A diverse group of uncommon congenital heart defects and genetic conditions may put a child in danger of sudden cardiac arrest (SCA), and at least two-thirds of these defects and conditions can be identified by an electrocardiogram (ECG), the test that analyzes the heart's electrical function. Much of the current debate centers on the practicalities and cost of universal ECG screening. Two clinicians offer opposing commentaries on the controversy in the August 19 issue of Circulation, the journal of the American Heart Association.