Brugada from Brussels
I really didn’t want to write about this…but Brugada criteria. It could be very confusing for practitioners (i.e. me). But it’s important to understand. Let’s get into it.
This is how you tell the difference between the scary VT and the not-as-scary SVT with aberrancy (ok maybe scary for some). A lot of my colleagues will see a rhythm like that and automatically say that it is VT — one of my pet peeves in the hospital. And I have a few if you ask my nursing friends haha…maybe I’ll write a quick post later. True, it could be VT but it also might not be. So better yet, say it’s a “wide-complex tachycardia.”
As the criteria is named, “Brugada” was introduced by Pedro Brugada, MD, a famous arrhythmia doc from Brussels. The Brugada Criteria is not to be confused with Brugada Syndrome but were definitely created by the same Pedro (and his brother) from Brussels.
It’s important to tell the difference because the management of each is different from each other. One is a ventricular arrhythmia and the other one is a supraventricular arrhythmia with aberrant conduction. They both use different pharmacological management and shocks (depending on the stability of the patient). As with most criteria, diagnosing for the likelihood of one over the other should be a step-wise approach (you should do this with most ECGs). I will try to explain it as simply as possible. First you should do an ECG. And have someone check if the patient has a baseline/previous RBBB or LBBB! Here is the algorithm.
- Is there concordance in the precordial leads (V1–V6)?
Concordance meaning are all the QRS complexes in V1-V6 all upright or downward? Upright complexes is a +concordance with only R waves. Downward complexes is -concordance with only QS waves. If there is concordance, treat as VT. If not, move on to the next step.
2. Is the RS interval>100ms in ONE precordial lead?
Measure the interval. Remember that one small box is 40ms. If yes, treat as VT. If not, move on to the next step.
3. Is there AV dissociation?
This one might be difficult. But look for P waves. Sometimes they are buried in the QRS complex or not seen at all since the rate is so fast. If the P and the QRS are at different rates (like CHB), treat as VT. If not, move on to the next step.
4. Look at V1.
Do you see it upright (RBBB pattern) with the left ear higher than the right ear (RSR’)? If yes, treat as VT.
How to treat VT? If any of these is MMVT, use synchronized cardioversion and your IV anti-arrhythmics like amio. If it’s PMVT (Torsades), IV magnesium STAT (shortens the QT interval) and defibrillation if unstable.
What to do with this info?
This is great to recognize because MMVT can degenerate into PMVT or VF (defib). SVT is treated with adenosine or synchronized cardioversion. So recognize that you have a wide-complex tachycardia. See if the patient is stable. Get an ECG too. If the pt is unstable, you have to cardiovert (both SVT/MMVT). If stable, you have time to decide what IV antiarrhythmics to push while you attempt to deduce VT vs SVT with aberrancy. This is a tough one to remember. You can use MDCalc for this too.
Dk
