Comparative Study of Speckle Tracking Echocardiography in Normal and Hypertrophic Cardiomyopathy Cats

Background: Speckle tracking echocardiography (STE) is a well-established tool in human cardiology for detecting subtle myocardial dysfunction using strain indices. In cats with hypertrophic cardiomyopathy (HCM), STE has been applied in several studies and has identified myocardial deformation abnormalities. This study aimed to identify sensitive echocardiographic markers of myocardial dysfunction in cats with HCM by comparing global strain and strain rate parameters with those of healthy cats. Methods: Sixty cats were examined, including 31 healthy controls and 29 HCM-affected cats. Echocardiographic assessments included global circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS), their corresponding strain rates (GCSR, GRSR, and GLSR), left atrial ejection fraction (LAEF), and atrial reservoir strain (RS). Results: GLS and GRS were significantly lower in HCM cats than in controls, while GCS showed no significant difference. Among strain rate parameters, only GRSR was significantly reduced in the HCM group. Additionally, both LAEF and RS were markedly decreased, suggesting atrial dysfunction associated with HCM. Conclusions: These findings indicate that GLS and GRS are reliable indicators of left ventricular dysfunction in feline HCM and that GRSR may offer additional insight into myocardial deformation dynamics. Overall, STE provides a useful, non-invasive tool for improving the diagnosis and clinical evaluation of feline HCM.