Marcus Kelm

Marcus Kelm
Deutsches Herzzentrum Berlin · Department of Congenital Heart Disease / Pediatric Cardiology

MD

About

76
Publications
5,205
Reads
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497
Citations
Additional affiliations
January 2019 - October 2020
Charité Universitätsmedizin Berlin
Position
  • Researcher
January 2014 - October 2020
Deutsches Herzzentrum Berlin
Position
  • Medical Doctor

Publications

Publications (76)
Article
Full-text available
We aimed to assess surrogate markers for left ventricular (LV) myocardial power and efficiency in patients with isolated aortic stenosis (AS) and combined stenosis/regurgitation (AS/AR). In AS (n = 59), AS/AR (n = 21) and controls (n = 14), surrogates for LV myocardial power and circulatory/external myocardial efficiency were obtained from cardiac...
Article
Full-text available
Background Undesirable outcomes in health care are associated with patient harm and substantial excess costs. Coarctation of the aorta (CoA), one of the most common congenital heart diseases, can be repaired with stenting but requires monitoring and subsequent interventions to detect and treat disease recurrence and aortic wall injuries. Avoidable...
Article
Full-text available
Optimizing treatment planning is essential for advances in patient care and outcomes. Precisely tailored therapy for each patient remains a yearned-for goal. Cardiovascular modelling has the potential to simulate and predict the functional response before the actual intervention is performed. The objective of this study was to proof the validity of...
Article
Full-text available
Objective We aimed to investigate the combined effects of arterial hypertension, bicuspid aortic valve disease (BAVD) and age on the distensibility of the ascending and descending aortas in patients with aortic coarctation. Design Cross-sectional study. Setting The study was conducted at two university medical centres, located in Berlin and Londo...
Article
Full-text available
This paper presents the first transcatheter management of severe aortic regurgitation in a 77-year-old woman with a criss-cross heart—an extremely rare and complex congenital heart disease. The procedure achieved an elimination of aortic regurgitation and resulted in a remarkable improvement of the patient’s physical condition. (Level of Difficulty...
Article
Full-text available
Although disease etiologies differ, heart failure patients with preserved and reduced ejection fraction (HFpEF and HFrEF, respectively) both present with clinical symptoms when under stress and impaired exercise capacity. The extent to which the adaptation of heart rate (HR), stroke volume (SV), and cardiac output (CO) under stress conditions is al...
Article
Full-text available
Background: Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quant...
Article
Background: Many heart diseases can develop a reduced pumping capacity of the heart muscle. A mismatch between ATP demand and ATP production of cardiomyocytes is one of the possible causes. Assessment of the relation between the myocardial ATP production (MV ATP ) and cardiac workload is important for better understanding disease development and ch...
Article
Sodium can accumulate in the skin, at concentrations exceeding serum levels. High sodium environment can lead to pathogenic T helper (Th)17 cell expansion. Psoriasis is a chronic inflammatory skin disease in which interleukin (IL)-17-producing Th17 cells play a crucial role. In an observational study, we measured skin sodium content in psoriasis pa...
Article
Full-text available
Background: Myocardial efficiency should be maintained stable under light-to-moderate stress conditions, but ischemia puts the myocardium at risk for impaired functionality. Additionally, the measurement of such efficiency typically requires invasive heart catheterization and exposure to ionizing radiation. In this work, we aimed to non-invasively...
Article
CONTEXT Pro-opiomelanocortin (POMC) and the melanocortin-4 receptor (MC4R) play a pivotal role in the leptin-melanocortin pathway. Mutations in these genes lead to monogenic types of obesity due to severe hyperphagia. In addition to dietary-induced obesity, a cardiac phenotype without hypertrophy has been identified in MC4R knockout mice. OBJECTIV...
Article
Modeling of hemodynamics and artificial intelligence have great potential to support clinical diagnosis and decision making. While hemodynamics modeling is extremely time- and resource-consuming, machine learning (ML) typically requires large training data that are often unavailable. The aim of this study was to develop and evaluate a novel methodo...
Article
Full-text available
Aims: Although heart failure (HF) is a leading cause for hospitalization and mortality, normalized and comparable non-invasive assessment of haemodynamics and myocardial action remains limited. Moreover, myocardial deformation has not been compared between the guideline-defined HF entities. The distribution of affected and impaired segments within...
Article
Full-text available
Background Left ventricular non-compaction cardiomyopathy (LVNC) has been reported in association with almost all types of congenital heart valve disease. The presence of LVNC-related ventricular dysfunction increases the perioperative risk in these patients. The advantages of transcatheter treatment modalities outweigh those of surgical strategies...
Article
Background Pharmacological stress testing can help to uncover pathological hemodynamic conditions and is, therefore, used in the clinical routine to assess patients with structural heart diseases such as aortic coarctation with borderline indication for treatment. The aim of this study was to develop and test a reduced-order model predicting dobuta...
Article
