title: The Lewis Lead for Detection of Ventriculoatrial Conduction Type.
abstract: BACKGROUND
  Identification of a possible ventriculoatrial (VA) dissociation in wide QRS complex tachycardias is one of the most reliable criteria for differentiation of tachycardia origin. The Lewis lead has been proposed for detection of atrial activity during ventricular tachycardias.
  
  
  OBJECTIVE
  A modified Lewis-lead-ECG will be superior to the standard-lead ECG for detection of ventriculoatrial conduction during ventricular tachycardia.
  
  
  METHODS
  Forty-seven patients underwent electrophysiological study, stimulated with a fixed cycle length of 400 ms in the ventricle. During stimulation, a standard-lead ECG and a modified Lewis-lead ECG were recorded. Simultaneously, VA conduction was documented by intracardiac electrograms. Surface ECGs were presented to 6 blinded examiners for VA conduction assessment.
  
  
  RESULTS
  Type of VA conduction was correctly diagnosed in significantly more ECGs in the Lewis-lead ECG group (mean, 35.0 [75%]) than in the standard-lead ECG group (mean, 29.2 [62%]; P = 0.045). Ventriculoatrial dissociation also was significantly more often correctly diagnosed in the Lewis-lead ECG group (mean, 17.7 [71%]) than in the standard-lead ECG group (mean, 12.7 [49%]; P = 0.014). Interobserver agreement was moderate in both groups (κ = 0.45 and κ = 0.49, respectively).
  
  
  CONCLUSIONS
  Compared with standard-lead ECG, modified Lewis-lead ECG is associated with significantly improved detection of VA conduction type during fast ventricular pacing and thus may help improve ECG diagnosis.
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Huemer
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Meloh
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Attanasio
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wutzler
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Abdul S
authors.initials: AS
authors.lastname: Parwani
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Hisao
authors.initials: H
authors.lastname: Matsuda
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Blaschke
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Leif-Hendrik
authors.initials: LH
authors.lastname: Boldt
authors.affiliation: Department of Cardiology, Campus Virchow Klinikum, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Haverkamp
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography / Q000295:instrumentation*; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult
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