Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Mar 28;27(4):euaf084.
doi: 10.1093/europace/euaf084.

Ablation characteristics associated with steam pops in ablation index-guided radiofrequency ablation of atrial fibrillation

Xue-Si Wang  1 , Ze-Yang Wu  1   2 , Qi Wu  3 , De-Yong Long  1 , Cai-Hua Sang  1 , Chen-Xi Jiang  1 , Wei Wang  1 , Xin Zhao  1 , Chang-Yi Li  1 , Rong-Hui Yu  1 , Nian Liu  1 , Song-Nan Li  1 , Xiao-Xia Liu  1 , Xue-Yuan Guo  1 , Song Zuo  1 , Meng-Meng Li  1 , Tong Liu  1 , Wen-Li Dai  1 , Ming-Yang Gao  1 , Chang-Qi Jia  1 , Man Ning  1 , Li Feng  1 , Wen-He Lv  1 , Yu-Kun Li  1 , Xiao-Ying Liu  1 , Zhuo-Hang Du  1 , Jia-Lin Li  1 , Xin-Ru Li  1 , Jian-Zeng Dong  1 , Chang-Sheng Ma  1 , Ri-Bo Tang  1
Affiliations

Ablation characteristics associated with steam pops in ablation index-guided radiofrequency ablation of atrial fibrillation

Xue-Si Wang et al. Europace. .

Abstract

Aims: Steam pops present a significant concern during radiofrequency (RF) ablation of atrial fibrillation (AF). It is crucial to analyse the incidence and ablation characteristics associated with steam pops. This study aims to investigate the occurrence and potential predictors of steam pops.

Methods and results: This study included 3263 patients with AF who underwent RF ablation. Patients with paroxysmal AF received bilateral circumferential pulmonary vein (PV) ablation, while those with persistent AF underwent additional linear ablation. The ablation parameters at the sites of steam pops were compared to those at adjacent anatomical locations. A total of 81 steam pops (2.5%) with one pericardial tamponade were recorded. Steam pops were observed at liner ablation sites: 6 (0.4%) at the mitral isthmus, 16 (0.9%) at the tricuspid isthmus (CTI), and 7 (0.5%) along the roofline. The most common sites of steam pops were the anterior edge of the left superior PV and the inferior vena cava side of the CTI. The impedance drop was significantly higher (18.2 ± 9.5 Ω vs. 13.5 ± 4.8 Ω, P < 0.001) at steam pop sites. The optimal cut-off points of impedance drop for predicting steam pops were > 9.5 Ω within the first 3 s, > 10.5 Ω within the first 5 s, > 13.5 Ω within the first 10 s, and > 18.5 Ω in the whole ablation, respectively.

Conclusion: The incidence of steam pops during ablation of AF is infrequent. Impedance drop is the only ablation parameter that could predict the occurrence of steam pops.

Keywords: Ablation; Ablation index; Atrial fibrillation; High power; Steam pop.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: None declared.

Figures

Graphical Abstract
Graphical Abstract
Figure 1
Figure 1
The distribution of steam pops. Red dots represent the sites of steam pops. PA, posterior–anterior view of the left atrium; LAA, left atrial appendage; LSPV, left superior pulmonary vein; LIPV, left inferior pulmonary vein; RSPV, right superior pulmonary vein; RIPV, right inferior pulmonary vein; MAI, mitral isthmus; CFAEs, complex fractional atrial electrograms; CS, coronary sinus; TA, tricuspid annulus; CTI, tricuspid isthmus; IVC, inferior vena cava.
Figure 2
Figure 2
The ablation parameters of steam pops. The changes in ablation parameters for all steam pops. (A) RF duration. (B) RF power. (C), AI value. (D) Minimum temperature. (E) Maximum temperature. (F) Average temperature. (G) Minimum impedance. (H) Maximum impedance. (I) Impedance drop. (J) Minimum contact force. (K) Maximum contact force. (L) Average contact force. RF, radiofrequency; AI, ablation index.
Figure 3
Figure 3
Forest plot of logistic regression analysis of ablation parameters. RF, radiofrequency.
Figure 4
Figure 4
ROC curve analysis. (A) ROC curve analysis for Δimpedance in the first 3 s to predict the occurrence of steam pops (AUC was 0.70, 95% CI 0.63–0.78). (B) ROC curve analysis for Δimpedance in the first 5 s to predict the occurrence of steam pops (AUC 0.71, 95% CI 0.64–0.79). (C) ROC curve analysis for Δimpedance in the first 10 s to predict the occurrence of steam pops (AUC 0.71, 95% CI 0.63–0.79). (D) ROC curve analysis for whole Δimpedance to predict the occurrence of steam pops (AUC 0.66, 95% CI 0.59–0.74). AUC, area under the curve.
See this image and copyright information in PMC

References

    1. Tzeis S, Gerstenfeld EP, Kalman J, Saad EB, Sepehri Shamloo A, Andrade JG et al. 2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation. Europace 2024;26:euae043.
    1. Boersma L, Andrade JG, Betts T, Duytschaever M, Pürerfellner H, Santoro F et al. Progress in atrial fibrillation ablation during 25 years of Europace journal. Europace 2023;25:euad244. - PMC - PubMed
    1. Habibi M, Berger RD, Calkins H. Radiofrequency ablation: technological trends, challenges, and opportunities. Europace 2021;23:511–9. - PubMed
    1. Viles-Gonzalez JF, Berjano E, d'Avila A. Complications of radiofrequency catheter ablation: can we prevent steam pops? JACC Clin Electrophysiol 2018;4:501–3. - PubMed
    1. Phlips T, Taghji P, El Haddad M, Wolf M, Knecht S, Vandekerckhove Y et al. Improving procedural and one-year outcome after contact force-guided pulmonary vein isolation: the role of interlesion distance, ablation index, and contact force variability in the ‘close’-protocol. Europace 2018;20:f419–27. - PubMed