The present invention provides nucleic acid inhibitors of MYH7B and compositions thereof. The present invention also provides methods of treating or preventing a cardiac disorder such as cardiac hypertrophy, myocardial infarction, or heart failure in a subject by administering to the subject an inhibitor of MYH7B. The present invention further provides methods of modulating the activity or expression of β-MHC in cardiac cells of a subject by administering to the subject an inhibitor of MYH7B.本發明提供MYH7B之核酸抑制劑及其組合物。本發明亦提供藉由向個體投與MYH7B之抑制劑來治療或預防該個體中諸如心臟肥大、心肌梗塞或心臟衰竭之心臟病症的方法。本發明進一步提供藉由向個體投與MYH7B之抑制劑來調節該個體心臟細胞中之β-MHC之活性或表現的方法。