title: Influence of clinical and hemodynamic characteristics on signal-averaged electrocardiogram in postoperative tetralogy of Fallot.
abstract: This study examines the relation between signal-averaged electrocardiographic measurements and the occurrence of spontaneous ventricular arrhythmias in 86 patients with a postoperative right bundle branch block after repair of tetralogy of Fallot; special attention was given to the influence of age, body surface area and right ventricular systolic pressure on signal-averaged electrocardiograms. Twenty-eight of the 86 patients had significant ventricular arrhythmias on 24-hour ambulatory monitoring. A positive linear correlation was found between filtered QRS duration and age at evaluation or body surface area (r = 0.45, p = 0.00001; r = 0.54, p < 0.00001, respectively) and between amplitude of the last 40 ms of the filtered QRS and right ventricular systolic pressure (r = 0.48, p < 0.001). A negative linear correlation was found between amplitude of the last 40 ms of the filtered QRS and age at evaluation or body surface area (r = -0.27, p = 0.01; r = -0.34, p = 0.002, respectively). When the age of the patients or the body surface area was considered with an analysis of covariance, the presence of ventricular arrhythmias was associated with a higher amplitude of the last 40 ms of the filtered QRS. In addition, an amplitude of the last 40 ms of the filtered QRS > 170 microV had an excellent sensitivity (100%) and a good specificity (88%) for identifying patients with both right ventricular systolic hypertension and spontaneous ventricular arrhythmia. Thus, adjustment of signal-averaged parameters for age at evaluation and body size is mandatory when studying postoperative tetralogy of Fallot.
authors.affiliation: Department of Pediatric Cardiology, Hôpital Cardiologique de Lille, France.
authors.forename: G
authors.initials: G
authors.lastname: Vaksmann
authors.forename: M
authors.initials: M
authors.lastname: el Kohen
authors.forename: D
authors.initials: D
authors.lastname: Lacroix
authors.forename: S
authors.initials: S
authors.lastname: Kacet
authors.forename: G M
authors.initials: GM
authors.lastname: Brevière
authors.forename: C
authors.initials: C
authors.lastname: Rey
authors.forename: C
authors.initials: C
authors.lastname: Dupuis
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D011184:Postoperative Period; D012044:Regression Analysis; D013771:Tetralogy of Fallot / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D013997:Time Factors; D016278:Ventricular Function, Right