Oversensing issues leading to device extraction: When subcutaneous implantable cardioverter-defibrillator reached a dead-end

Abstract Background Subcutaneous implantable cardioverter defibrillators (S-ICD) implantations are rapidly expanding. However, the subcutaneous detection and interpretation of cardiac signals is much more challenging than in conventional devices. There is a complete paradigm shift in cardiac signal sensing with subcutaneous signal detection, leading in some cases to oversensing with restricted programming options. OBJECTIVES The aim of this single-center study was to quantify and describe cases where recurring oversensing made the extraction of the device necessary. METHODS Consecutive patients (n=108) implanted with a S-ICD in our tertiary referral hospital were considered for analysis. Clinical and remote monitoring data were analyzed. RESULTS The S-ICD had to be explanted in 6 out of 108 implanted patients (5.6%) due to refractory oversensing issues: myopotentials oversensing, P- or T-wave oversensing, rate-dependent LBBB aberrancy during exercise with R-wave double counting and R-wave amplitude drop after VT ablation leading to noise detection. Seventeen out of 108 (15.7%) patients experienced oversensing: 9 (8.3%) patients had at least one inappropriate charge without shock, 3 (2.8%) patients had at least one inappropriate shock and 5 (4.6%) patients had both episodes. CONCLUSION So far, cardiologists have had to deal with transvenous ICD leads fractures but signal oversensing without correcting programming option could be the equivalent weakness of S-ICDs, despite an adequate screening.