i'm taking Ramipril and Metorolol have had an aortic valve replaced along with a triple by pass, not over weight, don't smoke, drink wine once in awhile, am very active out in the yard, along with tennis, and golf, but now and again I feel jittery or out of sorts, don't know what that's from?? Is it dehydration, to much or not enough potassium, or something I should not be eating?/