This article contains a review of some of the most significant advances in cardiac arrhythmias that have taken place in the last year, particularly those concerning the most common clinical conditions associated with the risk of arrhythmia, such as sudden cardiac death, atrial fibrillation and syncope, and genetically determined and hereditary heart disease, as well as advances concerning the principal nonpharmacologic treatments, such as catheter ablation, and the use of implantable defibrillators and cardiac resynchronization therapy.