Subcutaneous ICD lead position affects defibrillation threshold

Introduction Subcutaneous implantable cardioverter-defibrillators (S-ICD) provide an alternative to traditional transvenous implantable cardioverter-defibrillators (TV-ICD) and avoid complications associated with intravascular access and leads. They are highly effective in detecting and treating ventricular arrhythmias, with comparable inappropriate shock rates. Use of S-ICD is anticipated to increase significantly. Defibrillation testing (DT) is no longer routinely recommended for TV-ICDs. Although S-ICD systems have high rates of successful defibrillation threshold, DT is routinely recommended as part of the procedure. Implant factors that affect defibrillation threshold have not been fully evaluated. Initial experience has suggested that factors such as amount of adipose tissue below the coil and generator, along with