Cardiac arrhythmias are associated with significant morbidity and mortality. Antiarrhythmic drug therapy was traditionally the mainstay of arrhythmia treatment; however, the limited efficacy and proarrhythmic potential of conventional antiarrhythmic drugs has generated interest in new approaches to the treatment of arrhythmias. Over the last decade, there has been improved characterization of the molecular pathways that culminate in arrhythmias. By analyzing mechanisms that increase susceptibility to arrhythmias in individuals with genetic syndromes, it might be possible to not only improve current therapies but also to develop novel approaches to treat and prevent common arrhythmias.