need help with ekg interpretation
- 0Jan 20, '13 by Kaysmom8Hello,So I've been trying to learn ekg's for 3 days now and I'm lost. How many different variations can one wave have? Like the p wave can be close to the qrs, upside down, absent sometimes it has a little dip in the middle. I tried the website skillstat ekg but its not helping. Any help or notes would be apreciated
- 0Jan 20, '13 by Kaysmom8I don't have an acls book, i can go to the library tomorrow. I'm starting to wonder if I'm making this harder than it really is. When i try to learn the rhythms i jump around. I understand the waves in relationship to the heart contracting and relaxing but when i start looking at the strips what i think is abnormal isn't. Should i start off with memorizing what they look like?
- 0Jan 21, '13 by dah dohThere are lots of EKG made easy types of books available. You should learn the normal values of the pri, qrs, qt intervals and abnormals. You should be systematic about evaluating the rhythm strip...regular versus irregular, measure the above intervals, etc. then use the process of elimination to figure out what the rhythm is and what each rhythm means. Eventually, you will be able to identify the most of the rhythm strips be just glancing at them.
- 0Jan 21, '13 by iluvivtYes I agree.. The EKG Made Incredibly Easy book is very entertaining and great and fun for students. Yes! make sure you really understand the normal EKG and what each thing represents and what is going on in the heart. So for example, the P wave represents atrial depolarization. If you cannot remember what that is go back and look it over. You cannot possibly understand anything abnormal unless you understand what is normal. This book will give you the steps you need to take to identify any rhythm as stated by dah doh.
During clinical make friends with the monitor techs and ask them to share. Most love to teach and will show you a few strips. I also did this once I got my license a long time ago. I learned to respect those that do that all day.
- 0Jan 21, '13 by GrnTea, BSN, MSN, RNAre you looking at the same leads?
Thought experiment here:
You are at your favorite baseball diamond. You are holding a piece of plexiglas in front of you, and you have a wax crayon in your dominant hand. You will be drawing lines on it based on what you see on the other side of it. Ready?
You are sitting in the stands between home plate and first base. The pitcher throws the ball to the catcher. You follow its progress and draw the line on the plexiglas as you see it go. The line goes from...? Correct, a long line, going from your right to your left, dropping down a bit with gravity.
Through the miracle of time travel, you are now on the other side of the diamond, between third base and home. The pitcher throws the same pitch. Where do you draw your line? Correct-- the ball appears to go a long way from left to right, again dropping down a bit with gravity. Same pathway, different vantage point, different crayon tracing on the plexiglas.
OK, now you are sitting right behind the pitcher. Same pitch, coming straight at you. When you trace its path on your plexiglas, what does the line look like? NO right-to-left, because it's coming straight towards you, so you draw a very short line from the center of the plexiglas, where you see the pitch leaving the pitcher's hand, dropping a little bit to account for the gravity as it settles into the pitcher's mitt.
Last, you could even pretend you were in the grass between the pitcher's mound and the plate, and seeing the ball coming by. Your line would rise as the ball approached you, and then fall as it went past you.
In EKG-land, the electrical impulse traveling through the heart's anatomical conduction system is that ball. The different lines you have drawn on your plexiglas are the picture of that impulse as seen from many different vantage points. Why bother? Because it's important to see the path clearly as it moves about the heart. Some leads "see" the P wave better than others. Other leads, because of their vantage point, show the QRS upright or downgoing. Depending on where the lead is, it might show derangements in conduction better, like a bundle branch that's damaged (bundle branch block). So the derangements in some leads specifically tell you about how the conduction goes through specific areas of the myocardium, with the understanding that abnormal conduction (an abnormal line) means something wrong in the muscle.
That may be why you are getting confused-- you might not see the P wave in one lead and wonder where it is. There's (probably) still conduction from the SA node to the AV node, but you're looking from behind the plate, not from first base, so you don't see its movement so well.
I hope that helps some. I love baseball.
- 0Jan 21, '13 by GrnTea, BSN, MSN, RNNow, as to why a P wave might have a little dip in its middle, well, baseballs generally follow a fairly direct path. At least they don't generally go up and down and the up again (exception: knuckleball on a good day). So to see what's going on with the conduction to make that sort of tracing, you have to imagine the impulse going towards the electrode (upgoing trace), away from it briefly (down) and then turning back towards it again (up again). This will give you that sort of "M" shape you're describing.
Why does this happen?
One of the cool things about myocardial cells (they have several properties that skeletal muscle doesn't) is their ability to share their electricity with their neighbors. (If one skeletal muscle cell is jolted into contracting, its neighbors do not follow its lead.) Normally the impulse goes down specific tracts and as it passes the cells, they depolarize and contract. The effect is a coordinated muscle contraction, sort of like wringing a washcloth, to expel the blood efficiently.
But if that pathway is damaged (infarct or other trauma), the impulse can't travel as efficiently through the myocardial cells. When it reaches the "break in the wire," as it were, it spreads around the damaged area via the myocardial cells, cell to cell. The contraction still happens, but it's a little different than if it were running on its normal coordinated circuit. And because the electrical impulse isn't running in its normal circuit, the electrode that picks up its signal sees an abnormal pattern-- like a "biphasic" (two humps) P.
This also tells you why atrial fibrillation doesn't give you any P waves at all, just a jagged sorta of line. The atrial have become so stretched out that the normal conduction pathway through them is all torn up. You can help visualise this by holding your fingers interleaved and imagining a straight line drawn on the backs of them from right pinky to left pointer. Slide your hands apart, and there is no more pathway. So the electrical impulses are going willy-nilly all over the atria, and all they can do is produce this uncoordinated quivering effect. No good contraction (increased risk of growing clots in there -> anticoagulant therapy) and a messy line where there ought to be P waves. Cool, huh?Last edit by GrnTea on Jan 21, '13