Left ventricular geometric characteristics predict response to carvedilol in cats with asymptomatic hypertrophic obstructive cardiomyopathy caused by systolic anterior motion of the mitral valve.

Beta-blockers are used to treat cats with hypertrophic obstructive cardiomyopathy (HOCM). However, there are various hemodynamic responses to beta-blockers. This retrospective study aimed to explore the relationship between the response to carvedilol and the presence of geometric abnormalities. Medical records were reviewed for 16 cats diagnosed with HOCM. Cats were divided into two groups based on the velocity of the left-ventricular outflow-tract after carvedilol treatment (responder: eight cats, non-responder: eight cats). Baseline intergroup comparison revealed that anterior mitral valve leaflet length and diastolic left-ventricular posterior-wall thickness were significantly greater in the non-responder group. Longer anterior mitral valve leaflet and thicker left-ventricular posterior-wall may cause poor response to carvedilol. Thus, these properties may predict a lack of response to carvedilol therapy.