Objective To evaluate the early changes of left atrial (LA) volume and function by speckle tracking imaging (STI) and real-time three-dimensional echocardiography (RT-3DE) in patients with obstructive sleep apnea syndrome (OSAS).

Methods A total of 92 patients with moderate to severe OSAS (apnea-hypopnea index AHI> 15/h) and 50 healthy people were prospectively included. According to the left ventricular mass index (LVMI), OSAS patients were stratified into two groups: 30 patients with left ventricular hypertrophy (LVH) and 62 patients without LVH. All subjects were assessed for LA function through conventional echocardiography combined with STI and RT-3DE.

Results OSAS patients showed lower LA global longitudinal strain during early diastole (LA S-E), systole (LA S-S), while higher strain during late diastole (LA S-A) than controls (P < 0.05). While OSAS patients with LVH had lower LA S-S, LA S-E and higher LA S-A than patients without LVH (all P < 0.05). RT-3DE results should that LA volume before systole (LAVIpreA), and minimum volume (LAVImin) were significantly higher in OSAS patients (P < 0.05). The AHI was correlated with LA S-S, LA S-E, LAVImax, LAVIpreA, LAVImin, LATEVI, LAAEVI in OSAS patients.

Conclusions The combination of STI and RT-3DE can evaluate the early changes of LA volume and function in patients with OSAS. With the progress of LVH and OSAS, LA function damage will be further aggravated.