You are a general paediatric trainee in a cardiology outpatient clinic and you see Thomas, a 14-year-old boy who was recently diagnosed with congenital long QT syndrome (LQTS) following the sudden death of his uncle, aged 45, while at work in his office. The diagnosis of LQTS was made postmortem on a molecular autopsy and the family subsequently underwent cascade screening. Thomas has been diagnosed as carrying a pathogenic mutation for LQT1 and commenced on a beta blocker. His resting ECG is sinus rhythm, you calculate the corrected QT interval (QTc) as 440 ms using Bazett’s formula and he otherwise has a normal physical examination and has had no symptoms of palpitations, syncope or presyncope. Prior to this diagnosis, Thomas played football for his school and would like to go back to training.

Do children with a confirmed diagnosis of congenital LQTS, who are symptom-free and on appropriate medication (PATIENT), who participate in competitive sports (INTERVENTION) compared with those who do not compete (COMPARISON) have more breakthrough cardiac events (BCEs)? (OUTCOME)

A literature search was conducted on Embase and PubMed on 19 January 2025 using the search terms ((children) OR (young people) OR (adolescent) OR (teenager)) AND ((long qt syndrome) OR (genetic heart disease)) OR (inherited channelopathy)) AND ((sport) OR (physical activity) OR (competition)) (see online supplemental figure 1 for search terms). This search identified 2047 original articles. Abstract and title screening was performed. Articles were included if they included children (<18 years old) with congenital LQTS, who had been diagnosed prior to participating in sports or competitive sports and were treated. Review articles, abstracts, articles not in English, only in adults and conducted solely on participants with implantable cardioverter defibrillators (ICDs) were excluded. 12 articles were eligible for full-text screening. Five were then excluded (see online supplemental figure 2). …