title: Fibrillatory wave amplitude as a marker of left atrial and left atrial appendage function, and a predictor of thromboembolic risk in patients with rheumatic mitral stenosis.
abstract: BACKGROUND
  Patients with mitral stenosis, especially those with atrial fibrillation, are at increased risk for thromboembolic complications. Size of the left atrium, left atrial appendage dysfunction and severity of mitral stenosis are known risk factors for thromboembolism in patients with mitral stenosis. It has been postulated that F-wave amplitude on surface ECG is correlated with left atrial size, left atrial appendage function, and risk of thromboembolism in patients with nonrheumatic atrial fibrillation. The aims of this study were as follows: (1) to examine the relationship between surface ECG F-wave amplitude and left atrial appendage function, and (2) to assess the clinical significance of F-wave amplitude as it relates to risk of thromboembolism in a group of patients with rheumatic mitral stenosis.
  
  
  METHODS
  One hundred patients with rheumatic mitral stenosis and permanent atrial fibrillation but without moderate to severe mitral insufficiency were investigated by transthoracic and transesophageal echocardiography. Two groups were formed according to the presence of a coarse (Group 1; n=60; F-wave in lead V1> or =1 mm) or fine (Group 2; n=40; F-wave in lead V1<1 mm) F-wave on surface ECG.
  
  
  RESULTS
  Comparison showed that Group 1 had significantly smaller mitral valve area (1.44+/-0.6 versus 1.7+/-0.74 cm2, respectively; P<0.05), lower peak left atrial appendage flow velocity (18.8+/-2.1 versus 25.6+/-1.9 cm/s, respectively; P<0.005), higher-grade spontaneous echo contrast (2.05+/-1.44 versus 0.98+/-1.14, respectively; P<0.0001), and higher prevalence of thromboembolism (35% versus 12.5%, respectively; P<0.012). Multiple logistic regression analysis revealed that mitral valve area, left atrial appendage peak velocity, and coarse F-wave were independent clinical risk factors for thromboembolism in this patient group.
  
  
  CONCLUSIONS
  The data suggest that presence of a coarse F-wave on surface ECG is associated with left atrial appendage dysfunction, and indicates higher thromboembolic risk in patients with predominant rheumatic mitral stenosis.
authors.affiliation: Department of Cardiology, Kosuyolu Heart and Research Hospital, Kadikoy, 81190 Istanbul, Turkey. dr.bmutlu@superonline.com
authors.forename: Bülent
authors.initials: B
authors.lastname: Mutlu
authors.forename: Mustafa
authors.initials: M
authors.lastname: Karabulut
authors.forename: Elif
authors.initials: E
authors.lastname: Eroglu
authors.forename: Kürsat
authors.initials: K
authors.lastname: Tigen
authors.forename: Fatih
authors.initials: F
authors.lastname: Bayrak
authors.forename: Hakan
authors.initials: H
authors.lastname: Fotbolcu
authors.forename: Yelda
authors.initials: Y
authors.lastname: Basaran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology*; D016279:Atrial Function, Left / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D004452:Echocardiography; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D015995:Prevalence; D012189:Retrospective Studies; D012214:Rheumatic Heart Disease / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology*; D012307:Risk Factors; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D013923:Thromboembolism / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology*