2:1 AVB & LBBB

Unsure of patient presentation.
Pathological left axis deviation.

Strong left-vectors indicating LBBB

Click on the image above.
There is 2:1 conduction, most visible in the septal leads(red arrows indicate nonconducted p-waves).
This is atria tachycardia with 2:1 conduction, most likely caused by increased digoxin levels.


Rogue Medic said...

Nice catch. It is hard to notice without V1.

V2 has a more subtle P wave on the T wave.

Much harder to notice in leads II and III.

Few people would look for a heart block in a tachycardic patient.

Adam Thompson, EMT-P said...

Found this strip laying in the front of the ambulance. I'm pretty sure the medic who left it didn't notice the 2:1 conduction. He probably did what so many do and called it a LBBB, and threw it away.

Shaggy said...

The P waves seem obvious to me, but that was because I saw the title and looked and found the P waves in the first strip. If I had this call, I wonder if I too would not consider expecting to find a heart block in a tachycardic patient. I hate to admit it, but on a late at night or after the umpteenth call, would consider it just a LBBB and do the same with it. All the reason to avoid tunnel vision.

Anonymous said...

So the only difference between this and a complete heart block would be the regular conduction of one of the P waves (as opposed to complete AV dissociation). Isn't it pretty rare to have a tachycardic block ? Would it be fair to say that this could usually only be pharmacological (Digoxin) as opposed to structural ?