The evolution of sports participation guidelines and the influence of genotype–phenotype correlation in long QT syndrome

Sudden cardiac death in young athletes with long QT syndrome: the role of genetic testing and cardiovascular screening

INTRODUCTION

Sudden cardiac death (SCD) of young athletes during competition or training is a tragic event. The long QT syndrome (LQTS) is an arrythmogenic disorder characterized by prolonged ventricular repolarization leading to torsade de pointes evident at electrocardiogram (ECG). Implantable cardioverter defibrillator is an option to revert ventricular fibrillation to sinus rhythm, although the implantation may result in denial of sports participations to the athlete. The authors reviewed the current literature on LQTS in young athletes, to clarify the role of different screening technologies to prevent SCD.

SOURCES OF DATA

A systematic review of the literature was performed applying the PRISMA guidelines according to the PRISMA checklist and algorithm. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases using various combinations of the keywords: 'QT', 'syndrome', 'screening', 'young', 'athletes', 'genetic', 'electrocardiogram', 'echocardiography' and 'prevention' were used.

AREAS OF AGREEMENT

Young athletes with LQTS are at greater risk of SCD.

AREAS OF CONTROVERSY

Different detection screening technologies, including ECG monitoring and genetic testing, are recommended, even though their role is not fully understood.

GROWING POINTS

ECG and genetic testing screening programmes could reduce the incidence of SCD, and they may positively impact on the health and safety of young athletes during sport.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies should analyze other modalities of screening to allow early detection of cardiovascular conditions to prevent SCD in young athletes.

Cardiac channelopathies: The role of sodium channel mutations

INTRODUCTION AND OBJECTIVES

The importance of sodium channels for the normal electrical activity of the heart is emphasized by the fact that mutations (inherited or de novo) in genes that encode for these channels or their associated proteins cause arrhythmogenic syndromes such as the Brugada syndrome and the long QT syndrome (LQTS). The aim of this study is to conduct a review of the literature on the mutations in the sodium channel complex responsible for heart disease and the implications of a close relationship between genetics and the clinical aspects of the main cardiac channelopathies, namely at the level of diagnosis, risk stratification, prognosis, screening of family members and treatment.

METHODS

The online Pubmed® database was used to search for articles published in this field in indexed journals. The MeSH database was used to define the following query: "Mutation [Mesh] AND Sodium Channels [Mesh] AND Heart Diseases [Mesh]", and articles published in the last 15 years, written in English or Portuguese and referring to research in human beings were included.

CONCLUSIONS

In the past few years, significant advances have been made to clarify the genetic and molecular basis of these syndromes. A greater understanding of the underlying pathophysiological mechanisms showed the importance of the relationship between genotype and phenotype and led to progress in the clinical approach to these patients. However, it is still necessary to improve diagnostic capacity, optimize risk stratification, and develop new specific treatments according to the genotype-phenotype binomial.