Welcome to healthcaremagic.com. Sorry about the heart trouble. Your husband had a response to the nitroglycerin tablets as the took two of them, you are supposed to wait for a few minutes to take the next one for angina pain. I would not worry about it at the moment, he will be fine. In the future he should take one pill wait for results and if he needs to take another one then he can. I hope this helps, good luck and thank you for your question.