It is currently recognised that obstructive sleep apnea (OSA) may affect the function and geometry of heart chambers, which has promoted the development of echocardiographic exploration as one of the tools for screening for the diagnosis of OSA and its severity in the general population. However, few studies have investigated the impact of echocardiographic findings on screening for OSA or its severe forms in patients with atrial fibrillation (AF).

Investigate the echocardiographic abnormalities that would be correlated with the positive diagnosis of OSA and the diagnosis of its severity in non-valvular AF patients.

This is a cross-sectional study that included 100 patients with non-valvular AF. All patients had an echocardiographic study and overnight polygraphy.

OSA's diagnosis was retained in 90% of patients: mild in 32% of cases, moderate in 27% of cases and severe in 31% of cases. In our study, there was no significant difference between groups with and without OSA in terms of left ventricular systolic function, percentage of patients with left ventricular hypertrophy (LVH), left atrium area, systolic function right ventricle and pulmonary systolic blood pressure level.

Comparing patients with severe OSA to patients with non-severe OSA, analysis of echocardiographic parameters showed that LVH was significantly more found in patients with severe OSA compared with those with IAH<30 (58% versus 35.4%, P=0.036, OR=2.52, CI_95%: 1.05–6.07). In addition, the surface of the left atrium was positively correlated with hypnea–apnea index (P=0.018) and therefore with the severity of OSA.

In our study conducted in a Tunisian population with AF, we pointed out that OSA was not significantly associated with the different echocardiographic parameters used, whereas LVH and the left atrial area were significantly more noticeable in the severe OSA group compared to the rest of the population.