Prevalence and Prognosis of Atenolol-Responsive Systolic Anterior Motion of the Septal Mitral Valve Leaflet in Young Cats with Severe Dynamic Left Ventricular Outflow Tract Obstruction.

The long term benefit of twice-daily atenolol therapy was documented in 9% of cats. Whether the cats where atenolol failed to resolve DLVOTO on long-term had HCM, or a therapy-resistant congenital primary mitral valve disorder remains unclear.