Local modifications in tissular conditions before PFA increases acute lesion size.

Area of Science:

• Cardiovascular Ablation Technologies
• Electroporation-Based Therapies
• Cardiac Tissue Engineering

Background:

• Pulsed field ablation (PFA) is a novel nonthermal cardiac ablation technology utilizing irreversible electroporation.
• While calcium-enhanced electroporation shows promise for solid tumors, its efficacy in creating deeper cardiac lesions in the left ventricle is unexplored.

Purpose of the Study:

• To investigate the impact of altered local tissular conditions on lesion formation during PFA.
• To assess if calcium chloride (CaCl2) modifies PFA lesion characteristics in cardiac tissue.

Main Methods:

• The study involved anesthetized pigs undergoing epicardial injections of CaCl2 or a buffer solution, followed by PFA treatment.
• Control groups included CaCl2 injections without PFA and buffer injections with PFA.
• Acute lesion formation was evaluated after 2 hours using 2,3,5-triphenyltetrazolium chloride staining.

Main Results:

• PFA combined with CaCl2 injections resulted in significantly larger lesions (5.9 ± 0.9 mm) compared to PFA with buffer solution (4.3 ± 0.9 mm; P < .01).
• CaCl2 injections alone did not produce observable lesions.
• Ventricular fibrillation was induced in 48% of CaCl2 + PFA applications, versus 0% for buffer + PFA.

Conclusions:

• Local tissue conditions, specifically the presence of calcium, demonstrably influence PFA lesion size.
• The combination of calcium and PFA increases lesion depth but elevates the risk of inducing ventricular fibrillation.
• This proof-of-concept study highlights the critical role of tissue environment in PFA efficacy and safety for cardiac applications.