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Li W, Stauske M, Luo X, Wagner S, Vollrath M, Mehnert CS, Schubert M, Cyganek L, Chen S, Hasheminasab SM, Wulf G, El-Armouche A, Maier LS, Hasenfuss G, Guan K. Disease Phenotypes and Mechanisms of iPSC-Derived Cardiomyocytes From Brugada Syndrome Patients With a Loss-of-Function SCN5A Mutation. Front Cell Dev Biol 2020; 8:592893. [PMID: 33195263 PMCID: PMC7642519 DOI: 10.3389/fcell.2020.592893] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 10/01/2020] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS) is one of the major causes of sudden cardiac death in young people, while the underlying mechanisms are not completely understood. Here, we investigated the pathophysiological phenotypes and mechanisms using induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) from two BrS patients (BrS-CMs) carrying a heterozygous SCN5A mutation p.S1812X. Compared to CMs derived from healthy controls (Ctrl-CMs), BrS-CMs displayed a 50% reduction of INa density, a 69.5% reduction of NaV1.5 expression, and the impaired localization of NaV1.5 and connexin 43 (Cx43) at the cell surface. BrS-CMs exhibited reduced action potential (AP) upstroke velocity and conduction slowing. The Ito in BrS-CMs was significantly augmented, and the ICaL window current probability was increased. Our data indicate that the electrophysiological mechanisms underlying arrhythmia in BrS-CMs may involve both depolarization and repolarization disorders. Cilostazol and milrinone showed dramatic inhibitions of Ito in BrS-CMs and alleviated the arrhythmic activity, suggesting their therapeutic potential for BrS patients.
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Hoffmann M, Kant TA, Emig R, Rausch JSE, Newe M, Schubert M, Künzel K, Winter L, Klapproth E, Peyronnet R, Ravens U, El-Armouche A, Künzel SR. Repurposing mesalazine against cardiac fibrosis in vitro. Naunyn Schmiedebergs Arch Pharmacol 2020; 394:533-543. [PMID: 33064167 PMCID: PMC7892689 DOI: 10.1007/s00210-020-01998-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022]
Abstract
Cardiovascular diseases are exacerbated and driven by cardiac fibrosis. TGFβ induces fibroblast activation and differentiation into myofibroblasts that secrete excessive extracellular matrix proteins leading to stiffening of the heart, concomitant cardiac dysfunction, and arrhythmias. However, effective pharmacotherapy for preventing or reversing cardiac fibrosis is presently unavailable. Therefore, drug repurposing could be a cost- and time-saving approach to discover antifibrotic interventions. The aim of this study was to investigate the antifibrotic potential of mesalazine in a cardiac fibroblast stress model. TGFβ was used to induce a profibrotic phenotype in a human cardiac fibroblast cell line. After induction, cells were treated with mesalazine or solvent control. Fibroblast proliferation, key fibrosis protein expression, extracellular collagen deposition, and mechanical properties were subsequently determined. In response to TGFβ treatment, fibroblasts underwent a profound phenoconversion towards myofibroblasts, determined by the expression of fibrillary αSMA. Mesalazine reduced differentiation nearly by half and diminished fibroblast proliferation by a third. Additionally, TGFβ led to increased cell stiffness and adhesion, which were reversed by mesalazine treatment. Collagen 1 expression and deposition—key drivers of fibrosis—were significantly increased upon TGFβ stimulation and reduced to control levels by mesalazine. SMAD2/3 and ERK1/2 phosphorylation, along with reduced nuclear NFκB translocation, were identified as potential modes of action. The current study provides experimental pre-clinical evidence for antifibrotic effects of mesalazine in an in vitro model of cardiac fibrosis. Furthermore, it sheds light on possible mechanisms of action and suggests further investigation in experimental and clinical settings.
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Sadek MS, Cachorro E, El-Armouche A, Kämmerer S. Therapeutic Implications for PDE2 and cGMP/cAMP Mediated Crosstalk in Cardiovascular Diseases. Int J Mol Sci 2020; 21:E7462. [PMID: 33050419 PMCID: PMC7590001 DOI: 10.3390/ijms21207462] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022] Open
Abstract
Phosphodiesterases (PDEs) are the principal superfamily of enzymes responsible for degrading the secondary messengers 3',5'-cyclic nucleotides cAMP and cGMP. Their refined subcellular localization and substrate specificity contribute to finely regulate cAMP/cGMP gradients in various cellular microdomains. Redistribution of multiple signal compartmentalization components is often perceived under pathological conditions. Thereby PDEs have long been pursued as therapeutic targets in diverse disease conditions including neurological, metabolic, cancer and autoimmune disorders in addition to numerous cardiovascular diseases (CVDs). PDE2 is a unique member of the broad family of PDEs. In addition to its capability to hydrolyze both cAMP and cGMP, PDE2 is the sole isoform that may be allosterically activated by cGMP increasing its cAMP hydrolyzing activity. Within the cardiovascular system, PDE2 serves as an integral regulator for the crosstalk between cAMP/cGMP pathways and thereby may couple chronically adverse augmented cAMP signaling with cardioprotective cGMP signaling. This review provides a comprehensive overview of PDE2 regulatory functions in multiple cellular components within the cardiovascular system and also within various subcellular microdomains. Implications for PDE2- mediated crosstalk mechanisms in diverse cardiovascular pathologies are discussed highlighting the prospective use of PDE2 as a potential therapeutic target in cardiovascular disorders.
