The St.Emlyn's Podcast

Do you remember when it took three days to 'rule in' or 'rule out' an acute myocardial infarction (AMI)?  When I was a medical student doing my first clinical attachments, I remember doing ward rounds on the CCU seeing patients with suspected AMI.  The way they were managed is a million miles from what we do now.  Back then, patients would have serial ECGs and then be admitted for cardiac enzyme evaluation over the course of the next 3 days.  We'd measure CK, AST and LDH.  'CK' was the so-called 'early marker', which would rise early after the start of an AMI.  Today we use CK as a marker of skeletal muscle damage (e.g. rhabdomyolysis).  AST and LDH (today we think of these as liver function tests, I know) were the 'late markers' - and by late I really mean late - we might see a rise on days 2 and 3.

Could you imagine for a second, in today's world, ruling out AMI because their CK and LFTs were normal?  It's completely unthinkable.  That's how much cardiac troponin has changed our practice.  We rely on it so completely to diagnose AMI.  And yet, it's one of the most misunderstood tests in medicine.  Given how much we use it, I guess we feel that we all should know lots about this test.  But doctors still have so many questions.  Here are just a few:

• What is cardiac troponin?
• Why is it a marker of AMI?
• What else causes a raised troponin and how?
• Should we be doing troponins at 3 hours, 6 hours, 12 hours?  What's the difference and what's the evidence?
• What is a 'delta troponin'?
• What do you need to 'rule in' AMI?
• How do you use cardiac troponin in patients with renal failure?

This is just a brief list.  With the research I do in this area and my experience developing protocols/guidelines, people get in touch to ask questions like this quite a lot.  There are loads of questions that people ask - but there are lots of themes in common.  We thought it was about time we produced a handy run down in the true spirit of #FOAMed.

Take a listen to Part 1 of our troponin podcast.  While Simon and Iain have been prolifically churning out spectacular stuff for some time now, this is my debut on the St. Emlyn's podcast.  I really enjoyed talking about troponin with Iain - and I hope we covered some useful stuff.

We'll cover more in part 2, when we'll move on to discussing high sensitivity troponins, what they are, how to use them and how to speak the troponin lingo.  Please get in touch if there's anything we haven't covered that you'd like us to, or if there's anything you'd like us to elaborate on some more!

Rick

Recently we published part one of our series on cardiac troponins.  If you haven't checked it out yet, you can find it here.    In the second part, we're going to take a look at high sensitivity troponins and some of the more advanced areas around understanding cardiac troponin and its use in practice.  We'll give you a quick run down on the troponin lingo - the language you need to be able to speak in order to fully understand how to use high sensitivity troponin in your practice, including terms like the limit of blank, limit of detection, co-efficient of variation and 99th percentile.

We'll also ask whether Joe Lex had a point when he stirred up controversy around these assays with this legendary tweet:

What if we called it "low specificity troponin" instead of "high sensitivity troponin?" Would that knock some sense into people?

— Joe Lex (@JoeLex5) October 9, 2012

So, check out the associated BLOG POST here and listen to the podcast. There is more on diagnostics and troponin to come very soon.

Hope you enjoy! Please keep the feedback, questions and comments coming. As always, we'd love to hear from you.

Rick

DOI: Much of my research work involves HsT. To help with this I have received reagents from companies who make HsT assays, but I not received any other financial benefit or gifts in kind as part of my work and have no financial ties to any companies.

Rick and Iain explore how the latest guidance about the use of high sensitivity troponin was developed and how far we can be assured that it is evidence based.

The NICE guidance is available here. http://www.nice.org.uk/guidance/dg15

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Live from the London Trauma Conference 2014. Iain Beardsell interviews Mark Wilson on the need for rapid response, digital technology and the GoodSAM app.

Barbra Backus joins Rick Body to discuss the origin, development and future of risk scores for ED patients with possible acute coronary syndromes. Two researchers at the top of their game, and  authors of the HEART and MACS scores.

Salim Rezaie from the REBEL EM podcast takes us through the optimal management of cardiac arrest and also explores some of the controversies and difficulties that make the difference to our patients. 

You can read a lot more about the background to this talk, see the evidence and watch the video on the St Emlyn's site. Just follow this link. https://www.stemlynsblog.org/beyond-acls-salim-rezaie-at-stemlynslive/ 

Back in late 2018 we gathered in Manchester for the inaugural #stemlynsLIVE conference. Our friend Dr George Wills gave a great talk on Aortic Emergencies.

All emergency physicians know that it's all to easy to miss an aortic catastrophe. Listen to George's wisdom on common pitfalls and top tips to make you a better emergency clinician.

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Also check out these excellent #FOAMed resources.

• Subscribe to the blog (look top right for the link)
• Subscribe to our PODCAST on iTunes
• Follow us on twitter @stemlyns
• PLEASE Like us on Facebook
• Find out more about the St.Emlyn’s team

Here’s our regular monthly round up of the best of the blog from March 2019

This is the first in a two part podcast series discussing Adult Congenital Heart Disease (ACHD) and how these patients may present to the Emergency Department (ED). Dr Sam Fitzsimmons, our guest on the podcast, is a Consultant in Adult Congenital Heart Disease at University Hospital Southampton. There is more information in this blog post.

Look out for Part 2, which will be released next week, where we discuss Eisenmenger Syndrome, Transposition of the Great Arteries and Coarctation of the Aorta. 

Background

With advances in paediatric cardiac surgery, more and more patients with complex congenital heart disease are surviving to adulthood: in the 1950s you might expect a survival rate of about 10%, whereas now this is more like 85%. In fact, there are more patients in the adult congenital heart disease population than there are in the paediatric one (with 2.3 million adults vs 1.9 million children in Europe).

Many patients with Adult Congenital Heart Disease are young and able to live a relatively normal life. This means that they can travel and take part in just the same sort of activities as those without ACHD. They may well turn up in your Emergency Department one day, regardless of whether you are a tertiary centre or a district general hospital (DGH).

They are experts, and know their disease well, but this does not abstain you from a responsibility to know about them too! When these patients become unwell, they can go downhill very fast and you may not have the chance to discuss with them their exact lesion and its management.

The anatomy and physiology of these patients is abnormal, so they may present in atypical ways, and may not respond to usual medical interventions: in fact, some of our usual treatments may even be harmful.

However, starting with our usual 'ABC' approach is by far the best way to go, whilst gathering more information and contacting their specialist centre. Many patients will have their last clinic letter and ECG with them (which will also have the direct dial number of their specialist). And if they, or their relative, say there is something wrong you must believe them and do all you can to make sure they are fully investigated.

The presence of scars may give you some clues as to the patient's underlying condition and previous surgical repairs. (BMJ 2016; 354: i3905)

A General Approach

• Do your usual ABC assessment.
• Pay particular attention to the respiratory rate - this should be normal.
• Give oxygen if they look unwell.
• They should have a 'normal' blood pressure - any hypotension should be taken as abnormal and investigated.

The Fontan Circulation

This is not a condition in itself, but in fact the resulting circulation after a series of operations that could've been performed due to a number of different underlying conditions:

• Tricuspid Atresia
• Double Inlet Left Ventricle
• Atrio-ventricular Septal Defect – unbalanced
• Pulmonary Atresia
• Hypoplastic Left Heart Syndrome

In essence these patients are born with a single functioning ventricle, that has to be utilised to supply the systemic side of the circulation, whilst the Fontan acts as a passive means of returning blood to the pulmonary circulation.

It was first devised in the early 1970s by Dr Francis Fontan, so the majority of patients with this are in their mid thirties and younger.

Potential reasons for admission to the ED - Fontan circulation

1, Arrythmia

As the patient is entirely dependent on their systemic ventricle to work optimally, any disturbance of the delivery into it is very poorly tolerated. Thus, any arrhythmia is life threatening, even a mild atrial tachycardia.

These patients need to be returned to sinus rhythm as quickly as possible and the recommended method for this is DC cardioversion in expert hands.

Fontan patients have an incredibly fragile circulation and any change in their respiratory physiology can be life threatening, especially if it increases their pulmonary pressures (and thus prevents the passive flow within the Fontan circulation). These patients are not candidates for sedation in the ED and should have an experienced anaesthetist to manage them during the procedure.

Beware if the patient comes in and tells you they are fasted! This means they have been in this situation before and needed DC cardioversion.

2, Haemoptysis

Over time the patient develops venous hypertension within the Fontan connection. This causes the formation of collateral vessels, that may link into the bronchial arterial tree.

If the patient presents in shock treat them as you would any other patient with emergency blood transfusion.

Any haemoptysis, however small, may herald the beginning of a massive bleed. These patients need further investigation, probably a CT chest with contrast. These vessels may then be coiled by interventional radiology.

3, Cyanosis

If the patient has a non fenestrated Fontan they should have normal oxygen saturations. However, if there is a fenestration there will be shunting and therefore a reduction in oxygenation.

For patients this is trade of between being pink or blue, each of which have complications.

Dr Sam Fitzsimmons

Dr Sam Fitzsimmons is a Consultant Cardiologist in Adult Congenital Heart Disease (ACHD) at the University Hospital Southampton, UK. Sam also subspecialises in pulmonary hypertension and maternal cardiology. Working within a tertiary surgical ACHD centre, Sam delivers an ACHD on call service for emergency admissions, inpatient care, routine outpatient follow-up, intra-operative imaging and post-surgical care, as well as specialist clinics in Pulmonary Hypertension and Maternal Cardiology. Sam holds a Honorary Senior Clinical Lecturer post with the University of Southampton as she is passionate about teaching and in particular, she is enthusiastic about helping demystify congenital heart disease for many non-specialist to improve patient care. Sam is well published in peer review journals, cardiology textbooks and specialist guidelines.

This is the second in a two part podcast series discussing Adult Congenital Heart Disease (ACHD) and how these patients may present to the Emergency Department (ED). Dr Sam Fitzsimmons, our guest on the podcast, is a Consultant in Adult Congenital Heart Disease at University Hospital Southampton. There is more information in this blog post.

In this episode we discuss Eisenmenger Syndrome, Transposition of the Great Arteries and Coarctation of the Aorta. 

This is the first podcast in our new series from St Emlyn's Medical School. They are specifically aimed at healthcare students and focus on the Medical Licensing Assessment (UK) presentations in particular but will be useful wherever you listen in the world. 

Each episode has a standard format with a case to set the scene, a set of learning objectives, a discussion, a summary and a case resolution. 

There are comprehensive listening notes on the dedicated website, as well as a growing set of other resources. 

We hope you enjoy listening. The rest of the podcasts can be found on Spotify, or wherever you get your podcasts. 

The music for this series (just as it is for the St Emlyn's Podcast) is composed by Greg Beardsell

Our monthly podcast round up from St Emlyn's Blog. This month Simon and Iain discuss the prehospital use of troponin measurement in the assessment of patients with chest pain and the use of AI in medicine, as well as an update about St Emlyn's WILD.

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