Altered gene expression has been traditionally focused on transcriptional regulation. Nevertheless, recent large-scale analyses have revealed that as many as half of all changes in the amounts of mRNA in responses to cellular signals can be attributed to altered rates of mRNA decay. In preliminary data, we show that HuR, a member of a class of RNA stabilizing proteins that bind to AU-rich elements (ARE), is expressed in the heart and contributes to Na+ channel mRNA stability by binding to SCN5A transcript. Furthermore, HuR appears to be downregulated in human HF, perhaps contributing to the downregulation of ion channels and increased arrhythmic risk seen in HF. We propose that HuR is downregulated in HF, that this downregulation contributes to reduced Na+ and other currents and increased arrhythmic risk, and that upregulation of HuR will reduce ion channel downregulations and arrhythmic risk in HF. The investigators specific aims are: