Abstract
Background : Two-dimensional speckle tracking (2DST) technique has been validated in numerous animal species, but neither studies of repeatability, nor measurements after exercise or in animals with cardiac disease have been reported in goats. Therefore, the aim of this study was to validate this technique in goats for further clinical and experimental applications in this species. This study was divided into several steps. First, a standardized echocardiographic protocol including several right parasternal short-axis views at papillary muscles level was performed three times at one-day intervals in ten healthy adult unsedated Saanen goats to test repeatability and variability of 2DST measurements. Then, the same measurements were performed immediately before and after a standardized exercise on treadmill in seven of the goats, and at 24h after induction of an experimental ischemic cardiomyopathy in five of the goats, to test the reliability of the technique to assess physiological and pathological changes.
Results: Global and regional measurements of radial and circumferential strain and strain rate, radial displacement, rotation and rotation rate were obtained. Comparisons were performed using ANOVA II (p<0.05). Caprine 2DST measurements demonstrated a good repeatability for global measurements except for the late diastolic peak of the circumferential and radial strain rate. Segmental 2DST measurements were also repeatable except for the anteroseptal segment diastolic peaks and several rotation and rotation rate measurements. Overall variability was moderate to high. Segmental and global peak values obtained after exercise and after myocardial ischemia were significantly different than curves obtained at baseline.
Conclusions: The results of this study are consistent with those previously described in other animal species and humans. 2DST echocardiography is a valid technique to evaluate physiological and pathological changes in myocardial function in goats, despite the technical limitations observed in this species.
Two-dimensional strain and strain rate imaging of the right ventricle in adult patients before and after percutaneous closure of atrial septal defects