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Mollenhauer M, Mehrkens D, Klinke A, Lange M, Remane L, Friedrichs K, Braumann S, Geißen S, Simsekyilmaz S, Nettersheim FS, Lee S, Peinkofer G, Geisler AC, Geis B, Schwoerer AP, Carrier L, Freeman BA, Dewenter M, Luo X, El-Armouche A, Wagner M, Adam M, Baldus S, Rudolph V. Nitro-fatty acids suppress ischemic ventricular arrhythmias by preserving calcium homeostasis. Sci Rep 2020; 10:15319. [PMID: 32948795 PMCID: PMC7501300 DOI: 10.1038/s41598-020-71870-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 07/22/2020] [Indexed: 12/01/2022] Open
Abstract
Nitro-fatty acids are electrophilic anti-inflammatory mediators which are generated during myocardial ischemic injury. Whether these species exert anti-arrhythmic effects in the acute phase of myocardial ischemia has not been investigated so far. Herein, we demonstrate that pretreatment of mice with 9- and 10-nitro-octadec-9-enoic acid (nitro-oleic acid, NO2-OA) significantly reduced the susceptibility to develop acute ventricular tachycardia (VT). Accordingly, epicardial mapping revealed a markedly enhanced homogeneity in ventricular conduction. NO2-OA treatment of isolated cardiomyocytes lowered the number of spontaneous contractions upon adrenergic isoproterenol stimulation and nearly abolished ryanodine receptor type 2 (RyR2)-dependent sarcoplasmic Ca2+ leak. NO2-OA also significantly reduced RyR2-phosphorylation by inhibition of increased CaMKII activity. Thus, NO2-OA might be a novel pharmacological option for the prevention of VT development.
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Kirstein B, Neudeck S, Gaspar T, Piorkowski J, Wechselberger S, Kronborg MB, Zedda A, Hankel A, El-Armouche A, Tomala J, Schmidt T, Mayer J, Wagner M, Ulbrich S, Pu L, Richter U, Huo Y, Piorkowski C. Left atrial fibrosis predicts left ventricular ejection fraction response after atrial fibrillation ablation in heart failure patients: the Fibrosis-HF Study. Europace 2020; 22:1812-1821. [DOI: 10.1093/europace/euaa179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/04/2020] [Indexed: 11/12/2022] Open
Abstract
Abstract
Aims
Atrial fibrillation (AF) and heart failure (HF) often coexist. Catheter ablation has been reported to restore left ventricular (LV) function but patients benefit differently. This study investigated the correlation between left atrial (LA) fibrosis extent and LV ejection fraction (LVEF) recovery after AF ablation.
Methods and results
In this study, 103 patients [64 years, 69% men, 79% persistent AF, LVEF 33% interquartile range (IQR) (25–38)] undergoing first time AF ablation were investigated. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. Continuous rhythm monitoring was used to assess ablation success. Improvement in post-ablation LVEF was measured as primary study endpoint. An absolute increase in post-ablation LVEF ≥10% was defined as ‘Super Response’. Left atrial fibrosis was present in 38% of patients. After ablation LVEF increased by absolute 15% (IQR 6–25) (P < 0.001). Left ventricular ejection fraction improvement was higher in patients without LA fibrosis [15% (IQR 10–25) vs. 10% (IQR 0–20), P < 0.001]. An inverse correlation between LVEF improvement and the extent of LA fibrosis was found (R2 = 0.931). In multivariate analysis, the presence of LA fibrosis was the only independent predictor for failing LVEF improvement [odds ratio 7.2 (95% confidence interval 2.2–23.4), P < 0.001]. Echocardiographic ‘Super Response’ was observed in 55/64 (86%) patients without and 21/39 (54%) patients with LA fibrosis, respectively (P < 0.001).
Conclusion
Presence and extent of LA fibrosis predict LVEF response in HF patients undergoing AF ablation. The assessment of LA fibrosis may impact prognostic stratification and clinical management in HF patients with AF.
