What is hypertrophic cardiomyopathy?
HCM, is found in all animals including us humans, it is not a common disease. However, your animal can have a HCM scan one day with perfect results and then sadly and suddenly drop dead the next day from HCM. Thank goodness it is not common in any animal.
It is a heart muscle disease in which the papillary muscles (the muscles in the left ventricle that anchor the mitral valve) and the walls of the left ventricle become abnormally thickened. HCM is often a progressive disease, and a proportion of affected cats develop heart failure if the muscle hypertrophy and subsequent scarring of the heart muscle significantly affects heart function.
Cats with the disease may die suddenly and may develop a blood clot in the chamber above the left ventricle (i.e., the left atrium) that often then gets carried into the systemic arterial system, most commonly lodging in the terminal aorta, stopping blood flow to the rear legs.