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Cardiovascular magnetic resonance guided ablation and intra-procedural visualization of evolving radiofrequency lesions in the left ventricle.
J Cardiovasc Magn Reson. 2018 03 15; 20(1):20.JC

Abstract

BACKGROUND

Radiofrequency (RF) ablation has become a mainstay of treatment for ventricular tachycardia, yet adequate lesion formation remains challenging. This study aims to comprehensively describe the composition and evolution of acute left ventricular (LV) lesions using native-contrast cardiovascular magnetic resonance (CMR) during CMR-guided ablation procedures.

METHODS

RF ablation was performed using an actively-tracked CMR-enabled catheter guided into the LV of 12 healthy swine to create 14 RF ablation lesions. T2 maps were acquired immediately post-ablation to visualize myocardial edema at the ablation sites and T1-weighted inversion recovery prepared balanced steady-state free precession (IR-SSFP) imaging was used to visualize the lesions. These sequences were repeated concurrently to assess the physiological response following ablation for up to approximately 3 h. Multi-contrast late enhancement (MCLE) imaging was performed to confirm the final pattern of ablation, which was then validated using gross pathology and histology.

RESULTS

Edema at the ablation site was detected in T2 maps acquired as early as 3 min post-ablation. Acute T2-derived edematous regions consistently encompassed the T1-derived lesions, and expanded significantly throughout the 3-h period post-ablation to 1.7 ± 0.2 times their baseline volumes (mean ± SE, estimated using a linear mixed model determined from n = 13 lesions). T1-derived lesions remained approximately stable in volume throughout the same time frame, decreasing to 0.9 ± 0.1 times the baseline volume (mean ± SE, estimated using a linear mixed model, n = 9 lesions).

CONCLUSIONS

Combining native T1- and T2-based imaging showed that distinctive regions of ablation injury are reflected by these contrast mechanisms, and these regions evolve separately throughout the time period of an intervention. An integrated description of the T1-derived lesion and T2-derived edema provides a detailed picture of acute lesion composition that would be most clinically useful during an ablation case.

Links

Authors+Show Affiliations

Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. philippa.krahn@mail.utoronto.ca. Sunnybrook Research Institute, Toronto, ON, Canada. philippa.krahn@mail.utoronto.ca.

Schulich Heart Research Program, Sunnybrook Research Institute, Toronto, ON, Canada. Division of Cardiology, Schulich Heart Centre, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. Faculty of Medicine, University of Toronto, Toronto, ON, Canada.

Sunnybrook Research Institute, Toronto, ON, Canada.

Sunnybrook Research Institute, Toronto, ON, Canada.

Sunnybrook Research Institute, Toronto, ON, Canada.

Sunnybrook Research Institute, Toronto, ON, Canada.

Sunnybrook Research Institute, Toronto, ON, Canada.

Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. Sunnybrook Research Institute, Toronto, ON, Canada. Schulich Heart Research Program, Sunnybrook Research Institute, Toronto, ON, Canada.

Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. Sunnybrook Research Institute, Toronto, ON, Canada. Schulich Heart Research Program, Sunnybrook Research Institute, Toronto, ON, Canada.

MeSH

AnimalsEdema, CardiacHeart VentriclesMagnetic Resonance Imaging, CineMagnetic Resonance Imaging, InterventionalModels, AnimalPredictive Value of TestsRadiofrequency AblationSus scrofaTime FactorsVentricular Function, Left

Pub Type(s)

Journal Article

Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

29544514

Citation

Krahn, Philippa R P., et al. "Cardiovascular Magnetic Resonance Guided Ablation and Intra-procedural Visualization of Evolving Radiofrequency Lesions in the Left Ventricle." Journal of Cardiovascular Magnetic Resonance : Official Journal of the Society for Cardiovascular Magnetic Resonance, vol. 20, no. 1, 2018, p. 20.

Krahn PRP, Singh SM, Ramanan V, et al. Cardiovascular magnetic resonance guided ablation and intra-procedural visualization of evolving radiofrequency lesions in the left ventricle. J Cardiovasc Magn Reson. 2018;20(1):20.

Krahn, P. R. P., Singh, S. M., Ramanan, V., Biswas, L., Yak, N., Anderson, K. J. T., Barry, J., Pop, M., & Wright, G. A. (2018). Cardiovascular magnetic resonance guided ablation and intra-procedural visualization of evolving radiofrequency lesions in the left ventricle. Journal of Cardiovascular Magnetic Resonance : Official Journal of the Society for Cardiovascular Magnetic Resonance, 20(1), 20. https://doi.org/10.1186/s12968-018-0437-z

Krahn PRP, et al. Cardiovascular Magnetic Resonance Guided Ablation and Intra-procedural Visualization of Evolving Radiofrequency Lesions in the Left Ventricle. J Cardiovasc Magn Reson. 2018 03 15;20(1):20. PubMed PMID: 29544514.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Cardiovascular magnetic resonance guided ablation and intra-procedural visualization of evolving radiofrequency lesions in the left ventricle. AU - Krahn,Philippa R P, AU - Singh,Sheldon M, AU - Ramanan,Venkat, AU - Biswas,Labonny, AU - Yak,Nicolas, AU - Anderson,Kevan J T, AU - Barry,Jennifer, AU - Pop,Mihaela, AU - Wright,Graham A, Y1 - 2018/03/15/ PY - 2017/09/13/received PY - 2018/02/15/accepted PY - 2018/3/17/entrez PY - 2018/3/17/pubmed PY - 2019/3/15/medline KW - Arrhythmias KW - Catheter ablation KW - Image-guided intervention KW - Tissue characterization SP - 20 EP - 20 JF - Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance JO - J Cardiovasc Magn Reson VL - 20 IS - 1 N2 - BACKGROUND: Radiofrequency (RF) ablation has become a mainstay of treatment for ventricular tachycardia, yet adequate lesion formation remains challenging. This study aims to comprehensively describe the composition and evolution of acute left ventricular (LV) lesions using native-contrast cardiovascular magnetic resonance (CMR) during CMR-guided ablation procedures. METHODS: RF ablation was performed using an actively-tracked CMR-enabled catheter guided into the LV of 12 healthy swine to create 14 RF ablation lesions. T2 maps were acquired immediately post-ablation to visualize myocardial edema at the ablation sites and T1-weighted inversion recovery prepared balanced steady-state free precession (IR-SSFP) imaging was used to visualize the lesions. These sequences were repeated concurrently to assess the physiological response following ablation for up to approximately 3 h. Multi-contrast late enhancement (MCLE) imaging was performed to confirm the final pattern of ablation, which was then validated using gross pathology and histology. RESULTS: Edema at the ablation site was detected in T2 maps acquired as early as 3 min post-ablation. Acute T2-derived edematous regions consistently encompassed the T1-derived lesions, and expanded significantly throughout the 3-h period post-ablation to 1.7 ± 0.2 times their baseline volumes (mean ± SE, estimated using a linear mixed model determined from n = 13 lesions). T1-derived lesions remained approximately stable in volume throughout the same time frame, decreasing to 0.9 ± 0.1 times the baseline volume (mean ± SE, estimated using a linear mixed model, n = 9 lesions). CONCLUSIONS: Combining native T1- and T2-based imaging showed that distinctive regions of ablation injury are reflected by these contrast mechanisms, and these regions evolve separately throughout the time period of an intervention. An integrated description of the T1-derived lesion and T2-derived edema provides a detailed picture of acute lesion composition that would be most clinically useful during an ablation case. SN - 1532-429X UR - https://www.unboundmedicine.com/medline/citation/29544514/Cardiovascular_magnetic_resonance_guided_ablation_and_intra_procedural_visualization_of_evolving_radiofrequency_lesions_in_the_left_ventricle_ DB - PRIME DP - Unbound Medicine ER -