Abstract:
Hypertrophic cardiomyopathy (HCM) is one of the most common myocardial diseases in cats. The left atrial (LA) function plays an essential role in compensatory mechanism of left ventricle with diastolic dysfunction to maintain cardiac output in cats affected with HCM. Nowadays, there are several echocardiographic techniques used to evaluate the left atrial function; however, each technique has limitations. To overcome the limitations, two-dimensional speckle tracking echocardiography (2D-STE) is a novel technique for assessment the LA function. To date, no study focusing on assessment of the left atrial function by 2D-STE in feline HCM has been reported. The objective of this study was to evaluate changes in LA function in HCM cats compared to normal cats by using 2D-STE. Twenty healthy control cats and seventeen client-owned cats affected with HCM were included in this study. The intra-observer and inter-observer measurement variability of peak atrial longitudinal strain (PALS) were 4.17% and 14%, respectively. The mean value and standard deviation of PALS in the HCM group (13.16 ± 8.64%) was lower than those of the control group (28.54 ±10.31%) (p < 0.001). The atrial longitudinal strain of septal and lateral regions was significantly reduced in the HCM group compared to the normal group. The atrial longitudinal strain was lowest at the LA roof region. The PALS correlated with the percentage of fractional shortening of the LA (LA-FS) (r=0.538, p=0.001), the percentage of the LA ejection fraction (LA-EF) (r =0.797, p<0.001), and the LA fractional area change (FAC) (r =0.746, p<0.001). In conclusion, the PALS can be used to evaluate changes in LA function in HCM cats. It is a reproducibility method for assessing the LA function in cats affected with HCM.
