Scar tissue in the heart has been associated with abnormal heart rhythms among healthy, long-time male endurance athletes aged 50 or older, potentially elevating their risk of sudden cardiac death, according to a study published in Circulation: Cardiovascular Imaging, an American Heart Association journal. The study, named VENTOUX after a challenging climb in the Tour de France, involved 106 male cyclists and triathletes who trained at least 10 hours weekly for over 15 years, revealing a significant link between myocardial fibrosis and ventricular tachycardia, a serious type of abnormal heart rhythm.
Myocardial fibrosis, or the scarring of heart muscle tissue, was previously known to be associated with irregular heartbeats, but its impact on healthy endurance athletes was unclear until now. The research utilized cardiovascular magnetic resonance imaging and implanted ECG recorders to monitor participants over two years, finding that nearly half showed signs of scarring on the left ventricle, and a small percentage experienced sustained, dangerous fast heart rates.
Senior study author Peter Swoboda, M.B.B.S., Ph.D., emphasized the rarity of dangerous heart rhythms during sports but highlighted the importance of identifying at-risk individuals to ensure their continued safe participation in sports. The study's findings, while preliminary, suggest a need for heightened awareness and preventive strategies among older endurance athletes, including the knowledge of CPR and the use of automated external defibrillators.
The study's limitations include its small, selective participant pool and the inability to determine whether cardiac scarring directly causes irregular heart rhythms or serves as a marker for another underlying process. Future research aims to include women to broaden the understanding of this phenomenon across different demographics.
Funded by several health research organizations in the U.K., the study underscores the critical need for further investigation into the long-term effects of endurance training on heart health, offering valuable insights for athletes, coaches, and healthcare providers in mitigating risks associated with high-level physical activity.
