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Wednesday, 18 June 2014

#ECGclass - Summer 3 - Aortic Stenosis and chest pain

Welcome! 
If you are new to ECGclass, b
efore we start, you may like to read this brief explanation of what it's all about:   #ECGclass and how it works

Each 'term' is spilt into 5 cases, launched a 2 weekly intervals.  

So here goes with the next case of this term!


Summer 3



A 49yr old man presents to you with a 6 month history of chest pain.

Sometimes this is triggered by exertion, sometimes at rest. 
It can be prolonged, often lasting several hours and on occasions, all weekend.
He considers himself fit and active, so he light-heartedly dismisses his symptoms, and works through his 'mild' discomfort, which is very localised in the left upper chest, without radiation. He has no arm pain, no dizziness, and no breathlessness. 
In fact, he has only presented under duress from his wife.

He is a non smoker, with no risk factors for IHD and not on any medication. 
On examination, as always, his BP is normal.  However, you do hear a systolic heart murmur at the left sternal edge.

You obtain an ECG below:


What are you thinking now?
What is your next step?



Update

You press him a bit further to try and establish more detail about his history...
His symptoms are indeed predictably triggered by exertion on every occasion these days, and whilst he considers them mild enough to continue exercising through, they will usually settle within a minute or two of resting. On the other hand, he also gets episodes which are totally unprovoked and out of his control which can be prolonged at rest.  

He admits that his symptoms have become more progressive in nature (in terms of both frequency and severity) since their onset, over the past 6months. 

He insists he has no dizzy spells, syncope, no palpitations and  no family history of heart disease. He has alwasy made healthy lifestyle choices and has no risk factors for IHD.

Have these new revelations altered your suspicions, or swayed the urgency of your management?



***

Discussion 

ECG :  Widespread T-wave inversion with chest pain at rest. 

It wouldn't be wrong to admit this man, on the basis of his rest pain, and ECG changes.  You can't reassure him that nothing adverse will happen if he stays at home. 
Is this acute coronary syndrome? 
Has he had a recent cardiac event with ongoing T-wave changes and unstable symptoms at rest? 
Was there a recent episode of pain that was more significant than the others?

On the other hand - he looks, and feels, quite well as he sits in front of you. He's clincially stable and given his dismissive nature, he may take some persuading to go in - but with rest symptoms he is at risk.


At very least, this presentation should prompt an urgent referral to the RACPC.  
In the meantime he should be started on aspirin, a beta-blocker and a statin and given GTN/999 advice. The referral should include a copy of his ECG and make note of the murmur
(Note: Not all RACPC are set up with ECHO facilities, so if this information is included with the referral, an "ECHO on arrival" request can be made by the clinician receiving the referral).

In this case scenario, the gentleman refused admission at time of presentation but an ECHO at RACPC confirmed severe Aortic stenosis.   As such, an  ETT was contraindicated.  

He required same day admission for monitoring, and an in-patient work up for diagnostic cardiac catheterisation to exclude coronary atheroma before dealing with his valve disorder. 

Aortic Stenosis as a cause of angina must not be missed

Aortic stenosis can cause cause anginal symptoms in people with healthy coronary arteries and it's management, is therefore, completely different.  Treating someone with antianginal therapy for "IHD", when they actually have undiagnosed aortic stenosis a). won't help them, and b). is indefensible. 
Severe anginal symptoms in an individual with low risk factors for coronary artety disease should always raise suspicion - but most importantly - examinination for a murmur should always be sought in those patients presenting with chest pain.  

Frequently, prolonged severe aortic stenosis gives rise to voltage criteria for LVH on the ECG. 

The above ECG shows no voltage criteria for LVH, and we know he is normotensive.

Below is another example of severe Aortic Stenosis, this time causing the typical 'strain' pattern seen with LVH:







Note the similarities in the two ECG's. 
However, in this second example, there is gross voltage criteria for LVH (fulfilled in Leads I, aVL, V1-6).  There is widespread T-wave depression, and typical of LVH,  T-wave inversion in the leads which face the left ventricle (i.e. leads I, aVL, v4-6).

T-wave inversion is also seen in leads V2 and V3.  This is suggestive of other pathology, such as co-existing coronary disease.



Lesson - Don't let the stoical nature of some patients disarm you! :-) 





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#ECGclass - Summer term Case 3


Welcome! 

