Iatrogenic pacemaker-induced ventricular arrhythmia: a case report

Abstract

Introduction Minimising right ventricular (RV) pacing to reduce progression of heart failure is an established practice. Proprietary algorithms to reduce unnecessary RV pacing have been incorporated into both simple and complex cardiac pacemaker devices, for reducing the possibility of heart failure and arrhythmias. Case Summary We present a case of a 43-year-old male implanted with a dual chamber primary prevention implantable cardioverter defibrillator (ICD) (AUTOGEN EL, Boston Scientific) for sudden cardiac death. At the time of implant, the patient had hypertrophic cardiomyopathy with mild LV systolic impairment, and sinus rhythm with intact AV conduction. The patient developed progression of his disease with symptoms (dyspnoea) and LV impairment. This led to a decision to activate the minimal RV pacing algorithm (RYTHMIQTM). A deterioration in AV conduction caused intrinsic ventricular beats to fall in the atrial blanking period, and subsequent VVI backup pacing resulted in R on T pacing. This induced ventricular arrhythmia. RYTHMIQTM was subsequently deactivated, and the patient has had no further device-induced arrhythmias. Discussion Numerous studies have demonstrated the adverse effect of RV pacing on LV function. Minimising RV pacing is therefore encouraged in individuals with intact AV conduction. However, underlying conduction abnormalities must be assessed prior to activating algorithms designed to minimise RV pacing. This case demonstrates the importance of careful intracardiac electrogram interpretation and individual case-based device programming, to avoid device-induced complications.