The long-QT syndrome and exercise practice: The never-ending debate.

Today, understanding the true risk of adverse events in long-QT syndrome (LQTS) populations may be extremely complex and potentially dependent on many factors such as the affected gene, mutation location, degree of QTc prolongation, age, sex, and other yet unknown factors. In this context, risk stratification by genotype in LQTS patients has been extremely difficult, also during exercise practice, especially due to the lack of studies that would lead to a better understanding of the natural history of each mutation and its impact upon athletes. The creation of individualized guidelines for sport participation is a goal yet to be achieved not only due to the complexity of genotype effect on the phenotype in this patient population, but also due to penetrance in genotype-positive patients. This article summarizes current knowledge and raises questions concerning the difficult relationship between exercise practice and LQTS.