A PACES station on MedMock, start to finish

Hello, I'm one of the examiners for this station. This is Mr Hughes. You have fifteen minutes with the patient, and then I will ask you some questions. Please begin when you're ready.

Hello, Mr Hughes. My name is Dr Reid, and I'm one of the doctors on the acute medical unit. Could you confirm your full name and date of birth for me? Your GP has written to us about your heartbeat and some weight loss, but I'd like to hear in your own words what's been happening.

Daniel Hughes, ninth of June, nineteen seventy-four. Well, it's my heart, mainly. Four days ago it started racing, and it feels all over the place, like it can't keep a steady beat. It hadn't settled, so I saw my GP this morning and she sent me straight here. To be honest, I've not felt right for a few months, but I put that down to work.

Thank you, and I'm sorry you've been feeling like this. Let's start with the heartbeat. Did it come on suddenly, and has it been there all the time since, or does it come and go? Have you had any chest pain, or felt faint, or blacked out?

It came on suddenly. I was sitting on the sofa one evening and it just started thumping. It's been there pretty much all the time since, worse when I'm moving about. No chest pain. I haven't fainted or felt like I was going to. I can just feel it going, all the time, and it's hard to get to sleep with it.

That's helpful. Has it affected your breathing? For example, do you get more out of breath walking or on the stairs than you used to?

A bit, yes. I'm a teacher, and my classroom's on the second floor. This week I've been puffed out by the top of the stairs, which isn't like me. It goes off once I sit down.

Thank you. Your GP mentions you've lost some weight over the last few months. Roughly how much, and how has your appetite been?

About a stone in three months. My belt's gone in two notches. That's the odd thing, though: I'm eating more than ever. My wife says I'm always in the fridge. I thought the stress of the new term was burning it off.

Losing weight while you're eating more is an important clue. Can I ask about a few things that sometimes go with that? Have you been feeling the heat more than other people, or sweating more? Any shakiness in your hands? Any change in your bowels? And how have your sleep and your mood been?

The heat, yes. I'm the one opening windows in the staffroom while everyone else has their coats on, and I sweat a lot more than I used to. My hands are a bit shaky; my marking has gone scrawly. My bowels are looser, two or three times a day, but no blood or anything like that. Sleep's poor, and I've been short-tempered, which my wife has noticed. I just feel wired all the time.

That all fits together, and I'll explain what I think in a moment. A couple more areas first. Have you noticed anything with your eyes, such as grittiness, watering, them looking more staring, or double vision? Any swelling or pain in your neck, or trouble swallowing? And have you had a sore throat or a flu-like illness in the last couple of months?

My eyes have been gritty and watery, especially in the wind. My wife says I've got a bit of a stare in photos lately, but I thought she was pulling my leg. No double vision. My neck's fine, no pain or lumps that I've noticed, and I haven't been ill at all. No colds, nothing.

Thank you. Now a little background. Your GP says you've no medical problems and take no regular medicines. Is that right? Do you take anything over the counter, any herbal remedies or supplements such as kelp? Have you had a scan with contrast dye recently? Any asthma or wheeze? And any allergies?

That's right, I'm never at the doctor. I don't take anything at all, not even vitamins. No scans. No asthma, I've never had any chest problems. No allergies.

Does anything run in the family, particularly thyroid problems or heart problems? And do you smoke, and how much alcohol and coffee do you have?

My sister has an underactive thyroid; she's on tablets for it. And my dad died of a heart attack when he was sixty-one, which is partly why this has rattled me, to be honest. I smoke, about ten a day. I know, I know. A few pints at the weekend, not much in the week. Probably too much coffee: four or five mugs a day at school.

Thank you for being so open. You said this has rattled you because of your dad. What's been going through your mind about what this might be?

That it's my heart going, like his did. He was fine, and then he wasn't. My daughter's getting married in five weeks and I'm walking her down the aisle, and I keep thinking, what if something happens before then? I was half expecting you to tell me I'm having a heart attack.

I can hear how worrying that's been, and I'm glad you told me. What were you hoping we could do for you today?

Find out what it is and sort it out. And if I'm honest, I'd like to go home tonight if I can. My wife's waiting in the car park, and I've got Year 11 first thing tomorrow.

Let me explain what I think is going on. I can't be certain until the blood tests are back, but everything you've told me, losing weight while eating more, feeling the heat, the sweating, the shaky hands, the looser bowels, poor sleep and feeling wired, fits very well with an overactive thyroid gland. The thyroid is a small gland at the front of your neck that sets the pace of the body, and when it makes too much hormone, everything runs too fast. The commonest cause is a condition called Graves' disease, where the immune system switches the gland on, and your sister's thyroid problem and your gritty eyes make that the most likely cause for you. An overactive thyroid can also trigger an irregular heart rhythm called atrial fibrillation, and from what you describe, and the irregular pulse your GP found, I think that's what the racing is. So, to your worry about your dad: I don't think this is a heart attack. You've had no chest pain, and this sounds like a rhythm problem driven by the thyroid rather than a blocked artery. We'll check that with a heart tracing, an ECG. Does that make sense so far?

So it's my thyroid, not my heart. That's actually a relief. But is the rhythm thing dangerous? And can you fix the thyroid?

Fair questions. Atrial fibrillation isn't usually dangerous in itself, but two things matter. A fast rate over several days can tire the heart, so we'll slow it down today. And an irregular rhythm can sometimes let clots form. Whether you need a blood thinner depends on your other risk factors; at your age, with no other conditions, your risk is low, so you may well not need one, but I'll confirm that once I've seen everything. The good news is that in many people the rhythm goes back to normal by itself once the thyroid is under control. And yes, the thyroid is very treatable. Today I'd examine you, your pulse, your neck, your eyes, your hands, and your heart and chest, and we'd do the ECG and blood tests: the thyroid hormones, an antibody test for Graves' disease, a blood count and liver tests. I'd also like a scan of your heart, an echocardiogram. For treatment, I'd start a tablet called propranolol today. It's a beta-blocker: it slows the heart and usually settles the shaking, the sweating and that wired feeling within a day or two. Then, once the blood tests confirm it, a tablet called carbimazole to calm the gland itself, which works over several weeks. I'll talk to the thyroid specialists about you today. How does that sound?

A lot better than what I'd imagined. Will I have to take these tablets for ever? And will I be all right for the wedding?

Not usually for ever. Carbimazole is normally taken as a course, often for a year to eighteen months, with regular blood tests. Some people stay well after that; others relapse, and then there are permanent options, radioactive iodine or an operation, which the thyroid team would talk through with you. As for the wedding, five weeks is a reasonable amount of time. The propranolol should make you feel much better within days, and the carbimazole will have started working by then. I can't promise everything will be back to normal, including the heart rhythm, but I'd expect you to be well enough to walk her down the aisle.

Right. And tonight? Can I go home?

Possibly, yes. If your heart rate comes down well with the first doses of propranolol, the tests don't show anything unexpected, and the thyroid team are happy, people with this can often go home the same day with early follow-up. I can't promise that until I've seen the results, but it's a realistic plan. I'd suggest a few days off work, though, until the heart rate has settled. Two important safety points. First, carbimazole very rarely stops the bone marrow making the white cells that fight infection. If you ever get a sore throat, mouth ulcers, a fever, unexplained bruising or feel unwell with an infection while you're taking it, stop it and get a blood test the same day. I'll give you that in writing. Second, if you get chest pain, feel faint or become very breathless, call 999. And smoking makes the eye problems that can come with Graves' disease more likely and worse, so this is a really good time to stop, and we can help you with that. Could you tell me in your own words what you'll tell your wife in the car park, so I know I've explained it clearly?

I'll tell her it's my thyroid, probably this Graves' thing, and not a heart attack. My heart's in a funny rhythm because of the thyroid, and you'll slow it down with a tablet today, then another tablet for the thyroid once the bloods are back. If I get a sore throat or a fever on that one, I stop it and get a blood test that day. Chest pain or fainting, it's 999. Hopefully home tonight, a few days off school, and I'm to stop smoking. She'll like that bit.

That's exactly right. Your wife is very welcome to come in and hear the plan, and to come to your follow-up appointment too. Is there anything else you'd like to ask me?

No, I think that's everything. Thank you, doctor. I came in thinking the worst.

Thank you, that's the fifteen minutes with the patient. His blood results and ECG are now on the screen. Please summarise the case for me and give me your differential diagnosis.

Mr Hughes is a 52-year-old teacher with no past medical history and no regular medicines. He has three months of weight loss despite an increased appetite, with heat intolerance, sweating, tremor, looser stools, poor sleep and irritability, and four days of continuous palpitations with a fast irregular pulse and mild exertional breathlessness. He has gritty eyes, his sister has hypothyroidism, and he smokes. My leading diagnosis is thyrotoxicosis complicated by new atrial fibrillation. The most likely cause is Graves' disease: it's the commonest cause, there's autoimmune thyroid disease in the family, and his gritty eyes may be early thyroid eye disease, although a stare can occur with any cause of thyrotoxicosis. The differential is a toxic multinodular goitre or toxic adenoma, and a painless thyroiditis; subacute thyroiditis is less likely without neck pain or a preceding illness, and he has no exposure to amiodarone, iodine or thyroxine. Weight loss with a good appetite points away from malignancy, but if his thyroid tests were normal I'd investigate it further.

His TSH is below 0.01, free T4 is 46 picomoles per litre and free T3 is 15. His full blood count, kidney and liver function are normal. The ECG shows atrial fibrillation with a ventricular rate of 120 and no ischaemic changes. How do you interpret these, and what else would you request?

This is primary hyperthyroidism: a suppressed TSH with raised free T4 and T3. The ECG confirms atrial fibrillation with a fast ventricular rate and no ischaemia. To establish the cause, I'd send TSH receptor antibodies. If they're positive, that confirms Graves' disease; if they're negative, a thyroid uptake scan would separate nodular disease from thyroiditis, which takes up little tracer. I'd request an echocardiogram to look at his valves and left ventricular function. The normal blood count and liver tests are a useful baseline before carbimazole.

How would you manage his atrial fibrillation?

Rate control with a beta-blocker. Propranolol is a good choice in thyrotoxicosis because it also eases the adrenergic symptoms, and he has no asthma; if a beta-blocker weren't suitable, I'd use a rate-limiting calcium channel blocker such as diltiazem. Digoxin works poorly while he's thyrotoxic. I wouldn't attempt cardioversion now: he's been in AF for more than 48 hours, and while he's thyrotoxic it's likely to recur. Many patients revert to sinus rhythm once they're euthyroid; if he doesn't, he'd be referred to cardiology to consider rhythm control. For stroke prevention, his CHA2DS2-VASc score is zero, so anticoagulation isn't indicated at present, but I'd recalculate it if anything changes.

You've said he can probably go home. How sure are you that he isn't in heart failure?

Not sure enough. I asked about breathlessness on exertion, which he has on the stairs, but I didn't ask about breathlessness lying flat, waking breathless at night or ankle swelling, and I should have, because fast AF with thyrotoxicosis can cause heart failure. That would make me more cautious with the beta-blocker and would mean admitting him. I'd go back and ask, examine him for signs of heart failure, and the echocardiogram would help.

And how would you manage the thyrotoxicosis itself?

I'd discuss him with the on-call endocrinology team today. With the biochemistry confirming hyperthyroidism and a picture pointing to Graves' disease, I'd start carbimazole with their agreement, alongside the propranolol, with written advice about agranulocytosis, and arrange early endocrine follow-up with repeat thyroid function tests. Longer term, the options are a course of antithyroid drugs, radioactive iodine or surgery. His eyes need assessing, because radioactive iodine can worsen thyroid eye disease, especially in smokers, so stopping smoking matters. He could go home tonight if his rate settles, there's no heart failure and no features of thyroid storm, such as fever, confusion or vomiting. His main concern was a heart attack like his father's; what matters most to him is walking his daughter down the aisle in five weeks, which I think is realistic.

Thank you. That's the end of the station.