It is telling that the medical specialty who most commonly believes themselves capable of all fields of medicine has decided to turn this over. Cardiology manages endocrine, vascular, and lung issues routinely with supplemental incomes associated with each of those service lines in addition to their primary cash cow of cardiology. I have seen so many patients who basically have their cardiologist acting like their PCP where I am.
The real reason they wont do sedation--reimbursement is horrible if you are also doing the procedure. Reimbursement for conscious sedation from CMS is less than a happy meal at mcdonalds. If they were allowed to bill the same as anesthesiology does I guarantee they would not be asking for you to do these cases.