title: Usefulness of ST-segment elevation in lead aVR during tachycardia for determining the mechanism of narrow QRS complex tachycardia.
abstract: In the present study, we analyzed ST-segment elevation in lead aVR during tachycardia to differentiate the narrow QRS complex tachycardia. A total of 338 12-lead electrocardiograms during narrow QRS complex tachycardia were analyzed. Each patient underwent a complete electrophysiologic study. There were 161 episodes of atrioventricular nodal reentrant tachycardia (AVNRT), 165 episodes of atrioventricular reciprocating tachycardia (AVRT), and 12 episodes of atrial tachycardia (AT). The prevalence of aVR ST-segment elevation was 71% for AVRT, 31% for AVNRT, and 16% for AT. For ST-T changes in different leads, logistic regression analysis showed aVR ST-segment elevation was the only significant factor to differentiate the types of narrow QRS complex tachycardia (p<0.001 for AVRT and AVNRT; p=0.02 for AVRT and AT). The sensitivity, specificity, and accuracy of aVR ST-segment elevation to differentiate AVRT from AVNRT and AT were 71%, 70%, and 70%, respectively. Among 117 episodes of AVRT with aVR ST-segment elevation, there were 76 (65%) left side, 23 (20%) right side, 14 (12%) posterior septal, and 4 (3%) antero- and mid-septal accessory pathways (p=0.002). In conclusion, aVR ST-segment elevation during narrow QRS complex tachycardia favors the atrioventricular reentry through an accessory pathway as the mechanism of the tachycardia.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yi-Lwun
authors.initials: YL
authors.lastname: Ho
authors.forename: Lian-Yu
authors.initials: LY
authors.lastname: Lin
authors.forename: Jiunn-Lee
authors.initials: JL
authors.lastname: Lin
authors.forename: Ming-Fong
authors.initials: MF
authors.lastname: Chen
authors.forename: Wen-Jone
authors.initials: WJ
authors.lastname: Chen
authors.forename: Yuan-Teh
authors.initials: YT
authors.lastname: Lee
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis*; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis*