Therapeutic Research

Abstract

A 75 years old patient with recurrent syncope caused by sick sinus syndrome was admitted for permanent pacemaker implantation. Pacemaker leads were screwed in right atrial lower septum and right ventricular lower septum and confirmed satisfactory pacing parameters, threshold and sensing, in both leads. However, there was no problem in the result of the bipolar electrogram in right ventricular（RV） lead next day, RV pacing failure was revealed by unipolar electrogram threshold test. Although, non–dislodgement of RV lead tip position screwed in RV lower septum near the free–wall was confirmed by echocardiogram, but distal side of helix was seemed to be reached to epicardium. RV lead was replaced to RV apex from lower septum to prevent cardiac perforation. Perforation of the RV free wall during pacemaker implantation is often clinically silent. Only lead impedance test, without unipolar and bipolar electrogram threshold test, could not predict cardiac perforation like this case. It is important to perform both unipolar and bipolar electrogram threshold test in the postoperative period to avoid complications and detect possible risk for implant permanent pacemaker.