Speckle tracking echocardiography in cats with preclinical hypertrophic cardiomyopathy

Abstract

Background: Cats with hypertrophic cardiomyopathy (HCM) have decreased left ventricular (LV) longitudinal deformation detected by mitral annular plane systolic excursion (MAPSE) and speckle tracking echocardiography. People with preclinical HCM have decreased systolic LV longitudinal and radial strain (S) and strain rate (SR), with preserved circumferential S and SR.

Hypothesis/objectives: Cats with preclinical HCM have decreased systolic LV deformation compared to normal cats.

Animals: Seventy-three client-owned cats with (n = 37) and without (n = 36) preclinical HCM.

Methods: Retrospective echocardiographic study. Left and right ventricular longitudinal S and SR, LV radial and circumferential S and SR were calculated by STE. Left ventricular mass was also calculated. Correlation between STE variables and LV hypertrophy was determined and receiver-operating characteristic (ROC) curves were plotted for prediction of HCM.

Results: Cats with HCM had smaller absolute longitudinal S (-14.8 ± 3.3% vs -19.7 ± 2.7%, P < .001), longitudinal SR (-2.36 ± 0.62 vs -2.95 ± 0.68 second^-1 , P < .001), radial S (46.2 ± 21.3% vs 66.7 ± 17.6%, P < .001), and radial SR (5.60 ± 2.08 vs 6.67 ± 1.8 second^-1 , P < .001) compared to healthy controls. No difference was observed for circumferential S and SR. Cats with HCM had greater LV mass (13.2 ± 3.7 g vs 8.6 ± 2.7 g, P < .001). The ROC with the greatest area under the curve (AUC) for the identification of HCM (0.974) was plotted from a logistic regression equation combining LV mass, MAPSE at the free wall, and LV internal diameter in diastole (LVIDd).

Conclusions and clinical importance: Cats with preclinical HCM have decreased long axis and radial deformation. Decreased longitudinal deformation and decreased LVIDd are factors that would support a diagnosis of HCM.

Keywords: echocardiography; feline; hypertrophic cardiomyopathy.