Myocardial gene transfer has shown tremendous potential to investigate pathophysiology and potential therapies for cardiac diseases. In the field of cardiac arrhythmias, there is a tremendous need for new therapeutic options. The current work reviews the need for new therapies for cardiac arrhythmias, the use of gene transfer to evaluate cellular electrophysiology, the application of in vivo gene transfer to treatment of common arrhythmias, and the current problems in the field of cardiac gene therapy. Arrhythmia gene therapy is a field in its infancy, and future human applications are dependent on solutions to the problems discussed here.