Concomitant Use of the Subcutaneous Implantable Cardioverter Defibrillator and a Permanent Pacemaker

Background: The subcutaneous implantable cardioverter defibrillator (S-ICD) is a novel implanted defibrillator for the prevention of sudden cardiac death that avoids intravascular access. Use of this device is limited by its inability to provide backup pacing. Combined use of the S-ICD with a permanent pacemaker may be the optimal choice in certain situations though experience with the use of both devices together remains limited.

Methods: We reviewed our single-center experience with the S-ICD from March 2011 to November 2015. Four patients with concomitant use of the S-ICD and a permanent pacemaker were identified. Clinical indication for device therapy, operative details, and subsequent follow-up was reviewed. During implantation, S-ICD sensing of paced morphologies was evaluated at maximal voltage output. After S-ICD implant, if feasible, the upper rate was adjusted to ≤50% of the S-ICD tachycardia zone to minimize risk of inappropriate shocks.

Results: After a mean follow-up of over 1 year, no adverse events occurred, including no inappropriate shock, lead malfunction, or device infection. One patient had a total of eight appropriate shocks, while another individual had no inappropriate shocks despite having a unipolar pacing lead.

Conclusions: In unique situations, combined use of the S-ICD and a permanent pacemaker may be preferable to alternative options. In our experience, this approach was successful in varying conditions including complex congenital heart disease, recurrent device infection, and limited vascular access.