title: [Use of P-wave polarity during atrial tachycardia to predict site of origin in children].
abstract: OBJECTIVE
  To perform a detailed analysis of the P-wave polarity in focal atrial tachycardia (FAT) on the basis of surface electrocardiograms (ECGs) and construct an algorithm for identification of the anatomic site of origin in children.
  
  
  METHODS
  P-wave polarities for 40 consecutive children(14 boys and 26 girls, mean age of(8±3)years) with FAT undergoing successful radiofrequency ablation of a single atrial focus at First Hospital of Tsinghua University (2009-2014) were analyzed retrospectively from 12-lead ECGs during tachycardia.P waves were classified as positive, negative, isoelectric, or biphasic.The relations between P-wave and anatomic site of origin were analyzed using a chi-square test.
  
  
  RESULTS
  The P-wave polarities in leads V1(χ(2)=23.509, P=0.000) andⅠ(χ(2)=14.315, P=0.001) were significantly helpful in distinguishing left from right atrial origin of the tachycardia focus.The P-wave in lead V1 of a left atrial tachycardia was always positive or isoelectric in tachycardia.The P-wave in leadⅠof a right atrial tachycardia was always positive or isoelectric during tachycardia.The P-wave polarities in leads Ⅱ, Ⅲ, aVR and aVF(χ(2)=26.447, 23.974, 19.613, 17.415, all P=0.000)distinguished superior from inferior atrial foci significantly.Tachycardia arising from the superior foci (n=22) had positive P waves in leads Ⅱ, Ⅲ and aVF ( 95% (n=21), 86% (n=19), 95% (n=21), respectively) and negative P wave in lead aVR (73%, n=16). The P-wave was frequently negative in leads Ⅱ, Ⅲ and aVF(n=12) and positive in lead aVR (n=11) for a tachycardia arising from the inferior foci (n=18). The anatomic sites of FAT in children located mainly at right atrial appendage (23%, n=9), coronary sinus (18%, n=7), left atrial appendage (15%, n=6) and right superior pulmonary vein (10%, n=4).
  
  
  CONCLUSIONS
  The anatomic sites of FAT in children are located mainly at right and left atrial appendage, coronary sinus and right superior pulmonary vein.P-waves in leads V1 andⅠprove to be significantly useful in differentiating left from right atrial tachycardia foci.P-waves in leads Ⅱ, Ⅲ, aVR and aVF are helpful in distinguishing superior from inferior atrial foci.
authors.affiliation: Heart Center, Division of Pediatric Cardiology, First Hospital of Tsinghua University, Medical Center, Tsinghua University, Beijing 100016, China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Ge
authors.forename: X M
authors.initials: XM
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.forename: Y H
authors.initials: YH
authors.lastname: Li
authors.forename: H J
authors.initials: HJ
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000465:Algorithms; D020517:Atrial Appendage / Q000503:physiopathology; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D054326:Coronary Sinus / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D008297:Male; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000601:surgery