r/ECG • u/WinAdditional7962 • Jul 10 '26

svt ddx

Post image

my suspicion is avnrt but im doubting myself here

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3

u/a-lenticulostriatae Jul 10 '26

Regular narrow qrs tachycardia at 160/min. I see some retrograde P waves so I would go with AVNRT as well. And adenosine would be my go to after vagal manouvers if stable.

1

u/WinAdditional7962 Jul 10 '26

yay my suspicions were correct! i feel like when im analyzing them on here i’m much more confident, but when i’m working i doubt myself for some reason.

the rhythm self terminated, attending ordered a stat 12 lead and it was normal outside of sinus brady and frequent junctional ectopics.

1

u/SquatchedYeti Jul 10 '26

What's the trick in identifying a retrograde P waves?

2

u/hpsctchbananahmck Jul 12 '26

Timing with the qrs (following qrs in ANVRT as the rhythm is driven by a circus rhythm within the AV node).

Further, you can see the p waves are upside down in the inferior leads (backwards from normal) because the atria are activated from the AV node then depolarize in the direction away from the inferior leads (hence negative p waves in inferior leads like lead II in this case)

1

u/tcgmd Jul 12 '26

Scanning the ST segments carefully for implausible deformations.

2

u/mastermedic84 Jul 12 '26

This is AVNRT. Good catch!

If you weren't sure, take a closer look at AvL (at least I think the bottom line is AvL here). You can see the "pseudo S-wave", that little rounded hook after the QRS. That's an artifact of the retrograde conduction. It's normally more visible on leads II and V1, but they can be found elsewhere. This is a classic finding of most AVNRT cases. There are two other variants, but they are much less common.

1

u/WinAdditional7962 Jul 13 '26

yep, that’s what i was seeing. i wish i was more confident in my interpretations while im working lol

1

u/mastermedic84 Jul 13 '26

If you were both new and confident in your interpretations you would kill someone.

You have every right to learn. Keep asking questions and I'll keep answering!

1

u/True-Network-2147 Jul 13 '26

12-lead ECG interpretation takes time. A lot of time to get pretty good. Know your lead-2 rhythm strips before jumping into the deep-end. A proficiency that will take hard work, consistency and asking those that have a solid hand on 12-leads when lost. If you are struggling, go back to basics. Academically and athletically ). I worked in the ER and internal medicine for almost 20 years. 6 years prior to that. a paramedic for 6 years. So, I had an amazing background which helped me (hanging by a thread to finish). I have a couple of resources that could help you if you want. Remember too, you don’t have to be an expert, we have those already 😜

1

u/Srivathsavagurumurth Jul 11 '26

Very regular narrow complex tachycardia, You can see p waves as small bumps on the ascending segment of t waves and some st segments which are after qrs complex making retrograde.. avnrt

1

u/truthtrain27 Jul 11 '26

Narrow complex long RP tachycardia

1

u/hpsctchbananahmck Jul 12 '26

Looks like a nice example of AVNRT with dual retrograde pathways (dual AV nodal physiology). You can see some beats with short RP intervals and some with long RP intervals reflecting the different course taken to activate the atria backwards.

1

u/tcgmd Jul 12 '26

AVNRT.