Hypertrophic Cardiomyopathy (HCM) is a condition that causes the muscular walls of a cats heart to thicken, decreasing the heart's efficiency and sometimes creating symptoms in other parts of the body. HCM is the most commonly diagnosed cardiac disease in cats. Although the cause of HCM has not been clearly identified, the fact that the condition is more prevalent in certain breeds (including Maine Coon, Ragdoll, British Shorthair, Sphynx, Chartreux, and Persian cats) and that mutations of several cardiac (heart) genes have been identified in some cats with this disease suggests that genetics plays a role.
Many cats with HCM do not appear to be ill. Others may show signs of congestive heart failure, including labored or rapid breathing, open-mouthed breathing, and lethargy. These symptoms occur when fluid accumulates in or around the lungs. A potentially devastating complication of HCM is thromboembolism. Medication can help manage HCM, and can be administered orally to stable patients or by injection in more serious situations. Other drugs, such as nitroglycerine, may be applied to the cat’s skin for absorption. Unfortunately, no therapy has been shown to prevent the progression of HCM.
