Many advances in the care of children with cardiac rhythm disturbances have been made in the past year. From the fetus with supraventricular tachycardia to the adolescent with vasovagal syncope, new and effective therapies have evolved. Molecular genetics has led to monumental leaps in the understanding of long QT syndrome, and a new pharmacologic alternative to cardioversion has been introduced. There have also been new and noteworthy developments in the more established area of radiofrequency ablation. These concern safety and also touch on one of today's most controversial areas, cost effectiveness. This article discusses each of these advances in the realm of pediatric cardiac electrophysiology.