Endurance Athlete Atrial Fibrillation (AF) Risk Score Calculator

Endurance Athlete Atrial Fibrillation (AF) Risk Score: Explanation and Clinical Context Endurance athletes, particularly those engaged in long-term high-volume aerobic training, have an increased risk of developing atrial fibrillation compared with the general population. The pathophysiology involves atrial remodeling due to chronic volume overload, elevated vagal tone, and atrial fibrosis. The Endurance Athlete AF Risk Score is designed to estimate the likelihood of developing AF based on key clinical and echocardiographic variables known to contribute to atrial structural and electrical remodeling.

The most influential predictors include age, male sex, cumulative training years, weekly exercise hours, left atrial volume index (LAVI), resting heart rate, and the presence of premature atrial contractions (PACs) on ECG monitoring. The score reflects the cumulative exposure of the atria to hemodynamic stress and vagal predominance, both of which promote atrial ectopy and fibrosis. A higher LAVI or the presence of PACs substantially increases the risk, particularly when combined with a low resting heart rate (<50 bpm).

Clinically, this tool helps in risk stratification and early counseling of endurance athletes, guiding decisions on training modulation, arrhythmia screening, and echocardiographic monitoring. Although primarily research-based, its parameters are derived from population-level data and prospective cohorts of endurance athletes. Normal Range and Interpretation: Low Risk: <10% Moderate Risk: 10–24% High Risk: 25–49% Very High Risk: ≥50% Clinical Interpretation Summary: Athletes with high or very high predicted risk should undergo periodic ECG/Holter monitoring, echocardiography, and be counseled regarding moderation in high-intensity endurance load, especially after the age of 40.