Cheaters' Shortcuts for Rhythm Interpretation

[live4today, RN]

Dont' stop now, gwenith! You're on a roll! Thanks for the sites to look up, too. :kiss

[gwenith, BSN, RN]

I have to go to work soon so I will post the rest tonight or tomorrow. I WILL go through the "blocks" because I have found that they are usually the ones everyone has difficulty with and it is all because of a couple of missing conepts within the common texts.

[Whisper]

patiently waiting for more;)

[Sarah, RNBScN]

Gwenith,

Can you tutor me? Move to Canada and you can teach. We need educators like you.

Sarah

[gwenith, BSN, RN]

It has been a while but I will wake this thread again for the blocks.

[gwenith, BSN, RN]

There are four concepts that make learning the blocks easier.

1) The heart has a triple redundancy backup system in case of failure. In other words if the sino-atrial node gives out then the Atrio-ventricular node can take over. If the A-V node fails then the ventricles have an inherent rhythm. Why doesn't the heart get confused? Because it has a simple rule - follow the fastest. The inherent rate of the SA node is 60-100 beats/minute the A-V node is 40 - 60 beats per minute the ventircles are even slower at around 30 -50 beats pe minute.

Here is an ecample of a rhythm originating from the A-V node. This is known as a nodal or junctional rhythm.

actually the site that came from is worth a visit http://www.cyber-nurse.com/veetac/cham5.htm

2) Both the sino-atrial node and the atrio-venticular node are so important to the heart that they have thier own dedicated arterioles. This is why there can be ischemia around the A-V node but it can remain unaffected.

3) The A-V node is not only the pathway allowing impulse conduction from the atria to the ventircles it is the only access point as the atria and the ventricles are divided by a firm sheet of fibrous tissue that is like a sheet of rubber.

4) Ischemia can act to slow conduction of impulses. Infarction causes scar tissue which is non conductive to impulses.

So the blocks include:-

1 st degree block - prolongation of the P-R interval.

http://www.rnceus.com/ekg/ekgframe.html

2nd degree block there are two types called type 1 and type 2.

2nd Degree heart block type 1 also known as mobitz 1 or weinkebach ( confused? join the club)

This is where the conduction of the p wave sets up an increase in the resistance of the tissue so that the next impulse takes longer to go from the SA node to the A-V node. This reistance increases and the P-R interval increases until the p wave cannot get through and there is a p wave without a ventricular response.

http://www.rnceus.com/ekg/ekgframe.html

The mental image I get is of a group of sheep jumping a gate. The first sheep sails over the gate easily but it's back hoof kicks the top bar and makes it higher so the next sheep really struggles to get over and his struggles set the top bar even higher and the poor next sheep can't get through at all and wanders off. In the meantime the top bar drops back down to where it was before the sheep came:)

Second degree heart block type II also known as Mobitz II is where there are unconducted p waves. This can be a pattern of 2 P waves to 1 ventricular response or it could be more as is shown on the example

http://www.rnceus.com/ekg/ekgframe.html

Third degree block is where there is no communication between the atria and the ventricles

http://www.rnceus.com/ekg/ekgframe.html

This is very breif overview so questions? Comments???

[Whisper]

Thanks for all the great information, I am sure I will have a load of questions but I need to get my head around it all first.

[gwenith, BSN, RN]

Use the websites I found some really great ones.

This one is very comprehensive and also worth a look

http://www.bardep.com/education/

[Whisper]

Thanks, but I couldn't get the link to work, I have bought a book on how to read ECGS, so I am hoping that will help as well.

Thanks again

Whisper

[BarbPick]

Bah Humbug, this really happened last night, the monitor tech really insisted I was "wrong" she said a RBBB was a paced Rhythm

[MarkHammerschmidt]

May I humbly suggest my site for your consideration: http://www.icufaqs.org - where we have a couple of articles on cardiac rhythms and heart blocks, with strips, etc.?

[gwenith, BSN, RN]

Originally posted by MarkHammerschmidt

May I humbly suggest my site for your consideration: http://www.icufaqs.org - where we have a couple of articles on cardiac rhythms and heart blocks, with strips, etc.?

Sorry to leave you out of it Mark - I didn't mean to snub you:roll

I really just did this as a bit of a hobby thing to help people get an insight into rhythms.