Prevalence and Clinical Significance of Left Atrial Remodeling in Competitive Athletes

Abstract

In a large population of highly trained athletes, enlarged LA dimension > or = 40 mm was relatively common (20%), with the upper limits of 45 mm in women and 50 mm in men distinguishing physiologic cardiac remodeling ("athlete's heart") from pathologic cardiac conditions. Atrial fibrillation and other supraventricular tachyarrhythmias proved to be uncommon (prevalence < 1%) and similar to that in the general population, despite the frequency of LA enlargement. Left atrial remodeling in competitive athletes may be regarded as a physiologic adaptation to exercise conditioning, largely without adverse clinical consequences.

Atrial remodelling is less pronounced in female endurance-trained athletes compared with that in male athletes

“…In line with previous studies, athletes have larger left atrial volumes compared to gender matched controls (6)(7)(8). Furthermore, this study shows that right atrial volumes increase with increasing fitness.…”

“…Few studies have investigated the effects on atrial volumes. Using echocardiography and cardiac magnetic resonance imaging (CMR), recent studies have shown increased atrial dimensions and volumes in endurance athletes (6)(7)(8). However, studies of atrial adaptation to training in women are scarce and data on the effects on right atrial volumes in both men and women is lacking.…”

“…This form of scaling may be useful in a normal population where atrial volumes vary with BSA (11). However, in an athletic population the atrial volumes are also increased due to training and therefore all volumes normalized for BSA will be higher and often above the limits of normal remodeling (6). We therefore suggest normalizing for THV which takes both BSA and fitness into consideration.…”

Potential Adverse Cardiovascular Effects From Excessive Endurance Exercise

“…26 Highly trained individuals develop cardiac adaptations including enlarged LV and RV volumes, increased LV wall thickness and cardiac mass, and increased left atrial size. [21][22][23] In the general population, these structural changes are associated with poor cardiac prognosis. 27 However, these structural alterations, together with a preserved LV ejection fraction (EF), have been considered typical findings of the "athlete's heart."…”

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…350,351 Indeed, AF is the primary arrhythmia observed in middle-aged athletes. 352 AF in athletes tends to be paroxysmal, vagally mediated, and highly symptomatic.…”