Inappropriate Shocks in a Patient With Subcutaneous ICD and Transvenous Pacemaker: Is it as it Seems?

A male patient with dextro-transposition of great arteries previously treated with palliative Mustard procedure, sinus node dysfunction and intra-atrial reentrant tachycardias, underwent transvenous implantation of dual-chamber pacemaker (PM) in 1991. In October 2013, at the age of 30 years, NYHA class II, moderate dysfunction of systemic ventricle was diagnosed (ejection fraction 32%) and symptomatic non-sustained ventricular tachycardias (NSVT, maximum duration 14 beats, cycle length 330-350ms) were recorded by the PM. According to current guidelines,(1,2) the decision was made to implant a subcutaneous cardioverter defibrillator (S-ICD, Boston Scientific, Natick, MA, USA) for primary prevention of sudden death. The patient underwent the pre-implantation screening ECG, using the selection tool of the device manufacturer. This article is protected by copyright. All rights reserved.