Study Links Older Age and Low Fitness to Higher Risk of Arrhythmias in Healthy Adults

Older age and lower aerobic fitness are independent risk factors for irregular heartbeats, or arrhythmias, in otherwise healthy adults, according to research presented at the European Society of Cardiology (ESC) Congress in Madrid. The findings suggest that arrhythmias, once thought to be benign, may indicate increased risk for future cardiovascular disease.

The study included 1151 participants aged 40 to 65 years (mean age 52; 88% men) without symptoms of heart disease or structural abnormalities. Participants underwent exercise stress testing with continuous electrocardiography (Holter monitoring) to detect abnormal heart rhythms.

Researchers reported that 32% of participants had supraventricular tachycardia, 4% had atrial fibrillation, and 6% had nonsustained ventricular tachycardia, all classified as complex arrhythmias. Atrial arrhythmias were strongly associated with older age and lower fitness, while ventricular arrhythmias were linked primarily to older age and reduced kidney function.

The analysis showed that each additional year of age increased the likelihood of atrial arrhythmia by 9% and ventricular arrhythmia by 4%. The prevalence of arrhythmias rose significantly beginning in the 50–54 age group. Multivariable analysis confirmed that both older age and lower fitness were strong, independent predictors of atrial arrhythmia burden.

Investigators suggested that arrhythmia screening beginning at age 50 may allow for early identification of individuals at risk for cardiovascular events, even in those without symptoms. The results also highlight the protective role of maintaining aerobic fitness, which was associated with reduced risk of frequent and complex atrial arrhythmias.

Study authors cautioned that as an observational study, causation cannot be established. The study population was also not diverse, with relatively few women enrolled. Further research is needed to determine whether interventions such as exercise programs or medications could lower arrhythmia risk.

Reference: European Society of Cardiology. Older age and low fitness levels are associated with heartbeat abnormalities that increase future cardiovascular risk. News release. August 27, 2025. Accessed September 4, 2025. https://www.escardio.org/The-ESC/Press-Office/Press-releases/Older-age-and-low-fitness-levels-are-associated-with-heartbeat-abnormalities-that-increase-future-cardiovascular-risk#