Double sensing by atrial automatic tachycardia-terminating pulse generator

This report describes two cases of double sensing of the P and QRS signals by an implanted atrial bipolar automatic burst tachycardia-terminating puise generator (Inlermedics CyherTach 60) used for the treatment of supraventricular tachycardia. Double sensing occurred during normai sinus rhythm at a rate slower than the tachycardia detection criterion and caused inappropriate delivery of burst stimulation. These observations underscore the importance of the far-field QRS signal in the detection of supraventricular tachycardia by automatic puise generators sensing the atrial eiectrogram.