Left atrial function in elite athletes: A meta-analysis of two-dimensional speckle tracking echocardiographic studies

Abstract

Background: We sought to investigate left atrial (LA) volume, function, and strain in elite athletes by a meta-analysis including echocardiographic studies that provided volumetric and strain analysis of LA phasic function.

Methods: The OVID-MEDLINE, PubMed, and Cochrane CENTRAL databases were searched for English-language articles without time restriction up to February 2018 through focused and high sensitive search strategies. Studies were identified by crossing the following search terms: "athletes," "left atrial size," "left atrial volume," "atrial function," "atrial strain," "atrial strain rate," "echocardiography," "2D speckle echocardiography."

Results: Meta-analysis included 403 athletes and 314 active but not trained healthy controls from 9 studies. Pooled data showed that average LA volume index was higher in athletes than in healthy controls (28.0 ± 1.0 vs 20.7 ± 0.8 mL/m² , P < 0.001). Global LA longitudinal strain, showing LA reservoir function, was lower in the athletes than in healthy controls with borderline significance (37.0 ± 1.2 vs 38.3 ± 1.5%, P = 0.044). Late diastolic LA strain rate, resembling LA contractile function, was also lower in elite athletes than in control group (-1.56 ± 0.08 vs -1.74 ± 0.09 seconds -1, P = 0.007).

Conclusions: Our meta-analysis shows that LA volume is higher, while LA reservoir and contractile functions are impaired in elite athletes during active training compared to untrained controls. Whether these changes persist during deconditioning periods remains to be determined. These alterations may be related to the higher risk of arrhythmias, in particular atrial fibrillation, reported among middle/old aged athletes.

Keywords: left atrium; meta-analysis; phasic function; strain; volume.

Figure 1

The echocardiographic assessment of left atrial strain and strain rates in four‐ and two‐chamber views. LASRearly, LA peak longitudinal strain rate during early diastole, LASR_late, LA peak longitudinal strain rate during late diastoleLASR_syst, LA peak longitudinal strain rate during ventricular systole; PACS, global peak atrial contraction strain; PALS, global peak atrial longitudinal strain

Figure 2

Forest plot for standard means difference (SMD) global peak atrial longitudinal strain (PALS) in elite athletes and healthy non‐athletic controls; data from eight studies (CI, confidence intervals, P = 0.04)

Figure 3

Forest plot for standard means difference (SMD) global peak atrial contraction strain (PACS) in elite athletes and healthy non‐athletic controls; data from seven studies (CI, confidence intervals P = 0.29)