Assessment of left ventricular systolic dysfunction and its relationships with cardiovascular risk factors in patients with obstructive sleep apnea syndrome by two-dimensional speckle tracking imaging

Abstract

Objective To investigate left ventricular (LV) systolic dysfunction of different left ventricular geometric patterns and its relationships with cardiovascular risk factors by two-dimensional speckle tracking imaging (2D-STI) in patients with obstructive sleep apnea syndrome (OSAS) with normal left ventricular ejection fraction (LVEF).Methods 95 patients with habitual snoring were diagnosed as OSAS by polysomnography with apnea hypopnea index(AHI)≥ 5/h.Blood pressure and general clinical characteristics were collected and echocardiography was done next morning.LV geometric patterns was categorized as normal geometry (NG),concentric remodeling (CR),eccentric hypertrophy (EH) and concentric hypertrophy (CH) on the basis of relative wall thickness (RWT)＞0.42 and LV mass index (LVMI)＞46.7 g/m27 (female) or 49.2 g/m2.7 (male).LVEF was calculated by bi-plane Simpson's rule.Global peak systolic circumferential strain (GCS),radial strain (GRS) and longitudinal strain (GLS) were measured by 2D-STI.Multivariate linear regression analysis was applied to analyse the relationships between 2D-STI parameters and cardiovascular risk factors.Results ① Of 95 OSAS patients,there were 41(43.1 ％) in NG,23 (24.2％) in CR,16 (16.8％) in EH and 15 (15.9％) in CH respectively.There was no significant difference in LVEF between groups (P ＞ 0.05).Male,age,heart rate,blood pressure,neck circumference,waist,hip circumference,smoking,TC,TG,HDL,LDL,fasting glucose,AHI,saturation of artery oxygen (SaO2) and oxygen desaturation index (ODI) did not differ between groups (P ＞0.05).②GLS was lower in patients with CH (P ＜0.05).GCS and GRS had no significant difference between groups (P ＞0.05).③In Pearson correlation analysis,GLS was correlated with AHI (r =0.326),LVMI (r =0.274),T90 (r =0.294),minimum SaO2 (r =-0.299),body mass index(BMI) (r =0.367).In multivariate linear regression analysis,AHI,LVMI,BMI were independent predictors of GLS (R2 =0.219,P ＜0.05).Conclusions ①LV longitudinal systolic dysfunction was damaged more severiously in patient of CH with OSAS.②Severity of OSAS,LV hypertrophy and obesity were associated with LV longitudinal systolic dysfunction in patient with OSAS. Key words: Echocardiography; Sleep apnea,obstructive; Ventricular function,left