Rabbit model to simulate the residual conduction gaps after radiofrequency ablation on the anterior wall of left atrial appendage
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Radiofrequency ablation (RFA) is widely used to treat patients with atrial fibrillation (AF), but its recurrence rate is still high mainly due to pulmonary vein reconnection and residual conduction gaps. We aim to establish a rabbit model to simulate the residual conduction gaps after ablation.
Sixty-nine adult New Zealand white rabbits were randomly assigned to six groups. RFA on the anterior wall of left atrial appendage (LAA) were performed with the ablation power from 6 to 21 W. The electrophysiological pacing and mapping technology was used to evaluate the bidirectional conduction of LAA. Histological study and fluorescence techniques were used to evaluate the effect of RFA and the accumulation of drug-loaded liposome on the loop ablation lesions of LAA.
Typical loop ablation lesions of LAA could be observed in vivo and vitro of rabbit models. Histological evaluation revealed coagulative necrosis on the loop ablation lesions. Electrical conduction between inside and outside loop lesions recovered after 1 or 2 weeks after initial unidirectional conduction block. The recurrence rates were significantly different among six groups with varying ablation powers (p < 0.05). Compared with exit conduction block, entrance conduction block was significantly different at 5 min after ablation (p = 0.02). IR-775-loaded liposomes were accumulated on the loop ablation lesions at 48 h after RFA.
RFA associated with electrophysiological pacing and mapping technology successfully established a novel rabbit model to simulate the residual conduction gaps after RFA.
KeywordsRadiofrequency ablation Residual conduction gaps Recovered electrical conduction Rabbit model Inflammation-targeted drugs
We thank for the support of grants (16140901400) from the Science and Technology Commission of Shanghai Municipality.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All animal protocols in this study were approved by the Animal Care and Use Committee, Research Institute of Medicine, Shanghai Jiao Tong University, in accordance with the guide for the Care and Use of Laboratory Animals published by the National Institutes of Health (Publication No. 85–23, revised 1996).
Informed consent was not required.
- 2.Singh-Manoux A, Fayosse A, Sabia S, Canonico M, Bobak M, Elbaz A, et al. Atrial fibrillation as a risk factor for cognitive decline and dementia. Eur Heart J. 2017;38:2612–8. https://doi.org/10.1093/eurheartj/ehx208.
- 4.Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, et al. 2016 ESC guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Europace. 2016;18(11):1609–78. https://doi.org/10.1093/europace/euw295.
- 5.Verma A, Jiang CY, Betts TR, Chen J, Deisenhofer I, Mantovan R, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med. 2015;372(19):1812–22. https://doi.org/10.1056/NEJMoa1408288.
- 7.Yagishita A, Sparano D, Cakulev I, Gimbel JR, Phelan T, Mustafa H, et al. Identification and electrophysiological characterization of early left atrial structural remodeling as a predictor for atrial fibrillation recurrence after pulmonary vein isolation. J Cardiovasc Electrophysiol. 2017;28:642–50. https://doi.org/10.1111/jce.13211.
- 11.Ouyang F, Antz M, Ernst S, Hachiya H, Mavrakis H, Deger FT, et al. Recovered pulmonary vein conduction as a dominant factor for recurrent atrial tachyarrhythmias after complete circular isolation of the pulmonary veins: lessons from double Lasso technique. Circulation. 2005;111(2):127–35. https://doi.org/10.1161/01.cir.0000151289.73085.36.
- 12.Tzou WS, Marchlinski FE, Zado ES, Lin D, Dixit S, Callans DJ, et al. Long-term outcome after successful catheter ablation of atrial fibrillation. Circ Arrhythm Electrophysiol. 2010;3(3):237–42. https://doi.org/10.1161/CIRCEP.109.923771.
- 14.Sadek MM, Maeda S, Chik W, Santangeli P, Zado ES, Schaller RD, et al. Recurrent atrial arrhythmias in the setting of chronic pulmonary vein isolation. Heart Rhythm. 2016;13(11):2174–80. https://doi.org/10.1016/j.hrthm.2016.08.026.
- 17.Bisleri G, Rosati F, Bontempi L, Curnis A, Muneretto C. Hybrid approach for the treatment of long-standing persistent atrial fibrillation: electrophysiological findings and clinical results. Eur J Cardiothorac Surg. 2013;44(5):919–23. https://doi.org/10.1093/ejcts/ezt115.CrossRefPubMedGoogle Scholar
- 18.Toita R, Kawano T, Murata M, Kang J-H. Anti-obesity and anti-inflammatory effects of macrophage-targeted interleukin-10-conjugated liposomes in obese mice. Biomaterials. 2016;110:81–8. https://doi.org/10.1016/j.biomaterials.2016.09.018.CrossRefPubMedGoogle Scholar
- 20.Salas J, Castellanos E, Peinado R, Madero S, Barrio-Lopez T, Ortiz M, et al. Atrial mapping during pulmonary vein pacing: a novel maneuver to detect and close residual conduction gaps in an ablation line. J Interv Card Electrophysiol. 2016;47(3):299–307. https://doi.org/10.1007/s10840-016-0159-9.CrossRefPubMedPubMedCentralGoogle Scholar
- 21.Zhuge Y, Zheng ZF, Xie MQ, Li L, Wang F, Gao F. Preparation of liposomal amiodarone and investigation of its cardiomyocyte-targeting ability in cardiac radiofrequency ablation rat model. Int J Nanomedicine. 2016;11:2359–67. https://doi.org/10.2147/IJN.S98815.CrossRefPubMedPubMedCentralGoogle Scholar
- 22.Moussa M, Goldberg SN, Kumar G, Sawant RR, Levchenko T, Torchilin VP, et al. Nanodrug-enhanced radiofrequency tumor ablation: effect of micellar or liposomal carrier on drug delivery and treatment efficacy. PLoS One. 2014;9(8):e102727. https://doi.org/10.1371/journal.pone.0102727.
- 23.Lau M, Hu B, Werneth R, Sherman M, Oral H, Morady F, et al. A theoretical and experimental analysis of radiofrequency ablation with a multielectrode, phased, duty-cycled system. Pacing Clin Electrophysiol. 2010;33(9):1089–100. https://doi.org/10.1111/j.1540-8159.2010.02801.x.CrossRefPubMedGoogle Scholar
- 24.Nakasone Y, Ikeda O, Kawanaka K, Yokoyama K, Yamashita Y. Radiofrequency ablation in a porcine kidney model: effect of occlusion of the arterial blood supply on ablation temperature, coagulation diameter, and histology. Acta Radiol. 2012;53(8):852–6. https://doi.org/10.1258/ar.2012.110530.CrossRefPubMedGoogle Scholar
- 25.Yorgun H, Canpolat U, Kocyigit D, Coteli C, Evranos B, Aytemir K. Left atrial appendage isolation in addition to pulmonary vein isolation in persistent atrial fibrillation: one-year clinical outcome after cryoballoon-based ablation. Europace. 2017;19(5):758–68. https://doi.org/10.1093/europace/eux005.CrossRefPubMedGoogle Scholar
- 26.Di Biase L, Burkhardt JD, Mohanty P, Mohanty S, Sanchez JE, Trivedi C, et al. Left atrial appendage isolation in patients with longstanding persistent AF undergoing catheter ablation: BELIEF Trial. J Am Coll Cardiol. 2016;68(18):1929–40. https://doi.org/10.1016/j.jacc.2016.07.770.CrossRefPubMedGoogle Scholar