title: Left ventricular subclinical dysfunction associated with myocardial deformation changes in obstructive sleep apnea patients estimated by real-time 3D speckle-tracking echocardiography.
abstract: BACKGROUND
  Previous studies have demonstrated that patients with obstructive sleep apnea (OSA) may develop left ventricular (LV) diastolic dysfunction. We aimed to study whether OSA patients have LV regional systolic dysfunction with myocardial deformation changes, despite a normal LV ejection fraction, using real-time 3D speckle-tracking echocardiography (Rt3D-STE).
  
  
  METHODS
  Seventy-eight patients with OSA and no comorbidities were studied. They were divided into the following three groups according to the apnea-hypopnea index (AHI): 5~15/h as group I (mild OSA, 26 cases), 15~30/h as group II (moderate OSA, 29 cases), and ≥30/h as group III (severe OSA, 23 cases). Thirty gender-age-matched normal subjects were included as controls. The parameters of LV diastolic function were acquired with traditional echocardiography. The LV myocardial deformation parameters were obtained, including the longitudinal (LS), circumferential (CS), radial (RS), and area (AS) strains, with Rt3D-STE.
  
  
  RESULTS
  LV global systolic function was normal in all patients, but diastolic function was impaired in groups II and III (E/E' was 9.6 ± 2.8 and 10.4 ± 2.5, respectively, p < 0.0001). The global LS and AS were significantly reduced in groups II and III compared with the controls and group I (LS 15.9 ± 1.4 % and 14.8 ± 1.5 % vs 18.2 ± 1.7 % and 17.8 ± 1.5 %; AS 27.4 ± 1.8 % and 24.9 ± 2.3 % vs 33.4 ± 2.2 % and 32.7 ± 2.9 %, respectively, p < 0.0001), but the global CS and RS were significantly reduced only in group III (17.3 ± 1.4 % and 43.1 ± 6.5 % vs 19.6 ± 1.6 % and 55.4 ± 4.0 %, respectively, <0.0001). The severity of OSA was significantly associated with the LV global AS value (r = -0.80, p < 0.0001), LS (r = -0.64, p < 0.0001), CS (r = -0.51, p < 0.0001), and RS (r = -0.62, p < 0.0001).
  
  
  CONCLUSIONS
  Patients with moderate and severe OSA tended to have both LV diastolic dysfunction and abnormalities in regional systolic function with myocardial deformation changes, in spite of the normal LV ejection fraction. Myocardial strains of the LV were negatively correlated with the AHI. Rt-3DST had important clinical significance in the early evaluation of cardiac dysfunction in OSA patients.
authors.affiliation: Department of Cardiology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China.
authors.forename: Dian
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China.
authors.forename: Gen Shan
authors.initials: GS
authors.lastname: Ma
authors.affiliation: Department of Geriatric Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Xiao Yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Pneumology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China.
authors.forename: Qiang Qiang
authors.initials: QQ
authors.lastname: Lu
authors.affiliation: Department of Cardiology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China. liunaifengseu@126.com.
authors.forename: Nai Feng
authors.initials: NF
authors.lastname: Liu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003971:Diastole / Q000502:physiology; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D020257:Ventricular Remodeling / Q000502:physiology*
keywords: Left ventricular dysfunction; Myocardial deformation; Obstructive sleep apnea; Real-time 3D speckle-tracking echocardiography