RESUMO
OBJECTIVES: To evaluate endomyocardial and epimyocardial left ventricular circumferential and longitudinal peak systolic strain and strain rate in dogs with myxomatous mitral valve disease using two-dimensional feature tracking imaging echocardiography. MATERIALS AND METHODS: Epimyocardial and endomyocardial global and regional myocardial peak systolic strain and strain rate using two-dimensional feature tracking imaging were evaluated in healthy dogs and those in stages B1, B2 and C of myxomatous mitral valve disease. Strain and strain rate in circumferential and longitudinal aspect were evaluated in 48 small- and medium-sized dogs. RESULTS: Global endomyocardial circumferential strain and global epimyocardial circumferential strain systolic peak were lower in stage C than in stage B2 (P = 0 · 04 and P = 0 · 02) and similar to healthy dogs. Endomyocardial circumferential strain rate in septal and inferior segments were lower in stage C compared to B2 (P = 0 · 0007 and P = 0 · 0056), but not different from healthy dogs. There were no statistical differences in the epimyocardial circumferential strain rate, longitudinal strain and strain rate between healthy and affected dogs. CLINICAL SIGNIFICANCE: Two-dimensional feature tracking imaging determination of myocardial deformation in epimyocardial and endomyocardial layers allows detection of increased compensatory circumferential left ventricular myocardial systolic performance due to volume overload and absence of this response as disease advances to congestive heart failure.
Assuntos
Doenças do Cão/diagnóstico por imagem , Prolapso da Valva Mitral/veterinária , Ultrassonografia Doppler em Cores/veterinária , Animais , Estudos de Casos e Controles , Cães , Feminino , Masculino , Prolapso da Valva Mitral/diagnóstico por imagem , Valor Preditivo dos Testes , Sístole , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Avaliaram-se os aspectos ecocardiográficos da doença valvar crônica, comparando-os com os aspectos clínicos, radiográficos e eletrocardiográficos em cães. Estudaram-se 70 animais, realizando-se exames físicos, radiografias torácicas, eletrocardiograma e ecocardiograma. Observaram-se correlações entre a gravidade da regurgitação, a classe funcional da insuficiência cardíaca e a intensidade de sopro. O eletrocardiograma mostrou baixa sensibilidade para detectar aumento de câmaras cardíacas causadas por regurgitação mitral. Todos os cães com regurgitação mitral grave apresentaram cardiomegalia nas radiografias torácicas.
