Patrick's vet heard a 3-4 grade heart murmur when he had a check up this past January (2004). Patrick is a 16 lb., 12-year-old orange tabby, who had been irradiated for hyperthyroidism the previous March, and been given a clean bill of health in June. The vet was surprised by the murmur, and suggested we take Patrick for an echocardiogram. When we did, Patrick was diagnosed with asymptomatic HCM, and I was told there was nothing to do, other than come back in a year for another echocardiogram.
In despair, I joined the feline-heart Yahoo! group, and asked for feedback. Thanks to the replies I received, and the links I found on the group's site, I decided to take Patrick to another veterinary cardiologist for a second opinion. Unlike the first cardiologist (who, in retrospect, seems more like a glorified sonogram technician), the second doctor took a good deal of time with Patrick and made it a point to check his blood pressure. It was 220, and his eyes showed signs of damage.
Now, here's the interesting part for owners of HCM cats: this doctor believes the high blood pressure is causing Patrick's HCM--not the other way around. He now has been on daily blood pressure medicine (as well as 20 mg of aspirin 2x a week) for about a month and a half. Several days ago, the vet told us that his bp seems to have stabilized at approximately 142 and his eyes now appear to be back to normal. To my delight, he is also much more his old, affectionate self. And although his heart murmur hasn't yet improved, in all probability it (and 2 out of 3 of the vets he saw) saved him from stroking out.
The main point is that, apparently, hypertension can occasionally be the cause of HCM. Hopefully, the veterinary cardiologist is correct in her diagnosis, and when we take him back for an echocardiogram in February, the disease will have been halted.
-- Maggie