Assessment of left atrial function in cats with arterial thromboembolism by using two-dimensional speckle tracking echocardiography

Feline arterial thromboembolism (ATE) is an acute and distressing clinical presentation with high mortality and poor prognosis. ATE may be related to cardiogenic causes such as the underlying myocardial disease or non-cardiogenic causes. Echocardiography is the routine diagnostic tool to evaluate cardiac structural changes and myocardial function in cats. Two-dimensional speckle tracking echocardiography (2D-STE) is a novel ultrasound modality based on 2D echocardiographic images, that allows multidirectional active deformation assessment and provides comprehensive information on myocardial contractile properties and function. 2D-STE echocardiography has been used to estimate the strain and strain rate of left atrial myocardial deformation in humans, dogs and cats with HCM, but there has been no study in cats with ATE. The objective of this study was to investigate left atrial myocardial deformation in cats with ATE and normal cats using 2D-STE. This study included twenty-three normal cats and twenty-one ATE cats diagnosed with fifteen cardiogenic ATE and six non-cardiogenic ATE. The left atrial stain and stain rate were significantly decreased in cats with cardiogenic ATE compared with the normal group (p<0.001), but no significant difference between the non-cardiogenic ATE and normal groups. From the correlation test, the use of left atrial stain during the reservoir phase assessed by 2D-STE could represent the overall LA deformation. In addition, the intra- and inter-observer coefficient of variation was acceptable for LASr. From the logistic regression, the LASr value of less than 11% was a significant factor for the occurrence of ATE, with a crude odds ratio of 189.0 (95%CI: 15.73-2,269.86, p-value<0.001). In conclusion, the left atrial longitudinal strain of reservoir phase derived by 2D-STE is a repeatable and non-invasive technique to assess LA myocardial deformation in cats with ATE. By 2D-STE, impaired LA function was detected in cats with cardiogenic ATE, but not in cats with non-cardiogenic ATE. LASr <11% could predict the risk of occurrence of ATE in the cat population.