Evaluation Of Left Ventricular Function In Patients With Obstructive Sleep Apnea Syndrome By 3D Speckle Tracking Echocardiography

Objective: Patients with obstructive sleep apnea syndrome(OSAS)can develop left ventricular dysfunction.The conventional echocardiography is hard to detect the damage of myocardium in the early stage of the OSAS.This study focus on evaluating left ventricular function in OSAS patients while the left ventricular ejection fraction is normal.Methods:Select thirty patients in each group as mild OSAS、moderate OSAS、severe OSAS as well as thirty gender-age-matched normal subjects as control according to the AHI(apnea hypopnea index).Their parameters such as global three-dimensional strain(GS),global systolic strain rate(GSRS),global early diastolic strain rate(GSRE)and global late diastolic strain rate(GSRA)、 TTP-max(maximum difference of time to peak)values in longitudinal,circumferential and radial directions as well as rotation were measured by three-dimensional speckle tracking imaging.Analysis the relationship between the AHI and the strain of all the three-dimensional directions.Results: Three-dimensional longitudinal systolic function were significant lower in moderate and severe groups comparing with the control and mild groups,decreasing along with the disease severity(P<0.05).Three-dimensional circumferential contraction function were observed deteriorated in the late stage of the OSAS(P<0.05).There is a much lower radial contraction function in the severe group with a compensatory increasing in the early stage(P<0.05).The GSRE in three-dimensional longitudinal,radial and circumferential diastolic function is decreased from moderate group(P<0.05)while the GSRA is increased(P<0.05).There is a high correlation between the AHI and the strain of all the three-dimensional directions.Conclusion : Subclinical LV dysfunction can be established in the early stage of OSAS even in the absence of abnormal ejection fraction.The application of the three-dimensional speckle tracking imaging has important clinical significance in evaluating the myocardial function in the early stage of OSAS patients.