodynamic targets. In the past, studies have found that the NO-pathway antagonist methylene blue improves hemodynamics. However, the optimal dosing strategy remains elusive. Therefore, we investigated the...

The perioperative quantification of left and right ventricular function is cornerstone to provide optimal patient care. Echocardiography has emerged as the most important cardiac imaging modality in this setting, mainly due to its rapid availability, non-invasiveness and cost-efficiency. Both the transthoracic and the transesophageal acoustic windo...

Background and Goal of Study: While global right ventricular (RV) systolic function is well-known to be associated with the outcome of patients undergoing elective cardiac surgery, the influence of regional RV function on short-term outcome is unknown. Hence, this study aimed to investigate regional RV function using 3D transesohpagel echocardiogra...

OBJECTIVES The aim of this study was to assess preoperative dissection flap motility and to evaluate its impact on the aortic remodelling and the development of distal stent-induced new entry after thoracic endovascular aneurysm repair (TEVAR)/frozen elephant trunk (FET). METHODS Patients with primary or residual type B dissections were included i...

Background Temporary extracorporeal life support (ECLS) by venoarterial extracorporeal membrane oxygenation is an emerging therapy for patients with severe, ongoing cardiogenic shock. After stabilization of the hemodynamic status and end-organ function, sedation weaning, extubation, and noninvasive ventilation (NIV) can be attempted. The goal of th...

Vasopressoren kommen besonders in kritischen, nicht selten lebensbedrohlichen Situationen der Anästhesie, Notfall- und Intensivmedizin zum Einsatz. Die Wahl der geeigneten Substanz sowie die Erkennung und Beherrschung möglicher Nebenwirkungen sind von großer Bedeutung. Im folgenden Beitrag sollen daher die klinisch wichtigsten Substanzen vorgestell...

Introduction Right ventricular (RV) strain analysis proved to be prognostically relevant in various cardiac diseases. However, data regarding outcome prediction by RV strain analysis during surgical coronary revascularization are limited. Three-dimensional (3D) transesophageal echocardiography-based (TEE) methods dedicated to the RV might be advant...

Introduction Although right ventricular (RV) function assessment is important in cardiac surgical patients, dedicated software solutions to measure RV strain on three-dimensional (3D) speckle-tracking echocardiography-based (STE) meshes are lacking. Hence, a novel tool to do so was developed and tested for its feasibility in a clinical setting. Me...

Abstract Background: Right ventricular (RV) function is an important prognostic indicator. The acute effects of cardiac interventions or cardiac surgery on global and longitudinal RV function are not entirely understood. In this study, acute changes of RV function during mitral valve surgery (MVS), percutaneous mitral valve repair (PMVR) and off- p...

Longitudinal right ventricular (RV) function is substantial and might be reflected by free wall longitudinal strain (FWLS). Software solutions for FWLS analysis by two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) are available, but data on validation are sparse. In this study, a novel method for FWLS analysis o...

Background General anesthesia induction with the initiation of positive pressure ventilation creates a vulnerable phase for patients. The impact of positive intrathoracic pressure on cardiac performance has been studied but remains controversial. 3D echocardiography is a valid and MRI-validated bed-side tool to evaluate the right ventricle (RV). T...

Background: General anesthesia induction with the initiation of positive pressure ventilation creates a vulnerable phase for patients. The impact of positive intrathoracic pressure on cardiac performance has been studied but remains controversial. 3D echocardiography is a valid and MRI-validated bed-side tool to evaluate the right ventricle (RV). T...

Background: General anesthesia induction with the initiation of positive pressure ventilation creates a vulnerable phase for patients. The impact of positive intrathoracic pressure on cardiac performance has been studied but remains controversial. 3D echocardiography is a valid and MRI-validated bed-side tool to evaluate the right ventricle (RV). T...

To the Editor: Landoni et al. (March 28 issue)¹ conclude that, among patients undergoing elective coronary-artery bypass grafting (CABG), anesthesia with a volatile (inhaled) agent did not result in significantly fewer deaths at 1 year than total intravenous anesthesia. They powered their trial by hypothesizing that 1-year all-cause mortality would...

Background: General anesthesia induction with the initiation of positive pressure ventilation creates a vulnerable phase for patients. The impact of positive intrathoracic pressure on cardiac performance has been studied but remains controversial. 3D echocardiography is a valid and MRI-validated bed-side tool to evaluate the right ventricle (RV). T...

Perioperative bleeding disorders leading to major blood losses have a severe impact on patient morbidity and mortality. Despite efficient communication with the surgical team, a profound knowledge concerning the underlying mechanisms, diagnostic possibilities and available therapeutic strategies is essential for the anesthesiologist in charge. This...

Background: General anesthesia induction with the initiation of positive pressure ventilation creates a vulnerable phase for patients. The impact of positive intrathoracic pressure on cardiac performance has been studied but remains controversial. 3D echocardiography is a valid and MRI-validated bed-side tool to evaluate the right ventricle (RV). T...

