title: [Comparison of effectiveness of radiofrequency catheter  ablation of left arterial isthmuses for treatment of  postablational perimitral atrial flutter].
abstract: OBJECTIVE
  To compare results of radiofrequency (RF) ablation (A) of mitral and inferior septal isthmuses in the left atrium for the treatment of perimitral atrial flutter (AF) in patients with atrial fibrillation previously subjected to RF isolation of pulmonary veins and modification of the left atrial anatomical arrhythmia substrate.
  
  
  METHODS
  We treated 20 patients (3 women, mean age 57.1+/-9.3 years) with recurrent postablational perimitral AF verified by 3-dimensional reconstruction of left and right atrial activation by nonfluoroscopic mapping and pacing techniques of entrainment into tachycardia cycle. At first stage RFA was carried out in the region of mitral isthmus (its endocardial parts). At second stage RFA was performed in the region of coronary sinus (CS) roof (epicardial portions of the mitral isthmus). At the third stage RFA influences were applied in the region of inferior septal isthmus (endocardial portions of the inferioseptal isthmus). At the fourth stage RFA was applied in the region of roof of proximal CS (epicardial portions of inferioseptal isthmus).
  
  
  RESULTS
  Application of RF influences to endocardial parts of the mitral isthmus resulted in sinus rhythm (SR) restoration in 6 cases. Change of length of the tachycardia cycle was noted in 5cases. SR restoration was observed after RFA in the region of the roof of distal CS in 3 cases and change of length of the tachycardia cycle was noted in 2 more cases. RFA of epicardial parts of the inferioseptal isthmus resulted in SR restoration in 3 cases and in increase of atypical AF cycle length in 6 cases. In 12 cases SR was restored during RFA application in the region of the roof of proximal CS parts. RF influences in the region of endocardial (stage 1) and epicardial (stage 2) parts of the mitral isthmus resulted in SR restoration in 9 cases while continuation of RFA in the region of endocardial (stage 3) and epicardial (stage 4) parts of the inferioseptal isthmus led to SR restoration in the remaining 15 cases (p<0.05).
  
  
  CONCLUSIONS
  RFA of endocardial and epicardial parts of the inferioseptal isthmus significantly more often led to termination of perimitral atypical AF in patients previously operated because of atrial fibrillation.
authors: E G
authors: EG
authors: Zheliakov
authors: A V
authors: AV
authors: Ardashev
authors: Iu N
authors: IuN
authors: Belenkov
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery; D001282:Atrial Flutter / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D004699:Endocardium / Q000503:physiopathology / Q000601:surgery; D056149:Epicardial Mapping; D005260:Female; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000503:physiopathology / Q000601:surgery; D011183:Postoperative Complications; D011667:Pulmonary Veins / Q000601:surgery; D012074:Remission Induction / Q000379:methods; D055502:Secondary Prevention; D016896:Treatment Outcome