Evolução das modificações morfo-funcionais cardíacas no processo de adaptação crônica à insuficiência aórtica aguda experimental em ratos
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Data
2011-02-10
Autores
Roscani, Meliza Goi [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A adaptação cardíaca à insuficiência aórtica resulta em hipertrofia excêntrica seguida de disfunção ventricular e insuficiência cardíaca. A evolução desse processo ainda não é bem compreendida. Avaliar a adaptação cardíaca à insuficiência aórtica aguda experimental por meio de ecocardiografia, identificar os marcadores anatâmicos de transição da hipertrofia excêntrica compensada para a fase descompensada e verificar se existe associação entre marcadores anatâmicos e de disfunção ventricular e fibrose miocárdica. Estudo experimental com 35 ratos Wistar machos, 23 animais submetidos à insuficiência aórtica aguda (grupo IAO) e 12 animais a procedimento simulado (Grupo Controle). Todos os animais foram seguidos com ecocardiogramas seriados com 1, 4, 8 e 16 semanas. No término do protocolo, foi realizada mortometria do tecido cardíaco. A análise estatística foi efetuada por meio do teste t de Student, Mann-Whitney, ANOVA de medidas repetidas, Modelo de Regressão Longitudinal (GEE) e Modelo de Regressão Linear simples e múltipla. Em todos os casos, o nível de significância adotado foi p<O,05. Houve interação entre tempo e insuficiência aórtica para aumentar o diâmetro diastólico do ventrículo esquerdo (DDVE, p<O,001), a área normalizada do átrio esquerdo (AAE(AAD, p==O,0011) e índice de esfericidade (I(L, p<O,001) e diminuir a do ventrículo esquerdo (pp (DDVE, p=O,009) e a porcentagem de encurtamento (%E, p<O,001). Comparativamente à semana 1, o aumento do l(L na semana 4 (0,72±O,10 vs. O,65±O,60; p<O,001) ocorreu anteriormente ao aumento do DDVE (9,OO±1,30 mm vs. 7,60±O,63 mm; p<O,05), observado na semana 8. Também precedeu o aumento da AAE(AAD (1,59±O,35 vs. 1,45±O,20; p<O,05) e a redução da PP(DDVE (O,18±O,04 vs. O,20±O,02; p=O,003), observados na semana 16. Houve interação entre tempo e I(L para reduzir a %E (p<O,001)...
To evaluate the cardiac adaptation to experimental acute aortic regurgitation by echocardiography, to identify the anatomical markers of the transition from compensated eccentric hypertrophy to decompensated stage and to investigate the association between anatomical markers of ventricular dysfunction and myocardial flbrosis. Thirty flve Male Wistar rats underwent surgical procedure for inducing acute aorta regurgitation (AR group, n= 23) or sham operation (SH group, n= 12). Transthoracic echocardiograms were performed at 1, 4, 8 and 16 weeks after procedure. At the end of the protocol, morphometry of the heart tissue was performed. Statistical analyses used t test, Mann-Whitney, repeated measures ANOVA, GEE model (General Estimative Equation, STATA 10.0), linear regression model and multiple linear regression. In ali cases, the levei of significance was p <0.05. There were interactions between time and AR for increasing left ventricle diastolic diameter (LVDD, p<0.0011), normalized left atrium area (LAA, p=0.0011) and sphericity index (SI, p<0.0011), and for decreasing relative wall thickness (RWT, p=0.002) and fractional shortening (F5, p<0.001). Compared to week 1, the increased SI at week 4 (0.72±0.10 vs. 0.65±0.60; p<0.001) preceded the LVDD enlargement (9.00±1.30mm vs. 7.60±0.63mm; p<0.05) and LAA increasing (1.59±0.35 vs. 1.45±0.20; p<0.05) observed at week 8 and RWT decreasing observed at week 16 (O.18±0.04 vs. 0.20±0.02; p=0.003). There was an interaction between time and SI for reducing F5 (p<0.001). LV systolic dysfunction was detected at week 8 and preceded LAA enlargement at week 16. This suggested increased LV diastolic pressure and it was coincident with the decreased RWT indicating LV dilation
To evaluate the cardiac adaptation to experimental acute aortic regurgitation by echocardiography, to identify the anatomical markers of the transition from compensated eccentric hypertrophy to decompensated stage and to investigate the association between anatomical markers of ventricular dysfunction and myocardial flbrosis. Thirty flve Male Wistar rats underwent surgical procedure for inducing acute aorta regurgitation (AR group, n= 23) or sham operation (SH group, n= 12). Transthoracic echocardiograms were performed at 1, 4, 8 and 16 weeks after procedure. At the end of the protocol, morphometry of the heart tissue was performed. Statistical analyses used t test, Mann-Whitney, repeated measures ANOVA, GEE model (General Estimative Equation, STATA 10.0), linear regression model and multiple linear regression. In ali cases, the levei of significance was p <0.05. There were interactions between time and AR for increasing left ventricle diastolic diameter (LVDD, p<0.0011), normalized left atrium area (LAA, p=0.0011) and sphericity index (SI, p<0.0011), and for decreasing relative wall thickness (RWT, p=0.002) and fractional shortening (F5, p<0.001). Compared to week 1, the increased SI at week 4 (0.72±0.10 vs. 0.65±0.60; p<0.001) preceded the LVDD enlargement (9.00±1.30mm vs. 7.60±0.63mm; p<0.05) and LAA increasing (1.59±0.35 vs. 1.45±0.20; p<0.05) observed at week 8 and RWT decreasing observed at week 16 (O.18±0.04 vs. 0.20±0.02; p=0.003). There was an interaction between time and SI for reducing F5 (p<0.001). LV systolic dysfunction was detected at week 8 and preceded LAA enlargement at week 16. This suggested increased LV diastolic pressure and it was coincident with the decreased RWT indicating LV dilation
Descrição
Palavras-chave
Insuficiencia cardiaca - Estudos experimentais, Percussão, Heart failure
Como citar
ROSCANI, Meliza Goi. Evolução das modificações morfo-funcionais cardíacas no processo de adaptação crônica à insuficiência aórtica aguda experimental em ratos. 2011. 52 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2011.