Need help interpreting ECG strips.


Hi all:

I have been a Nurse for the last 3 years. I spent all that time on a med/surg floor.

I wanted critical care experience and have taken a new job on a surgical stepdown ICU unit.

I started orientation yesterday. There is no formal classroom instruction, it is all computer modules.

Yesterday I did the computer modules for the ECG interpretation. I understand how the heart works and I can interpret all the normal strips. I'm having a problem interpreting the abnormal strips. For example: PAC and the heart blocks, the junctional rhythms etc.

I've reviewed the modules online at home using different books and practice ECG's on line, but still having difficulties and need to pass a multiple choice test tomorrow.

Help! Extremely nervous, and need to pass. Any suggestions on better understanding this information would be very helpful.


Thank you all in advance!


106 Posts

I frequently refer orientees to this site:

Lots of information about various subjects.

Good Luck!


223 Posts

Specializes in Critical Care, Nsg QA. Has 28 years experience.

Dale Dubin

Rapid Interpretation of EKGs

Excellent book!


162 Posts

Specializes in pcu/stepdown/telemetry.

it's tough at first. you need to just look at a lot and start off the same with each strip, do not guess the answers

but some simple things to remember without getting complicated are:

1. is there a P wave

2. is it regular (is the narrow QRS the same distance from next narrow QRS)

3. what is the rate

4. if a P and narrow QRS complex come in a bit earlier and then it goes back to being regular QRS-QRS then it's a PAC

5. if a narrow QRS complex comes in early and there is no P wave then it's a PJC

6. if a beat comes in that's a wide looking QRS among narrow QRS's then PVC


1.first degree is only a longer P wave nothing more

2. 2nd degree type 1 wenkeback. P wave is near QRS then next P is farther awayand then the next P is alone without a QRS. short, long then drops

3. 2nd degree type 2 is classical and constant. The P wave is always the same distance from the QRS and then it drops the beat. short, short then drop.



3rd degree the p wave is not associated with the QRS they are independant of one another so the P is regular and can be mapped out as the same distance to each other and the QRS is regular and the same distance. but it doesn't flow the way sinus rhythm does. P wave will get hidden in the T waves and you may see an increased bump at the t wave

;)hope it helps a bit

casi, ASN, RN

2,063 Posts

Specializes in LTC. Has 3 years experience.

-PAC is a normal beat just a little bit early. What differentiates it from a sinus arrhythmia is the P wave is shaped a little bit differently.

-1st degree AV block: PR is greater than 0.20. You'll see this fairly frequently

-2nd degree AV block Mobitz I or Wenckebach: Is where you see the PR getting longer each beat until a QRS is dropped.

-2nd degree AV block Mobitz II: Your PR stays consistant, but the QRS is getting frequently dropped.

-3rd degree heart block: the ventricles and the atrium have absolutely no electrical connection. So you'll be seeing the Atrium beating away at a regular rate. The ventricles can either be regular or irregular (I've mostly seen them regular). The big thing you'll see here is that the PR and QRS have absolutely NO relationship.

-Junctional: There either is NO p-wave or the PR is less than 0.10.

My favorite heart rhythm resources are on youtube. diagnosis wenckebach and living arrhythmias.

I also keep EGG Notes on me whenever I work as a monitor tech. It's a great little flip book.

Specializes in Critical Care. Has 6 years experience.
Dale Dubin

Rapid Interpretation of EKGs

Excellent book!

I agree, I think this is the best book out there. It is written in very plain terminology. You should be able to find it in any local bookstore, or you can find it on for pretty decent prices (somewhere aorund $25-35).

It does take a while of reading and re-reading EKG books and materials to really feel comfortable with it. And seeing some of these abnormal rhythms on the unit is helpful.


1 Article; 2,636 Posts

Specializes in ER. Has 15 years experience.

i really like this website:

i also bought a book that's comprehensive, using fun little facts (and pictures too) for common sense info and approach on ecg rhythms:

ecg interpretation an incredibly visual pocket guide - a lippincott williams and wilkins book. it's awesome!!!

ImThatGuy, BSN, RN

2,139 Posts

I always thought PACs were hard too. I bet I wouldn't guess one now if I saw it.

Like someone else suggested, do the Dubin.


1 Article; 1,327 Posts

Has 23 years experience.

There is a book by Gail Walraven that I like as well as Dubin. It has TONS of practice strips.


517 Posts

There is a book by Gail Walraven that I like as well as Dubin. It has TONS of practice strips.

I also like Gail Walraven's books. I still have a difficult time supporting Dubin even though he wrote a decent book.


55 Posts

Wow. Thanks for the info everyone!