most heart problems are treated by primary care physicians and more complicated problems by cardiologists but heck if the heart problems are hypertension, CAD, CHF, A fib, needs a pacemaker etc that's likely not much of an issue.

Turn that CAD into the need for a stent, or a CABG and it's likely a different story. In our hospital here in small town OR you go in with an MI and angio says you have one or more coronary arteries blocked and you are in the cath lab immediately, and if CABG needed you get that ASAP, in Canada it could work that way but usually doesn't. We have two cardiovascular surgeons in our stake. They see Canadian patients not all that infrequently and we are a long way from the border.