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Your search keyword '"Mason, Fleur E."' showing total 2 results
Start Over Author "Mason, Fleur E." Topic arrhythmia
2 results on '"Mason, Fleur E."'

1. Through the haze: unveiling the link between smoking and atrial fibrillation.

Author

Mason, Fleur E. and Voigt, Niels

Subjects
*ATRIAL fibrillation, *SMOKING statistics, *SMOKING, *HAZE, *ARRHYTHMIA
Abstract

Smoking is a major public health issue and the leading preventable cause of illness and death worldwide. It is known to contribute to the development of cardiac arrhythmias, including atrial fibrillation (AF). The addictive component of cigarettes and e-cigarettes, nicotine, is believed to have proarrhythmic effects. A recent study suggests that chronic nicotine exposure may reduce sympathetic innervation in the heart, potentially contributing to ventricular arrhythmogenesis in smokers. Additionally, smoking has been associated with an increased risk of AF, and nicotine may have direct effects on the atria. The study also found that chronic nicotine exposure increases susceptibility to alternans of action potential duration and calcium transient amplitude, which are risk factors for AF. The protective effect of acute sympathetic nerve stimulation against alternans was lost with chronic nicotine exposure. The article highlights the need for further research on the effects of nicotine on atrial sympathetic innervation and fibrosis, as well as efforts to reduce smoking and its impact on health. [Extracted from the article]

Published
2024
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2. Cellular mechanisms of the anti-arrhythmic effect of cardiac PDE2 overexpression

Author

Wagner, Michael, Sadek, Mirna S., Dybkova, Nataliya, Mason, Fleur E., Klehr, Johann, Firneburg, Rebecca, Cachorro, Eleder, Richter, Kurt, Klapproth, Erik, Kuenzel, Stephan R., Lorenz, Kristina, Heijman, Jordi, Dobrev, Dobromir, El-Armouche, Ali, Sossalla, Samuel, Kaemmerer, Susanne, Cardiologie, and RS: Carim - H01 Clinical atrial fibrillation

Subjects
QH301-705.5, Medizin, Action Potentials, heart failure, arrhythmia, Article, Mice, MITOCHONDRIA, Cyclic AMP, Animals, Guanine Nucleotide Exchange Factors, Humans, LEAK, Myocytes, Cardiac, ddc:610, Biology (General), PHOSPHORYLATION, QD1-999, Cyclic GMP, CaMKII, PHOSPHODIESTERASE-2, fungi, Isoproterenol, Arrhythmias, Cardiac, Heart, Cyclic Nucleotide Phosphodiesterases, Type 2, SODIUM, MODEL, Chemistry, Gene Expression Regulation, cardiovascular system, HEART-FAILURE, Calcium, CAMP, Calcium-Calmodulin-Dependent Protein Kinase Type 2, Anti-Arrhythmia Agents, PDE2
Abstract

Background: Phosphodiesterases (PDE) critically regulate myocardial cAMP and cGMP levels. PDE2 is stimulated by cGMP to hydrolyze cAMP, mediating a negative crosstalk between both pathways. PDE2 upregulation in heart failure contributes to desensitization to β-adrenergic overstimulation. After isoprenaline (ISO) injections, PDE2 overexpressing mice (PDE2 OE) were protected against ventricular arrhythmia. Here, we investigate the mechanisms underlying the effects of PDE2 OE on susceptibility to arrhythmias. Methods: Cellular arrhythmia, ion currents, and Ca2+-sparks were assessed in ventricular cardiomyocytes from PDE2 OE and WT littermates. Results: Under basal conditions, action potential (AP) morphology were similar in PDE2 OE and WT. ISO stimulation significantly increased the incidence of afterdepolarizations and spontaneous APs in WT, which was markedly reduced in PDE2 OE. The ISO-induced increase in ICaL seen in WT was prevented in PDE2 OE. Moreover, the ISO-induced, Epac- and CaMKII-dependent increase in INaL and Ca2+-spark frequency was blunted in PDE2 OE, while the effect of direct Epac activation was similar in both groups. Finally, PDE2 inhibition facilitated arrhythmic events in ex vivo perfused WT hearts after reperfusion injury. Conclusion: Higher PDE2 abundance protects against ISO-induced cardiac arrhythmia by preventing the Epac- and CaMKII-mediated increases of cellular triggers. Thus, activating myocardial PDE2 may represent a novel intracellular anti-arrhythmic therapeutic strategy in HF.

Published
2021

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