EKG of the Week – Week 8 ANSWERS
Couple of questions here:
- 1) What’s going on?
- 2) What makes a heart beat this fast?
- 3) How do you want to treat it?
This one was a tricky one.
Let’s start with a refresher on how to approach a tachycardic EKG.
Remember, there are 2 questions I want you to ask yourself…
- 1) Are the QRS complexes wide or narrow?
- 2) Is the rate regular or irregular?
Remember your cheat sheet:
Narrow and Regular: Sinus Tachycardia, Atrial Tachycardia, Atrial Flutter with a fixed block (remember if you see a rate of 150 on the inservice exam LOOK FOR FLUTTER WAVES), and AVNRT/AVRT
Narrow and IRREGULAR: Sinus tach with PACs (remember, there’s a non compensatory pause), Afib, MAT, Atrial flutter with variable block
Wide and Regular: SVT with BBB, Vtach, V Paced (Check every EKG for pacer spikes)
Wide and IRREGULAR: Polymorphic VTach, VFib, Torsade de pointes
This EKG is a little tough. Because it’s going so fast, I’d argue that it’s difficult to tell if it’s wide or narrow. The EKG machine read the QRS duration as 176 msec. Which would make it wide, but do we believe the machine? In this case, I think so. This looks like a wide complex tachycardia. I think.
Now the question is what is it?
- Wide and regular makes us look at SVT with BBB, VTach and paced.
- Hint: this person is not paced.
What do you do with someone like this?
Shock them. Quickly. I’d treat this like VTach. I’d also argue that even if they aren’t hypotensive yet, they will be shortly. I’d syncronize cardiovert this patient immediately.
Now then, What makes a heart beat this fast? 272 is a really fast heart rate. That makes me think that there’s some kind of accessory pathway that’s bypassing the AV node completely or a conducted 1:1 flutter. If we look at the EKG below (EKG_Converted) you can see flutter waves (quite well in lead III).
This patient was in 1:1 flutter! But wait. Flutter is supposed to be narrow and regular. Did the chart lead us astray? Sorta. But not on purpose.
Notice that in the converted EKG, the patient has an incomplete RBBB. Seen by the RSR’ in aVR and V1 and a QRS duration of >110 msec but not yet 120 msec. After cardioversion, technically, the QRS complex is not wide (<120 msec). My guess (and this is a total guess) is that the patient had an incomplete RBBB that became a complete RBBB due to rate related changes. What we were really seeing on that first EKG was SVT with a RBBB (remember Aflutter is a type of SVT). But that’s monday morning quarterback talk. What’s your big take away from this EKG?
****If it’s a wide complex tachycardia and the patient is unstable, treat it like VTach every time****
I’m going to quote Life in the Fast Lane here, because I think they say it best:
“With ventricular rates as rapid as this, spending any further time evaluating the ECG is unwise! Resuscitation is the priority… This patient will almost certainly be haemodynamically unstable, requiring emergent DC cardioversion.”
This patient needed therapeutic electricity.
That was a tough one! Hope it got you thinking!