AV hysteresis causing initiation of recurrent atrial arrhythmias.

A 73-year-old male with dual-chamber implantable cardioverter defibrillator (Teligen, Boston Scientific, Marlborough, MA, USA) had multiple episodes of automatic mode switch (AMS) during clinical follow-up. Over 50% of these demonstrated a similar pattern of initiation. AV Search+ in combination with sensor rate pacing can cause short-coupled atrial paced intervals that can be proarrhythmic. After programming changes were made AMS burden has significantly decreased.