, Author, knows too much about heart disease from personal experience. 1  If space aliens bombed all the pharmaceutical factories and we had to go back to herbs, Coleus forskohlii (Indian coleus) would act as a natural beta-blocker, whether or not it was used for hypertension or cardiomyopathy.
Heartworm prevention is recommended, and may cost up to $40. The cat should also be checked out by a vet, to make sure there are no problems; the vet bills may be between $50 (for a simple check up) to $300 for advanced tests, if these are needed.
I'd guess $500 to $1000/year, depending on how expensive your food and vet is. The important part is that at some point there will be a $500 to $3000 vet bill that you weren't expecting. Last week my cat collapsed and it cost $1800 to diagnose and treat the problem, high blood pressure.