Longitudinal Strain And Peak Strain Dispersion For Evaluating Left Ventricular Systolic Function In Patients With Sleep Apnea Syndrome

ObjectiveTo explore the value of longitudinal peak systolic strain(GLS),peak strain dispersion(PSD)in evaluating left ventricular synchronization and systolic function and diastolic function in patients with obstructive sleep apnea syndrome(OSAS),by evaluating the changes of left ventricular structure,diastolic function,global longitudinal strain and synchronization parameters in the early stage(left ventricular ejection fraction > 50%).MethodsSeventy male patients with OSAS diagnosed by polysomnography and LVEF over 50% measured by Simpson's method were selected.According to AHI,the OSAS patients were divided into three groups: mild group,moderate group and severe group.Twenty-six healthy volunteers without snoring or daytime sleepiness were enrolled in this study.Echocardiography was performed on the next day.The Left ventricular ejection fraction(LVEF),diastolic blood pressure,systolic blood pressure,left ventricular end-diastolic diameter(LVDd),left ventricular end-systolic diameter(LVDs),left atrial diameter(LAD),interventricular septum thickness(IVST),left ventricular posterior wall thickness(LVPW),Early peak flow velocity of diastolic mitral anterior blood flow(E),peak flow velocity in late diastole(A),and early peak velocity of mitral annulus in left ventricular wall(e'),global systolic Iongitudinal strain(GLS)and peak strain dispersion(PSD)were compared among four groups.And analyze the correlation between GLS,PSD and AHI.Results(1)Among the 70 male patients with OSAS,24 were mild,23 were moderate,23 were severe,and 26 were healthy male volunteers.There was no significant difference in LVEF between the 4 groups(P>0.05).Age,height,weight,body mass index(BMI),diastolic blood pressure,systolic blood pressure,LVDd,LVDs,LAD and LVPW were not statistically different among the four groups(P>0.05).IVST in severe groups was increased than control groups(P<0.05).(2)E,E/A,E/E' in patients with mild,moderate,and severe OSAS were lower than those in the control group(P<0.001).There is a significant difference in E/A and E/E' between the mild and moderate groups(P<0.05).(3)Compared with the control group and the mild group,the PSD increased and the GLS decreased significantly in the moderate and severe groups(P<0.05),and there were statistically significant decrease in the GLS between the severe group and the moderate group(P< 0.05),There was no statistical difference in other parameters between groups(P >0.05).(4)Pearson correlation analysis showed that AHI was associated with GLS(r=-0.709)and PSD(r=0.827)(P < 0.05).PSD was negatively correlated with GLS(r=-0.714),E(r=-0.424),E/A(r=-0.391),E /e'(r=-0.224),and were positively correlated with IVST(r=0.334)and BMI(r=-0.211)(all P < 0.05).But PSD were not related to age,height,weight,systolic blood pressure,diastolic blood pressure,LVEF,LVPW,LVDd,LVDs,LAD,A,e'(all P>0.05).Conclusions1)OSAS patients often have left ventricular diastolic dysfunction in the early stage.The changes of global longitudinal strain and synchronization parameters areprior to the changes of left ventricular morphology and cardiac function measured by conventional echocardiography.2)Left ventricular systolic function and synchronization were impaired in OSAS patients with normal left ventricular ejection fraction,and the degree of impairment was related to the degree of synchronization decline.3)With the increase of AHI,GLS gradually decreased and PSD gradually increased,indicating the damage of myocardial systolic function of OSAS patients increased.4)GLS,PSD and other parameters can early evaluate left ventricular myocardial synchronization,systolic and diastolic function changes in OSAS patients,which is important to clinic.