Full-text available
In patients with aortic coarctation it would be desirable to assess pressure gradients as well as information about blood flow profiles at rest and during exercise. We aimed to assess the hemodynamic responses to physical exercise by combining MRI-ergometry with computational fluid dynamics (CFD). MRI was performed on 20 patients with aortic coarct...
Article
Full-text available
Wrist-worn devices with heart rate monitoring have become increasingly popular. Although current guidelines advise to consider clinical symptoms and exercise tolerance during decision-making in heart disease, it remains unknown to which extent wearables can help to determine such functional capacity measures. In clinical settings, the 6-minute walk...
Article
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Background: Fast strain-encoded cardiac magnetic resonance imaging (cMRI, fast-SENC) is a novel technology potentially improving characterization of heart failure (HF) patients by quantifying cardiac strain. We sought to describe the impact of isometric handgrip exercise (HG) on cardiac strain assessed by fast-SENC in HF patients and controls. Meth...
Article
Full-text available
Objective Aortic distensibility (AD) represents a well-established parameter of aortic stiffness. It remains unclear, however, whether AD can be obtained with high reproducibility in standard 4-chamber cine CMR images of the descending aorta. This study investigated the intra- and inter-observer agreement of AD based on different angles of the aort...
Article
Full-text available
Computational modelling has made significant progress towards clinical application in recent years. In addition to providing detailed diagnostic data, these methods have the potential to simulate patient-specific interventions and to predict their outcome. Our objective was to evaluate to which extent patient-specific modelling influences treatment...
Article
Full-text available
Early-onset obesity is known to culminate in type 2 diabetes, arterial hypertension and subsequent cardiovascular disease. The role of sodium (Na+) homeostasis in this process is incompletely understood, yet correlations between Na+ accumulation and hypertension have been observed in adults. We aimed to investigate these associations in adolescents...
Article
Introduction Population-based models of morphological variability are useful for automating medical image processing tasks, diagnosis, device and tool design, education and training as well as exploratory hypothesis formation in clinical research. We present a method to (a) generate such a model of the thoracic aorta, (b) explore the morphological...
Article
Aortic valve replacement (AVR) does not usually restore physiological flow profiles. Complex flow profiles are associated with aorta dilatation, ventricle remodeling, aneurysms, and development of atherosclerosis. All these affect long-term morbidity and often require reoperations. In this pilot study, we aim to investigate an ability to optimize t...
Article
Objectives: Complex blood flow profiles in the aorta are known to contribute to vessel dilatation. We studied flow profiles in the aorta in patients with aortic valve disease before and after surgical aortic valve replacement (AVR). Methods: Thirty-four patients with aortic valve disease underwent 4-dimensional velocity-encoded magnetic resonanc...
Article
Full-text available
Introduction: Exercise testing has become a diagnostic standard in the evaluation and management of heart disease. While different methods of exercise and pharmacological stress testing exist, only little is known about their comparability. We aimed to assess hemodynamic changes during dynamic exercise, isometric exercise, and dobutamine stress tes...
Article
Full-text available
Introduction: Exercise testing has become a diagnostic standard in the evaluation and management of heart disease. While different methods of exercise and pharmacological stress testing exist, only little is known about their comparability. We aimed to assess hemodynamic changes during dynamic exercise, isometric exercise and dobutamine stress test...
Article
Full-text available
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Article
Background Invasive peak‐to‐peak pressure gradients are the current clinical reference standard for assessing aortic coarctation. To obtain them, patients need to undergo arterial heart catheterization. Unless an intervention is performed, the procedure remains purely diagnostic, while the concomitant risks remain. Purpose To validate MRI‐based pr...
Chapter
A population of 54 cases diagnosed with coarctation of the aorta (CoA) was investigated for correlations between complex 3D shape and clinical parameters. Based on a statistical shape model (SSM) of the aortic arch (AA) including supra-aortic branches, clustering was performed. The result confirmed the current clinical classification scheme (normal...
Article
Sodium can be buffered in the skin, which mechanism is altered during aging and in certain diseases such as hypertension. High salt environment can promote autoimmunity by expanding pathogenic IL-17 producing T helper (Th17) cells. Psoriasis is a relapsing and remitting inflammatory autoimmune disease affecting the skin and joints and involves proi...
Article
Full-text available
Introduction: Stenotic aortic valve disease (AS) causes pressure overload of the left ventricle (LV) that may trigger adverse remodeling and precipitate progression towards heart failure (HF). As myocardial energetics can be impaired during AS, LV wall stresses and biomechanical power provide a complementary view of LV performance that may aide in...
Article
Full-text available
