title: Uncovering the septal Q wave and other electrocardiographic changes in pediatric patients with pre-excitation before and after ablation.
abstract: In patients with pre-excitation, a short PR interval and a delta wave are not always clearly seen, particularly if the pre-excitation is mild. Absent septal Q waves have been used as additional evidence suggestive of pre-excitation. The purpose of the present study was to determine the incidence of normalization of septal Q waves after successful ablation of a manifest accessory pathway in pediatric patients with normal hearts. We performed a retrospective review of electrocardiograms (ECGs) obtained before and after successful catheter ablation of a single manifest accessory pathway in patients <21 years old (84 pairs of ECGs). The ECGs obtained in patients before ablation for atrioventricular nodal re-entry tachycardia were used as controls (n = 62). The absence of Q waves in the lateral leads (V(5) to V(7)) and inferior leads (II, III, aVF) were determined. p Values <0.05 were considered significant. Before the ablation, 72 ECGs (85%) demonstrated absent Q waves in the lateral leads, and only 17 (20%) did not show evidence of Q waves after successful ablation of the accessory pathway (p <0.001). On the inferior leads, 37 ECGs (44%) showed no evidence of Q waves before ablation compared to 24 (29%) after ablation (p <0.05). The findings on the postablation ECG were not statistically different from the findings on the ECGs of the control patients. In conclusion, Q waves in the lateral and inferior leads are often absent in patients with manifest pre-excitation. Absent septal Q waves in the lateral and inferior leads frequently normalize after successful ablation of an accessory pathway.
authors.affiliation: Pediatric Arrhythmia Service, Department of Pediatrics, New York-Presbyterian Morgan Stanley Children's Hospital, Columbia University Medical Center, New York, New York, USA. ll202@columbia.edu
authors.forename: Leonardo
authors.initials: L
authors.lastname: Liberman
authors.forename: Robert H
authors.initials: RH
authors.lastname: Pass
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Starc
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Hordof
authors.forename: Eric S
authors.initials: ES
authors.lastname: Silver
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001283:Atrioventricular Node / Q000503:physiopathology; D002036:Bundle of His / Q000503:physiopathology; D017115:Catheter Ablation; D002648:Child; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D011226:Pre-Excitation Syndromes / Q000503:physiopathology* / Q000601:surgery*; D020127:Recovery of Function; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult