Sheath shape pattern during leadless pacemaker implantation

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Leadless pacemakers (LPs) offer a less invasive approach to bradyarrhythmia treatment.
• Current methods for shaping LP delivery sheaths lack patient-specific anatomical customization.
• Optimizing sheath shape is crucial for successful and safe LP implantation.

Purpose of the Study:

• To predict the required shape of the leadless pacemaker (LP) delivery sheath during implantation.
• To correlate preoperative computed tomography (CT) measurements with intraoperative sheath configuration.
• To identify anatomical predictors for the alpha-loop sheath shape.

Main Methods:

• Retrospective analysis of 48 patients who received LPs.
• Categorization into alpha-loop and non-alpha-loop groups based on sheath head shape.
• Measurement of angles between the inferior vena cava (IVC) and interventricular septum (IVST), and IVC and right ventricular apex (RVA) using CT.
• Assessment of sheath position relative to a vertical line in fluoroscopy (LAO view).

Main Results:

• Significantly smaller IVC-IVST and IVC-RVA angles were observed in the alpha-loop group (p < 0.01).
• A combined IVC-IVST angle < 50° and IVC-RVA angle < 55° predicted alpha-loop shape with 81.8% sensitivity.
• The delivery sheath was more frequently positioned to the right of the vertical line in the alpha-loop group (90.9% vs. 23.1%, p < 0.01).

Conclusions:

• Preoperative CT-derived angles (IVC-IVST and IVC-RVA) can predict the need for an alpha-loop sheath.
• Narrower preoperative angles suggest the necessity of shaping the delivery sheath head into an alpha-loop.
• This prediction aids in tailoring the delivery sheath to individual cardiac anatomy for LP implantation.