Myocardial layer-specific and dyssynchorony analysis in patients with OSAS using speckle-tracking echocardiography

To evaluate the subclinical left ventricular (LV) myocardial dysfunction by myocardial layer-specific and dyssynchorony analysis in patients with obstructive sleep apnoea syndrome (OSAS) with normal left ventricular ejection fraction (LVEF) and without any confounding disease that can cause myocardial dysfunction.

A total of 32 patients with moderate (n = 14) or severe (n = 18) OSAS and 20 controls underwent both standard conventional echocardiography assessment, myocardial layer-specific and dyssynchorony analysis. Changes in the levels of norepinephrine (NE) were analysed.

Patients in the OSAS group had higher BMI (p = .002) and BSA (p = .017), significantly increased DBP (p < .001) and NE (p = .028) level than those in control group. Compared with the controls, OSAS patients had thickened left ventricular posterior wall (LVPWT) (p < .001) and lager LVMI/H^2.7 (p = .04). Three layers (endocardial, myocardial and epicardia) in the apical long-axis view, apical 4 C and 2 C views were decreased in both moderate and severe OSAS groups. PSD was significantly increased in severe OSAS patients (p = .044), TTP in the severe OSAS group was significantly shorter than in control group in the ant-sept wall (p = .04) and inferior wall (p = .03) from basal segment, inferior wall (p = .005) from the middle segment, and all segments from apical segments. PSD and TTP in the moderate OSAS group had no significant differences when compared with control group.

Despite normal LVEF, three layers (endocardial, myocardial and epicardia) of LV wall are decreased in OSOA patients, patients in the severe OSAS group suffer from myocardial systolic dyssynchrony earlier compared with controls.