Journal Review : Long-termendurance sport practice increases the incidence of lone atrial fibrillation inmen: a follow-up study

Michela Madalosso,Antonio Raviele

Cardiovascular Department, Umberto I Hospital, Mestre, Italy.

Original Citation

Molina L, Mont L, Marrugat J, Berruezo A, Brugada J, Bruguera J, Rebato C,Elosua R. Long-term endurance sport practice increases the incidence of lone atrial fibrillation in men: a follow-up study. Europace. 2008 May;10(5):618-23.   [ Pubmed Citation ]

doi : 10.4022/jafib.v1i1.416

Introduction

The study is aimed to determine the incidenceof lone atrial fibrillation in males according to sport practice levels and toidentify possible clinical markers that increase the risk of lone atrialfibrillation (LAF) among marathon runners.

Methods

A retrospective cohort study was designed witha group of 252 marathon runners recruited in 1990-92 and a population sample of305 sedentary men recruited in 1994-96. The physical activity was evaluatedwith the Minnesota leisure time physical activity questionnaire. At therecruitment moment, a physical examination, a BP measure and an ECG wereperformed in all men. A maximal exercise test and an echocardiogram wasobtained only in the marathon runners. They were all contacted in 2002-03 andinvited to attend an outpatients clinic to identify suggestive symptoms ofhaving experienced an arrhythmia requiring medical attention. In those withsuggestive symptoms of atrial fibrillation, medical records were reviewed.Finally, LAF was diagnosed on the basis of the presence of atrial fibrillationin an electrocardiogram in the absence of structural heart disease and otheridentifiable cause of arrhythmia (i.e. alcohol, hyperthyroidism). In the groupof marathon runners, a second two-dimensional echocardiogram was obtained atthe end of the follow up. Moreover, a new questionnaire to access the lifetimetotal physical activity practice was administered.

Results

Of the initial 252 marathon runners, 183 completedthe follow up (72,9%) with a mean follow up of 11.6 years, while 290 (95.7%) ofthe 305 elegible sedentary men concluded the follow up with a mean follow up of6.4 years.

Marathon runners were younger and showedlower BMI, heart rate, blood pressure and higher consumption of alcohol,smoking prevalence and leisure time physical activity then the sedentary men.The annual incidence rate of LAF among marathon runners and sedentary men was0,43/100 and 0,11/100, respectively. Only paroxysmal or persistent LAF wasrecorded, and any atrial flutter episode was recorded during the follow up. Theonly statistically significant difference between participants with and withoutlone atrial fibrillation was that those with the arrhythmia were thinner andpracticed more physical activity. In the group of marathon runners, the onlystatistically difference between groups according to the presence of LAF, wasthe left atrial size measured in the follow up echocardiogram. Left atrialinferosuperior diameter and left atrial volume were both associated with ahigher risk of incident LAF. Endurance sport practice was associated with ahigher risk of incident LAF in the multivariate age- and blood pressure-adjusted Cox regression models (HR = 8.80; 95% confidence interval: 1.26-61.29)

Conclusion and Comment

While an active lifestyle improveoverall health, this study demonstrate that the long-term endurance sportpractice is associated with a higher risk of symptomatic LAF in men. Moreover,the risk of LAF is associated with a larger left atrial inferosuperior diameterand volume in physically active subjets. The atrial dilatation, may be aconsequence of increases in preload, autonomic changes (i.e. increased vagaltone) and inflammatory changes due to sports participation. Treatment for theathletes with LAF has not been described previously, but catheter ablation isemerging as a potential cure for LAF, especially in symptomatic athletes withimpaired athletic performance and poor quality of life.