Electrical and Ionic Abnormalities in the Heart of Cardiomyopathic Hamsters: in Quest of a New Paradigm for Cardiac Failure and Lethal Arrhythmia

Cardiomyopathy is primary degenerative disease of myocardium, which leads to cardiac failure and lethal arrhythmia. An appropriate model animal of a particular disease is, in general, greatly helpful for better understanding of its pathogenesis. In 1962, a naturally occurring mutant line of Syrian hamster named BIO1.50 was reported, which inherited cardiomyopathy and muscular dystrophy as autosomal recessive mode with 100% penetrance. To date, several sublines of cardiomyopathic hamsters (CM hamsters) have been derived. The genomic deletion of delta-sarcoglycan, a member of dystrophin-associated proteins, was demonstrated to be the common genetic cause of CM hamsters in 1997. Over the past 40 years, hundreds of papers have been published on the pathophysiological aspects of CM hamsters. The aim of this paper is to annotate every one of the CM hamsters with its historical background and then summarize the previous findings on CM hamsters with special focus on electrical and ionic properties. This review article is expected to serve as a basis to build up a new paradigm for the pathogenesis of cardiac failure and severe arrhythmia.