Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Outros Autores: | , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.17/272 |
Resumo: | INTRODUCTION: Vagal activity is thought to influence atrial electrophysiological properties and play a role in the initiation and maintenance of atrial fibrillation (AF). In this study, we assessed the effects of acute vagal stimulation (vagus_stim) on atrial conduction times, atrial and pulmonary vein (PV) refractoriness, and vulnerability to induction of AF in the rabbit heart with intact autonomic innervation. METHODS: An open-chest epicardial approach was performed in 11 rabbits (New Zealand; 3.9-5.0 kg), anesthetized and artificially ventilated after neuromuscular blockade. A 3-lead ECG was obtained. Atrial electrograms were recorded along the atria, from right to left (four monopolar electrodes), together with a circular electrode adapted for proximal left PV assessment. Acute vagus nerve stimulation was obtained with bipolar electrodes (20 Hz). Epicardial activation was recorded in sinus rhythm, and the conduction time from right (RA) to left atrium (LA), and from RA to PVs, was measured in basal conditions and during vagus_stim. The atrial effective refractory period (ERP) and dispersion of refractoriness (Disp_A) were analyzed. Vulnerability to AF induction was assessed at the right (RAA) and left (LAA) atrial appendages and the PVs. Atrial stimulation (50 Hz) was performed alone or combined with vagus_stim. Heart rate and blood pressure were monitored. RESULTS: In basal conditions, there was a significant delay in conduction from RA to PVs, not influenced by vagus_stim, and the PV ERPs were shorter than those measured in LA and LAA, but without significant differences compared to RA and RAA. During vagus_stim, conduction times between RA and LA increased from 16+8 ms to 27+6 ms (p < 0.05) and ERPs shortened significantly in RA, LAA and LA (p < 0.05), but not in RAA. There were no significant differences in Disp_A. AF induction was reproducible in 45% of cases at 50 Hz and in 100% at 50 Hz+vagus_stim (p < 0.05). The duration of inducible AF increased from 1.0 +/- 0.2 s to 12.0 +/- 4.5 s with 50 Hz+vagus_stim (p < 0.01). AF lasted >10 s in 45.4% of rabbits during vagus_stim, and ceased after vagus_stim in 4 out of these 5 cases. In 3 animals, PV tachycardia, with fibrillatory conduction, induced with 50 Hz PV pacing during vagus_stim. CONCLUSIONS: Vagus_stim reduces interatrial conduction velocity and significantly shortens atrial ERP, contributing to the induction and duration of AF episodes in the in vivo rabbit heart. This model may be useful for the assessment of autonomic influence on the pathophysiology of AF. |
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Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in VivoEffects of Vagal Stimulation on Induction and Termination of Atrial Fibrillation in an in Vivo Rabbit Heart ModelFibrilhação AuricularModelos Animais de DoençasCoelhosEstimulação do Nervo VagoINTRODUCTION: Vagal activity is thought to influence atrial electrophysiological properties and play a role in the initiation and maintenance of atrial fibrillation (AF). In this study, we assessed the effects of acute vagal stimulation (vagus_stim) on atrial conduction times, atrial and pulmonary vein (PV) refractoriness, and vulnerability to induction of AF in the rabbit heart with intact autonomic innervation. METHODS: An open-chest epicardial approach was performed in 11 rabbits (New Zealand; 3.9-5.0 kg), anesthetized and artificially ventilated after neuromuscular blockade. A 3-lead ECG was obtained. Atrial electrograms were recorded along the atria, from right to left (four monopolar electrodes), together with a circular electrode adapted for proximal left PV assessment. Acute vagus nerve stimulation was obtained with bipolar electrodes (20 Hz). Epicardial activation was recorded in sinus rhythm, and the conduction time from right (RA) to left atrium (LA), and from RA to PVs, was measured in basal conditions and during vagus_stim. The atrial effective refractory period (ERP) and dispersion of refractoriness (Disp_A) were analyzed. Vulnerability to AF induction was assessed at the right (RAA) and left (LAA) atrial appendages and the PVs. Atrial stimulation (50 Hz) was performed alone or combined with vagus_stim. Heart rate and blood pressure were monitored. RESULTS: In basal conditions, there was a significant delay in conduction from RA to PVs, not influenced by vagus_stim, and the PV ERPs were shorter than those measured in LA and LAA, but without significant differences compared to RA and RAA. During vagus_stim, conduction times between RA and LA increased from 16+8 ms to 27+6 ms (p < 0.05) and ERPs shortened significantly in RA, LAA and LA (p < 0.05), but not in RAA. There were no significant differences in Disp_A. AF induction was reproducible in 45% of cases at 50 Hz and in 100% at 50 Hz+vagus_stim (p < 0.05). The duration of inducible AF increased from 1.0 +/- 0.2 s to 12.0 +/- 4.5 s with 50 Hz+vagus_stim (p < 0.01). AF lasted >10 s in 45.4% of rabbits during vagus_stim, and ceased after vagus_stim in 4 out of these 5 cases. In 3 animals, PV tachycardia, with fibrillatory conduction, induced with 50 Hz PV pacing during vagus_stim. CONCLUSIONS: Vagus_stim reduces interatrial conduction velocity and significantly shortens atrial ERP, contributing to the induction and duration of AF episodes in the in vivo rabbit heart. This model may be useful for the assessment of autonomic influence on the pathophysiology of AF.Sociedade Portuguesa de CardiologiaRepositório do Centro Hospitalar Universitário de Lisboa Central, EPEOliveira, MMNogueira da Silva, MGeraldes, VPostolache, GXavier, RLaranjo, SRocha, ICruz Ferreira, RSilva-Carvalho, L2011-06-22T11:19:45Z20102010-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.17/272porRev Port Cardiol. 