Previously presented at the 26th Annual Forum of the ACVIM, San Antonio, TX, June 4–7, 2008.†
Left Ventricular Radial and Circumferential Wall Motion Analysis in Horses Using Strain, Strain Rate, and Displacement by 2D Speckle Tracking
Article first published online: 1 JUN 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 23, Issue 4, pages 890–900, July/August 2009
How to Cite
Schwarzwald, C.C., Schober, K.E., Berli, A.-S.J. and Bonagura, J.D. (2009), Left Ventricular Radial and Circumferential Wall Motion Analysis in Horses Using Strain, Strain Rate, and Displacement by 2D Speckle Tracking. Journal of Veterinary Internal Medicine, 23: 890–900. doi: 10.1111/j.1939-1676.2009.0321.x
- Issue published online: 26 JUN 2009
- Article first published online: 1 JUN 2009
- Submitted November 13, 2008; Revised March 8, 2009; Accepted March 19, 2009
- Radiology and diagnostic imaging;
Background: Noninvasive assessment of left-ventricular (LV) function is clinically relevant, but is incompletely studied in horses.
Objectives: To document the feasibility, describe the techniques, and determine the reliability of 2D speckle tracking (2DST) for characterization of LV radial and circumferential wall motion in horses.
Animals: Three Standardbreds, 3 Thoroughbreds; age 8–14 years; body weight 517–606 kg.
Methods: Observational study. Repeated 2-dimensional echocardiographic examinations were performed in unsedated horses by 2 observers and subsequently analyzed by 2DST. Test reliability was determined for segmental and for averaged 2DST indices (including strain, strain rate, displacement, and rotation) by estimating measurement variability, within-day interobserver variability, between-day interobserver variability, and between-day intraobserver variability. Variability was expressed as coefficient of variation (percent) and the absolute value below which the difference between 2 measurements will lie with 95% probability.
Results: 2DST analyses were feasible in 16 of 18 echocardiographic studies. The automated tracking was accurate during systole but inaccurate during diastole. Reliability was higher for radial compared to circumferential measurements. For radial strain, radial systolic strain rate, and radial systolic displacement, the test-retest variabilities ranged between 2.4 and 33.1% for segmental and between 4.1 and 16.1% for averaged measurements.
Conclusions and Clinical Importance: Systolic radial motion of the LV at the chordal level could be reliably characterized in horses by 2DST. Circumferential measurements were less reliable. Diastolic measurements were invalid because of inaccurate tracking. The clinical value of LV wall motion analysis by 2DST in horses requires further investigation.