title: High incidence of echocardiographic abnormalities of the interatrial septum in patients undergoing ablation for atrial fibrillation.
abstract: BACKGROUND
  Atrial fibrosis or fatty deposition is known to increase the propensity for the development of atrial fibrillation (AF). Apart from the pulmonic veins, the interatrial septum (IAS) might play a role in the maintenance of AF. In contrast to left atrial anatomy and adjacent veins, the IAS cannot be visualized in detail with computed tomography. Thus, preprocedural transesophageal echocardiography (TEE) may provide important morphologic information beyond exclusion from atrial thrombi.
  
  
  METHODS
  The study comprised 108 consecutive patients (mean age 60 ± 11 years; 98 men). AF was paroxysmal in 91 (84%) and persistent in 17 (16%) patients. We investigated the morphological characteristics of the IAS by TEE in patients who underwent radiofrequency ablation of AF.
  
  
  RESULTS
  The IAS was structurally abnormal in 46 (43%) patients, showing the following echocardiograhic findings: atrial septal hypermobility or aneurysm (n = 27) associated with a patent foramen ovale (PFO) (n = 11) or with a small atrial septal defect (ASD) (n = 2), a septal flap associated with a PFO or an ASD (n = 8), and an abnormally thickened IAS (n = 12). A thrombus in the left atrial appendage was discovered in only 2 (2%) patients.
  
  
  CONCLUSIONS
  A structurally abnormal IAS was diagnosed in nearly half of the patients undergoing ablation therapy for AF. The information obtained by TEE is mandatory to exclude left atrial thrombi prior the ablation procedure. Moreover, detailed knowledge of morphologic characteristics of the IAS facilitates an optimized and safe performance of the transseptal puncture using long sheaths with large diameters.
authors.affiliation: Department of Cardiology, Paracelsus Private Medical University, Salzburger Landeskliniken, Salzburg, Austria. c.schernthaner@a1.net
authors.forename: Christiana
authors.initials: C
authors.lastname: Schernthaner
authors.forename: Franz
authors.initials: F
authors.lastname: Danmayr
authors.forename: Apollonia
authors.initials: A
authors.lastname: Daburger
authors.forename: Jörg
authors.initials: J
authors.lastname: Eichinger
authors.forename: Matthias
authors.initials: M
authors.lastname: Hammerer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Strohmer
mesh_terms: D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000601:surgery; D054087:Atrial Septum / Q000000981:diagnostic imaging* / Q000601:surgery; D001317:Austria / Q000453:epidemiology; D017115:Catheter Ablation / Q000706:statistics & numerical data; D004452:Echocardiography / Q000706:statistics & numerical data*; D005355:Fibrosis; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors