TWO-DIMENSIONAL SPECKLE TRACKING ECHOCARDIOGRAPHY IN CALVES: FEASIBILITY, REPEATABILITY AND VARIABILITY STUDY

Two-dimensional speckle tracking (2DST) is a non-invasive technique used in many species to evaluate global and regional left ventricular (LV) function; however it received little attention in the bovine species. The aim of this study was to assess the feasibility and reliability of 2DST for the evaluation of circumferential and radial LV wall motions in calves. Fourteen Holstein black calves (age: 62 11.6 days; body weight: 75.25 5.4 kg) were used in this observational study. Right parasternal short axis views at the level of the papillary muscles were recorded and subsequently analysed by 2DST for global and regional radial and circumferential strains and strain rates, radial displacement, rotation and rotation rate. Echocardiographic examinations were performed in unsedated, standing calves by two different observers to evaluate intra- and interobserver repeatability and variability. 2DST was feasible in all calves but 2 were excluded from analyses (ventricular septum defect and resting heart rate above 120 bpm, respectively). Automated tracking was better in systole than in diastole. Intraobserver repeatability was good to moderate for most systolic global and segmental peak values. Systolic peak values for radial strain and strain rate were more repeatable than for circumferential strain, circumferential train rate and diastolic measurements. Variability of the interobserver measurements was greater than the intraobserver measurements. Two-dimensional speckle tracking is feasible in calves and as in other species systolic radial function can be more reliably evaluated than circumferential and diastolic function.