Document Type

Report

Publication Date

3-25-2026

Comments

This article is the author’s final published version in JACC: Case Reports, Volume 31, Issue 12, 2026, Article number 107061.

The published version is available at https://doi.org/10.1016/j.jaccas.2026.107061. Copyright © 2026 The Authors.

 

Abstract

BACKGROUND: High-volume endurance training may shift exercise from cardioprotective to arrhythmogenic, increasing the risk of atrial fibrillation (AF) in healthy athletes.

CASE SUMMARY: A 38-year-old marathon runner with a 15-year history of high-intensity endurance training presented with episodic palpitations and reduced athletic performance. Electrocardiogram showed paroxysmal AF; echocardiography revealed mild left atrial enlargement without structural heart disease. Symptoms worsened during the recovery phase after runs, suggesting vagally mediated AF. After unsuccessful flecainide therapy, he underwent pulmonary vein isolation. Twelve months later, he remained free of recurrent AF on Holter monitoring and successfully resumed endurance training following an 8-week recovery period. However, ongoing high-volume exercise may still carry a residual risk of arrhythmia.

REVIEW SUMMARY: AF in athletes is associated with a 2- to 5-fold increased prevalence linked to atrial remodeling, autonomic imbalance, and inflammation. Rhythm control, especially catheter ablation, preserves performance and quality of life.

TAKE-HOME MESSAGE: Excessive endurance training increases AF risk; early rhythm control and structured return-to-play strategies optimize outcomes.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

PubMed ID

41906559

Language

English

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