Renal sympathetic denervation (RDN) is under investigation as a treatment option in patients with resistant hypertension (RH). Determinants of arterial compliance may, however, help to predict the BP response to therapy. Aortic distensibility (AD) is a well-established parameter of aortic stiffness and can reliably be obtained by CMR. This analysis...
Article
Purpose: Severe mitral valve regurgitation can either be treated by a replacement or a repair of the valve. The latter is recommended due to lower perioperative mortality and better long-term survival. On the other hand, recurrence rates after mitral valve repair are high compared to those after replacements and the repair intervention can cause in...
Article
We introduce a parameter estimation framework for automatically and robustly personalizing aortic haemodynamic computations from four-dimensional magnetic resonance imaging data. The framework is based on a reduced-order multiscale fluid-structure interaction blood flow model, and on two calibration procedures. First, Windkessel parameters of the o...
Article
Patient-specific models become increasingly important in cardiovascular research as they allow prediction of surgical procedures. While the left ventricular outflow profile is an essential boundary condition, it remains unknown before treatment takes place. To overcome this problem, hemodynamics after virtual valve replacement were calculated based...
Conference Paper
Full-text available
Personalised 3D modelling of the heart is of increasing interest in order to better characterise pathologies and predict evolution. The personalisation consists in estimating the parameter values of an electromechanical model in order to reproduce the observed cardiac motion. However, the number of parameters in these models can be high and their e...
Article
Modeling different treatment options before a procedure is performed is a promising approach for surgical decision making and patient care in heart valve disease. This study investigated the hemodynamic impact of different prostheses through patient-specific MRI-based CFD simulations. Ten time-resolved MRI data sets with and without velocity encodi...
Article
Full-text available
Background In aortic coarctation, current guidelines recommend reducing pressure gradients that exceed given thresholds. From a physiological standpoint this should ideally improve the energy expenditure of the heart and thus prevent long term organ damage. Objectives The aim was to assess the effects of interventional treatment on external and...
Data
Clinical trial protocol (English computer translation). (PDF)
Data
Clinical trial protocol (German original). (PDF)
Article
Full-text available
Aortic valve repair is still emerging, and its role in the treatment of bicuspid aortic valve disease (BAVD) is not yet fully understood. Our objective is to synthesise available evidence on outcomes after surgical aortic valve repair in patients with BAVD. We conducted a systematic review of clinical studies using prespecified methods for searchin...
Article
Background—There is no systematic assessment of available evidence on effectiveness and comparative effectiveness of balloon dilatation and stenting for aortic coarctation. Methods and Results—We systematically searched 4 online databases to identify and select relevant studies of balloon dilatation and stenting for aortic coarctation based on a p...
Article
Aim: While the overall concept of aortic coarctation has changed from one of simple obstruction to one that includes significant vascular dysfunction, this has not yet been translated into the diagnostic and treatment process. To close this gap, we sought to demonstrate the usefulness of an additional non-invasive vascular profile. Method: Durin...
Article
The coarctation of the aorta (CoA), a local narrowing of the aortic arch, accounts for 7 % of all congenital heart defects. Stenting is a recommended therapy to reduce the pressure gradient. This procedure is associated with complications such as the development of adverse flow conditions. A computer-aided treatment planning based on flow simulatio...
Article
Full-text available
Objective: Effective neonatal cardiopulmonary resuscitation (CPR) requires 3:1 coordinated manual inflations (MI) and chest compressions (CC). We hypothesized that playing a musical prompt would help coordinate CC and MI during CPR. Study design: In this pilot trial we studied the effect the "Radetzkymarsch" (110 beats per minute) on neonatal CP...
Article
Full-text available
Introduction Guidelines on neonatal cardiorespiratory resuscitation (CPR) suggest the provision of coordinated compressions to inflations at a rate of 3:1. However, manikin studies, and human trials have shown that coordinated chest compression/manual ventilation is difficult to achieve. In a manikin study, we aimed to investigate how music might h...
Article
Neonatal resuscitation training is considered to be multifarious and includes manual ventilation as an essential competence for any health-care provider. Usually, ventilation is applied with self-inflating bags (SIBs). These devices have been shown to produce highly variable, operator-dependent peak inspiratory pressures (PIPs) and tidal volumes (V...
Article
Full-text available
Introduction: Self-inflating (SI) bags and T-piece resuscitators are used for mask ventilation of neonates. Leaks between face and mask occur frequently. Little is known about the effects of mask leak on applied pressure and volume. We investigated these effects in an in-vitro study.
Article
Introduction: Self-inflating (SI) bags and T-piece resuscitators are used for mask ventilation of neonates. Leaks between face and mask occur frequently. Little is known about the effects of mask leak on applied pressure and volume. We investigated these effects in an in-vitro study.