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.