Editorial QTc Behavior During Exercise and Genetic Testing for the Long-QT Syndrome

The quest to facilitate the diagnosis of the long-QTsyndrome (LQTS) and even to predict genotype is neverending. The study by Sy et al1 published in the current issue of Circulation adds a new piece to the puzzle and has the potential to be very useful. Article see p 2187 Since the early days,2 diagnosis of the long-QT syndrome (LQTS) has undergone several levels of progressive upgrade. Initially, the diagnosis was made only in the presence of multiple factors, such as very bizarre T waves and marked prolongations of the QT interval in a child or teenager or abrupt loss of consciousness during emotional or physical stress, and it also required one of the few medical doctors who had heard about LQTS. The first attempt to provide diagnostic criteria for LQTS came in 19853 and, in their simplicity, they are still useful now for a first assessmen