Fragmented QRS complex in athletes’ electrocardiogram: physiological adaptation or pathological sign? A scoping review

BACKGROUND: Fragmented QRS (fQRS) complex, characterized by notching/slurring in the QRS complex, has been linked with myocardial fibrosis and sudden cardiac death (SCD) in cardiomyopathies. While fQRS is a recognized arrhythmogenic marker in hypertrophic cardiomyopathy, it is not included in the International Criteria for ECG interpretation in athletes. METHODS: This review aims to evaluate the prevalence and clinical significance of fQRS in athletes. This review was done according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guideline. A search was conducted across PubMed, ScienceDirect, and Google Scholar to identify relevant studies reporting fQRS in athletes across all age groups and sports discipline. RESULTS: A total of 7 studies were included in the final review, revealing higher prevalence of fQRS in older age groups, with the highest prevalence occurring in lead V1. Athletes with fQRS also experienced no adverse events on follow-ups. CONCLUSIONS: Current data suggests that isolated fQRS, especially in lead V1, is likely benign. However, fQRS in ≥ 2 contiguous leads warrant further investigations. A longer follow-up duration is needed to ascertain the possibilities of adverse events occurring in athletes.