Determination of multidirectional myocardial deformations in cats with hypertrophic cardiomyopathy by using two-dimensional speckle-tracking echocardiography

Objectives Hypertrophic cardiomyopathy, a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of myocardial deformation with two-dimensional speckle-tracking echocardiography in cats with various stages of hypertrophic cardiomyopathy has not yet been reported. This study was designed to measure quantitatively multidirectional myocardial deformations of cats with hypertrophic cardiomyopathy. Methods Thirty-two client-owned cats with hypertrophic cardiomyopathy and 14 healthy cats serving as controls were enrolled and underwent assessment of myocardial deformation (peak systolic strain and strain rate) in the longitudinal, radial and circumferential directions. Results Longitudinal and radial deformations were reduced in cats with hypertrophic cardiomyopathy, despite normal systolic function determined by conventional echocardiography. Cats with severely symptomatic hypertrophic cardiomyopathy also had lower peak systolic circumferential strain, in addition to longitudinal and radial strain. Conclusions and relevance Longitudinal and radial deformation may be helpful in the diagnosis of hypertrophic cardiomyopathy. Additionally, the lower circumferential deformation in cats with severe hypertrophic cardiomyopathy may contribute to clinical findings of decompensation, and seems to be related to severe cardiac clinical signs. Indices of multidirectional myocardial deformations by two-dimensional speckle-tracking echocardiography may be useful markers and help to distinguish between cats with hypertrophic cardiomyopathy and healthy cats. Additionally, they may provide more detailed assessment of contractile function in cats with hypertrophic cardiomyopathy.