Lower atmospheric pressure is associated with shallower radiofrequency ablation lesions and more frequent steam pops: an ex vivo porcine study
- 1Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University
- 2Department of Cardiology, Lhasa People’s Hospital
Abstract
Background: Atmospheric pressure affects the boiling point of water and may influence thermal lesion formation during radiofrequency (RF) ablation. However, whether atmospheric pressure alters RF lesion formation and steam-pop risk under fixed ablation index (AI) targets remains unknown.
Methods: A total of 360 analyzable lesions were created in 36 ex vivo porcine hearts using the same RF ablation system, which was transported and used consistently at three sites with different atmospheric pressures: Beijing (1,014 hPa), Xining (770 hPa), and Lhasa (650 hPa). At each site, 30 analyzable lesions were obtained at each target AI value (300, 400, 500, and 600). Lesion dimensions, impedance reduction, ablation duration, temperature, and steam-pop occurrence were recorded. Differences among sites were assessed using analysis of variance and Fisher's exact test. A multiple linear regression model was constructed to evaluate the relationship between atmospheric pressure, AI, and lesion volume.
Results: At fixed AI targets, lesions created at lower-pressure sites were significantly shallower and had smaller volumes (all P < 0.05), whereas surface and maximum diameters remained similar among the three sites. Steam pops occurred in 0/120 (0.0%) RF applications in Beijing, 2/122 (1.6%) in Xining, and 6/126 (4.8%) in Lhasa (overall P = 0.031). Impedance reductions differed significantly among sites at 3 and 10 s (both P < 0.001), but not at 5 s ( P = 0.498). Atmospheric pressure and AI jointly explained 88.4% of the variation in lesion volume (R ² = 0.884), enabling derivation of a hypothesis-generating AI correction equation.
Conclusion: Within the natural range of atmospheric pressures examined, lower atmospheric pressure was associated with shallower and smaller-volume RF lesions at fixed AI targets and a higher observed incidence of steam pops. These findings suggest that atmospheric pressure may influence RF lesion formation and steam-pop occurrence, warranting further mechanistic and in vivo validation.
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BibTeX
@article{li2026lower,
title = {{Lower atmospheric pressure is associated with shallower radiofrequency ablation lesions and more frequent steam pops: an ex vivo porcine study}},
author = {Jia-Lin Li and Gesang Luobu and Xin Zhao and Wei Wang and Chang-Yi Li and Meng-Meng Li and Tong Liu and Chen-Xi Jiang and Ri-Bo Tang and De-Yong Long and Biao Fu},
journal = {Frontiers in Cardiovascular Medicine},
year = {2026},
month = nov,
doi = {10.3389/fcvm.2026.1964283},
url = {https://www.frontiersin.org/articles/10.3389/fcvm.2026.1964283/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Lower atmospheric pressure is associated with shallower radiofrequency ablation lesions and more frequent steam pops: an ex vivo porcine study
AU - Jia-Lin Li
AU - Gesang Luobu
AU - Xin Zhao
AU - Wei Wang
AU - Chang-Yi Li
AU - Meng-Meng Li
AU - Tong Liu
AU - Chen-Xi Jiang
AU - Ri-Bo Tang
AU - De-Yong Long
AU - Biao Fu
PY - 2026
DA - 2026/11/06
JO - Frontiers in Cardiovascular Medicine
DO - 10.3389/fcvm.2026.1964283
UR - https://www.frontiersin.org/articles/10.3389/fcvm.2026.1964283/full
AB - Background: Atmospheric pressure affects the boiling point of water and may influence thermal lesion formation during radiofrequency (RF) ablation. However, whether atmospheric pressure alters RF lesion formation and steam-pop risk under fixed ablation index (AI) targets remains unknown. Methods: A total of 360 analyzable lesions were created in 36 ex vivo porcine hearts using the same RF ablation system, which was transported and used consistently at three sites with different atmospheric pressures: Beijing (1,014 hPa), Xining (770 hPa), and Lhasa (650 hPa). At each site, 30 analyzable lesions were obtained at each target AI value (300, 400, 500, and 600). Lesion dimensions, impedance reduction, ablation duration, temperature, and steam-pop occurrence were recorded. Differences among sites were assessed using analysis of variance and Fisher's exact test. A multiple linear regression model was constructed to evaluate the relationship between atmospheric pressure, AI, and lesion volume. Results: At fixed AI targets, lesions created at lower-pressure sites were significantly shallower and had smaller volumes (all P < 0.05), whereas surface and maximum diameters remained similar among the three sites. Steam pops occurred in 0/120 (0.0%) RF applications in Beijing, 2/122 (1.6%) in Xining, and 6/126 (4.8%) in Lhasa (overall P = 0.031). Impedance reductions differed significantly among sites at 3 and 10 s (both P < 0.001), but not at 5 s ( P = 0.498). Atmospheric pressure and AI jointly explained 88.4% of the variation in lesion volume (R ² = 0.884), enabling derivation of a hypothesis-generating AI correction equation. Conclusion: Within the natural range of atmospheric pressures examined, lower atmospheric pressure was associated with shallower and smaller-volume RF lesions at fixed AI targets and a higher observed incidence of steam pops. These findings suggest that atmospheric pressure may influence RF lesion formation and steam-pop occurrence, warranting further mechanistic and in vivo validation.
SN - 2297-055X
ER -