Long QT syndrome and short QT syndrome: how to make correct diagnosis and what about eligibility for sports activity.

Cardiologists are involved in evaluating the eligibility of athletes to practise competitive sport and they should therefore be able to identify the electrocardiographic markers of long QT syndrome (LQTS) and short QT syndrome (SQTS). An overview of the clinical criteria to perform measurement of QT interval on 12-lead electrocardiogram is provided herein and several instances in which the diagnosis of either LQTS or SQTS may leave the clinician uncertain are discussed. A critical appraisal of current recommendations for eligibility to competitive sport is also provided as well as some of the authors' personal opinions on the practice of recreational activities in patients with abnormal repolarization.