If you are new to ECGclass, before we start, you may like to read this brief explanation of what it's all about: #ECGclass and how it works

Each 'term' is spilt into 5 cases launched a 2 weekly intervals.  

So here goes with the next case of this term!

Summer 3

A 49yr old man presents to you with a 6 month history of chest pain.

Sometimes this is triggered by exertion, sometimes at rest. 
It can be prolonged, often lasting several hours and on occasions, all weekend.
He considers himself fit and active, so he light-heartedly dismisses his symptoms, and works through his 'mild' discomfort, which is very localised in the left upper chest, without radiation. He has no arm pain, no dizziness, and no breathlessness. 
In fact, he has only presented under duress from his wife.

He is a non smoker, with no risk factors for IHD and not on any medication. 
On examination, as always, his BP is normal.  However, you do hear a systolic heart murmur at the left sternal edge.

You obtain an ECG below:


What are you thinking now?
What is your next step?

update

You press him a bit further to try and establish more detail about his history...
His symptoms are indeed predictably triggered by exertion on every occasion these days, and whilst he considers them mild enough to continue exercising through, they will usually settle within a minute or two of resting. On the other hand, he also gets episodes which are totally unprovoked and out of his control which can be prolonged at rest.  

He admits that his symptoms have become more progressive in nature (in terms of both frequency and severity) since their onset, over the past 6months. 

He insists he has no dizzy spells, syncope, no palpitations and  no family history of heart disease. He has alwasy made healthy lifestyle choices and has no risk factors for IHD.

Have these new revelations altered your suspicions, or swayed the urgency of your management?





DON'T FORGET!
Please use the hashtag #ECGclass if joining in the live and interactive conversation Twitter
and...If you want to ask the patient any questions, or request any further investigations this can  be done by the hashtag during the course of this evening. 


Alternatively, if referring to this blog at a later date, please leave comments below.
Thank you.



***



Discussion/update later/see next blog post once available

Wednesday, 4 June 2014

Summer 2 - Voltage Criteria for LVH

Summer term - Case 2

This 56yrs lady attends an appoitnment with your HCA requesting a 'well-woman' and blood pressure check.  After 3 repeated measurements, a minute apart, her mean BP is 146/90.
In accordance with the practice protocol, your HCA performs an ECG.

        Image courtesy of www.frca.co.uk 

What is your impression of this ECG?

Does she need any further investigations?

Does her Blood Pressure need treating?



*  *  * 

Discussion

The main purpose of showing this ECG is to discuss the various voltage criteria for left ventricular Hypertrophy (LVH). 

Interestingly, there is no one universally agreed criteria for diagnosis of LVH by ECG.  A few of the more commonly accepted ones are listed below. 

This ECG is compatible with Left Ventricular Hypertrophy (LVH) in that it meets the voltage criteria for LVH, in leads I and aVL.  
As no other criteria for LVH are met, it is often better to say ‘This ECG meets the voltage criteria for LVH’, rather than diagnose hypertrophy. Don’t forget, LVH can only be truly diagnosed on scanned images, such as an ECHO.

On crude eye-balling, the axis on this ECG is around -30 degrees ( -30 degrees falls within normal axis parameters). So whilst we have possible borderline Left Axis Deviation (LAD) it's probably not significant without a predominantly negative deflection in lead II as well.

The ECG also shows T wave inversion in Lead I and aVL .  When seen together, a leftward axis and T wave inversion, would further support the diagnosis of LVH and strain (see below).

In accordance with latest NICE Hypertension Guidelines, you may want to offer this lady an ambulatory BP monitoring (ABPM), or Home BP monitoring (HBPM), for confirmation of diagnosis.

Her CVD risk and any target organ damage, should also be assessed. Urinalysis should be checked for proteinuria, and bloods for underlying causes, or evidence of target organ damage (including U&E's, Glucose).

Regardless of whether she turns out to have Stage 1 or Stage 2 Hypertension on the basis of her ABPM (see page 6 of NICE 2011 Hypertension Guidelines – CG127) her LVH will certainly sway you towards a lower threshold to treat. 

The clinic BP described for this lady is surprisingly low for someone with LVH and strain. In this situation, ABPM may demonstrate higher pressures than seen in clinic – known as ‘masked hypertension’ (a condition less recognized and less discussed than ‘White Coat Hypertension’) and that would reinforce need for antihypertensive treatment.  More commonly, significant obesity can add to the effects of hypertension so an assessment of weight and lifestyle is also appropriate.


