Quantification of left ventricular diastolic wall motion by Doppler tissueimaging in healthy cats and cats with cardiomyopathy

Objective-To assess Doppler tissue imaging (DTI) for evaluating left ventri cular diastolic wall motion in healthy cats and cats with cardiomyopathy. Animals-20 healthy cats, 9 cats with hypertrophic cardiomyopathy (HCM), and 9 cats with unclassified cardiomyopathy (UCM). Procedure-A pulsed wave DTI sample gate was positioned at a subendocardial region of the left ventricular free wall in the short axis view and at the lateral mitral annulus in the apical 4-chamber view. Indices of diastolic w all motion were measured, including peak diastolic velocity (PDV), mean rat e of acceleration and deceleration of the maximal diastolic waveform (MDWac cel and MDWdecel, respectively), and isovolumetric relaxation time (IVRT). Results-The PDV of cats with HCM and 6 of 9 cats with UCM was significantly decreased, compared with that of healthy cats. In the 3 cats with UCM that had a PDV that was not different from healthy cats, MDWaccel and MDWdecel were greater, and IVRT was shorter than those of healthy cats. The IVRT in cats with HCM was longer than that of other cats. Conclusions and Clinical Relevance-Indices of diastolic function in cats wi th HCM, and in many cats with UCM, differed from those of healthy cats and were similar to those reported in humans with HCM and restrictive cardiomyo pathy, respectively. However, the hemodynamic abnormality was not the same for all cats with UCM; some cats with an enlarged left atrium and a normal left ventricle (ie, UCM) had abnormal left ventricular wall motion consiste nt with restrictive cardiomyopathy while others did not.