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Heijman J, Muna AP, Veleva T, Molina CE, Sutanto H, Tekook M, Wang Q, Abu-Taha IH, Gorka M, Künzel S, El-Armouche A, Reichenspurner H, Kamler M, Nikolaev V, Ravens U, Li N, Nattel S, Wehrens XHT, Dobrev D. Atrial Myocyte NLRP3/CaMKII Nexus Forms a Substrate for Postoperative Atrial Fibrillation. Circ Res 2020; 127:1036-1055. [PMID: 32762493 DOI: 10.1161/circresaha.120.316710] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
RATIONALE Postoperative atrial fibrillation (POAF) is a common and troublesome complication of cardiac surgery. POAF is generally believed to occur when postoperative triggers act on a preexisting vulnerable substrate, but the underlying cellular and molecular mechanisms are largely unknown. OBJECTIVE To identify cellular POAF mechanisms in right atrial samples from patients without a history of atrial fibrillation undergoing open-heart surgery. METHODS AND RESULTS Multicellular action potentials, membrane ion-currents (perforated patch-clamp), or simultaneous membrane-current (ruptured patch-clamp) and [Ca2+]i-recordings in atrial cardiomyocytes, along with protein-expression levels in tissue homogenates or cardiomyocytes, were assessed in 265 atrial samples from patients without or with POAF. No indices of electrical, profibrotic, or connexin remodeling were noted in POAF, but Ca2+-transient amplitude was smaller, although spontaneous sarcoplasmic reticulum (SR) Ca2+-release events and L-type Ca2+-current alternans occurred more frequently. CaMKII (Ca2+/calmodulin-dependent protein kinase-II) protein-expression, CaMKII-dependent phosphorylation of the cardiac RyR2 (ryanodine-receptor channel type-2), and RyR2 single-channel open-probability were significantly increased in POAF. SR Ca2+-content was unchanged in POAF despite greater SR Ca2+-leak, with a trend towards increased SR Ca2+-ATPase activity. Patients with POAF also showed stronger expression of activated components of the NLRP3 (NACHT, LRR, and PYD domains-containing protein-3)-inflammasome system in atrial whole-tissue homogenates and cardiomyocytes. Acute application of interleukin-1β caused NLRP3-signaling activation and CaMKII-dependent RyR2/phospholamban hyperphosphorylation in an immortalized mouse atrial cardiomyocyte cell-line (HL-1-cardiomyocytes) and enhanced spontaneous SR Ca2+-release events in both POAF cardiomyocytes and HL-1-cardiomyocytes. Computational modeling showed that RyR2 dysfunction and increased SR Ca2+-uptake are sufficient to reproduce the Ca2+-handling phenotype and indicated an increased risk of proarrhythmic delayed afterdepolarizations in POAF subjects in response to interleukin-1β. CONCLUSIONS Preexisting Ca2+-handling abnormalities and activation of NLRP3-inflammasome/CaMKII signaling are evident in atrial cardiomyocytes from patients who subsequently develop POAF. These molecular substrates sensitize cardiomyocytes to spontaneous Ca2+-releases and arrhythmogenic afterdepolarizations, particularly upon exposure to inflammatory mediators. Our data reveal a potential cellular and molecular substrate for this important clinical problem.
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Künzel SR, Rausch JSE, Schäffer C, Hoffmann M, Künzel K, Klapproth E, Kant T, Herzog N, Küpper JH, Lorenz K, Dudek S, Emig R, Ravens U, Rog-Zielinska EA, Peyronnet R, El-Armouche A. Modeling atrial fibrosis in vitro-Generation and characterization of a novel human atrial fibroblast cell line. FEBS Open Bio 2020; 10:1210-1218. [PMID: 32421922 PMCID: PMC7327914 DOI: 10.1002/2211-5463.12896] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/07/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022] Open
Abstract
Atrial fibrillation (AF) is regularly accompanied by cardiac fibrosis and concomitant heart failure. Due to the heterogeneous nature and complexity of fibrosis, the knowledge about the underlying mechanisms is limited, which prevents effective pharmacotherapy. A deeper understanding of cardiac fibroblasts is essential to meet this need. We previously described phenotypic and functional differences between atrial fibroblasts from patients in sinus rhythm and with AF. Herein, we established and characterized a novel human atrial fibroblast line, which displays typical fibroblast morphology and function comparable to primary cells but with improved proliferation capacity and low spontaneous myofibroblast differentiation. These traits make our model suitable for the study of fibrosis mechanisms and for drug screening aimed at developing effective antifibrotic pharmacotherapy.
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Kirstein B, Neudeck S, Kronborg MB, El-Armouche A, Gaspar T, Piorkowski J, Wechselberger S, Zedda A, Tomala J, Mayer J, Wagner M, Ulbrich S, Richter U, Huo Y, Piorkowski C. P457Incidence of LA fibrosis and substrate-based AF ablation success rates in HF patients. Europace 2020. [DOI: 10.1093/europace/euaa162.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Funding Acknowledgements
The author(s) received no specific funding for this work.
Background
In heart failure (HF) patients, sinus rhythm maintenance after catheter ablation for atrial fibrillation (AF) is mandatory to achieve better long-term outcome. Presence of left atrial (LA) fibrosis significantly attenuates ablation success rates. Incidence of LA fibrosis and the effect of an individualized substrate-based ablation concept on rhythm outcome in HF patients with AF is unclear.
Methods
This study investigated 103 patients (64 years, 69% men) with persistent AF (79%) and left ventricular (LV) dysfunction (EF 33% IQR [25; 38]) undergoing first time AF ablation. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. All patients received pulmonary vein isolation (PVI). LA fibrosis ablation was individualized by (i) homogenization of small areas, (ii) linear lesions connecting fibrosis and anatomical obstacles and (iii) linear lesions isolating large fibrotic areas. Rhythm outcome was measured by continuous device monitoring (AF detection ≥ 6 min) or Holter-ECG. A total post-procedural AF burden < 0.1% was defined as successful rhythm control.
Results
LA fibrosis in the overall cohort, in paroxysmal and persistent AF patients was detected in 39/103 (38%), 6/22 (27%) and 33/81 (41%), respectively. After 11 ± 5 months and 1.2 procedures/patient, freedom from AF recurrence was similar between patients with and without LA fibrosis (33/39 (84%) vs. 54/64 (84%); p = 0.485). With continuous monitoring, 73/87 (84%) patients recorded a total AF burden < 0.1%. There was no significant difference in AF burden outcome between patients with and without LA fibrosis (3.1% SD ±17.4 vs. 2.2% SD ±8.1; p = 0.4). No correlation between presence or extent of LA fibrosis and AF burden was found; p = 0.299.
