Ventricular nanosecond pulsed electric field delivery using active fixation leads: a proof-of-concept preclinical...

Area of Science:

• Cardiovascular Medicine
• Electrophysiology
• Medical Devices

Background:

• Mid-myocardial ventricular arrhythmias present significant therapeutic challenges.
• Cardiac electroporation using pulsed electric fields (PEFs) shows potential for treating these arrhythmias.
• Investigating PEF delivery via screw-in pacemaker leads as a proof-of-concept.

Purpose of the Study:

• To evaluate the feasibility and safety of delivering pulsed electric fields (PEFs) to the ventricular myocardium using active fixation pacemaker leads.
• To assess the impact of varying energy levels on myocardial tissue response and lesion formation.

Main Methods:

• Nanosecond PEF (300 ns pulse width) applied to the canine right ventricular septum using bipolar configurations (1 or 2 leads).
• Electrograms (EGMs) recorded pre- and post-PEF.
• Cardiac magnetic resonance imaging (cMRI) and histopathology performed at 2 weeks and 1 month post-treatment.

Main Results:

• Low-energy PEF (1 lead) resulted in transient ectopy and ST elevations with no lasting damage.
• High-energy PEF (2 leads) induced persistent ST elevations, decreased EGM amplitudes, and created discrete fibrotic lesions with minimal cardiomyocyte presence.
• No significant extracardiac stimulation or mortality observed during PEF delivery.

Conclusions:

• Ventricular electroporation using active fixation pacemaker leads is feasible and safe.
• Lower energy PEF delivery caused reversible myocardial changes.
• Higher energy PEF delivery resulted in durable, localized myocardial lesions.