Time flies

Another year in the books, hopefully we’ve learned a great deal about EKG’s with some of the pitfalls or surprises they can present. With the close of one year comes the opening of another. There’re big changes coming up for many of us. For some of you it will be your first true professional job. Others will step up in responsibility. And for a few of us it will mean some life changes that will take some getting used to.

Black-bellied (or Grey if you’re in Europe) Plovers fly away too

Moving on to the EKG (whose rate is also flying!)

20’s y.o. man s/p syncope

Based on 30 QRS complexes our approximate rate is 180. The rhythm is the primary point of interest obviously. It’s clearly too fast to be sinus. It’s fairly wide so VT is likely the first thing that occurs to us. That being said, the patient is in his 20’s so we should consider whether this could be supraventricular in some way. It could be SVT with a wide QRS, though it also doesn’t make a ton of sense for a young person to have a wide QRS. Re-entry therefore needs to be considered. An accessory pathway would allow for a wide QRS that still originates above the ventricles, which is called AVRT.

Axis is left. We discussed the QRS. There is some rate related depression of the lateral chest leads which is seen fairly commonly.

EMS protocol for a very fast, very regular, rhythm (not sure if it was categorized narrow or fast by their team, V1 and inferior leads do look narrow-ish) allows for adenosine, and adenosine was given, with the following result…

It worked! Now we see sinus tach, with short PR intervals, and delta waves!

Take-homes from this patient with AVRT in the setting of WPW? First off is that apparent VT in young people has a reasonable shot of not being VT. Next up is the role of adenosine in tachycardia associated with WPW. Adenosine is a big no-no if the rhythm is irregular; blocking the AV node can allow Afib to generalize down the accessory pathway into Vfib. However, if the rhythm is regular then adenosine can generally be used. Interrupting a cycle anywhere will break it, what we fear is situations where the stimulus for the fast heart rate will continue. And while if A flutter is the reason that the rhythm is regular then the stimulus will continue, but we’re already seeing the rate go at a 1:1 rate if so, it won’t get worse.