Echocardiographic assessment of left ventricular geometry and the mitral valve apparatus in cats with hypertrophic cardiomyopathy.
OBJECTIVE
This retrospective study addressed the general hypothesis that abnormalities of the mitral valve apparatus are common in cats with idiopathic hypertrophic cardiomyopathy (HCM) and contribute to dynamic obstruction of the left ventricular outflow tract (LVOT).


METHODS
106 cats (28 controls and 78 with HCM) had transthoracic two-dimensional and Doppler echocardiography performed with quantification of 33 variables. Three groups of cats (control [Group-1], HCM without obstruction [Group-2], and HCM with obstruction [Group-3]) were identified and compared by analysis of variance, chi(2) analysis, and correlation analysis.


RESULTS
Cats in Group-3 had more LV and papillary muscle hypertrophy, increased length of the anterior mitral valve leaflet, and a higher prevalence of false tendons in the LVOT compared to cats in Group-2 (P < or = 0.05). The length of the anterior mitral valve leaflet was correlated to the severity of dynamic obstruction (P < or = 0.05) and the magnitude of LV hypertrophy (P < or = 0.001). Systolic anterior motion of chordae tendineae (CAM) was observed in 16% of control cats and >50% of cats with HCM (P < or = 0.05).


CONCLUSIONS
Abnormalities of the mitral valve are common in cats with HCM suggesting a possible role in the pathogenesis of dynamic outflow tract obstruction.
Schober
Karsten
K
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L Tharp Street, Columbus, OH 43210, USA. schober.4@osu.edu
Todd
Amanda
A
D000818:Animals; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000662:veterinary*; D016022:Case-Control Studies; D002371:Cat Diseases / Q000000981:diagnostic imaging*; D002415:Cats; D004452:Echocardiography / Q000662:veterinary; D015150:Echocardiography, Doppler / Q000662:veterinary; D005260:Female; D006337:Heart Murmurs / Q000662:veterinary; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000662:veterinary; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000662:veterinary