Impact of contact parameters on lesion dimensions during circular Pulsed-Field ablation in ex vivo and in vivo models

Q: What are the key findings of this study?

Pulsed-field ablation under contact conditions produced significantly deeper myocardial lesions compared to non-contact conditions after five applications (5.80 mm vs 3.55 mm).

Q: What is the clinical evidence from this study?

Population: Cardiac arrhythmias (experimental model) (n=3). Intervention: Bipolar biphasic circular Pulsed-Field Ablation (PFA) under contact conditions vs. PFA under non-contact conditions. Primary outcome: Lesion depth after 5 applications in porcine myocardium (mm) (p=<0.001).

Q: What question did this study set out to answer?

To evaluate the impact of contact force, contact status, and application count on lesion dimensions and acute histopathological features during circular pulsed-field ablation.

Xianjin Hu; Wenjie Li; Bangjiaxin Ren; Fanghui Li; Ao Gong; Xianzhao Zhu; Luyang Xie; Ying Cao; Ziru Li; R U I Zeng

doi:10.1038/s41598-026-42503-1

March 3, 2026Scientific ReportsOpen Access

Impact of contact parameters on lesion dimensions during circular Pulsed-Field ablation in ex vivo and in vivo models

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Key result

Contact PFA produces ~63% deeper myocardial lesions than non-contact ablation.

P<0.001
n=3

Figures

Why the study?

The influence of contact force, contact status, and application count on lesion characteristics during bipolar biphasic circular pulsed field ablation remained uncertain.

Does stable catheter-tissue contact and increased application count improve lesion depth during circular pulsed-field ablation in preclinical models?

Key Points

To evaluate the impact of contact force, contact status, and application count on lesion dimensions and acute histopathological features during circular pulsed-field ablation.
Tested pulsed-field ablation (PFA) delivery in an ex vivo potato model under non-contact and stratified contact force conditions (0–25 g, 25–50 g, > 50 g; 5 applications each).
Created 36 in vivo ventricular lesions in porcine myocardium using a bipolar biphasic circular PFA catheter (1, 3, or 5 applications under contact vs. non-contact conditions).
Assessed acute lesion dimensions and histopathology via hematoxylin-eosin and Masson's trichrome staining.
In potato tissue, contact conditions produced significantly deeper lesions than non-contact (p < 0.001), but lesion depth did not differ significantly across contact force subgroups.
In porcine myocardium, contact lesions were significantly deeper than non-contact lesions after 3 applications (4.82 ± 0.91 mm vs. 3.33 ± 0.74 mm; p < 0.05) and 5 applications (5.80 ± 0.49 mm vs. 3.55 ± 0.45 mm; p < 0.001), with the shallowest lesions occurring after 1 non-contact application (1.66 ± 0.65 mm).
Lesion width was not significantly altered by contact status or application count, while histology showed contraction-band necrosis, neutrophilic infiltration, edema, and preserved microvasculature.

Structured PICO

Does stable catheter-tissue contact and increased application count improve lesion depth during circular pulsed-field ablation in preclinical models?

P

Population

Ex vivo potato model (58 slices) and in vivo porcine myocardial model (3 Landrace swine, 36 ventricular lesions)

I

Intervention

Bipolar biphasic circular Pulsed-Field Ablation (PFA) under contact conditions (stratified contact forces of 0-25 g, 25-50 g, >50 g in potato; contact in porcine) with 1, 3, or 5 applications

C

Comparator

Pulsed-Field Ablation (PFA) delivered under non-contact conditions

O

Outcome

Lesion dimensions (depth and width) and acute histopathological changessurrogate

Main Result

Absolute Event Rate: 5.8% vs 3.55%

p-value: p=<0.001

Stable catheter-tissue contact and increased application counts are critical for maximizing lesion depth during circular pulsed-field ablation, whereas the magnitude of contact force has minimal impact.

Limitations

The potato model does not replicate the mechanical properties, catheter stability, or perfusion dynamics of in vivo cardiac tissue.
Utilized tissue proximity index (TPI) rather than quantitative contact force sensing in the porcine model.
Limited sample size may have introduced Type II error.
Histological analysis was restricted to the acute post-ablation period (2 hours).
Potato model does not replicate the mechanical properties, catheter stability, or perfusion dynamics of in vivo cardiac tissue
Utilized tissue proximity index (TPI) rather than quantitative contact force sensing in the porcine model
Limited sample size may have introduced Type II error
Histological analysis was restricted to the acute post-ablation period

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Implication

Supports prioritizing stable catheter contact during PFA; hypothesis-generating for impact on clinical efficacy in AF ablation.

Abstract

Pulsed field ablation (PFA) is a novel nonthermal therapy for cardiac arrhythmias. The influence of contact force (CF), contact status, and application count on lesion characteristics in bipolar biphasic circular PFA remains uncertain. This study investigated lesion dimensions and acute histopathological changes using potato and porcine myocardial models. PFA was delivered in potato models under non-contact conditions or stratified contact forces (0–25 g, 25–50 g, > 50 g; 5 applications each). Porcine myocardium lesions were created with 1, 3, or 5 applications under contact or non-contact. Contact conditions yielded deeper lesions than non-contact in potato models (p < 0.001), with no significant differences among CF subgroups. In porcine myocardium, contact lesions were significantly deeper after three (4.82 ± 0.91 mm vs. 3.33 ± 0.74 mm; p < 0.05) and five applications (5.80 ± 0.49 mm vs. 3.55 ± 0.45 mm; p < 0.001) compared to non-contact. Lesion width was unaffected by contact status or application number. Histology demonstrated contraction-band necrosis, neutrophilic infiltration, edema, and hemorrhage with preserved microvasculature; these changes were more pronounced under contact. In the phantom model, lesion dimensions were predominantly governed by contact stability rather than contact force magnitude. In vivo validation confirmed that maintaining stable contact is a prerequisite for effective lesion formation. Furthermore, increasing the number of applications augmented lesion depth in porcine myocardium, while width remained stable.

Discussion

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Cite This Study

Hu et al. (2026) studied Cardiac arrhythmias (experimental model) (n=3). Bipolar biphasic circular Pulsed-Field Ablation (PFA) under contact conditions vs. PFA under non-contact conditions was evaluated on Lesion depth after 5 applications in porcine myocardium (mm) (p=<0.001). Pulsed-field ablation under contact conditions produced significantly deeper myocardial lesions compared to non-contact conditions after five applications (5.80 mm vs 3.55 mm).

synapsesocial.com/papers/69a91e02d6127c7a504c181f https://doi.org/10.1038/s41598-026-42503-1

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Impact of contact parameters on lesion dimensions during circular Pulsed-Field ablation in ex vivo and in vivo models

Figures

Key Points

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Impact of contact parameters on lesion dimensions during circular Pulsed-Field ablation in ex vivo and in vivo models

Figures

Key Points

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

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