Author: Chris Connolly / Questions: Chris Connolly / Codes:  / Published: 06/02/2018

Chest pain is one of the most common reasons adults come to an ED. By the end of your placement you should be awesome at reading ECGs, and be some way along your journey to ‘getting’ who needs tests and who doesn’t.   Not an expert, not amazing, just better than you are now. Expertise takes time…most of your seniors are still on that journey too (and I also put myself well and truly in that camp!!!). Make sure you have bookmarked LITFL ECG library and Dr Smiths ECG blogs as 2 go-to guides, and if you’re more into paediatric ECGs, visit our blog here.

Let’s take things by diagnosis of badness.

Myocardial Infarction or ACS

The first part of your patient encounter should include taking a history. We know about history taking in suspected MI right? Chest pain, radiating to the left arms and jaw, sometimes just left arm pain….easy? Nope.

There is a great summary of the bigger published papers on predictive features here from Salim Rezaie.

In terms of history features – there is NO FEATURE that can rule in or (more importantly) RULE OUT the cause as being cardiac or non-cardiac. Reproduction with palpation is not a valid reason to not investigate someone further, neither is a history of GORD or associated belching – in fact there’s some evidence out there that the presence of belching may be associated with inferior MI.

The next part of you encounter MUST include a careful look at the ECG. Getting skilled at this is important, for EM, for medicine, for life….

Make sure you know what a STEMI mimic is. You have to know these as they are the first group of patients that can really trip you up. If you don’t know what Wellen’s syndrome is, you need to know. You can’t diagnose what you don’t know. And if you don’t appreciate that ST depression doesn’t localise, and therefore you should be looking for the reciprocal ST elevation, then you will NEVER call it. You have to be the master of this. Check out the EMDocs’ posting on these.

Once you’ve identified a concerning history and hopefully decided there’s no active ECG changes you’ll probably want to do some further tests. It is important to know what your local policy is and what risk scoring system you use, there are hundreds to choose from, but commonly used and quoted are HEART, EDACS, ADAPT, T-MACs, TIMI, GRACE etc. etc. Interestingly there is also some emerging evidence (largely from Rick Body in Manchester) about limit of detection models using a high sensitivity troponin and a normal ECG to exclude significant cardiac disease. This is a really interesting and exciting area of research but as previously mentioned, relies heavily on the ECG interpretation.

Aortic Dissection

“Remember that patient you saw on Sunday evening” – words that cause us all to feel sick to the pit of our stomachs. This is one of those diagnoses that make those words happen. ED misses these. It happens. It’s devastating for the patient and family and clinician when it happens. Don’t let it be you.

The aorta will *%&” you up. One of the best talks from SMACC (well ever actually) is on this exact topic and I really hope you’ll take the 20mins to go and listen to it.

The key learning point for me when thinking about dissection is that it can present in a multitude of ways, and the only way to diagnose it, is to think about it. I am concerned when someone has chest pain that makes them uncomfortable, not in a ‘trapped wind’ sort of way, but in a renal colic way. Sweating, needing lots of opiates, agitated. Patients like these need investigating.

Patients with chest pain and neurological symptoms need testing.

Chest pain and limb ischemia: test them.

Dr Carr talks about the notion of chest pain +1 and this is a great mind-set to have when considering a diagnosis of aortic dissection. But remember if you don’t think about it, even when its hiding in plain sight, you CANNOT diagnose it.

The test you want is an aortogram. This is the gold standard. I’m lucky, I’m a consultant that works in an ivory tower and can access a scan easily. I appreciate not all hospitals have this facility and ease of access. If this is your place find out how they want you to investigate, ultimately ending up at a CT –it may be a combination of Chest X-ray, D-Dimer and ECHO but please involve your senior colleagues as soon as you are considering dissection as a diagnosis.

There’s been a lot of excellent work from RCEMlearning on aortic dissection, and we recommend you listen to this great podcast, and read this blog, as well as consider reading our reference guide and learning module.

Pulmonary Embolus

So, PE. This is a cause of great discussion on social media, in EDs and on the wards. It’s probably because they kill young people. Often without warning. Patients may present with any number of symptoms including chest pain that may be constant and sharp and worse on breathing. It may not. It may cause them to have transient loss of consciousness. It may not. It may present with shortness of breath, dry cough, wet cough, haemoptysis an isolated tachycardia. It may not.

But don’t worry too much.

What should you do? First (and it goes without saying) check your department’s suspected PE protocol. If they don’t have one, why not write one?

An approach that’s used in lots of places is to apply the PERC criteria to patients with suspected PE. PERC works by trying and clinically ‘exclude’ PE by identifying those who are higher risk and also identifying those who won’t benefit from further testing. I.e. we’re back to the ‘first do no harm’ thing here.

You may still miss around 1.5% of PEs.. BUT you are unlikely to miss a big one, and you are more likely to do harm by investigating further.. and the risks of false positive testing… and the harms from mis-treatment with anticoagulants.. and the ‘incidental-omas’..the list goes on. (St Emlyn’s have a superb piece on this)

Now an important thing to note is that the PERC negative patients have to have been assessed by the attending clinician to be low risk for PE in the first place. There is some debate about what this constitutes and a number of places I have worked have suggested that applying the Wells’ score and a patient who is low risk on this is suitably and objectively deemed low risk.

Once you have deemed someone is not low risk for a PE, and you think they probably have a PE as the cause of their symptoms then depending on where you work you need to do more tests. This may include a D-dimer (depending on how not low risk they are), a Chest X-ray and then a CTPA.

Treatment for PE is with anticoagulation and in cases of instability consideration of thrombolysis – if you have an unstable patient in your department with a big PE then you MUST involve your senior docs and maybe get some help from your friendly ICU team depending on how your unit is set up.

There is still some debate about who should get thrombolysis in certain circumstances, and what you’re hoping to achieve by doing it – I think we’re all happy in cardiac arrest and in the crashingly unstable patient but there is some debate about submassive PE (have a read of some great work here).

Pneumothorax

This is another relatively common reason for complaining of chest pain.

We all have learned the dos and don’ts with pneumothorax haven’t we? The signs of a tension? The site for needle decompression in the tension situation? Course you have?

Check out the following links for the info that’s needed to be real world knowledgeable on the subject:

  1. Signs and symptoms in tension pneumothorax – chest pain and respiratory distress. I think of it as compartment syndrome of the chest, the patient looks scared, the patient looks sick. The other stuff, well that happens rarely – tracheal deviation <25% of cases, hyper-resonance <10%. Have a read here for the full open access article.
  2. Decompression we all “know” is aimed for best with a needle in the 2nd intercostal space, mid-clavicular line right? Maybe not. I wonder if the increasing size of our population has to bear some responsibility here but have a look at this from REBEL-EM. In short, the better place is in the 4th or 5th IC space in the anterior axiliary line as you’ll fail less often here and ATLS has updated their guideline to reflect this.
  3. Diagnosis of pneumothorax is classically taught as x-ray findings and the BTS guidance talks about management based on size of the collapse at the hilar level. The emerging modality of lung POCUS should be considered as a diagnostic tool, but this is a skill to be learned and developed over time. Get your local trainers to show you how, develop some deliberate practice and go from there. These are a great set of videos to whet your appetite.

Other stuff…..

So, you have a patient with chest pain. They’re in pain. Proper pain. But its none of these conditions. What else could be going on?

  1. You’re wrong and they have one of these conditions. Honestly, if a patient is telling you something is seriously wrong, believe them, get a senior review, challenge your diagnostic biases.
  2. It could be shingles. Neuropathic pain from shingles can present after the rash or without the rash entirely. It can be really painful so if the pain is in a nerve root distribution then have this near the top of your working differentials.
  3. Pain that radiates from the back or to the back could be from the thoracic spine. Be suspicious of this and examine carefully in the elderly (fragility fractures, myeloma), those with a history of cancer (mets) and those with a history of fever (discitis, TB, epidural abscess).
  4. Be really cautious about making a diagnosis of ‘musculoskeletal chest pain’ in someone without a history that fits, i.e. if they weren’t at the gym working the pecs the day before then don’t go for it. You’ll trip up eventually and the consequences could be disastrous!

This is a really brief run thorough of the challenges around diagnostics in chest pain. It’s a really common reason to come to ED and some of the potential differential diagnoses are life threatening. If in doubt when assessing your patient ask. Remember the RCEM standard that anyone >30 with chest pain you want to discharge should be discussed with an ST4+ prior to discharge. Don’t neglect this. Most importantly enjoy your time in ED, you’ll learn more with us, see more, do more than in any other job you do. Promise.

This week’s infographic is The Spectrum of Pathology Presenting with Chest Pain. Thanks for the response for the previous weeks. It’s been great fun. I hope you like this one as well. More sizes and formats here https://t.co/N8iVKPzCAt #FOAMed #infographic pic.twitter.com/slOfkWn94l

— Strata5 (@Nrtaylor101) April 2, 2018