What do general cardiologists bill for, usually? I'm guessing lots of
level 4 and 5 consults, inpatient and outpatient, as well as EKGs and
ECGs.

So, let's say Dr Bob is working in private practice. Let's say in a
week he performs 70 level 4 outpatient consults, 10 level 4 inpatient
consults, 30 level 5 outpatient consults, and 10 level 5 inpatient
consults. That's already 460.20 RVUs/wk, based on the 2008 Medicare
fee schedule. If he gets reimbursed by insurance at an average of
$50/
RVU, and works 46wks/yr, he'll make $891940/yr. Is this correct, or
did I screw up? Dr Bob is an extremely busy and highly respected
physician, given that he's always being consulted and never referred
to, and for high level cases, too.

What if he owned his own EKG and ECG facilities too?

When I become an internal medicine subspecialist, I'll have a
"consultation-only" policy, and refuse to take referrals, but glady
offer my services as a consultant.