LVH

Left ventricular hypertrophy is defined as an increase in the mass of the left ventricle, which can be secondary to an increase in wall thickness, an increase in cavity size, or both. LVH as a consequence of hypertension usually presents with an increase in wall thickness, with or without an increase in cavity size.  Accurate assessment thus requires imaging with either echo or, even better, cardiac MR. Various ‘voltage criteria’ seen on ECG, however, can be suggestive of LVH.

The Left ventricle is represented by leads v5 and v6, so in LVH, we expect the ‘R’ waveforms to be enlarged/tall in these leads.  (Conversely, we expect the ‘S’ waves to be deep in the right ventricular leads, that is V1 and V2).

Suggested voltage criteria for LVH include:

        The sum of the S wave in v1 or v2, PLUS the R wave in v5 or 6 35mm,   OR,
          The sum of the deepest S wave +  the tallest R wave  > 40m
        Any single, R or S, wave in leads v1-v6  45mm
        The R wave in aVL   11mm
        The R wave in lead I 12mm
        The R wave in aVF 20mm

The predictive value of the voltage criteria is cumulative. i.e. The more voltage criteria met, the greater the likelihood of LVH.

An ECG diagnosis of LVH is also more secure when there are associated ST/T wave changes rather than voltage criteria alone, as in the example above.

In the ECG above, the precordial leads do not meet the voltage criteria for LVH (arguably borderline, at 35mm).

Many clinicians are aware of the R and S wave criteria in the precordial (chest) leads, but this can be dependent on body habitus. The chest leads placed on a tall, thin man, with little adipose tissue, are in close proximity to the heart so naturally, the waveform amplitude in the chest leads will be large.   The limb leads, being less affected by body habitus, are often more reliable in these individuals.  

To ECHO or not to ECHO?

One of the most common questions I’m asked by GP colleagues when they see and ECG which is reported as ‘LVH’ is ‘do they need to request an ECHO?’  Generally speaking, unless it is likely to change your management plan, an ECHO is not required to confirm a diagnosis of LVH.  If a patient with who is hypertensive is found to have LVH criteria on ECG, then an ECHO is only helpful if it will alter your threshold for treatment. If you plan to treat anyway, an ECHO is of dubious further value. 
 (See 2011 NICE CG127 Hypertension Guidelines for care management pathways).  

As outlined above, voltage criteria for LVH in V1-V6 alone, in a tall thin person, without other cause for concern, it not necessarily indicative or LVH, and doesn’t need an ECHO. Conversely in an obese patient, the body fat between ECG lead and heart will result in a lower voltage in the precordial leads, and that may be the explanation in this case.
So remember - Don't just look at the chest leads! 

Likewise, with an ECG suggestive of LVH in a normotensive person, an ECHO would only be indicated if a). Body habitus didn't explain the amplitude, or b). There was other signs/symptoms of concern (Possible HOCM? or Aortic Stenosis?).
In such cases, there would often be other suspicious features on the ECG (such as T wave changes) or symptoms of possible cardiac origin. Sinister underlying causes are less likely on the basis of simple voltage criteria for LVH alone.


Strain pattern
When LVH is associated with other pathology, such as hypertension or aortic stenosis, a 'strain pattern' is often seen:

        ST depression + flipped asymmetric T wave
        ST elevation + upright asymmetric T wave
        The strain pattern is greatest in the lead with the tallest/deepest QRS complex (seen in Lead I and aVL in the example above).

***


I hope this very simplified take on LVH helps clear up some of the conundrums around LVH, ECHOs and Hypertension – for GPs at least. 


Thank you. :)




#ECGclass - Summer Term - case 2

If you are new to ECGclass - Welcome!  Before we start you may like to read this to help explain what it's all about - #ECGclass and how it works

Each 'term' is spilt into 5 cases launched a 2 weekly intervals.  So here goes with the second case this term!


Summer term - Case 2

This 56yrs lady attends an appointment with your HCA requesting a 'well-woman' and blood pressure check.  After 3 repeated measurements, a minute apart, her mean BP is 146/90.
In accordance with the practice protocol, your HCA performs an ECG.

        Image courtesy of www.frca.co.uk 


  • What is your impression of this ECG? Is it normal?



  • Does she need any further investigations?



  • Does her BP need treating?

Please feel free to join in and ask questions, or simply follow the conversation thread on Twitter - but most importantly.don't forget to use the hashtag #ECGclass in your responses!  

Have fun. 



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