You know we'll be here, for you to tell us all about it. Get through it safely. Don't shut down your kidneys, as it just gets the doctors all upset. We expect you to behave better than that!
Glenda, as I understand it:
A cardiac catheterization is the prcedure that introduces a catheter into a large artery in your groin, arm, or neck. It can then be snaked up to (and into) the heart.
An angiogram is one of the things that they can do with the catheter while they're in there. They release an x-ray contrast dye, as you mentioned, and map how well the blood flows through the cardiac arteries and within/through the heart chambers/valves via xray. For most people, it just creates a hot feeling when the dye is released (for me, it felt disconcertingly as if I'd somehow internally wet myself). Lucky Sherrin is reactive to it, and her internal organs misbehave when it is introduced, so this procedure is undoubtedly a bit more nervewracking for her, premedicated or not.
Another frequent thing done during cardiac catheterization is the measurement of heart chamber and valve sizes and pressures, as well as opening and root sizes. Aside from what is learned from the dye, this is done via sonic tips, which perform an internal version of an echocardiogram. External echocardiograms can be quite accurate. However, the measurement of some items, such as internal pressures (like those across a stenotic aortic valve) is more accurate internally.
