Left Atrial Dysfunction Assessed by Two-Dimensional Speckle Tracking Echocardiography in Patients with Impaired Left Ventricular Ejection Fraction and Sleep-Disordered Breathing

AimsTo evaluate the relationship between left atrial (LA) structure and deformation obtained by two-dimensional speckle tracking echocardiography (2DSTE): peak longitudinal systolic strain (LAs), peak longitudinal systolic strain rate (LAS-SR), peak longitudinal early diastolic strain rate (LAE-SR), peak longitudinal late diastolic strain rate (LAA-SR), and sleep-disordered breathing (SDB) estimated by means of apnea-hypopnea index (eAHI). MethodsThirty-two individuals with ischemic heart disease (IHD) and impaired left ventricular ejection fraction (EF<50%) were included in the study. LA function was assessed using 2DSTE. eAHI index was calculated by means of the 24-hour ambulatory Holter electrocardiogram monitoring. Patients were categorized into two subgroups: SDB group (eAHI15; n=15) and non-SDB group (eAHI<15; n=17). ResultsAll 2DSTE parameters were decreased in the SDB group: LAS-SR (0.90 [0.60-1.25] 1/sec vs. 1.25 [1.00-1.27] 1/sec, P=0.043), LAE-SR (-0.760.49 1/sec vs. -1.18 +/- 0.55 1/sec, P=0.033), and LAA-SR (-1.26 +/- 0.71 1/sec vs. -1.48 +/- 0.75 1/sec, P=0.049). The eAHI was negatively correlated with LA reservoir function: LAS (r=-0.53, P=0.002) and LAS-SR (r=-0.47, P=0.006), while it is positively correlated with LAE-SR (r=0.67, P<0.001) and LAA-SR (r=0.46, P=0.009). Moreover, SDB severity was an independent predictor of impaired LA compliance (P=0.016) and conduit function (P=0.002) in multivariate linear regression model, even after adjustment for age, BMI, gender, LV systolic (EF), and diastolic (E/e) function and comorbidities. ConclusionsLA dysfunction and remodeling assessed using 2DSTE in patients with impaired systolic LV function, and IHD is influenced by the severity of sleep apnea independently from LV function.