Avaliação da deformação miocárdica pela ecocardiografia feature tracking em gatos com defeito perimembranoso do septo ventricular

Abstract

The development of new tools, such as two-dimensional feature tracking (2D-FTI), allows early diagnosis of myocardial dysfunction in heart diseases including congenital heart disease. The ventricular septal defect (VSD) is the most frequently observed congenital abnormality in cats, however, little is known about cardiac dysfunction, especially in asymptomatic animals. The objective of this study was to evaluate the left ventricular myocardial deformation through 2D-FTI by the measurement of the radial, circumferential and longitudinal echocardiographic strain (St) and strain rate (StR) indices. Twelve healthy cats and six cats with VSD were evaluated to obtain St and StR in several myocardial segments. In the longitudinal direction, there was a statistical difference (P<0.05) for the epimyocardial basal septal, mid-septal, apical septal (P=0.0017; P<0.0001; P=0.0288), epimyocardial mid-lateral (P=0.0327), endomyocardial mid-septal (P=0.0035), endomyocardial mid-lateral (P=0.0461), St epimyocardial (P=0.0250) and St global (P=0.0382). There was also difference in the circumferential endomyocardial mid-lateral segment (P=0.0248), radial mid-lateral (St: P=0.0409; StR: P=0.0166) and radial mid-posterior (P=0.0369). The study showed that even in asymptomatic animals with VSD there is a reduction in ventricular myocardial deformation mainly in the longitudinal direction, demonstrating the fragility of these fibers.