Probably difficult to give a definitive answer on here re: the regulatory authorities standpoint ASK, but I think, it's fair to say, you at least need to inform them. Which will probably result in an instant grounding.
I suspect the factors they may be interested in, initially, are how the diagnosis was made, and the nature of any associated symptoms (collapse, chest pain, shortness of breath, dizziness etc.).
I should imagine the first stages your quack would want to make, are taking a decent history, and investigations to rule out the obvious, (anaemia, thyroid tests etc). I think you should make it clear that your employment relies on this, which, hopefully, should prompt a low threshold for referral to a cardiologist.