2010 Mar;29(3):375-89info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-03-10T09:26:13Zoai:repositorio.chlc.min-saude.pt:10400.17/272Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T17:18:07.559437Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo Effects of Vagal Stimulation on Induction and Termination of Atrial Fibrillation in an in Vivo Rabbit Heart Model |
title |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo |
spellingShingle |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo Oliveira, MM Fibrilhação Auricular Modelos Animais de Doenças Coelhos Estimulação do Nervo Vago |
title_short |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo |
title_full |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo |
title_fullStr |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo |
title_full_unstemmed |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo |
title_sort |
Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo |
author |
Oliveira, MM |
author_facet |
Oliveira, MM Nogueira da Silva, M Geraldes, V Postolache, G Xavier, R Laranjo, S Rocha, I Cruz Ferreira, R Silva-Carvalho, L |
author_role |
author |
author2 |
Nogueira da Silva, M Geraldes, V Postolache, G Xavier, R Laranjo, S Rocha, I Cruz Ferreira, R Silva-Carvalho, L |
author2_role |
author author author author author author author author |
dc.contributor.none.fl_str_mv |
Repositório do Centro Hospitalar Universitário de Lisboa Central, EPE |
dc.contributor.author.fl_str_mv |
Oliveira, MM Nogueira da Silva, M Geraldes, V Postolache, G Xavier, R Laranjo, S Rocha, I Cruz Ferreira, R Silva-Carvalho, L |
dc.subject.por.fl_str_mv |
Fibrilhação Auricular Modelos Animais de Doenças Coelhos Estimulação do Nervo Vago |
topic |
Fibrilhação Auricular Modelos Animais de Doenças Coelhos Estimulação do Nervo Vago |
description |
INTRODUCTION: Vagal activity is thought to influence atrial electrophysiological properties and play a role in the initiation and maintenance of atrial fibrillation (AF). In this study, we assessed the effects of acute vagal stimulation (vagus_stim) on atrial conduction times, atrial and pulmonary vein (PV) refractoriness, and vulnerability to induction of AF in the rabbit heart with intact autonomic innervation. METHODS: An open-chest epicardial approach was performed in 11 rabbits (New Zealand; 3.9-5.0 kg), anesthetized and artificially ventilated after neuromuscular blockade. A 3-lead ECG was obtained. Atrial electrograms were recorded along the atria, from right to left (four monopolar electrodes), together with a circular electrode adapted for proximal left PV assessment. Acute vagus nerve stimulation was obtained with bipolar electrodes (20 Hz). Epicardial activation was recorded in sinus rhythm, and the conduction time from right (RA) to left atrium (LA), and from RA to PVs, was measured in basal conditions and during vagus_stim. The atrial effective refractory period (ERP) and dispersion of refractoriness (Disp_A) were analyzed. Vulnerability to AF induction was assessed at the right (RAA) and left (LAA) atrial appendages and the PVs. Atrial stimulation (50 Hz) was performed alone or combined with vagus_stim. Heart rate and blood pressure were monitored. RESULTS: In basal conditions, there was a significant delay in conduction from RA to PVs, not influenced by vagus_stim, and the PV ERPs were shorter than those measured in LA and LAA, but without significant differences compared to RA and RAA. During vagus_stim, conduction times between RA and LA increased from 16+8 ms to 27+6 ms (p < 0.05) and ERPs shortened significantly in RA, LAA and LA (p < 0.05), but not in RAA. There were no significant differences in Disp_A. AF induction was reproducible in 45% of cases at 50 Hz and in 100% at 50 Hz+vagus_stim (p < 0.05). The duration of inducible AF increased from 1.0 +/- 0.2 s to 12.0 +/- 4.5 s with 50 Hz+vagus_stim (p < 0.01). AF lasted >10 s in 45.4% of rabbits during vagus_stim, and ceased after vagus_stim in 4 out of these 5 cases. In 3 animals, PV tachycardia, with fibrillatory conduction, induced with 50 Hz PV pacing during vagus_stim. CONCLUSIONS: Vagus_stim reduces interatrial conduction velocity and significantly shortens atrial ERP, contributing to the induction and duration of AF episodes in the in vivo rabbit heart. This model may be useful for the assessment of autonomic influence on the pathophysiology of AF. |
publishDate |
2010 |
dc.date.none.fl_str_mv |
2010 2010-01-01T00:00:00Z 2011-06-22T11:19:45Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.17/272 |
url |
http://hdl.handle.net/10400.17/272 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
Rev Port Cardiol. 2010 Mar;29(3):375-89 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Sociedade Portuguesa de Cardiologia |
publisher.none.fl_str_mv |
Sociedade Portuguesa de Cardiologia |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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