Atrial fibrillation promotion in a rat model of heart failure induced by left ventricle radiofrequency ablation

Autor(es):Mostrar menos -

dos Santos, Luis ^[1] ; Antonio, Ednei L. ^[1] ; Serra, Andrey J. ^[2] ; Yoshizaki, Amanda ^[1] ; Seibt, Larissa ^[1] ; Silva, Flavio A. ^[1] ; Couto, Gisele K. ^[3] ; Rossoni, Luciana V. ^[3] ; Tucci, Paulo ^[1] ; de Paola, Angelo A. ^[1] ; Fenelon, Guilherme ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Paulista Sch Med, Dept Cardiol, Rua Pedro Toledo 781, 10 Vila Clementin, BR-04039032 Sao Paulo, SP - Brazil

^[2] Nove de Julho Univ UNINOVE, Biophoton Program, Rua Vergueiro 235-249 Vergueiro, BR-01504000 Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, Ave Prof Lineu Prestes 1524, Cidade Univ, BR-05508000 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: IJC HEART & VASCULATURE; v. 21, p. 22-28, DEC 2018.
• Citações Web of Science: 0

Resumo

Background: Atrial fibrillation (AF) frequently coexists with congestive heart failure (CHF). The increased susceptibility to AF in CHF has been attributed to a variety of structural and electrophysiological changes in the atria, particularly dilation and interstitial fibrosis. We evaluated atrial remodeling and AF vulnerability in a rat model of CHF induced by left ventricle (LV) radiofrequency (RF) ablation. Methods: Wistar rats were divided into 3 groups: RF-induced CHF (Ab, n = 36), CHF animals treated with spironolactone (AbSpi, n= 20) and shamcontrols (Sham, n= 29). After 12weeks, animals underwent echocardiographic and electrophysiological evaluation and were sacrificed for histological (atrial fibrosis) and Western blotting (TGF-beta 1, collagen I/III, connexin 43 and Ca(V)1.2) analysis. Results: Mild LV dysfunction and marked atrial enlargement were noted in both ablated groups. AF inducibility (episodes >= 2 s) increased in the Ab group compared to sham animals (31/36, 86%; vs. 15/29, 52%; p = 0.005), but did not differ from the AbSpi group (16/20, 80%; p = NS). Sustained AF (N30 s) was also more frequent in the Ab group compared to shams (56% vs. 28%; p = 0.04). Spironolactone reduced atrial fibrosis (p < 0.01) as well as TGF-beta 1 (p < 0.01) and collagen I/III (p b 0.01) expression but did not affect connexin 43 and Ca(V)1.2 expression. Conclusions: Rats with RF-induced CHF exhibit pronounced atrial structural remodeling and enhanced AF vulnerability. This model may be useful for studying AF substrate in CHF. (C) 2018 The Authors. Published by Elsevier B.V. (AU)

• Processo FAPESP: 13/23725-0 - Avaliação celular, eletrofisiológica e molecular do remodelamento atrial em ratos com insuficiência cardíaca induzida pela ablação por radiofrequência: impacto nos mecanismos da fibrilação atrial
• Beneficiário: Luís Felipe Neves dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/23553-5 - Avaliação celular, eletrofisiológica e molecular do remodelamento atrial em ratos com insuficiência cardíaca induzida pela ablação por radiofrequência: impacto nos mecanismos da fibrilação atrial
• Beneficiário: Guilherme Drummond Fenelon Costa
• Modalidade de apoio: Auxílio à Pesquisa - Regular