Objectives: In daily echocardiographic praxis, the right ventricle (RV) is mostly assessed by two-dimensional (2D) echocardiography. Parameters measuring longitudinal shortening, e.g., tricuspid annular plane systolic excursion, or changes in areas, e.g., fractional area change, are used as surrogates for the RV function. Three-dimensional (3D) ech...

Fragestellung: Eine Beeinträchtigung des longitudinalen Free Wall Strains (LFWS) im Rahmen einer rechtsventrikulären (RV) Dysfunktion ist mit einem schlechten Outcome assoziiert und dessen Messung dabei besonders im intensivmedizinischen und kardiochirurgischen Kontext interessant. Die LFWSBestimmung mithilfe der semi-automatischen Speckle-Tracking...

Background Atrial fibrillation is the most common new onset arrhythmia in patients hospitalized with sepsis; however, there are no specific treatment guidelines and the ideal therapeutic approaches still remain unclear. Objectives To begin with the current state of knowledge concerning the underling mechanisms, the incidence and prognostic impact...

Atrial fibrillation (AF) is the most common arrhythmia which occurs during sepsis or septic shock and is promoted by systemic inflammation and consecutive atrial remodeling (Fig. 1). • Approximately 10 % of septic patients and 23 % of patients in septic shock develop new-onset AF with no history of preexisting "typical" AF 1. • Its occurrence is as...

Background. Atrial fibrillation is the most common new onset arrhythmia in patients hospitalized with sepsis; however, there are no specific treatment guidelines and the ideal therapeutic approaches still remain unclear. Objectives. To begin with the current state of knowledge concerning the underling mechanisms, the incidence and prognostic impact...

Background Proliferation may predict response to neoadjuvant therapy of breast cancer and is commonly assessed by manual scoring of slides stained by immunohistochemistry (IHC) for Ki-67 similar to ER and PgR. This method carries significant intra- and inter-observer variability. Automatic scoring of Ki-67 with digital image analysis (qIHC) or asse...

Background Long axis strain (LAS) has been shown to be a fast assessable parameter representing global left ventricular (LV) longitudinal function in cardiovascular magnetic resonance (CMR). However, the prognostic value of LAS in cardiomyopathies with reduced left ventricular ejection fraction (LVEF) has not been evaluated yet. Methods and result...

Assessment of longitudinal function with cardiovascular magnetic resonance (CMR) is limited to measurement of systolic excursion of the mitral annulus (MAPSE) or elaborate strain imaging modalities. The aim of this study was to develop a fast assessable parameter for the measurement of long axis strain (LAS) with CMR. 40 healthy volunteers and 125...

Background: Myocardial deformation measurement is superior to left ventricular ejection fraction in identifying early changes in myocardial contractility and prediction of cardiovascular outcome. The lack of standardization hinders its clinical implementation. The aim of the study is to investigate a novel standardized deformation imaging approach...

Mean GLS values were -16.2±5.3% and -17.3±5.3% for echocardiography and CMR, respectively. GLS did not differ significantly between the two imaging modalities, which showed strong correlation (r=0.86), a small bias (-1.1%) and narrow 95% limits of agreement (LOA, ±5.4%). Mean GCS values were -17.9±6.3% and -24.4 ±7.8% for echocardiography and CMR,...

The expression of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors and key regulators of the extrinsic apoptosis pathway correlate with clinical features and the WHO grade of malignancy in some tumor entities. Expression of pro-apoptotic TRAIL receptors and executioners of apoptosis are a prerequisite for TRAIL-based th...

A meningioma is the most common primary intracranial tumor in adults. Here, we investigated the therapeutic potential of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in 37 meningiomas. Freshly isolated primary meningioma cells were treated with TRAIL with or without different sensitizing protocols, and apoptotic cell death wa...

Aim: The aim of this study was to determine the value of extracellular volume fraction (ECV) for the non-invasive assessment of diffuse myocardial fibrosis (MF) in different stages of systolic left ventricular (LV) dysfunction in dilated cardiomyopathy (DCM) in comparison with endomyocardial biopsy. Background: Non-invasive ECV assessment using...

Background: Routine quantitative assessment of left ventricular (LV) volumes with echocardiography is hindered by time-consuming methods requiring a manual trace of the LV cavity from two apical two-dimensional planes. Thus, the aim of this study was to evaluate faster new semiautomatic echocardiographic methods that could represent a feasible alt...

Evaluation of proliferative activity is a cornerstone in the classification of endocrine tumors; in pulmonary carcinoids, the mitotic count delineates typical carcinoid (TC) from atypical carcinoid (AC). Data on the reproducibility of manual mitotic counting and other methods of proliferation index evaluation in this tumor entity are sparse. Nine e...