title: An electrocardiography algorithm combined with clinical features could localize the origins of focal atrial tachycardias in adjacent structures.
abstract: OBJECTIVE
  It is difficult to differentiate the origins of focal atrial tachycardias (ATs) in adjacent structures by electrocardiography (ECG) alone. The aim of this study was to evaluate whether the clinical features of these ATs may help differentiate their origins.
  
  
  RESULTS
  One hundred and ninety-four patients (mean age, 43.5 ± 17.9 years; male, 53.6%) who underwent electrophysiological study for focal AT were included. We evaluated accuracy in differentiating the origin of AT by using ECG alone as well as with the addition of the clinical features. Electrocardiographs of ATs originating from the left superior pulmonary vein (LSPV, n = 24) vs. the left atrial appendage (LAA, n = 6), and from the right superior pulmonary vein (RSPV, n = 14) vs. the superior vena cava (SVC, n = 8) showed similar patterns. However, while no ATs from the LAA were found to be related to paroxysmal atrial fibrillation, 22 out of 24 ATs from the LSPV were associated with this condition. After localizing AT by using ECG, this clinical feature helped differentiate the ATs from the LSPV vs. the LAA with 93% accuracy. Moreover, while an on-and-off tachycardia (initiated and terminated more than 10 times per day) was observed in 4 of 8 ATs from the SVC, this pattern was observed in 13 of 14 ATs from the RSPV. After localizing the ATs by using ECG, on-and-off tachycardia helped differentiate the ATs from the RSPV vs. the SVC with 82% accuracy.
  
  
  CONCLUSIONS
  The clinical features and Holter monitoring can give additional information for differentiating the focal ATs originating from the adjacent structures.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae-Sun
authors.initials: JS
authors.lastname: Uhm
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jaemin
authors.initials: J
authors.lastname: Shim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Wi
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hee-Sun
authors.initials: HS
authors.lastname: Mun
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Moon-Hyoung
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea cby6908@yuhs.ac.
authors.forename: Boyoung
authors.initials: B
authors.lastname: Joung
mesh_terms: D000328:Adult; D000465:Algorithms; D020517:Atrial Appendage / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery; D012815:Signal Processing, Computer-Assisted; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D013997:Time Factors; D014683:Vena Cava, Superior / Q000503:physiopathology* / Q000601:surgery
keywords: Algorithm; Atrial tachycardia; Clinical feature; Electrocardiography; Localization