Cardiomyopathy in animal models of muscular dystrophy

Arrhythmia and cardiomyopathy frequently accompany muscular dystrophy. In t he last year, the cardiovascular consequences of muscular dystrophy gene mu tations have been established through studies of murine models. These model s have highlighted the potential role of primary defects in cardiac muscle as well as those secondary cardiovascular outcomes that arise from severe m uscle disease. This review focuses on three areas. Recent studies using mou se models have shown that the dystrophin-associated proteins, the sarcoglyc ans and alpha -dystrobrevin, are critical for both cardiac and skeletal mus cle membrane function, yet may exert their roles by different molecular mec hanisms. New findings have shown that cytoskeletal proteins at the nuclear membrane, such as emerin and lamin AC, cause muscular dystrophy and cardiom yopathy with cardiac conduction system disease. Finally, the mechanism of c ardiac and muscle degeneration in myotonic dystrophy has been re-evaluated through a series of studies using murine models. Implications for human the rapy are considered in light Of these new findings. (C) 2001 Lippincott Wil liams & Wilkins, Inc.