On my last visit to the cardiologist, he asked if I had headaches or woke up overnight. I meant to ask him what this signified, but I forgot. I have severe aortic stenosis which will require surgery soon. Ordinarily, I do not have headaches or wake up overnight, but of course, like everyone else, I do from time to time. What significance do these have in regards my condition, and when are they cause for concern? Thanks.