Conclusion
A substantial number of HF patients with AF have no evidence of LA fibrosis. Among HF patients with LA fibrosis, individualized substrate-based AF ablation beyond PVI was able to achieve similar ablation success.
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Dalan R, Bornstein SR, El-Armouche A, Rodionov RN, Markov A, Wielockx B, Beuschlein F, Boehm BO. The ACE-2 in COVID-19: Foe or Friend? Horm Metab Res 2020; 52:257-263. [PMID: 32340044 PMCID: PMC7339082 DOI: 10.1055/a-1155-0501] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 01/08/2023]
Abstract
COVID-19 is a rapidly spreading outbreak globally. Emerging evidence demonstrates that older individuals and people with underlying metabolic conditions of diabetes mellitus, hypertension, and hyperlipidemia are at higher risk of morbidity and mortality. The SARS-CoV-2 infects humans through the angiotensin converting enzyme (ACE-2) receptor. The ACE-2 receptor is a part of the dual system renin-angiotensin-system (RAS) consisting of ACE-Ang-II-AT1R axis and ACE-2-Ang-(1-7)-Mas axis. In metabolic disorders and with increased age, it is known that there is an upregulation of ACE-Ang-II-AT1R axis with a downregulation of ACE-2-Ang-(1-7)-Mas axis. The activated ACE-Ang-II-AT1R axis leads to pro-inflammatory and pro-fibrotic effects in respiratory system, vascular dysfunction, myocardial fibrosis, nephropathy, and insulin secretory defects with increased insulin resistance. On the other hand, the ACE-2-Ang-(1-7)-Mas axis has anti-inflammatory and antifibrotic effects on the respiratory system and anti-inflammatory, antioxidative stress, and protective effects on vascular function, protects against myocardial fibrosis, nephropathy, pancreatitis, and insulin resistance. In effect, the balance between these two axes may determine the prognosis. The already strained ACE-2-Ang-(1-7)-Mas in metabolic disorders is further stressed due to the use of the ACE-2 by the virus for entry, which affects the prognosis in terms of respiratory compromise. Further evidence needs to be gathered on whether modulation of the renin angiotensin system would be advantageous due to upregulation of Mas activation or harmful due to the concomitant ACE-2 receptor upregulation in the acute management of COVID-19.
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Tomasovic A, Brand T, Schanbacher C, Kramer S, Hümmert MW, Godoy P, Schmidt-Heck W, Nordbeck P, Ludwig J, Homann S, Wiegering A, Shaykhutdinov T, Kratz C, Knüchel R, Müller-Hermelink HK, Rosenwald A, Frey N, Eichler J, Dobrev D, El-Armouche A, Hengstler JG, Müller OJ, Hinrichs K, Cuello F, Zernecke A, Lorenz K. Interference with ERK-dimerization at the nucleocytosolic interface targets pathological ERK1/2 signaling without cardiotoxic side-effects. Nat Commun 2020; 11:1733. [PMID: 32265441 PMCID: PMC7138859 DOI: 10.1038/s41467-020-15505-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 03/13/2020] [Indexed: 12/16/2022] Open
Abstract
Dysregulation of extracellular signal-regulated kinases (ERK1/2) is linked to several diseases including heart failure, genetic syndromes and cancer. Inhibition of ERK1/2, however, can cause severe cardiac side-effects, precluding its wide therapeutic application. ERKT188-autophosphorylation was identified to cause pathological cardiac hypertrophy. Here we report that interference with ERK-dimerization, a prerequisite for ERKT188-phosphorylation, minimizes cardiac hypertrophy without inducing cardiac adverse effects: an ERK-dimerization inhibitory peptide (EDI) prevents ERKT188-phosphorylation, nuclear ERK1/2-signaling and cardiomyocyte hypertrophy, protecting from pressure-overload-induced heart failure in mice whilst preserving ERK1/2-activity and cytosolic survival signaling. We also examine this alternative ERK1/2-targeting strategy in cancer: indeed, ERKT188-phosphorylation is strongly upregulated in cancer and EDI efficiently suppresses cancer cell proliferation without causing cardiotoxicity. This powerful cardio-safe strategy of interfering with ERK-dimerization thus combats pathological ERK1/2-signaling in heart and cancer, and may potentially expand therapeutic options for ERK1/2-related diseases, such as heart failure and genetic syndromes. Drugs targeting dysregulated ERK1/2 signaling can cause severe cardiac side effects, precluding their wide therapeutic application. Here, a new and cardio-safe targeting strategy is presented that interferes with ERK dimerization to prevent pathological ERK1/2 signaling in the heart and cancer.
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Droth K, El-Armouche A, Andresen D, Bestehorn KP. 2406Role of implantation access on complication rates in pacemaker implantation. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Introduction
The implantation access (IA) either via vena cephalica (VC) or vena subclavia (VS) is the usual procedure in pacemaker implantation (PI). Valid data on head-to head comparisons between access via CV and VS regarding serious complications are missing.
Purpose
We analyzed potential associations between the type of implantation access and complication rates in a real world data set with 69.957 cases.
Methods
The 2013 dataset of the German Federal Council, containing information about all 1st pacemaker implantations for Germanywas analyzed. First two cohorts of patients treated via CV or CS access were compared for all relevant variables through descriptive statistics. Secondly all patient-clusters with exactly the same risk-/condition-vector were identified based on the following variables: age, sex, ASA classification (ASA 1–ASA 5), leading symptom, indication for implantation, etiology, ejection fraction (EF), estimated need of stimulation, and all possible 1:1 exact matchings were compared.
