title: Left atrial dysfunction is a predictor of postcoronary artery bypass atrial fibrillation: association of left atrial strain and strain rate assessed by speckle tracking.
abstract: BACKGROUND
  Even though atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass grafting (CABG), its etiology remains poorly understood. Several factors are linked to postoperative AF (POAF), including advanced age and systemic inflammation. However, left atrial (LA) contractile dysfunction has not been evaluated in the perioperative scenario.
  
  
  OBJECTIVE
  To evaluate LA function through strain and strain rate in patients with coronary artery disease undergoing CABG and its correlation with POAF.
  
  
  METHODS
  We studied 70 patients undergoing CABG in sinus rhythm at the time of surgery. Preoperative echocardiography with evaluation of LA strain and strain rate by speckle tracking was performed. The occurrence of POAF was evaluated by continuous monitoring. Baseline and postoperative C-reactive protein (CRP) levels were measured to evaluate systemic inflammation.
  
  
  RESULTS
  After 1-week follow-up 26% of subjects developed AF. LA strain s wave (LASs) and LA strain rate s (LASRs) and a wave (LASRa) were significantly decreased in patients who developed POAF: LASs (10 ± 1% vs. 24 ± 1%, P < 0.001), LASRs (0.6 ± 0.1 sec(-1) vs. 1.2 ± 0.1 sec(-1) , P < 0.001), LASRa (-0.6 ± 0.1 sec(-1) vs. -1.8 ± 0.1 sec(-1) , P < 0.001). LASRs, LASRa, age, and LA volume were independent predictors of POAF. CRP at baseline was similar irrespective of POAF development.
  
  
  CONCLUSIONS
  LA dysfunction, evaluated by strain and strain rate is an independent predictor of POAF and contributes to classic risk factors like age and atrial volume.
authors.affiliation: Cardiovascular Disease Division, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile. lgabriel@uc.cl
authors.forename: Luigi
authors.initials: L
authors.lastname: Gabrielli
authors.forename: Ramon
authors.initials: R
authors.lastname: Corbalan
authors.forename: Samuel
authors.initials: S
authors.lastname: Córdova
authors.forename: Andrés
authors.initials: A
authors.lastname: Enríquez
authors.forename: Paul
authors.initials: P
authors.lastname: Mc Nab
authors.forename: Hugo E
authors.initials: HE
authors.lastname: Verdejo
authors.forename: Iván
authors.initials: I
authors.lastname: Godoy
authors.forename: Ricardo
authors.initials: R
authors.lastname: Zalaquett
authors.forename: Sergio
authors.initials: S
authors.lastname: Lavandero
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004452:Echocardiography / Q000379:methods*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D016896:Treatment Outcome