Major kudos to you for adopting a senior kitty and taking such great care of him.
--- In firstname.lastname@example.org, "laurakist" <laurakist@...> wrote:
> Last week he went off his food and was acting nauseous and had some diarrhea and vomiting. I thought his kidneys had given in. Blood tests OK (though electrolytes a bit low, as well as some RBCs). Xrays showed an enlarged heart and his heart beat was very irregular and was 240 bpm. He had an echocardiogram by a cardiologist later that day and diagnosis of HCM.
What was the diagnosis for his irregular heartbeat?
> He has been prescribed: Aspirin 81mg, 1/2 tab every 3 days; enalapril 2.5mg 1 tab 1x day; diltiazem 30mg 1/4 tab every 8 hours (this is a challenge)
You can have the diltiazem compounded to make it easier to administer; if the challenge is the timing, you can ask about switching to atenolol which is a twice daily medication. It is not in the same category as diltiazem but also works to slow down the heart beat.
> I just read in two different animal medication books that enalapril and diltiazem should not be used together. One book leaves it at that and the other says if it is absolutely necessary extreme caution should be used. SO now I am even more upset.
That's funny, as there is actually a combined enalapril-diliazem tablet available in Europe. I think the caution is probably because, in humans, both medications can be used for hypertension so the concern is that combining them will cause hypOtension. Neither drug is a good medication for hypertension in cats however so this is not a concern. The diltiazem dose Duncan's on is actually very low, too, so it's even less of a concern.
From the medication he's been prescribed, it sounds like the cardiologist is concerned that he may go into heart failure :( You should start taking his respiratory rate at home, while he's resting, and making a note of it. A sleeping/sleepy cat should have less than ~35 breaths/min.
If you can take his heart rate at home, that may also help. If he has a certain type of arrhythmia, atrial fibrillation, it can be harder to take an accurate heart rate but you can try. The heart rate can be felt by putting your hand between his front 'armpits' and feeling just to the left of his breastbone. You can also check his femoral pulse on the inside of his thighs.
What are his most recent BUN/creatinine/urine specific gravity values?