title: Utility of implantable cardioverter defibrillator electrograms to estimate repolarization alternans preceding a tachyarrhythmic event.
abstract: Electrical alternans is a pattern of variation in the shape of the ECG waveform that appears on an every-other-beat basis. In humans, alternation in ventricular repolarization, namely, repolarization alternans, has been associated with increased vulnerability to ventricular tachycardia/ventricular fibrillation and sudden cardiac death. This study investigates the utility of implantable cardioverter defibrillator electrograms to estimate repolarization alternans preceding a tachyarrhythmic event. It is demonstrated that microvolt-level repolarization alternans is present prior to an arrhythmic event, and one can record low-amplitude-noise signals that can be used to obtain reliable estimates of repolarization alternans. This study eventually may lead to new methods that would prevent the onset of malignant tachyarrhythmias.
authors.affiliation: Division of Molecular Cardiobiology, Johns Hopkins University, Baltimore, Maryland, USA. aarmoundas@partners.org
authors.forename: Antonis A
authors.initials: AA
authors.lastname: Armoundas
authors.forename: Christine M
authors.initials: CM
authors.lastname: Albert
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cohen
authors.forename: Theofanie
authors.initials: T
authors.lastname: Mela
mesh_terms: D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis; D017147:Defibrillators, Implantable; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis*