The Automated Subcutaneous Implantable Cardioverter-Defibrillator Screening in Patients With Leadless Pacemakers

Area of Science:

• Cardiology
• Medical Devices
• Electrophysiology

Background:

• Leadless pacemaker (LPM) implantations are increasing, often in patients unsuitable for transvenous devices.
• Indications for LPMs overlap with subcutaneous implantable cardioverter-defibrillators (sICDs), necessitating evaluation of their combined use.
• sICD implantation requires successful QRS morphology screening in both intrinsic and paced rhythms.

Purpose of the Study:

• To assess the success rate of sICD screening in patients already implanted with an LPM.
• To evaluate the concordance of sICD screening vectors between intrinsic and paced rhythms in these patients.

Main Methods:

• Twenty-two patients with ventricular LPMs underwent automated sICD screening.
• Screening was performed in 2-4 body positions, assessing both intrinsic and paced rhythms (nominal and emergency outputs).

Main Results:

• All LPMs were implanted in the interventricular septum.
• 94.1% of patients passed sICD screening during intrinsic rhythm.
• Only 23.8% and 28.5% passed screening during nominal and emergency pacing, respectively, with 23.5% showing vector concordance.

Conclusions:

• While intrinsic rhythm screening is highly successful, pacing rhythm screening poses a challenge for co-implantation.
• Low positive QRS assessment during pacing may limit the optimal coexistence of LPM and sICD.
• Further research is needed to address concerns regarding combined LPM and sICD use in clinical practice.