Evaluation Of Left Ventricular Longitudinal Strain By Using Strain And Strain Rate Imaging In Patients With OSAHS

Objective: To evaluate left ventricular myocardial local and global movements in patients with isolated obstructive sleep apnea-hypopnea syndrome(OSAHS) via measuring myocardial longitudinal deformation by using strain and strain rate imaging technology,and to assess left ventricular systolic function.Methods:1 The object of studyThirty patients with isolated OSAHS were enrolled,who had been confirmed undergoing polysomnography in our hospital from 2014 June to 2014 December. We selected 30 healthy subjects as control group who were matched age,gender,weight and blood pressure.30 OSAHS patients were divided into 2 groups based on Sleep apnea hypopnea index(AHI)and minimum oxygen saturation at night(Sa02min):mild to moderate group:(AHI of 5—30,Sa02min>80%) 15 cases;severe group:(AHI of>30,Sa02min<80%) 15 cases.2 Apparatus and methodA commercially available Vivid E9 ultrasound machine were employed with a probe of M5 S probe. In addition,PSG was used to diagnose OSAHS.In the left ventricular long axis view and apical four chamber view,left ventricular end-diastolic diameter(LVEDD),peak early filling velocity(E),peak end-diastolic velocity(A),E/A,E/e’,left ventricular ejection fraction(LVEF) were measured by conventional echocardiography.The dynamic images of apical long axis view, four chamber view and two chamber view were stored. AFI was used to obtain left ventricular strain and strain rate:global strain in apical long axis view(GLPS-LAX),global strain in apical four chamber view(GLPS_A4C),global strain in apical two chamber view(GLPS_A2C),global left ventricular average strain(GLPS_AVG). The peak systolic strains consisting of 17 segments were also obtained,including apical segment, middle segment, basal segment.All the images and data were stored in the hardware.Results:1 Compared with the control group,the lowest oxygen saturation inpatients with OSAHS had statistical significance(P<0.01). Meanwhile, AHI were significantly different in the three groups(P<0.01).Age,gender,body mass index, heart rate and blood pressure among the three groups showed no significant difference.2 There were statistical significance in E/A and E between three groups(P<0.01),which were also be found in A and E/e’(P<0.05). There was no significant difference in LVEF and LVEDd between three groups(P>0.05).3 There were statistical significance in GLPS-LAX,GLPS_A4C,GLPS_A2C,GLPS_AVG between any two groups,and GLPS-LAX decreased gradually among the three groups(P<0.05),which could be seen in GLPS_A4C、GLPS_A2C、GLPS_AVG(P<0.01).Compared with the control group,LV peak systolic strains had different degrees of decline,the difference was statistically significant. P<0.05 in the apical ANT-SEPT segment,basal ANT-SEPT and POST segment,P<0.01 in all the remaining segments.Conclusions:1 Compared with normal control group, global left ventricular longitudinal deformation in patients with OSAHS has changed before cardiac structure changes,and the extent of Left ventricular damage was positively related to the degree of apnea severity.2 Left ventricular longitudinal strain is negatively related to AHI,and it is positive correlation with the lowest oxygen saturation.3 Compared with normal control group,The value of E,A,E/A,E/e’have changed significantly before cardiac structure changes.