Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Circ Res ; 94(11): 1458-65, 2004 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-15117823

RESUMO

Studies on patients and large animal models suggest the importance of atrial fibrosis in the development of atrial fibrillation (AF). To investigate whether increased fibrosis is sufficient to produce a substrate for AF, we have studied cardiac electrophysiology (EP) and inducibility of atrial arrhythmias in MHC-TGFcys33ser transgenic mice (Tx), which have increased fibrosis in the atrium but not in the ventricles. In anesthetized mice, wild-type (Wt) and Tx did not show significant differences in surface ECG parameters. With transesophageal atrial pacing, no significant differences were observed in EP parameters, except for a significant decrease in corrected sinus node recovery time in Tx mice. Burst pacing induced AF in 14 of 29 Tx mice, whereas AF was not induced in Wt littermates (P<0.01). In Langendorff perfused hearts, atrial conduction was studied using a 16-electrode array. Epicardial conduction velocity was significantly decreased in the Tx RA compared with the Wt RA. In the Tx LA, conduction velocity was not significantly different from Wt, but conduction was more heterogeneous. Action potential characteristics recorded with intracellular microelectrodes did not reveal differences between Wt and Tx mice in either atrium. Thus, in this transgenic mouse model, selective atrial fibrosis is sufficient to increase AF inducibility.


Assuntos
Fibrilação Atrial/genética , Átrios do Coração/patologia , Sistema de Condução Cardíaco/fisiopatologia , Fator de Crescimento Transformador beta/fisiologia , Potenciais de Ação , Substituição de Aminoácidos , Animais , Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Estimulação Cardíaca Artificial , Eletrocardiografia , Fibrose , Predisposição Genética para Doença , Camundongos , Camundongos Transgênicos , Modelos Animais , Fator de Crescimento Transformador beta/química , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta1
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA