title: Atrial electromechanical interval may predict cardioembolic stroke in apparently low risk elderly patients with paroxysmal atrial fibrillation.
abstract: BACKGROUND
  A considerable number of patients with atrial fibrillation (AF) develop cardioembolic stroke (CE) despite low CHADS2 score. We examined the possibility that use of the atrial electromechanical interval (AEMI) improves prediction of CE in patients with paroxysmal AF (PAF), particularly those with low CHADS2 score.
  
  
  METHODS
  We consecutively enrolled 108 patients with nonvalvular PAF and 52 healthy subjects as controls. The PAF patients were divided into 2 groups depending on presence (n = 36) or absence (n = 72) of the history of CE. Left atrial (LA) volume index (LAVI), peak myocardial velocity during late diastole (a'), and AEMI as time from onset of P-wave to onset of lateral a' were measured.
  
  
  RESULTS
  Patients with PAF had significantly larger LAVI, longer AEMI, and lower lateral a' than those in controls. Area under the curves for LAVI, lateral a', and AEMI for identifying patients with PAF were 0.70, 0.69, and 0.88, respectively. Multivariate logistic regression analysis indicated that age, use of antiarrhythmic drugs, and AEMI, but not LAVI or a', were independently associated with history of CE in patients with PAF. PAF patients were categorized into low risk by CHADS2 score (i.e. CHADS2 score = 0 or 1, n = 60), those with prolonged AEMI (>82 msec) had significantly higher rates of CE than those with ≤ 82 msec (48% vs. 15%, P < 0.05).
  
  
  CONCLUSIONS
  As compared with echocardiographic parameters of LA size and LA function, AEMI appears to be more useful for identifying PAF patients. AEMI may enable to detect high risk PAF patients, especially those categorized into low risk by CHADS2 score.
authors.affiliation: Division of Laboratory Diagnosis, Japanese Red Cross Asahikawa Hospital, Asahikawa, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hoshi
authors.forename: Yukinaga
authors.initials: Y
authors.lastname: Nozawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Ogasawara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yuda
authors.forename: Shoko
authors.initials: S
authors.lastname: Sato
authors.forename: Takuya
authors.initials: T
authors.lastname: Sakasai
authors.forename: Makoto
authors.initials: M
authors.lastname: Oka
authors.forename: Harumi
authors.initials: H
authors.lastname: Katayama
authors.forename: Masaya
authors.initials: M
authors.lastname: Sato
authors.forename: Hidemichi
authors.initials: H
authors.lastname: Kouzu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nishihara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Doi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Nishimiya
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Miura
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D056966:Excitation Contraction Coupling; D005260:Female; D006325:Heart Atria; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D009200:Myocardial Contraction; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*
keywords: CHADS2 score; cardioembolic stroke; left atrial function; paroxysmal atrial fibrillation; tissue Doppler imaging