title: Inhibition of bradycardia pacing caused by far-field atrial sensing in a third-generation cardioverter defibrillator with an automatic gain feature.
abstract: The diagnostic accuracy of implantable cardioverter defibrillators may be improved by automatically adjusting gain algorithms, which in general reduce the likelihood of oversensing while maintaining the ability to detect the low amplitude signals associated with ventricular fibrillation. We present a patient with a third-generation device who developed prolonged ventricular asystole arising as a complication of the automatic gain feature. During asystole the device automatically increased sensitivity in order to prevent undersensing of ventricular fibrillation, which in this case resulted in far-field sensing of atrial activity and inhibition of ventricular pacing.
authors.affiliation: Cardiac Unit, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Curwin
authors.forename: M
authors.initials: M
authors.lastname: Roelke
authors.forename: J N
authors.initials: JN
authors.lastname: Ruskin
mesh_terms: D000368:Aged; D000465:Algorithms; D016477:Artifacts; D016275:Atrial Function / Q000502:physiology; D001919:Bradycardia / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000379:methods; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004562:Electrocardiography; D004867:Equipment Design; D004868:Equipment Failure; D006323:Heart Arrest / Q000209:etiology*; D006801:Humans; D008297:Male; D014693:Ventricular Fibrillation / Q000628:therapy*