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Tuesday, 27 November 2012

Management of Recent Onset Chest Pain

Today's #ECGclass is looking at the management of recent onset chest pain. 
This case comprises of  6 questions, with updates after each. 
It's requires a bit more interaction than usual (!),  so if you're feeling brave, please do use the hashtag #ECGclass and join in.  
It's a bit drawn out, so we'll see how we do for time, but may spread the updates out over a couple of days.  

Keep posted as the case evolves!

Remember there are no right or wrong answers and everyone's opinion is valid. 
Do feel free to join in, and most important of all, have fun! :-)

OK. Here goes....

Case 17

A 52 yr old gentlemen comes to see you complaining of intermittent chest pains for the past 3 weeks.

Q1. What do you want to know?

Please use the  #ECGclass to ask anything else you want to know about this man's symptoms.

Update 1
You establish that prior to 3 weeks ago, he was symptom free and quite active for his age.
Over the past 3 weeks he has noticed a dull left chest discomfort, which is very mild, but comes on after 5 minutes of walking. This is quite reproducible each time he walks, but only lasts a couple of minutes once he stops and rests.
Sometimes it travels upwards, to both his shoulders and arms.
It has never come on at rest, or overnight.

Q2. Is there any other information you want to know?
Please use the #ECGclass 

Update 2
You want to establish some information about his risk factors.
He not is on any medication, has never smoked,  and is not overweight.
He has not had any blood tests for several years.
He has no family history of significant IHD (<65yrs in women or <60yrs in men).
In more recent years, he has suffered with a bit of indigestion after meals, but not sufficient to require any treatment.

You examine him.  His heart sounds her normal (no murmurs), and his BP is 132/76. His pulse is regular and strong at a rate of 78/min.
There is no chest wall or epigastric tenderness.

Q3. What now?

Update 3
Based on his symptoms, you make a clinical diagnosis of Angina.
You explain your thoughts to him, and start him on Aspirin, a beta-blocker and a Statin with some GTN and 999 advice.
You explain you would like to refer him the the Chest Pain clinic (RACPC) to get further information on the severity of any coronary heart disease.
Meanwhile you arrange an ECG, and some bloods to rule out secondary causes of angina (FBC, glucose, TFTs, lipids, U&E's and eGFR)

His resting ECG is below:

Q4.  If his Cholesterol level comes back at 5.8 mmo/l, use the information you have so far to to work out the % probability, that his presenting symptoms are a result of significant underlying IHD.  
Hint: Use the useful tool calculator below, kindly provided by West Herts Hospitals, to calculate his CAD risk probability (This on-line tool is just a simplified version of 'Table 1' - the CAD risk chart provided in the NICE 2010 chest pain guidelines):

 Coronary Risk Assessment Tool

(N.B. Don't confuse this with the 10yrs CVD risk score (eg Framingham) we frequently use to consider need for Primary Prevention strategies, in an asymptomatic person. This Coronary Risk Tool is ONLY for use with patients who present, with ischaemic sounding chest pain).

Next,  using the link below, refer to the NICE 2010 Clinical Guidelines for 'Chest Pain of Recent Onset'  (CG95) and determine what is the next most appropriate investigation?

For quick reference, refer to pages 12-14:

NICE 2010 Management of Chest Pain of Recent Onset - CG95

Please use the #ECGclass to share your findings.

Update 4
He attends his appointment at the RACPC within 42hrs of your referral. The team there get the same consistent history, and agree with your clinical diagnosis of angina. He is already feeling some benefit since starting on the beta-blocker, but hasn't had chance to trial the GTN yet.
The baseline ECG, above, is noted to be normal.

His CAD risk score is calculated at 74%.

On the basis of NICE guidelines, he is offered a Diagnositic Angiogram the following week.
His response to medically therapy can be reviewed when he attends for his angiogram, to consider the need for further intervention at that stage.

In the meantime, he is offered an Exercise ECG to help give prognostic information and risk stratification.
(In accordance with NICE, ETT should not be offered to people in whom a clinical diagnosis of angina has not been made. ETT, with its poor sensitivity and poor specificity, has NO role in the diagnosis of  IHD. It is certainly not a screening test for angina, but offers useful prognostic information, once a diagnosis has been made).

On the treadmill, he develops chest pains after only 3 minutes of the Bruce Protocol, and by 4 minutes he has the following exercise ECG trace:

Q5.  What do you think of the ST segments?  Just describe what you see. 
ST segments should be described in relation to the baseline - i.e. baseline, elevated or depressed?
Furthermore, as you recall from last week, elevated ST segments can be described as convex (eg STEMI),  saddle-shaped (eg pericarditis) or upsloping (e.g.. Bengin high take-off).

Likewise depressed ST segments can be 1. Upsloping ( often normal on exercise),  2. Horizontal (ischaemic)  or  3. Downsloping (more severe ischaemia).

So #ECGclass - what do you think??

Update 5
In general, symptoms coupled with 2mm of horizontal ST depression on Exercise ECG, is indication of significant ischaemia, and the test should be stopped.
(Without any symptoms, 3mm horizontal ST depression is the diagnostic threshold for the test should be stopped).

The above ECG shows significant, horizontal ST depression, which is widespread.
Inferior leads: Lead II looks a little upsloping, but leads III and aVF have 2mm of horizontal ST depression.
Lateral Leads V4-V6: There is 3-4mm of horizontal ST depression
aVR: You might also have noticed the elevation pattern seen in aVR.

This 'reciprocal' ST pattern in lead aVR during in an ischaemic ECG, in considered a high risk sign, and usually suggests major vessel disease.

The fact that these changes have been triggered in under 6 minutes of exercise, makes this a STRONG POSITIVE TEST and puts him in a high risk group.
The treadmill is stopped and his ECG is monitored further in recovery.

Now look what happens as he rests:

Q6.  What do you think of the above ECG changes (after 6 minutes of rest)?

Update 6
Despite his pain settling within 1-2 minutes of resting, his ST changes have continued to progress.
See how they are now downsloping inferolaterally, with flipping of the T waves.
That nasty, sinister,  reciprocal change in aVR persists.
So despite him feeling fine, his heart is still struggling. Assuming we haven't triggered an ACute Coronary Syndrome on the treadmill, these changes will almost certainly return to baseline over then next 10-15 minutes.

A week later, this man's Angiogram confirmed major vessel disease, which was not correctable by PCI. He was referred for urgent CABG. Of course, even very severe IHD such as this, cannot be ruled out  by his perfectly normal resting ECG.

Thank you so much for your time and for joining in.
The end.

In the light of several comments received during this #ECGclass, it is clear there is still a lot of uncertainty and confusion over the NICE chest pain Guidelines.
In view of this, I have added another blog for those interested, (see next) in an attempt to help clarify things.
H. :-)

1 comment:

  1. I did not know much about ECG, your blog has made me understand the basic things and what to ask when I go for ECG during chest pain.