title: Role of signal averaging of the surface QRS complex in selecting patients with nonsustained ventricular tachycardia and high grade ventricular arrhythmias for programmed ventricular stimulation.
abstract: Signal averaging of the surface QRS complex was performed before programmed ventricular stimulation in 53 individuals with high grade ventricular arrhythmias or nonsustained ventricular tachycardia, or both. An abnormal signal-averaged electrocardiogram (ECG) was recorded in 22 patients and was associated with inducible ventricular tachycardia in 12 (55%) of the 22. In contrast, a normal signal-average ECG was associated with inducible tachycardia in only 1 (3%) of 31 individuals (p less than 0.005). The group with inducible tachycardia had a longer duration of the signal-averaged QRS complex (124 +/- 19 versus 96 +/- 26 ms) and of low amplitude signals (44 +/- 13 versus 29 +/- 11 ms) (p less than 0.005). In addition, the root mean square voltage of the terminal 40 ms was lower in this group (20 +/- 14 versus 48 +/- 34 microV, p less than 0.005). Twenty-seven of the 53 subjects had a prior myocardial infarction; 17 (63%) of the 27 had an abnormal signal-averaged ECG, and ventricular tachycardia was inducible in 10 (59%) of the 17. A normal signal-averaged ECG was recorded in 10 of the 27 patients and only 1 (10%) of these 10 had inducible tachycardia. An abnormal signal-averaged ECG had a 91% sensitivity and a 56% specificity with respect to subsequent induction of tachycardia. During long-term follow-up, 2 (15%) of the 13 patients with inducible ventricular tachycardia who were treated with electrophysiologically guided antiarrhythmics therapy died suddenly; the remaining 11 patients (85%) are alive 15 +/- 10 months after electrophysiologic testing.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Mount Sinai School of Medicine, City University of New York, New York 10029.
authors.forename: S L
authors.initials: SL
authors.lastname: Winters
authors.forename: D
authors.initials: D
authors.lastname: Stewart
authors.forename: A
authors.initials: A
authors.lastname: Targonski
authors.forename: J A
authors.initials: JA
authors.lastname: Gomes
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology* / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000379:methods; D009202:Cardiomyopathies / Q000503:physiopathology; D004562:Electrocardiography; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies; D013610:Tachycardia / Q000503:physiopathology* / Q000628:therapy