Inappropriate Shock: A Failure of SVT Discriminators in a Dual Chamber ICD?


Address for reprints: Amin Al-Ahmad, M.D., Cardiac Arrhythmia Service, Stanford University School of Medicine, 300 Pasteur Drive, H2146, Stanford, CA 94305. Fax: (650) 725-7568; e-mail:


Inappropriate shock remains a major issue in patients with implantable cardioverter defibrillators. We examine an inappropriate shock delivered in a patient with atrial tachycardia that conducted 1:1. We reconstruct the device algorithms that led to therapy delivery and discuss programming changes that could be considered.