title: [High-resolution P-wave electrocardiogram in patients with a history of paroxysmal atrial fibrillation].
abstract: OBJECTIVE
  To study by using the signal-averaged P wave, the atrial activation of patients with documented episodes of paroxysmal atrial fibrillation (PAF).
  
  
  METHODS
  This study enrolled a total of 20 patients with documented episodes of paroxysmal atrial fibrillation (males 14; mean age 58.4 +/- 10.6 years). The signal-averaged P wave was recorded with a Corazonix Predictor II system. The total P wave duration was determined from the combined filtered x,y,z vector-magnitude and used for analysis. The results were compared with a normal group of 10 patients, matched in age.
  
  
  RESULTS
  In the control group, the total P wave duration ranged from 120.0 to 135.0 (mean = 128.3 +/- 5.8) ms. In the group of PAF, the total P wave duration ranged from 118.0 to 168.5 (mean = 151.5 +/- 13.7) ms (p < 0.000). Sixteen (80%) of this patients showed a P wave duration > 140.0 ms. With a cut < 140.0 ms for the normal atrial activation, the sensitivity was 76%, specificity was 100%, positive and negative predictive value were 100% and 60% respectively for the method detected patients with PAF.
  
  
  CONCLUSIONS
  Patients with PAF showed a prolonged signal-averaged P wave duration and should be differentiated by this method from the normal population.
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology*; D001282:Atrial Flutter / Q000175:diagnosis / Q000503:physiopathology; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis / Q000503:physiopathology*
vernacular_title: O eletrocardiograma de alta resolução da onda P em pacientes com história de fibrilação atrial paroxística.