I think what droliver says is true to some extent, but will vary from institution to institution and case to case. Being a CCU resident now, I have two cases on my service that were transfers to our Unit from the Trauma Service (one had a NQWMI in the context of a vfib arrest after a MVC, and the other Trauma patient had an ST elevation MI and required emergent intervention). Trauma follows along, but don't really offer a whole lot. One required cath/PTCA, and one requires a watch and wait stance. If it were me, I wouldn't want a surgeon managing me if I had an MI, cath lab or not. Here, surgeons are VERY reluctant to manage even fairly straightforward medical issues. When on CCU call, I get calls from my counterparts on the SICU and Burn ICU asking for management tips for things like afib with RVR all the time, or even questions like "why is this patient in Afib?". I don't consider rate controlled afib a malignant arrhythmia. ESRD patients, no matter what their primary problem and stability, are admitted to a medicine service. Being a Louisville grad, I know that General Surgeons there do manage a whole range of medical issues -- much more so than most places in the country. Part of this is the fact that Dr. Polk encourages his residents to be complete doctors, but part of it is because Medicine there is comparatively weak to surgery, so it's incumbent upon the GS there to be more on the ball with medical issues. Now whether or not this is appropriate is up for debate, but in most cases the surgeons do appropriate things. Where I train, on the medicine consult service we are inundated with consults from all the surgical services for both complex and stupid issues, with the occasional intention to dump. We get asked about which antibiotics are best to use in a particular situation to questions like "why is this patients creatinine 3 when it was 1.2 four days ago?". I don't know that the experience of having to get other medical consult services involved at Jewish and Norton (the Louisville privates) is so much political as it is medicolegal and on some level the right thing to do with patients with medical issues.
Again, this is not to say that general surgeons can't manage basic (and some complex) medical issues well. They do. That is only common sense. But there are just as many basic (and complex) issues that they can't/don't, and where calling a Medicine person or subspecialist is also commone sense.