title: Cardiac disease and arrhythmogenesis: Mechanistic insights from mouse models.
abstract: The mouse is the second mammalian species, after the human, in which substantial amount of the genomic information has been analyzed. With advances in transgenic technology, mutagenesis is now much easier to carry out in mice. Consequently, an increasing number of transgenic mouse systems have been generated for the study of cardiac arrhythmias in ion channelopathies and cardiomyopathies. Mouse hearts are also amenable to physical manipulation such as coronary artery ligation and transverse aortic constriction to induce heart failure, radiofrequency ablation of the AV node to model complete AV block and even implantation of a miniature pacemaker to induce cardiac dyssynchrony. Last but not least, pharmacological models, despite being simplistic, have enabled us to understand the physiological mechanisms of arrhythmias and evaluate the anti-arrhythmic properties of experimental agents, such as gap junction modulators, that may be exert therapeutic effects in other cardiac diseases. In this article, we examine these in turn, demonstrating that primary inherited arrhythmic syndromes are now recognized to be more complex than abnormality in a particular ion channel, involving alterations in gene expression and structural remodelling. Conversely, in cardiomyopathies and heart failure, mutations in ion channels and proteins have been identified as underlying causes, and electrophysiological remodelling are recognized pathological features. Transgenic techniques causing mutagenesis in mice are extremely powerful in dissecting the relative contributions of different genes play in producing disease phenotypes. Mouse models can serve as useful systems in which to explore how protein defects contribute to arrhythmias and direct future therapy.
authors.affiliation: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.
authors.forename: Lois
authors.initials: L
authors.lastname: Choy
authors.affiliation: School of Medicine, Imperial College London, SW7 2AZ, UK.
authors.forename: Jie Ming
authors.initials: JM
authors.lastname: Yeo
authors.affiliation: Department of Physiology, McGill University, Canada.
authors.forename: Vivian
authors.initials: V
authors.lastname: Tse
authors.affiliation: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.
authors.forename: Shing Po
authors.initials: SP
authors.lastname: Chan
authors.affiliation: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.
authors.forename: Gary
authors.initials: G
authors.lastname: Tse
keywords: Cardiac arrhythmia; Cardiomyopathy; Conduction; Ion channelopathy; Mouse model; Repolarization