The Ragdoll and the HCM
(Hypertrophic cardiomyopathy)

Hypertrophic cardiomyopathy or HCM is the most common heart disease with cats.

It can be defined as a heart disease caused by an abnormal thickening of its muscular walls.
Since the 1970s, it is assumed that the MHC is a common cause of cardiac arrest, thrombosis and sudden death with cats.

Cats with HCM get out of breath easily, because the blood does not contain enough oxygen anymore.
They may also have fluid in the lungs, which causes coughing, or have fluids in other parts of the body which are at the origin of edema.

Affected cats do not often show any signs of this disease before the age of 6 months, and the diagnosis of HCM can take several years to be established.
The disease develops on average around 5 to 7 years, but in the most severe form of the disease, the cat will die before the age of 3 years.

Unfortunately, the first sign of HCM is often sudden death of the cat caused by a sudden stop of the heart or a major disturbance of heart rhythm.

In some breeds (Maine Coon, American Shorthair, Ragdoll and Persian), the hereditary nature of this disease, transmitted by a dominant gene was observed in some cases, which makes the disease develop faster.

There is a genetic test (called HCM-C test) to detect a gen mutation specific to the Ragdoll and which is also associated with hypertrophic cardiomyopathy.
However, since the mode of transmission from one generation to another is not yet clear, we should not be satisfied with a negative CMH test.
An examination of the heart by a specialist in echocardiography should be performed regularly, and several times during the life of the cat.

Cats affected by HCM may be treated with diuretics to reduce the amount of fluids in the lungs and the body. Beta-receptor antagonists can also be used to reduce pressure in the ventricle and on the valve.

If the disease is caught in time, and well followed, drug treatment can only alleviate the symptoms of the disease and we can hope to extend the life expectancy of the animal and improve its comfort.
However, it can not be cured yet.

Source (partial): Pawpeds