Echocardiographic Assessment of Right Ventricular Size and Function in Cats With Hypertrophic Cardiomyopathy

• Published in: Journal of veterinary internal medicine 2017-05, Vol.31 (3), p.668-677
• Main Authors: Visser, L.C., Sloan, C.Q., Stern, J.A.
• Format: Article
• Language: English
• Subjects: Animals; Cardiomyopathy, Hypertrophic - diagnostic imaging; Cardiomyopathy, Hypertrophic - veterinary; Cat Diseases - diagnostic imaging; Cats; Echocardiography; Echocardiography - veterinary; Feline; Female; Heart Ventricles - diagnostic imaging; Male; Predictive Value of Tests; Right heart; Right ventricular hypertrophy; SMALL ANIMAL
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/jvim.14688

Background Studies evaluating right ventricular (RV) structural and functional abnormalities in feline hypertrophic cardiomyopathy (HCM) are limited. Hypothesis Right ventricular structural and functional abnormalities are present in cats with HCM and are associated with clinical severity. Animals Eighty‐one client‐owned cats. Methods Retrospective 2‐dimensional (2D) echocardiographic study. Right atrial diameter (RAD), RV free wall thickness (RVFWd), RV internal dimension (RVIDd), RV fractional area change (FAC), and tricuspid annular plane systolic excursion (TAPSE) were measured in control cats (n = 26), cats with subclinical HCM (subclinical HCM; n = 31), and cats with HCM and congestive heart failure (HCM + CHF; n = 24). Results Right heart size (RAD, RVFWd, and RVIDd) and RV function (FAC and TAPSE) significantly (all P < .05) increased and decreased, respectively, in the HCM + CHF group compared with controls. In the subclinical HCM group, only RVFWd was significantly (P < .05) higher than in controls. Compared with reference intervals derived from controls, 29% of cats with HCM had increased RVFWd. Increased left ventricular free wall thickness, increased RVIDd and decreased TAPSE independently correlated with increased left atrial size. Cats with HCM and pleural effusion were significantly more likely to have increased RVFWd and had increased RAD and decreased TAPSE compared with cats without pleural effusion. Conclusions and Clinical Importance Right ventricular remodeling and dysfunction occur in some cats with HCM and may be associated with clinical severity. Our results support involvement of RV in the pathophysiology of HCM in some cats and support echocardiographic assessment of the RV in cats with HCM.