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.
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 Noisy, difficult, open-mouthed breathing
Sudden inability to use one or more limbs
Odd posture of squatting or lying with chest down, head extended and elbows pointed outward
Lack of appetite
See your veterinarian immediately if you see these signs.
Diagnostic tests are needed to diagnose RCM and exclude other diseases:
Complete medical history and physical examination, including auscultation of the heart and lungs using a stethoscope
Echocardiogram (ultrasound examination of the heart) - a painless procedure in which a probe is held against a prepared area of the chest wall. The image generated confirms or refutes a provisional diagnosis of RCM.
Electrocardiogram (EKG)-a tracing derived by amplification of the minutely small electrical impulses normally generated by the heart.
Blood tests to evaluate your cat.
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.