title: Electroanatomic characteristics of atrial premature beats triggering atrial fibrillation in patients with persistent versus paroxysmal atrial fibrillation.
abstract: APBs in Persistent Versus Paroxysmal AF.
  
  
  BACKGROUND
  Although the electrical disconnection between the left atrium (LA) and pulmonary veins (PVs) by radiofrequency catheter ablation has been proven to be effective in controlling atrial fibrillation (AF), the recurrence rate is higher in patients with persistent AF (PeAF) than with paroxysmal AF (PAF). We hypothesized that the origin of the atrial premature beats (APBs) that trigger AF and the pattern of their breakthrough into the LA differ between PAF and PeAF.
  
  
  METHODS
  We mapped 75 APBs (53 APBs triggering AF, 22 isolated APBs) from the LA and PVs in 26 patients with AF (age: 49.5 +/- 9.6, males: 23, PAF = 17, PeAF = 9), using a noncontact endocardial mapping (NCM) system. The location of the preferential conduction (PC) sites and their conduction velocity (CV) were compared.
  
  
  RESULTS
  In patients with PeAF, the earliest activation (EA) site and exit of the PC were more frequently located on the LA side of the LA-PV junction as compared with PAF (P < 0.001). Eighty-one percent of the PCs were located in the area between the left and right superior PVs. The incidence of PCs was similar between the PeAF and PAF patients (P = NS). PCs were more commonly found with APBs inducing AF (63.3%) than with those not inducing AF (35.2%, P = 0.01). The CV of the PC was slower for PeAF than PAF (P < 0.001). The CV in the LA during sinus rhythm was also slower for PeAF than PAF (P < 0.01).
  
  
  CONCLUSIONS
  PeAF was more frequently triggered by APBs from the LA side of the LA-PV junction than PAF and resulted in slower conduction than did PAF. These findings may help explain the higher potential for recurrence after electrical PV isolation in patients with PeAF.
authors.affiliation: Division of Cardiology, Utah Valley Medical Center, Provo, Utah, USA.
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
authors.forename: Chun
authors.initials: C
authors.lastname: Hwang
authors.forename: Hong Euy
authors.initials: HE
authors.lastname: Lim
authors.forename: Jin Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Lee
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology*; D018880:Atrial Premature Complexes / Q000503:physiopathology*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery