You’re about to have a CT scan, and it’s a
CT scan of the heart, and I want to take a picture of the heart.
To do that, I need your help. Before you have the procedure, you’ll also
be asked to go over whether you’ve got any particular reactions or allergies that might
be important in the scan. And there’ll be a full questionnaire given
to you and asked prior to the procedure. So it depends a little bit on what we hear
from the patient. There will be a few questions to ask; it’s
not complicated; we rarely don’t do the scan. We’ll have to put a little plastic drip in
the arm, usually in the elbow if we can, sometimes in the back of the hand.
And that’s done before the procedure, and before you go into the room.
And we use that so we can give the dye (known as contrast) during the course of the scan.
We sometimes have to put in a bit of beta blocker, which is an intra-venous drug, which
slows the heart-rate down and takes a bit of the adrenaline that we all pump – takes
the edge off of that as it goes round the body.
So when you actually get invited into the room, the first thing to remember is try to
stay relaxed. It’s very straightforward, it’s not a difficult
test, you’re not going to have to do anything very complicated.
And the more relaxed you are, the better your heart-rate and the better the picture.
So remember that as your top priority. The second thing is, as soon as you’re lying
on the bed, we’ll almost certainly connect you up to an ECG monitor, using our four stickers.
And once we’ve done that, we’ll check what your heart-rate’s doing.
If you’re relaxed and your heart-rate is nice and relaxed, we can go straight ahead.
Now, before we start, I need to give you a little spray under your tongue of something
called GTN spray, which opens up the arteries, and we get a slightly better view of what’s
going on. Just to warn you: you may get a minor headache,
but it wears off very quickly. The crucial thing about this test is holding
your breath – apart from relaxing, it’s the most important thing we do.
The reason for that is, your heart is tucked underneath your ribs, and we have to take
a picture over a few seconds. When we take that picture, over about five
seconds, we don’t want the whole chest to move because if the whole chest is moving,
unfortunately, the heart underneath moves with it.
You’ll be lying on your back, so some people like to imagine they’ve got a drink or a cup
of water sitting on their chest. And when they hold it still, they imagine
it doesn’t move and they keep things nice and still.
If your chest is still, your heart is therefore still, and we get nice pictures.
What I’d like you to do is try and hold your breath for about five seconds, three times
– on three separate occasions – about a minute apart, so you’ve got plenty of time to recover.
And what you’ll to hear is: Breathe in
Breathe out Breathe in and hold it
And then I want you to hold your breath for five seconds…
… and then breathe away And you’re going to do that three times, with
about a minute gap in between the three scans. Sometimes we do four scans, but usually three.
The first scan is always a ‘set-up’ scan, and that’s a very quick scan.
The second and third scan usually involve a small amount of contrast, and as far as
you’re concerned, you’ll just get a slight hot sensation, so that’s the dye or the contrast
that goes in through the drip. And the second of the scans it’s a very tiny
dose, and you may get nothing at all, or you may get a very slight hot sensation.
But after the third scan, the final scan, which is the most important scan, at the end
of the scan, just as we’ve finished, you’ll start to get this flush sensation going through
the body – like having a quite impressive hot flush.
And it makes you feel like you want to go to the loo, or you’ve even been to the loo.
It gives you funny hot sensations and sometimes a funny taste in the mouth.
It’s very quick. It almost goes as quickly as it comes, but it’s a bit unexpected if
you’re not aware of it. And so we just warn people. It’s not a problem,
it’s not particularly nasty, it’s just a weird sensation for a few seconds, that’s all.
And so, in terms of how long you might be in the scanner – once you get in the scanner,
providing your heart-rate is fine and we don’t have to give you a little bit of beta blocker,
it’s a very quick scan. Once the scanning starts, it’s about three
minutes – it’s incredibly quick. There’s a little bit of setting up while we
connect you up to the ECG leads, and we usually allow about 15-20 minutes for each patient.
And that involves getting the patient on, reassuring them, connecting them up, doing
the test, and getting them off. So the actual test – the actual scanning – is
very short. And once you’ve had the scan, it’s very quick
afterwards, you can hang around for five to ten minutes – we usually recommend that, make
sure you’re happy. We take the drip out, make sure there’s no
bleeding from where the drip went in, and then we can send you on your way.
Most patients that we scan, actually, they don’t have heart disease, and it’s a good
test for saying that you haven’t got heart disease, and we can reassure you.
If you have, and we find a bit of narrowing in the arteries, then we can then go on and
do other tests as appropriate. But it’s a good test for sorting out people
who have got chest pains but we can’t quite work out what’s going on.
Occasionally we get referred for other reasons, including people who are a bit short of breath,
and other reasons, but that’s the main reason why we get to see you.