Surgery right away or wait until heart is more stable?

[April2]

I hope this is the right forum for this question. My 12 year old cat was found to have a hard lump which after being tested shows high probability of sarcoma cancer. Obviously, it will need to come out but she also was just diagnosed with Hypertrophic Cardiomyopathy at the same time. So the vet is concerned that it would be dangerous to put her under with her heart like this. Her suggestion is to put her on a beta blocker (Atenolol) for a month and then do the surgery to remove this lump. (Chest x-ray looked good, no enlarged heart or cancer).
Which is best? Is it ok to put the surgery off for a month if it's cancer? How dangerous would it be to put her under, either now or after she's been on the beta blocker? And she also said the beta blocker lowers blood pressure, which I wouldn't think would be good since blood pressure tends to become lowered while being under anesthesia. I really don't know what's best here! I don't know if I should do this surgery right away or wait until she's been on this medication for awhile. I really need to hear from some other vets on your opinion, please. I want to do what's best for my cat without endangering her. Thank you so much.
April

[April2]

Sorry, I wasn't sure which forum was best for this answer. Thank you so much for answering so quickly. I will follow your suggestions you gave. Thank you so much. I really do appreciate your answers.

[Arnold L Goldman, D.V.M.]

Please see my detailed reply on the "Cancer in Pets" Board. Thank you.

Arnold L. Goldman DVM, MS
MedHelp