My cardiologist wanted to give me a test of my heart but first checked if my insurance would pay, it wouldn't he didn't give the test. is that ethical?

Yes, in most cases: Every test or procedure in life has a cost-benefit decision. For example, if a test is low-cost and high-benefit (meaning it really may change the diagnosis or management), then doctors and patients want to do the test. If a test is high-cost and low-benefit (meaning the test result is unlikely to add anything to the diagnosis or management) then the patient should ask his doctor to skip the test.