Results
Out of the total cohort of 69,957 patients (mean age 76.2 years, 43.3% females, VC access 36%, VS access 64%) 19,643 pairs with identical profile of all factors contained in the database could be identified. These pairs of all 1:1 matchings had following profile: age 77.07 years, ASA 1 to 4 6.3%, 2 45.0%, 46.9%, 4 1.7%, leading symptoms (dizziness 51.9%, singular cardiac syncope 10.3%, recurring syncope 28,7%), pacemaker indication (AV-Block II/III 11.6%/26.3%, sick sinus syndrome 39,8%, bradycardia in atrial fibrillation 20.0%), unknown etiology 90.3%, estimated need of stimulation (permanent (>90%) 20.9%, frequent (5–90%) 70.2%, rare (<5%) 8.9%), EF (≤35%: 0.4%: 35, 50%: 9.1%, >50%: 79.9%, unknown: 10.5%).
Intra- and post-procedural complication [C] rates different between VC and VS are: at least one C: 2.6% (VC), 3.0% (VS) p=0.018; surgical C with need for intervention (haematothorax, pericardial effusion, pouch hematoma): 0.5% (VC), 1.0% (VS) p=0.005; asystole: 0.1% (VC), 0.2% (VS) p=0.047; pneumothorax: 0.1% (VC), 0.7% (VC) p<0.001; dislocated atrial lead: 0.8% (VC), 0.6% (VS) p=0.027. Intra-hospital mortality was 1.0% (VC), 1.1% (VS) p=0.521.
Conclusion
Our analysis of a large-scale database shows that in patients with first pacemaker implantation the overall rate of complications is relatively low. But even after adjustment for available risk factors there are differences between the access routes: whereas VS access route is associated with statistically significant higher risk of overall complications, i.e. surgical complications, asystole, pneumothorax the VC access has a greater risk of dislocated atrial lead. In view of the two times higher rate of implantations via VS (64 vs. 36%) the clinical implications should be considered when choosing the access route and the VC access should be preferred.
Acknowledgement/Funding
None
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Fahmi MS, Günscht M, Siegert J, Dutt F, Künzel S, Lorenz K, Wagner M, Kämmerer S, El-Armouche A. Abstract 576: Phosphodiesterase 2 in Cardiac Arrhythmias and Heart Failure. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Heart failure (HF) patients often suffer from lethal ventricular arrhythmias leading to sudden cardiac arrests. Phosphodiesterase 2 (PDE2), a cGMP activated enzyme hydrolyzing cAMP, is upregulated in HF. Cardiac-specific PDE2 overexpression revealed strong anti-arrhythmic and heart rate lowering effects of PDE2. Here, we validated the cardioprotective role of PDE2 upon modulating cardiac PDE2 activity, first, via assessing cardiac function of cardiac-specific PDE2-KO mice and second, via potentiating PDE2 mediated cGMP/cAMP crosstalk using natriuretic peptide type C (CNP), which are upstream of the cGMP/PDE2 axis. Cardiac function and arrhythmia susceptibility of PDE2-KO were assessed via echocardiography and ECG telemetry under basal conditions and after myocardial infarction (MI). Patch clamp technique was used to investigate CNP effects on action potentials and ion currents in WT isolated cardiomyocytes and in-vivo via ECG-telemetry. Already under basal conditions, PDE2-KO displayed severe irregularities in RR-intervals. 14 days post MI, PDE2-KO showed lower cardiac function and delayed increase in heart rate after arrhythmia provocation (double isoprenaline (ISO) injection (2 mg/kg i.p.) compared to WT controls, indicating diminished cardiac responsiveness. On the other hand, CNP treatment in WT displayed a PDE2-dependent antiarrhythmogenic effect. CNP (1 μM) significantly reduced the total number of delayed afterdepolarizations and spontaneous action potentials upon acute ISO (10 nM) stimulation. Furthermore, CNP significantly reduced the ISO-mediated increase of the L-type Ca
2+
and late Na
+
currents as well as SR Ca
2+
waves. These effects were reversed upon specific PDE2 inhibition with BAY 60-7550. Finally, in vivo, CNP (33 μg/g i.p.) significantly reduced the number of ventricular extrasystoles after arrhythmia provocation. This effect was significantly attenuated after PDE2 inhibition with BAY 60-7550. Here we provide evidence for acute antiarrhythmic effects of CNP upon downstream stimulation of cGMP-stimulated PDE2 and a critical role of PDE2 on heart rate regulation. Therefore, pharmacologically enhancing myocardial PDE2 activity may represent a novel cardioprotective strategy in cardiac arrhythmia and HF.
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Künzel SR, Schaeffer C, Sekeres K, Mehnert CS, Schacht Wall SM, Newe M, Kämmerer S, El-Armouche A. Ultrasonic-augmented Primary Adult Fibroblast Isolation. J Vis Exp 2019. [PMID: 31403625 DOI: 10.3791/59858] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Primary adult fibroblasts have become an important tool to study fibrosis, fibroblast interactions and inflammation in all body tissues. Since primary fibroblasts cannot divide indefinitely due to myofibroblast differentiation or senescence induction, new cultures must be established regularly. However, there are several obstacles to overcome during the processes of developing a reliable isolation protocol and primary fibroblast isolation itself: the method's degree of difficulty (especially for beginners), the risk of bacterial contamination, the required time until primary fibroblasts can be used for experiments, and subsequent cell quality and viability. In this study, a fast, reliable and easy-to-learn protocol to isolate and culture primary adult fibroblasts from mouse heart, lung, liver and kidney combining enzymatic digestion and ultrasonic agitation is provided.
