title: Long-term clinical experience with the EGM width detection criterion for differentiation of supraventricular and ventricular tachycardia in patients with implantable cardioverter defibrillators.
abstract: Inappropriate therapy by ICDs due to SVTs is an important problem. A third generation ICD with a new detection criterion ("EGM width criterion") for differentiation of SVTs and VTs by measuring the width of the intracardiac EGM was studied in 47 patients. A wide EGM was defined as the longest measured EGM plus 4-12 ms (programmed as EGM width threshold). EGM width detection function was programmed to the "Passive" mode so that no therapy was withheld. During a follow-up of 29.9 +/- 8.3 (12-45) months, 489 spontaneous episodes were analyzed. SVTs occurred in ten patients with 305 episodes; 301 were correctly classified by use of the new detection criterion. In four patients four episodes were incorrectly detected as wide QRS tachycardias. Thus specificity for SVT was 98.7% (on a per episode basis) and 60% on a per patient basis. Of 184 VTs in 23 patients, 118 episodes were correctly classified (19 patients), however, in 4 patients 66 VTs were falsely detected as SVTs, 62 (94%) of which occurred in 1 patient with complete left BBB and continuously increasing QRS width in 12-lead surface ECGs. Overall sensitivity (on a per episode basis) for VT detection was 64.1% and 96.7% in patients with stable width of the QRS complex in a 12-lead surface ECG. These data show that this criterion is not superior to data on rate dependent detection criteria and furthermore not applicable in patients with complete BBB.
authors.affiliation: University Clinic, Department of Cardiology, Robert-Koch-Strasse 40, D-37075 Göttingen, Germany. abbuw@aol.com
authors.forename: C
authors.initials: C
authors.lastname: Unterberg
authors.forename: J
authors.initials: J
authors.lastname: Stevens
authors.forename: D
authors.initials: D
authors.lastname: Vollmann
authors.forename: G
authors.initials: G
authors.lastname: Hasenfuss
authors.forename: A B
authors.initials: AB
authors.lastname: Buchwald
mesh_terms: D000328:Adult; D000368:Aged; D017147:Defibrillators, Implantable / Q000592:standards*; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000628:therapy; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000628:therapy; D013995:Time; D016896:Treatment Outcome