The following is a compilation of information on the disease for veterinarians and pet owners, including a list of other HCM Internet resources. In a fairly recent study, cats with HCM lived for an average of around 736 days, but I've heard of HCM-afflicted cats living for four or more years before heart failure. If diagnosed early, medication can slow the process down.
Late diagnosis is usually postmortem, or when the disease has reached an acute state.
The cause of HCM is believed to be genetic. The best hope for HCM, it seems, is to diagnose animals which carry the HCM gene and don't let them breed. Treatment is through medication to both thin the blood and retard the growth of the heart wall. The best technique is to kneel on the ground with your feet crossed, the cat held between your knees. Open the jaw with one hand and insert the medication with the other.