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Wechselberger S, Kronborg M, Huo Y, Piorkowski J, Neudeck S, Päßler E, El-Armouche A, Richter U, Mayer J, Ulbrich S, Pu L, Kirstein B, Gaspar T, Piorkowski C. Continuous monitoring after atrial fibrillation ablation: the LINQ AF study. Europace 2019; 20:f312-f320. [PMID: 29688326 PMCID: PMC6277150 DOI: 10.1093/europace/euy038] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 02/19/2018] [Indexed: 01/27/2023] Open
Abstract
Aims To study device performance, arrhythmia recurrence characteristics, and methods of outcome assessment using a novel implantable cardiac monitor (ICM) in patients undergoing ablation for atrial fibrillation (AF). Methods and results In 419 consecutive patients undergoing first-time catheter ablation for symptomatic paroxysmal (n = 224) or persistent (n = 195) AF an ICM was injected at the end of the procedure. Telemedicine staff ensured full episode transmission coverage and manually evaluated all automatic arrhythmia episodes. Device detection metrics were calculated for ≥2, ≥6, and ≥10 min AF detection durations. Four methods of outcome assessment were studied: continuous recurrence analysis, discontinuous recurrence analysis, AF-burden analysis, and analysis of individual rhythm profiles. A total of 43 673 automatic AF episodes were transmitted over a follow-up of 15 ± 6 months. Episode-based positive predictive values changed significantly with longer AF detection durations (70.5% for ≥2 min, 81.8% for ≥6 min, and 85.9% for ≥10 min). Patients with exclusive short episode recurrences (≥2 to <6 min) were rare and their arrhythmia detection was clinically irrelevant. Different methods of outcome assessment showed a large variation (46–79%) in ablation success. Individual rhythm characteristics and subclinical AF added to this inconsistency. Analysis of AF-burden and individual rhythm profiles were least influenced and showed successful treatment in 60–70% of the patients. Conclusion We suggest AF detection duration >6 min and AF burden >0.1% as a standardized outcome definition for AF studies to come in the future.
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Belau F, Metzner K, Christ T, Ravens U, Schaefer M, Künzel S, Li W, Wettwer E, Dobrev D, El-Armouche A, Kämmerer S. DPP10 is a new regulator of Nav1.5 channels in human heart. Int J Cardiol 2019; 284:68-73. [DOI: 10.1016/j.ijcard.2018.12.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 12/14/2018] [Accepted: 12/27/2018] [Indexed: 10/27/2022]
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Riedel K, Deussen AJ, Tolkmitt J, Weber S, Schlinkert P, Zatschler B, Friebel C, Müller B, El-Armouche A, Morawietz H, Matschke K, Kopaliani I. Estrogen determines sex differences in adrenergic vessel tone by regulation of endothelial β-adrenoceptor expression. Am J Physiol Heart Circ Physiol 2019; 317:H243-H254. [PMID: 31149843 DOI: 10.1152/ajpheart.00456.2018] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vessels of female rats constrict less and relax more to adrenergic stimulation than vessels of males. Although we have reported that these sex-specific differences rely on endothelial β-adrenoceptors, the role of sex hormones in β-adrenoceptor expression and related vessel tone regulation is unknown. We investigated the role of estrogen, progesterone and testosterone on β-adrenoceptor expression and adrenergic vessel tone regulation, along with sex-specific differences in human mammary arteries. The sex-specific differences in vasoconstriction and vasorelaxation in rat vessels were eliminated after ovariectomy in females. Ovariectomy increased vessel vasoconstriction to norepinephrine more than twofold. Vasorelaxations by isoprenaline and a β3-agonist were reduced after ovariectomy. Estrogen, but not progesterone substitution, restored sex-specific differences in vasoconstriction and vasorelaxation. Vascular mRNA levels of β1- and β3- but not β2-adrenoreceptors were higher in vessels of females compared with males. Ovariectomy reduced these differences by decreasing β1- and β3- but not β2-adrenoreceptor expression in females. Consistently, estrogen substitution restored β1- and β3-adrenoreceptor expression. Orchiectomy or testosterone treatment affected neither vasoconstriction and vasorelaxation nor β-adrenoceptor expression in vessels of male rats. In human mammary arteries, sex-specific differences in vasoconstriction and vasorelaxation were reduced after removal of endothelium or treatment with l-NMMA. Vessels of women showed higher levels of β1- and β3-adrenoceptors than in men. In conclusion, the sex-specific differences in vasoconstriction and vasorelaxation are common for rat and human vessels. In rats, these differences are estrogen but not testosterone or progesterone dependent. Estrogen determines these differences via regulation of vascular endothelial β1- and β3-adrenoreceptor expression. NEW & NOTEWORTHY This study proposes a mechanistic concept regulating sex-specific differences in adrenergic vasoconstriction and vasorelaxation. Estrogen increases vascular β1- and β3-adrenoceptor expression in female rats. This and our previous studies demonstrate that these receptors are located primarily on endothelium and when activated by norepinephrine act via nitric oxide (NO). Therefore, β-adrenergic stimulation leads to a more pronounced vasorelaxation in females. Coactivation of endothelial β1- and β3-adrenoreceptors leads to higher NO release in vessels of females, ultimately blunting vasoconstriction triggered by activation of smooth muscle α-adrenoceptors.
