Evaluation Of Left Ventricular Function In Patients With OSAS By 2D Speckle Tracking Imaging

Objective:In this study,our aim was to evaluate the LV?Left Ventricular?function in patients with obstructive sleep apnea without any cardiovascular abnormalities by the two-dimensional speckle tracking imaging?2D-STI?,and then analyse the relationships between the changes of LV function and the severity of OSAS.Methods:The OSAS groups:80 patients were diagnosed of OSAS by the gold standard Polysomnography with the sydrnorme of night snoring or daytime sleepiness,according to the apnea-hypopnea index?AHI?,they were divoded into 3 groups :mild group?AHI:5/h¹5/h?16 cases;moderate group?AHI:>15/h ³0/h?18 cases;severe group?AHI:>30/h?46 cases.The control group:38 cases of age and sex-matched normal control group,no night snoring or daytime sleepness and the ESS <10,normal ECG and echocardiogr-aphy,no systemic disease.Measure and record the height,weight,body mass index,waist circumference,neck circumference,systolic blood pressure,diastolic blood pressure of the control and the OSAS groups and Polysomnography data:the average SaO₂,the lowest SaO₂,the average heart rate,the maximum heart rate,the lowest heart rate at night of the OSAS groups.The conventional two-dimensional echocardiography measure LVDd,LVSd,LVFS,IVS,LVPW.In the apical four-chamber view,the early diastolic blood flow velocity?E?of the mitral valve was measured by PW,the lateral ventricular septal early diastolic velocity?e?of the mitral valve was measured by TDI,and calculate E/e.LVEF was calculated by bi-plane Simpson,s rule.The Global longitudinal strain?GLS?,Global radial strain?GRS?,Global circumferential strain?GCS?,the layered?endocardial,midcardial,epicardial?longitudinal strain of the left ventricular long axis views and the layered?endocardial,midcardial,epicardial?circumferential strain of the left ventricular short axis views were measured by the 2D-STI.And then analyse the relationships between the changes of LV function and the severity ofOSAS in pearson correlation methods.Results:?1?Compared with the control group,the weight,BMI,neck circumference and waist circumference of the mild,moderate OSAS groups showed no significant difference?P>0.05?,while those of the severe OSAS group increased than those of the control and the mild,moderate OSAS groups?P<0.05?.the average SaO₂ and the lowest SaO₂ of the severe OSAS group were lower than the mild,moderate OSAS groups?P<0.05?.The age,height,SBP,DBP among the control and the OSAS groups and the average heart rate,the highest heart rate and the lowest heart rate of the OSAS groups were not significantly different?P>0.05?.?2?The IVS,LVPW of the mild,moderate,severe OSAS groups increase compared with the control group?P<0.05?,but there were no statistical significance between each of the OSAS groups?P>0.05?.Compared with the control group,e?E/e of the mild OSAS group showed no significantly different,but e of the moderate,severe OSAS groups reduced,E/e increased,e of the moderate,severe OSAS groups was lower than the mild OSAS group,E/e was higher than the mild OSAS group?P <0.05?.The LVDd,LVSd,LVFS,LVEF and E among the four groups were not significantly different?P>0.05?.?3?The GLS,GCS of the mild OSAS group were not different compared with the control group?P>0.05?,but the Endo-LS of the apical long axis view was lower than the control group?P<0.05?.The GRS increased compared with the control group.The GLS,GCS of the moderate OSAS group were lower than the control group,characterized by the Endo-LS of the apical long axis view,the apical two-chamber view and the Endo-CS,Mid-CS of the left ventricular short axis views papillary muscle level,the apical level,the GRS of the moderate OSAS group was lower than of the control and the mild OSAS group?P<0.05?.The GLS of the severe OSAS group was lower than the control,the mild and the moderate OSAS group,characterized by the Endo-LS of the apical long axis view,the apical two-chamber view,the apical four-chamber view,the GCS of the severe OSAS group was lower than the control and the mild OSAS group,characterized by the Endo-CS,Mid-CS of the left ventricular short axis views base level,the papillary muscle level,the apicallevel,the GRS of the severe OSAS group was lower than the control and the mild OSAS group?P<0.05?.?4?Pearson correlation analysis :IVS,LVPW,E/e were positively related to AHI,and e,GLS,GRS,GCS were negatively related to AHI.Conclusion:1?OSAS subjects may develop left ventricular remodeling and subclinical LV systolic and diastolic dysfunction without any cardiovascular abnormalities,and the LV systolic and diastolic dysfunction worse with the severity of OSAS increasing.2?The two-dimensional speckle tracking imaging?2D-STI?can not only evaluate the global left ventricular systolic function through the GLS,GRS,GCS,but also learn more about left ventricular systolic dysfunction by 3-layer longitudinal and circumferential strain.