Congenital heart disease (CHD) affects six out of 1,000 babies born in the U.S. each year and is often complicated by arrhythmias, a condition where the heart beats too rapidly, too slowly or irregularly due to a misfiring of the body’s electrical impulses. While the last decade brought great advances in technologies that improve the care of adult arrhythmias, pediatric patients have been left behind, with only five devices approved for use in children in the same period. As a result, pediatric specialists are often using off-label or improvised devices to treat pediatric arrhythmias, including the smallest newborns.