Should i change my cardiologist? i first saw him for hypertension and palpitations which were unusual for my age, he did blood tests, echo, kidney us. but after 6 months he ordered a sleep apnea study. i feel like he should have ordered it back then?

Did you tell him about snoring then or now. OSA can cause HBP especially if you eat too much salt. And too much salt can aggravate OSA.

It sounds like your cardiologist is trying to work up your hypertension properly. There is a stepwise approach in the work up and treatment and a sleep study is not commonly ordered first. It is otherwise a matter of trust and communicating efficiently with your cardiologist remain critical in the medium to long run.