Left Atrial Remodelling May Predict Exercise Capacity in Obstructive Sleep Apnoea Patients

Abstract

Background: Left atrial volume (LAV) and LA deformation has been proposed as a good marker of exercise performance in patients with diastolic dysfunction (DD). As DD is more prevalent in obstructive sleep apnoea (OSA) we aimed to evaluate the influence of LAV and LA deformation parameters on exercise performance in varying severity of OSA. Materials and methods: OSA was diagnosed after polysomnography. Fifty-five OSA patients were enrolled in the study. OSA patients were divided into two groups with apnoea-hypopna-index (AHI)>30 and<30. LAV was calculated. LA strain and LA strain rates were assessed with speckle tracking echocardiography (STE). Exercise capacity was evaluated by treadmill exercise test. Results: MET values were lower in group II compared to group I (p<.05). Echocardiographic findings: Comparison within groups: In both groups E/E', LA stain, LA strain rate S and LA strain rate E were higher after exercise than before (p<.05). In group I LA strain rate A was higher after exercise than before (p<.05). Comparison between groups: LA strain, LA strain rate S, LA strain rate E and LA strain rate A were lower and E/E' and LAVI were higher in group II compared to group I before and after exercise (p<.05). Correlation with METs: AHI, LVEDV, E/E' and LAVI were negatively and LA strain was positively correlated with METs (p<.05). Conclusions: Left ventricular diastolic dysfunction is more prevalent in severe OSA and is associated with impaired exercise performance. Additionally, LA remodelling may predict exercise capacity in this subgroup of patients.