title: Impact of obstructive sleep apnea on the atrial electromechanical activation time.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is closely associated with atrial fibrillation, which is provoked by electrical and structural remodeling. However, the association between OSA and atrial remodeling has not been fully elucidated.
  
  
  RESULTS
  Atrial electromechanical activation time (EMAT) was investigated using tissue Doppler imaging (TDI) in men with severe OSA (n=24) and control subjects (n=24). The EMAT was determined as the time interval from the initiation of P-wave deflection until the peak of local lateral left atrial (LA) TDI signal. The early diastolic velocity of the mitral annulus (E(a)) and the EMAT were significantly lower and longer in OSA cases than in controls (E(a): 6.1+/-0.9 cm/s vs 7.3+/-1.5 cm/s, P=0.001; EMAT: 129.7+/-11.5 ms vs 118.5+/-12.3 ms, P=0.002). Among OSA cases, the apnea - hypopnea index (AHI) was significantly correlated with EMAT (r=0.660, P<0.001), E(a) (r=-0.609, P=0.002), LA dimension (r=0.486, P=0.016), and early diastolic velocity of mitral flow (E)/E(a) ratio (r=0.418, P=0.042). In multivariate stepwise linear regression analysis, EMAT was independently associated with AHI (P=0.025) and E(a) (P=0.028) in OSA cases.
  
  
  CONCLUSIONS
  EMAT measured by TDI could be a useful parameter for identifying atrial remodeling in patients with severe OSA.
authors.affiliation: Division of Cardiology, Cardiovascular Center, College of Natural Science, Kookmin University, Seoul, Korea.
authors.forename: Hong Euy
authors.initials: HE
authors.lastname: Lim
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Kim
authors.forename: Seong Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Eung Ju
authors.initials: EJ
authors.lastname: Kim
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Inkyung
authors.initials: I
authors.lastname: Baik
authors.forename: Chol
authors.initials: C
authors.lastname: Shin
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D004452:Echocardiography; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*