What can you do about a hospital misdiagnosing your husbands stroke resulting in his death?

First, get the medical records from the hospital. Have a third party physician review the records to see if there was a definite misdiagnosis. If there was, then contact a lawyer and present your evidence. I consult a physician first, because it would be a lot cheaper for a physician to review than to give directly to a lawyer and have him do the same thing.