The person who posted that 2/5 week days call sounded awful, I agree that it does...but I often take that much call,
BUT it's mostly 1 or 2 phone calls a night b/c it is ONLY patient phone calls and phone calls from 1 ER that is a pretty small hospital, and has hospitalists 24/7 on call. Patients, when they call our office @night, get an operator who immediately asks them if it's an emergency. If they say no, they are immediately told to call back during regular office hours. The ER also doesn't usually call unless it's a real MI or unstable angina, or very unstable CHF, which doesn't happen incredibly often. Hospitalists occasionally call for consults but most often it's between 7am-6p.m., unless they are really worried about a patient. Some hospitalist are more "independent" than others. Actually, getting reamed occasionally in clinic with multiple ER or consult calls, or calls to read a stat or urgent echo in the middle of a clinic day is actually more of a problem than middle-of-the-night calls. Private practice type setups are usually not like a large academic hospital, where nurses and other docs tend to call the fellow or resident a lot for every little thing - there are still nurses who call you to d/c a defunct order at 12:30 a.m. or to clarify a Tylenol order at 5:45 a.m. but it's more rare.
p.s. I agree the EP job market sucks. I would say the most job postings I have seen recently are for interventionalists (who would presumably do a lot of general cards as well), and followed closely by general and CHF docs. If you are general, it helps to be able to do TEE's and nuclear, but I have seen very few ads looking for people who need to be able to do CT or MRI (especially not MRI). I think being certified in CT could still give you an edge for certain jobs, however. MRI I expect will/would remain more of a research and big academic hospital type of thing - it's just not very cost effective and there aren't that many cardiac disorders that you really "need" an MRI to dx or treat.
I'm not sure about these people expecting to make 500k doing cardiology - if you want to work like a dog and live in Alabama or Oklahoma as an interventionalist, you can probably make that after a while, but you should expect to probably take a LOT of STEMI call. This might work for you if you have a stay-at-home spouse to take care of 99% of stuff at home and you like to work and don't have many hobbies, but I suspect many of use wouldn't want that life.
Also, some people on here seem to be expecting some magical rise in their income a few years after "starting a practice" but I know zero people from my program on the West coast who went and started up a practice, and only 1/4 graduating fellows who joined a private practice at all, and last I heard he was doing call all weekend every other weekend. Most jobs out here are employed by a hospital system , and several older docs either joined a hospital or large employed group, or moved out of state. There are some still-existing private practices but the cost of owning all that equipment such as echocardiogram machines, and employing the medical assistants, etc. to run one's office, is not affordable any more, from what I have been told. And you would probably have trouble getting "partners" to join you any more, given the uncertain future reimbursements in our field.
In an ideal world, I'd like to be in a group with 4-8 other docs and I'd like to dictate/determine my clinic schedule, and have more say in my call schedule, but that doesn't seem feasible any time soon.
I don't think you have to worry about having no job at all s/p cardiology fellowship right now, if you go to a decent program and have some skills, but if you are in a major metro area like Chicago or SF, you may have to move to get a job. I have heard Chicago is particularly bad - it's not just cardio but anesthesia and probably other fields also - perhaps this is due to the multiple number of residency and fellowship spots in the city, plus perhaps other ppl trying to move there from other parts of the Midwest (not sure about the latter).