title: Time course for resolution of left atrial appendage stunning after catheter ablation of chronic atrial flutter.
abstract: OBJECTIVE
  This study assessed the time course of resolution of left atrial appendage (LAA) stunning after catheter ablation of chronic atrial flutter (AFL).
  
  
  BACKGROUND
  Although the presence of LAA stunning after ablation of chronic AFL calls for anticoagulation in the post-cardioversion period, limited information has been obtained, particularly regarding its duration.
  
  
  METHODS
  Sixteen patients who underwent ablation of chronic, pure AFL were studied, only five of whom had structural heart disease and one of whom had a reduced left ventricular ejection fraction. The LAA emptying velocities (LAAEV) and left atrial spontaneous echo contrast (SEC) were assessed using transesophageal echocardiography before, within 24 h after, one week after, and two weeks after ablation.
  
  
  RESULTS
  Within 24 h after ablation, the LAAEV decreased from 39 +/- 10 cm/s during AFL to 21 +/- 10 cm/s during sinus rhythm (p < 0.01), with eight patients (50%) having documented SEC. After one week, the LAAEV increased (39 +/- 17 cm/s, p < 0.01 vs. within 24 h) and SEC resolved in five of eight patients. After two weeks, the increase in LAAEV persisted (54 +/- 14 cm/s, p < 0.01 vs. 1 week) and SEC was no longer present in any of the patients. The numbers of patients with LAAEV >30 cm/s and absence of SEC were three within 24 h, 11 at one week, and 16 at two weeks after ablation.
  
  
  CONCLUSIONS
  Patients with chronic, pure AFL and preserved left ventricular function who will undergo catheter ablation may not require anticoagulation therapy for more than two weeks after the procedure because of the presence of forceful mechanical LAA contractions and the absence of SEC.
authors.affiliation: Third Department of Internal Medicine, Toho University School of Medicine, Tokyo, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Takami
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sugi
authors.forename: Takanori
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D001282:Atrial Flutter / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D017115:Catheter Ablation / Q000009:adverse effects*; D002908:Chronic Disease; D017548:Echocardiography, Transesophageal; D004554:Electric Countershock / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017682:Myocardial Stunning / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D020127:Recovery of Function / Q000502:physiology*; D013997:Time Factors