Wednesday, 29 January 2014

ECG of the Week - 27th January 2014 - Interpretation

This week's ECG is from a 51yr old who presented with a post-prandial episode of syncope and subsequent sensation of episodic pre-syncope. No relevant past medical histroy or medications.
Check out the comments from the original post here.


Click to enlarge


Rate:

  • 66
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • LAD
Intervals:
  • PR - Normal (~200ms)
  • QRS - Normal (100ms)
  • QT - 400ms (QTc Bazette ~ 430 ms)
Segments:
  • ST elevation with coved morphology in leads V1 (2mm) and V2 (~3mm)
  • Upsloping ST depression leads II, III, aVF, V4-6
Additional:

  • T wave inversion leads V1, V2, aVR
  • Partial RBBB
  • Movement artefact obscures partially leads aVR, aVF, aVL

Interpretation:


  • Brugada Pattern
    • Patient with history of syncope
    • Type 1 pattern

What happened ?

The patient was admit to the Coronary Care Unit, continuous telemetary did not capture any episodes of arrhythmia. Investigation of alternate causes of syncope were performed with normal echo, negative troponins, and normal CT head.
The patient underwent ICD implantation, with a Boston Scientific Incepta Single Chamber ICD, and at ICD insertion VF was inducible on right ventricular long burst.


Brugada Resources / Cases

We've had a case of Brugada before on ECG ot the Week here, which also prompted a 'guest editoral' post by Dr Ken Grauer which you can find here.

I've copied the Brugada overview and resource section from our previous post below.

So what is Brugada Syndrome ?

It's an inherited sodium channelopathy, associated with sudden death and syncope due to polymorphic VT and, as in our case, VF. 
Three types of ECG pattern are describe in Brugada, although only type 1 is considered diagnostic, as shown in our ECG.  

Type 1 ECG pattern:

  • Cove-shaped ST elevation of at least 2mm followed by a negative T wave in one or more of leads V1-3
In conjuction with these ECG features you need, at least, one of the following:
  • Document VF / polymorphic VT
  • Family history of sudden cardiac death at <45 years
  • Type 1 pattern ECG i n family members
  • Inducibility of VT with programmed stimulation
  • Syncope
  • Nocturnal agonal respiration
    • Attributed to self-terminating VF/polymorphic VT
The above diagnostic criteria are taken from the CSANZ (Cardiac Society of Australia and New Zealand) Guidelines for the diagnosis and management of Brugada syndrome, this document is well worth a read as it covers pathophysiology, diagnostic criteria, management, and includes examples of the type 2 and type 3 ECG patterns. 

Also check out the following great blog posts on Brugada:

What to do about it ?

As an emergency physician encountering a case of suspected / likely Brugada it's easy, phone your cardiologist. For those patients with a Brugada pattern ECG with a history of syncope, arrest, or arrhythmias, definitive treatment is an AICD insertion. The incidental Brugada pattern in the otherwise well patient is a bit more controversial, again from an Emergency Medicine perspective phone your cardiology team. The CSANZ guideline contains a nice algorithm for the diagnostic approach to Brugada and also discusses management strategies in the incidental and asymptomatic Brugada.

We should also be aware that some drugs can cause Brugada-like ECG changes and should be avoided in patients with known or suspected Brugada. For more information on what not to give go to www.brugadadrugs.org which contains information for both clinicians and patients.

Check out these cases from Dr Smith's blog, here, and here, which illustrate Brugada-like changes secondary to drug therapy.

Avoiding certain drugs raises the question what should we give ?

The simple answer is electricity in the setting of acute arrhythmia. 
In those patients experiencing an arrythmic storm, or having repeated ICD shocks then iv isoprenaline has been proven to be useful and is recommended in the CSANZ guidelines.
For chronic prevention of arrythmia's the only oral agent shown to work is quinidine, but this is often very difficult to source. 

Ii is also worth noting that fever can unmask Brugada, due to impaired sodium channel function and aggressive management of fever should be instigated. Other potential precipitants include alcohol, hypokalaemia, cocaine, large carb meals, and very hot baths.

But I'll never see it ?

The simple answer to this is that it's entirely possible you will in real life and in the exam setting as in this question from the FACEM exam 2013.

The issue is will you recognise it?




    References / Further Reading
    Some interesting articles / guidelines
    • Guidelines for the diagnosis and management of Brugada Syndrome. Cardiac Society of Australia and New Zealand. 2011. Full text here.
    • Ohgo T, Okamura H, Noda T, Satomi K, Suyama K, Kurita T, Aihara N, Kamakura S, Ohe T, Shimizu W. Acute and chronic management in patients with Brugada syndrome associated with electrical storm of ventricular fibrillation. Heart Rhythm. 2007 Jun;4(6):695-700. Epub 2007 Feb 20. PMID: 17556186
    • Nademanee K, Veerakul G, Chandanamattha P, Chaothawee L, Ariyachaipanich A, Jirasirirojanakorn K, Likittanasombat K, Bhuripanyo K, Ngarmukos T.Prevention of ventricular fibrillation episodes in Brugada syndrome by catheter ablation over the anterior right ventricular outflow tract epicardium. Circulation. 2011 Mar 29;123(12):1270-9. Epub 2011 Mar 14. PMID: 21403098  Full text here
    • Maury P, Hoicini M, Haissaguerre. Electrical Storms in Brugada Syndrome: Review of Pharmacologic and Ablative Therapeutic Options. Indian Pacing Electrophysiol J. 2005 Jan-Mar;5(1): 25-34. PMMID: 1502067. Full text here.
    Textbook
    • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.