title: Electrophysiological abnormalities in patients with paroxysmal atrial fibrillation in the absence of overt structural heart disease.
abstract: OBJECTIVE
  The aim of the present study was to define the atrial electrical substrate in patients with paroxysmal atrial fibrillation (AF) occurring in the absence of overt structural heart disease and to assess if electrophysiological parameters could predict AF recurrence after radiofrequency ablation in this population.
  
  
  RESULTS
  45 consecutive patients (39 male, age 59 ± 10 years) with paroxysmal AF and without overt structural heart disease, referred for radiofrequency catheter ablation, were prospectively enrolled. A cohort of 12 age-matched patients without a history of AF, served as a control group. Atrial electrical substrate was assessed by P-wave signal-averaging, intracardiac conduction delays and refractory periods. Total P wave duration during signal-averaging was longer in patients with paroxysmal AF than in controls (140 ± 19 ms vs 123 ± 13 ms, p = 0.004). Patients with paroxysmal AF showed an increase in right intra-atrial (40.2 ± 11.3 ms vs 31.7 ± 11.8 ms, p = 0.02) and inter-atrial conduction delays (87.93 ± 22.0 ms vs 65.3 ± 15.6 ms, p = 0.001) in sinus rhythm. Refractory periods in the right atrium were longer in patients with paroxysmal AF (265 ± 44 ms vs 222 ± 32 ms, p = 0.002). After ablation, 22 patients had AF recurrence but showed no differences in electrophysiological parameters compared to patients without recurrence.
  
  
  CONCLUSIONS
  Electrophysiological abnormalities are present in patients with paroxysmal AF without overt structural heart disease. Neither signal-averaged P-wave duration nor intracardiac atrial electrophysiology could predict arrhythmia recurrence after pulmonary vein isolation.
authors.affiliation: Cardiology Department, University Hospital of Geneva, Switzerland.
authors.forename: José David
authors.initials: JD
authors.lastname: Arroja
authors.affiliation: Cardiovascular Department, Hôpital de La Tour, Meyrin, Switzerland; Cardiology Department, University Hospital of Geneva, Switzerland.
authors.forename: Haran
authors.initials: H
authors.lastname: Burri
authors.affiliation: Cardiovascular Department, Hôpital de La Tour, Meyrin, Switzerland.
authors.forename: Chan Il
authors.initials: CI
authors.lastname: Park
authors.affiliation: Cardiovascular Department, Hôpital de La Tour, Meyrin, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Giraudet
authors.affiliation: Cardiovascular Department, Hôpital de La Tour, Meyrin, Switzerland. Electronic address: zimmermann.family@bluewin.ch.
authors.forename: Marc
authors.initials: M
authors.lastname: Zimmermann
keywords: Inter-atrial conduction; Intra-atrial conduction; Paroxysmal atrial fibrillation; Signal-averaged ECG; “Lone” atrial fibrillation