title: ICD-antiarrhythmic drug and ICD-pacemaker interactions.
abstract: Antiarrhythmic drugs and separate bradycardia pacing systems are prescribed commonly in patients with implantable cardioverter defibrillators (ICDs). Adverse effects of antiarrhythmic drugs on ICD function and adverse interactions between ICDs and pacemakers have been documented. The effect of antiarrhythmic drugs on the defibrillation threshold (DFT) in patients has not been well assessed. Most studies have been performed in animal models in which cardiac function was normal and drug doses were supraphysiologic. In addition, most studies have utilized monophasic defibrillation shock waveforms and epicardial lead systems. Despite the lack of clinical data applicable to current defibrillation systems, it appears that chronic amiodarone administration causes a significant DFT increase. In addition, antiarrhythmic drugs can influence antitachycardia pacing and tachycardia sensing. Defibrillation shocks can cause transient failure of pacemaker sensing and pacing, and cause spurious pacemaker reprogramming. Pacemaker function can result in ICD oversensing, leading to inappropriate therapy, or cause ICD undersensing, potentially resulting in failure to deliver therapy during ventricular fibrillation. The susceptibility of an ICD to undersensing appears related to the amplitude of the pacing stimulus artifact recorded by the ICD rate-sensing circuit and to the characteristics of the fibrillation electrogram. Preliminary data suggest that undersensing of ventricular fibrillation by current ICDs is an unlikely event.
authors.affiliation: Clinical Electrophysiology Laboratory, Allegheny University School of the Health Sciences, Philadelphia, Pennsylvania, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Brode
authors.forename: D
authors.initials: D
authors.lastname: Schwartzman
authors.forename: D J
authors.initials: DJ
authors.lastname: Callans
authors.forename: C D
authors.initials: CD
authors.lastname: Gottlieb
authors.forename: F E
authors.initials: FE
authors.lastname: Marchlinski
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D017147:Defibrillators, Implantable / Q000009:adverse effects; D006801:Humans; D010138:Pacemaker, Artificial / Q000009:adverse effects
chemical_list: D000889:Anti-Arrhythmia Agents