Who's paying for Cheney's heart treatment?

A responsible journalist would hesitate to ask this question, so I will: Who is paying for the undoubtedly exorbitant expense of the treatment being administered to maintain the heart of former V.P. Dick Cheney?

From the NY Times story:

Former Vice President Dick Cheney is recuperating from surgery to implant the kind of mechanical pump now being given to a small but growing number of people with heart failure so severe that they would most likely die within a few months without it. The pumps are partial artificial hearts known as ventricular assist devices, and they come in various models. Mr. Cheney's kind is about the size of a D battery and leaves most recipients without a pulse because it pushes blood continuously instead of mimicking the heart’s own pulsatile beat.

You know that's got to cost a lot.

As a former member of Congress, Cheney has lifetime healthcare -- nice for him! And I don't begrudge it. Everyone deserves lifetime health insurance -- don't they?