The question to ask is why it costs so much to become a doctor in the USA vs other countries and then work to address that.
A serious problem should not be treated with a band-aid and if you think a band-aid is ok do not be surprised the problem gets worse.
Rural hospitals are lucky to have any doctor on staff let alone a cardiologist. They are mostly staffed by nurses for quick patch-up work and life flights to major medical centers.
H1B doesn't solve the problem of poor communities getting poor healthcare. Frankly, it costs too much to become a doctor which limits where doctors can be employed. Plenty would like to work rural, but not with $500,000 in student loans. And no, that's no joke. I have a nephew going to medical school in Idaho and that's what his loans are.