Multimodality Risk Stratification in Athletes With Long QT Syndrome

BACKGROUND: Long QT syndrome has traditionally led to exercise restriction due to concerns for exertion-triggered arrhythmia and sudden cardiac death. Emerging data, however, support individualized participation guided by genotype and physiologic risk markers. CASE SUMMARY: We describe 3 young athletes with distinct genotypes (KCNE1 D85N [long QT syndrome type 5-Lite], KCNQ1 R555H [long QT syndrome type 1], and KCNH2 p.T613M [long QT syndrome type 2]) evaluated through electrocardiography, exercise testing, and echocardiographic assessment of the electromechanical window. The electromechanical window ranged from mildly to severely negative (-11 to -103 ms) and corresponded with phenotypic severity. Personalized management, including selective β-blockade, mexiletine, and device therapy, enabled safe continuation of sports participation in all cases. DISCUSSION: This case series underscores the role of genotype-specific, multimodality assessment in risk stratifying athletes with long QT syndrome. Integration of individualized therapy, shared decision making, and structured emergency preparedness supports safe athletic participation while maintaining arrhythmic protection and quality of life. TAKE-HOME MESSAGES: Individualized risk assessment including resting and stress electrocardiography, genotype analysis, and electromechanical window measurement provides a more accurate estimate of arrhythmic risk than does resting QTc interval alone. Genotype-guided therapy and structured sports counseling allow most patients with LQTS to safely engage in exercise and even competitive athletics under expert supervision. Shared decision making and emergency preparedness, including automated external defibrillator access and multidisciplinary collaboration, are essential to balancing athletic participation with long-term safety in patients with LQTS.