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Tsata V, Kroehne V, Reinhardt S, El-Armouche A, Brand M, Wagner M, Reimer MM. Electrophysiological Properties of Adult Zebrafish Oligodendrocyte Progenitor Cells. Front Cell Neurosci 2019; 13:102. [PMID: 31031593 PMCID: PMC6473327 DOI: 10.3389/fncel.2019.00102] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/28/2019] [Indexed: 11/13/2022] Open
Abstract
Low remyelination efficiency after spinal cord injury (SCI) is a major restraint to successful axonal and functional regeneration in mammals. In contrast, adult zebrafish can: (i) regenerate oligodendrocytes and myelin sheaths within 2 weeks post lesion; (ii) re-grow axonal projections across the lesion site and (iii) recover locomotor function within 6 weeks after spinal cord transection. However, little is known about the intrinsic properties of oligodendrocyte progenitor cells (OPCs), the remyelinating cells of the central nervous system (CNS). Here, we demonstrate that purified OPCs from the adult zebrafish spinal cord are electrically active. They functionally express voltage-gated K+ and Na+ channels, glutamate receptors and exhibit depolarizing, tetrodotoxin (TTX)-sensitive spikes, as previously seen in rodent and human OPCs. Furthermore, we show that the percentage of zebrafish OPCs exhibiting depolarizing spikes and Nav-mediated currents is lower as compared to rodent white matter OPCs, where these membrane characteristics have been shown to underlie OPC injury susceptibility. These findings imply that adult zebrafish OPCs resemble electrical properties found in mammals and represent a relevant cell type towards understanding the biology of the primary cells targeted in remyelination therapies for non-regenerative species. The in vitro platform introduced in this study could be used in the future to: (i) elucidate how membrane characteristics of zebrafish OPCs change upon injury and (ii) identify potential signaling components underlying OPC injury recognition.
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Westhofen S, Dreher L, El-Armouche A, Vitzhum H, Reichenspurner H, Ehmke H, Schwoerer P. Altered Electrophysiological Remodeling Induced by Mechanical Unloading in Phospholamban Deficient Mice. Thorac Cardiovasc Surg 2019. [DOI: 10.1055/s-0039-1678819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Yao C, Veleva T, Scott L, Cao S, Li L, Chen G, Jeyabal P, Pan X, Alsina KM, Abu-Taha I, Ghezelbash S, Reynolds CL, Shen YH, LeMaire SA, Schmitz W, Müller FU, El-Armouche A, Eissa NT, Beeton C, Nattel S, Wehrens XH, Dobrev D, Li N. Enhanced Cardiomyocyte NLRP3 Inflammasome Signaling Promotes Atrial Fibrillation. Circulation 2018; 138:2227-2242. [PMID: 29802206 PMCID: PMC6252285 DOI: 10.1161/circulationaha.118.035202] [Citation(s) in RCA: 365] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/14/2018] [Indexed: 01/22/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) is frequently associated with enhanced inflammatory response. The NLRP3 (NACHT, LRR, and PYD domain containing protein 3) inflammasome mediates caspase-1 activation and interleukin-1β release in immune cells but is not known to play a role in cardiomyocytes (CMs). Here, we assessed the role of CM NLRP3 inflammasome in AF. METHODS NLRP3 inflammasome activation was assessed by immunoblot in atrial whole-tissue lysates and CMs from patients with paroxysmal AF or long-standing persistent (chronic) AF. To determine whether CM-specific activation of NLPR3 is sufficient to promote AF, a CM-specific knockin mouse model expressing constitutively active NLRP3 (CM-KI) was established. In vivo electrophysiology was used to assess atrial arrhythmia vulnerability. To evaluate the mechanism of AF, electric activation pattern, Ca2+ spark frequency, atrial effective refractory period, and morphology of atria were evaluated in CM-KI mice and wild-type littermates. RESULTS NLRP3 inflammasome activity was increased in the atrial CMs of patients with paroxysmal AF and chronic AF. CM-KI mice developed spontaneous premature atrial contractions and inducible AF, which was attenuated by a specific NLRP3 inflammasome inhibitor, MCC950. CM-KI mice exhibited ectopic activity, abnormal sarcoplasmic reticulum Ca2+ release, atrial effective refractory period shortening, and atrial hypertrophy. Adeno-associated virus subtype-9-mediated CM-specific knockdown of Nlrp3 suppressed AF development in CM-KI mice. Finally, genetic inhibition of Nlrp3 prevented AF development in CREM transgenic mice, a well-characterized mouse model of spontaneous AF. CONCLUSIONS Our study establishes a novel pathophysiological role for CM NLRP3 inflammasome signaling, with a mechanistic link to the pathogenesis of AF, and establishes the inhibition of NLRP3 as a potential novel AF therapy approach.
