title: An algorithm to predict the site of origin of focal atrial tachycardia.
abstract: BACKGROUND
  Only a few algorithms for predicting the site of origin of focal atrial tachycardia (AT) have been reported. We aimed to develop a new and more effective algorithm.
  
  
  METHODS
  Surface 12-lead electrocardiograms were collected during tachycardia and sinus rhythm in 61 patients who received successful radiofrequency ablation. P-wave polarities, durations, and amplitudes were analyzed. Predictive values of the most significant parameters were determined. An algorithm was then developed and prospectively evaluated in 30 new consecutive AT patients.
  
  
  RESULTS
  Thirty-six percent (22/61) of the foci were located at the ostium of coronary sinus (CS). Other common foci included pulmonary veins (PVs, n = 15), right atrial appendage (RAA, n = 7), parahisian area (n = 7), and crista terminalis (CT, n = 3). Positive P waves in inferior leads (II, III, and aVF) and a negative P wave in lead aVR indicated high atrial origins (high CT, superior PVs, and RAA, defined as Area A), with a sensitivity of 95% and a specificity of 90%. Negative P waves in inferior leads and a positive P wave in lead aVR suggested right low septal origins (CS ostium and inferior tricuspid annulus, defined as Area B), with good sensitivity and specificity (88% and 89%, respectively). This new P-wave diagnostic algorithm correctly identified the site of origin in 90% of AT cases.
  
  
  CONCLUSIONS
  Combination of data from multiple leads and regrouping of sites of origin provides a better predictive value.
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Qian
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Hou
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Xu
authors.forename: Bing
authors.initials: B
authors.lastname: Yang
authors.forename: Ming-Long
authors.initials: ML
authors.lastname: Chen
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Feng-Xiang
authors.initials: FX
authors.lastname: Zhang
authors.forename: Qi-Jun
authors.initials: QJ
authors.lastname: Shan
authors.forename: Ke-Jiang
authors.initials: KJ
authors.lastname: Cao
authors.forename: Jian-Gang
authors.initials: JG
authors.lastname: Zou
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis* / Q000601:surgery*; D016896:Treatment Outcome