IHD, or myocardial ischaemia is reduced blood flow to the heart due to coronary artery disease, smoking and other factors can make it worse.  There are two types, stable and unstable--each with different symptoms.  Depending on the risk and symptoms, you could be treated with medication, angioplasty or bypass surgery.  You didn't put your age or blood pressure or cholesterol levels, so it's difficult to speak to any of this.  It IS definitely important to get checked out with a complete blood work-up, x-rays and ECG (EKG).  A stress test might be ordered as well.  What are you looking at?  Well, without intervention and lifestyle changes, it is the leading cause of death from heart attacks in the Western world.  I'm not sure what you mean about hardening of the arteries in your brain--the post is not very cohesive.  The two things you are talking about are mutually exclusive--they don't directly affect each other's progress.  Atherosclerosis (hardening of the arteries) in vessels of the brain increase the risk of stroke manyfold.  This all needs to be checked out soon, and you need to work with your doctors to form a plan for prevention and change your lifestyle to lessen your odds of heart attack or stroke.