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Fischer TH, Eiringhaus J, Dybkova N, Saadatmand A, Pabel S, Weber S, Wang Y, Köhn M, Tirilomis T, Ljubojevic S, Renner A, Gummert J, Maier LS, Hasenfuß G, El-Armouche A, Sossalla S. Activation of protein phosphatase 1 by a selective phosphatase disrupting peptide reduces sarcoplasmic reticulum Ca 2+ leak in human heart failure. Eur J Heart Fail 2018; 20:1673-1685. [PMID: 30191648 DOI: 10.1002/ejhf.1297] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 07/11/2018] [Accepted: 07/14/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Disruption of Ca2+ homeostasis is a key pathomechanism in heart failure. CaMKII-dependent hyperphosphorylation of ryanodine receptors in the sarcoplasmic reticulum (SR) increases the arrhythmogenic SR Ca2+ leak and depletes SR Ca2+ stores. The contribution of conversely acting serine/threonine phosphatases [protein phosphatase 1 (PP1) and 2A (PP2A)] is largely unknown. METHODS AND RESULTS Human myocardium from three groups of patients was investigated: (i) healthy controls (non-failing, NF, n = 8), (ii) compensated hypertrophy (Hy, n = 16), and (iii) end-stage heart failure (HF, n = 52). Expression of PP1 was unchanged in Hy but greater in HF compared to NF while its endogenous inhibitor-1 (I-1) was markedly lower expressed in both compared to NF, suggesting increased total PP1 activity. In contrast, PP2A expression was lower in Hy and HF compared to NF. Ca2+ homeostasis was severely disturbed in HF compared to Hy signified by a higher SR Ca2+ leak, lower systolic Ca2+ transients as well as a decreased SR Ca2+ load. Inhibition of PP1/PP2A by okadaic acid increased SR Ca2+ load and systolic Ca2+ transients but severely aggravated diastolic SR Ca2+ leak and cellular arrhythmias in Hy. Conversely, selective activation of PP1 by a PP1-disrupting peptide (PDP3) in HF potently reduced SR Ca2+ leak as well as cellular arrhythmias and, importantly, did not compromise systolic Ca2+ release and SR Ca2+ load. CONCLUSION This study is the first to functionally investigate the role of PP1/PP2A for Ca2+ homeostasis in diseased human myocardium. Our data indicate that a modulation of phosphatase activity potently impacts Ca2+ cycling properties. An activation of PP1 counteracts increased kinase activity in heart failure and successfully seals the arrhythmogenic SR Ca2+ leak. It may thus represent a promising future antiarrhythmic therapeutic approach.
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Korovina I, Neuwirth A, Sprott D, Weber S, Sardar Pasha SPB, Gercken B, Breier G, El-Armouche A, Deussen A, Karl MO, Wielockx B, Chavakis T, Klotzsche-von Ameln A. Hematopoietic hypoxia-inducible factor 2α deficiency ameliorates pathological retinal neovascularization via modulation of endothelial cell apoptosis. FASEB J 2018; 33:1758-1770. [PMID: 30156910 DOI: 10.1096/fj.201800430r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A hallmark of proliferative retinopathies, such as retinopathy of prematurity (ROP), is a pathological neovascularization orchestrated by hypoxia and the resulting hypoxia-inducible factor (HIF)-dependent response. We studied the role of Hif2α in hematopoietic cells for pathological retina neovascularization in the murine model of ROP, the oxygen-induced retinopathy (OIR) model. Hematopoietic-specific deficiency of Hif2α ameliorated pathological neovascularization in the OIR model, which was accompanied by enhanced endothelial cell apoptosis. That latter finding was associated with up-regulation of the apoptosis-inducer FasL in Hif2α-deficient microglia. Consistently, pharmacological inhibition of the FasL reversed the reduced pathological neovascularization from hematopoietic-specific Hif2α deficiency. Our study found that the hematopoietic cell Hif2α contributes to pathological retina angiogenesis. Our findings not only provide novel insights regarding the complex interplay between immune cells and endothelial cells in hypoxia-driven retina neovascularization but also may have therapeutic implications for proliferative retinopathies.-Korovina, I., Neuwirth, A., Sprott, D., Weber, S., Sardar Pasha, S. P. B., Gercken, B., Breier, G., El-Armouche, A., Deussen, A., Karl, M. O., Wielockx, B., Chavakis, T., Klotzsche-von Ameln, A. Hematopoietic hypoxia-inducible factor 2α deficiency ameliorates pathological retinal neovascularization via modulation of endothelial cell apoptosis.
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Mollenhauer M, Lange M, Remane L, Friedrichs K, Wagner M, Geisler A, Rudolph TK, Carrier L, El-Armouche A, Klinke A, Baldus S, Rudolph V. P3441Anti-arrhythmic effects of nitrated fatty acids during acute myocardial ischemia. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p3441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Eiringhaus J, Fischer TH, Dybkova N, Saadatmand A, Pabel S, Weber S, Wang Y, Koehn M, El-Armouche A, Maier LS, Hasenfuss G, Sossalla S. P5703Selective activation of cardiac protein phosphatase 1 is of antiarrhythmic potential in human diseased myocardium. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Fahmi M, Richter K, Dybkova N, Vettel C, Dewenter M, Fischmeister R, Piorkowski C, El-Armouche A, Sossalla S, Wagner M. P514Investigating the mechanistic role of PDE2 in cardiac arrhythmia. Cardiovasc Res 2018. [DOI: 10.1093/cvr/cvy060.371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Alfar EA, El-Armouche A, Guan K. MicroRNAs in cardiomyocyte differentiation and maturation. Cardiovasc Res 2018; 114:779-781. [DOI: 10.1093/cvr/cvy065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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