Equine Clinic, Department of Companion Animals and Equids, Faculty of Veterinary Medicine, University of Liege, Boulevard de Colonster 20, Bât B41, Liege, Sart Tilman, Belgium.
Present address: Oniris, 102 Route de Gachet, 44307, Nantes, cedex 3, France.
BMC Vet Res. 2020 Feb 14;16(1):56. doi: 10.1186/s12917-020-02277-8.
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. Goats are an attractive candidate for animal models in human cardiology because they are easy to handle and have a body and heart size comparable to that of humans. 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 was performed and 5 cineloops of a right parasternal short-axis view at papillary muscles level were recorded 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 24 h 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. Average and regional measurements of radial and circumferential strain and strain rate, radial displacement, rotation and rotation rate were obtained. Comparisons were performed using two-way ANOVA (p < 0.05). Caprine 2DST average measurements have demonstrated a good repeatability with a low to moderate variability for all measurements except for the diastolic peaks of the circumferential strain rate, radial strain rate and rotation rate. Segmental 2DST measurements were less repeatable than average measurements. Time effect of two-way ANOVA was significant for anteroseptal segment diastolic peaks measurements, rotation and rotation rate measurements. Overall variability of segmental measurements was moderate or high. Segmental and average peak values obtained after exercise and after myocardial ischemia were significantly different than curves obtained at baseline.
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.
二维斑点追踪（2DST）技术已在许多动物物种中得到验证，但尚未有关于重复性的研究或关于运动后或在患有心脏病的动物中的测量结果的报道。山羊是人类心脏病学动物模型的理想候选者，因为它们易于处理，且身体和心脏大小与人类相当。因此，本研究的目的是在山羊中验证该技术，以便在该物种中进一步进行临床和实验应用。
本研究分为几个步骤。首先，进行了标准化的超声心动图方案，在 10 只健康成年未镇静的 Saanen 山羊中，在一天的间隔内记录三次右胸骨旁短轴乳头肌水平的 5 个 cineloops，以测试 2DST 测量的重复性和可变性。然后，在其中 7 只山羊进行标准化跑步机运动前后，以及在其中 5 只山羊诱导实验性缺血性心肌病后 24 小时，立即进行相同的测量，以测试该技术评估生理和病理变化的可靠性。获得了径向和圆周应变和应变率、径向位移、旋转和旋转率的平均和区域测量值。使用双因素方差分析进行比较（p<0.05）。除了圆周应变率、径向应变率和旋转率的舒张峰外，所有测量值的 2DST 平均测量值均表现出良好的重复性，变异性低至中度。节段性 2DST 测量值的重复性不如平均值测量值。双因素方差分析的时间效应对前间隔舒张峰测量值、旋转和旋转率测量值有显著影响。节段性测量值的整体变异性为中度或高度。运动后和心肌缺血后获得的节段和平均峰值与基线时获得的曲线明显不同。
本研究的结果与其他动物物种和人类中先前描述的结果一致。尽管在该物种中观察到技术限制，但 2DST 超声心动图是评估山羊心肌功能生理和病理变化的有效技术。
