heart blocks

Nurses General Nursing

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So I can explain heart blocks but, my problem is knowing it when I see it. First degree PR > 0.20, second degree type 1 lengthing PR with dropped QRS, second degree type 2 regular PR with QRS's dropped, third degree atria and ventricles beat independtly of one another but when I see it, it just doesn't hit me that it's third degree. Any suggestions/tips to help me out

Specializes in ED RN, Firefighter/Paramedic.
So I can explain heart blocks but, my problem is knowing it when I see it. First degree PR > 0.20, second degree type 1 lengthing PR with dropped QRS, second degree type 2 regular PR with QRS's dropped, third degree atria and ventricles beat independtly of one another but when I see it, it just doesn't hit me that it's third degree. Any suggestions/tips to help me out

3rd degree is easiest of all to recognize on an EKG. If it's big, wide, ugly, slow, and the patient looks like crap, then check to see that the qrs's are regular, the p-waves are regular, but the PR interval is irregularly irregular. I'm sure there are probably instances of an accelerated 3rd degree, but I've never seen one that wasn't profound bradycardia with significantly noticeable patient deficits.

Dixielee, BSN, RN

1,222 Posts

Specializes in ER.

I agree with Mike, the patient usually looks pretty grim and even if you can't recognize the rhythm as 3rd degree block, you know it looks like a sick heart. The P's are not married to the QRS, so even if the P waves look normal and the QRS looks normal, there is no consistent relationship between the two. That tells you there is a major disconnect between the two. Study strips and quick tips you will find in study guides and you will be able to pick them out pretty easily.

It doesn't matter if it is a high degree 2nd degree block or 3rd degree....your patient is in trouble and needs a pacer, so make sure you know how yours works and get the pads on the patient!

MinnieMomRN

223 Posts

Specializes in Med-Surg; Telemetry; School Nurse pk-8.

It always helps me to visualize what the heart is doing as I'm reading the strip. Atrial (P) followed by Ventricle (QRS). Repolarization of ventricles (T) Nice visual contraction? A delay? No organized pattern? Imagine seeing the heart beat. What's going to happen to the patient without good, steady ventricular response? How long can THAT be sustained? Hmmm...

Specializes in ER, progressive care.

I had trouble with 2nd and 3rd degree heart blocks for awhile...I found mnemonics helped.

Long, longer, drop...you have a Wenkebach (2nd degree type 1)

If your P's do not always go through, then you have a Mobitz II (2nd degree type 2)

If your P's and Q's do not agree, then you have a 3rd degree.

With a Mobitz II (2nd degree type II) you will have dropped QRS's, like you mentioned, but the PR interval stays the same. With a 3rd degree, you have complete AV-dissociation. The P's are off doing their own thing and the QRS's are doing their own thing. You'll notice the "PR interval" is pretty much variable, whereas with a Mobitz II the PR is consistent.

2nd degree blocks require close monitoring because they can quickly progress to a 3rd degree. They can also lead to ventricular standstill without warning.

netglow, ASN, RN

4,412 Posts

If ya got a itouch you can download the app called, Instant ECG. It explans them all, and shows you a live running animated strip, nice graphcs.

I found something that shows what it looks like... the running strips are great.

roxie144

14 Posts

Thanks for the tips, once I sat down and drug out the caliper, third degree blocks started to click in my head.

tokmom, BSN, RN

4,568 Posts

Specializes in Certified Med/Surg tele, and other stuff.

skillstat.com

It will really help you with your strips and its a game, so it's fun.

wannabecnl

341 Posts

Specializes in PACU, presurgical testing.

What I have noticed about 3rd degree blocks is that the P-to-P interval is consistent across the strip (like you said, get out the calipers and check it out), and the QRS-to-QRS interval is also consistent, but the two intervals are not equal. In musical terms, it's like the Ps are playing at one tempo and the QRSs are playing at another, and they are playing at the same time. That sounds like crap in music, and it works like crap in the heart! :)

I start on a cardiac floor in about a month, so I have learned a lot from this thread. My particular bugaboo is the 2nd degree type 2--for some reason, it looks like several things going on rather than a "regularly irregular" rhythm like some of the others.

Specializes in ER, progressive care.
My particular bugaboo is the 2nd degree type 2--for some reason, it looks like several things going on rather than a "regularly irregular" rhythm like some of the others.

Just continue to look for that consistent PR interval ;)

I find practicing EKGs helps. My favorite is ECG Workout by Jane Huff, RN. Explains things very well and has a cornucopia's-worth of practice strips. ECGs Made Incredibly Easy is another great source, but it lacks on practice - very limited compared to ECG Workout.

Good luck with your new job! :nurse:

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