Restrictive Cardiomyopathy in Cats

Overview of Feline Restrictive Cardiomyopathy (RCM)

Restrictive cardiomyopathy (RCM) is a heart condition that primarily affects cats. It is characterized by a variety of abnormalities, including thickening or dilation of the main pumping chamber of the heart (the left ventricle), dilation of the atria (the uppermost chambers of the right and left sides of the heart), and/or scarring of the lining of the heart. The internal scarring makes the left ventricle less distensible than normal. Together these factors may lead to chronic pulmonary hypertension (high blood pressure in the lungs) and thus to progressive enlargement of the right side of the heart.

Below is an overview of Restrictive Cardiomyopathy in Cats followed by in-depth information about the causes, diagnosis and treatment of this condition.

Restrictive cardiomyopathy can, in severe cases, cause heart failure when fluid accumulates in the lungs. Blood clots, too, can form in the heart and travel to distant blood vessels obstructing blood flow to one or more limbs, especially hind limbs. RCM can be mild to life-threatening.

Most affected cats are usually seven years of age or older, but cats of any age may be affected.

The main causes of RCM are genetic. Factors that may precipitate heart failure and/or difficult breathing in RCM affected cats include: fever, infection, stress (a veterinary visit, physical restraint), and anesthesia. In some cases, restrictive cardiomyopathy is associated with advanced hypertrophic cardiomyopathy.

What To Watch For

See your veterinarian immediately if you see these signs.

Diagnosis of Restrictive Cardiomyopathy in Cats

Diagnostic tests are needed to diagnose RCM and exclude other diseases:

Treatment of Restrictive Cardiomyopathy in Cats

There is no recommended treatment for mild, asymptomatic cases, but regular follow-up visits with your veterinarian are vital. In more advanced cases, your cat may have to be admitted into the veterinary clinic and may have to stay there for several days for initial treatment and monitoring. Severe cases of restrictive cardiomyopathy are life-threatening.

Home Care and Prevention

Give any prescribed medications as directed and observe your cat’s breathing pattern regularly to ensure that respiration is quit and uncompromised. Learn to take your cat’s heart rate, record the results, and relay this information to your veterinarian.

Minimize stressful situations. Affected cats are best kept as indoor-only pets.

This disease is thought to be genetic; therefore, there is no preventative care other than not breeding from cats with RCM.

In-depth Information on Restrictive Cardiomyopathy in Cats

Cardiomyopathy means disease of heart muscle. Some, but not all, cardiomyopathies have well defined causes. Symptoms of cardiomyopathy are not specific and many heart and lung diseases produce clinical signs similar to RCM. Diagnostic tests are required to differentiate RCM from other conditions that have similar clinical signs. Below is a list of such conditions:

Diagnosis In-depth

Diagnostic tests are essential for identifying RCM. Tests may include:

Treatment In-depth

Follow up Care for Cats with Restrictive Cardiomyopathy

Optimal treatment for a pet with RCM requires both home and professional veterinary care. You should administer prescribed medications as directed and alert your veterinarian if you have any difficulties in this respect.

The details of veterinary follow-up depend on the severity of your cat’s condition, his response to therapy, your veterinarian’s recommendations, and your views. A typical schedule involves follow-up veterinary visits every 6 months. Recheck examinations may be scheduled more frequently at first to monitor your pet’s initial response to therapy.

Follow-up may include:

Your cat’s condition can change rapidly, and tests to monitor disease progression will influence decisions about therapy and the prognosis.

The long-term prognosis of RCM is guarded and quite variable. Some cats have been managed successfully for over two years, but cats with relentless CHF, blood clots or fluid accumulation in the chest cavity have a poorer prognosis. Unfortunately, some affected cats die suddenly.