PE3-017 T-Wave Oversensing Related Inappropriate ICD Shocks Avoided with Automatic Algorithm: Bench Simulation of 3 Cases

Introduction: Inappropriate shock due to T-wave oversensing (TWOS) is an unsolved issue in implantable cardioverter defibrillator (ICD) therapy. New algorithm launched by Medtronic utilizes electrogram (EGM) sense-pattern and morphology to distinguish TWOS from ventricular arrhythmias. We have evaluated this algorithm using human data. Methods: Stored EGMs of TWOS from 3 Japanese patients were fed into ICD bench system equipped with the new algorithm. We used original detection parameters to reproduce TWOS from recorded episodes. Then we re-analyzed the same episode using the new algorithm to test whether it could properly reject the TWOS and avoid shocks. Results: Case1: Brugada patient who recieved inappropriate shock due to TWOS in VF zone. Amplitude of R-wave and T-wave was 2mV and 3mV, respectively. Successful TWOS rejection was observed. Case2: Idiopathic VF patient who experienced inappropriate shock in VF zone. R-wave was variable (1.5-7.5mV) and T-wave was 2mV. Appropriate TWOS rejection was achieved. Case3: Hypertrophic cardiomyopathy patient who recieved 11 shocks due to TWOS in VT zone. R-wave was 14mV and T wave was 4mV. The algorithm rejected this episode properly. Conclusion: The new algorithm rejected TWOS and avoided the inappropriate shocks successfully in all these cases in the bench test.