Med-Surg - Cardiovascular System, part 6: Dysrhythmias

September 29, 2021 Updated: October 01, 2021 5 min read

Full Transcript

I am Cathy with Level Up RN. In this video, I am going to cover cardiac dysrhythmias, and at the end of the video, I'm going to give you guys a little quiz to test your knowledge of some of the key facts I'll be covering in this video. So definitely stay tuned for that. If you have our medical-surgical nursing flashcards, definitely pull those out so you can follow along with me.

So in this video, I will not be covering how to interpret EKGs. We actually have a whole separate flashcard deck and video playlist for that. So if you need help with interpretation of EKGs, definitely head on over there to get help. Here, we're just going to go over some basic facts about dysrhythmias and the treatment of those dysrhythmias.

First up, let's talk about sinus dysrhythmias, which includes sinus tachycardia.

With sinus tachycardia, we have a regular cardiac rhythm, but our heart rate is over 100 beats per minute.

Causes include physical activity, anxiety, fever, pain, anemia. It can also be caused by your body, compensating for decreased blood pressure or decreased cardiac output.

Treatment is focused on treating the underlying cause. So, for example, if your patient has sinus tachycardia due to unresolved pain when we give them pain medication that often allows that heart rate to come down.

Then we have sinus bradycardia. This is where we have a regular cardiac rhythm, but our heart rate is under 60 beats per minute.

Causes include excess vagal stimulation, cardiovascular disease, hypoxia, as well as certain medications. It's also important to note that with athletes, they often have sinus bradycardia, and this is a normal and expected finding in athletes. So I'm not saying I'm an athlete, but I do work out a lot and my resting heart rate is around 50 beats per minute.

In terms of treatment, if the patient is symptomatic, if they have a shortness of breath and fatigue associated with their bradycardia, we can give them atropine as well as a pacemaker. But for asymptomatic bradycardia, treatment is often not required.

And finally, we have sinus arrhythmia. So this is a normal variant from normal sinus rhythm. This is where the heart rate increases slightly with inspiration and decreases slightly with expiration.

It's common in children, and it usually disappears with age, and treatment is not necessary for sinus arrhythmia.

Next up, we have our atrial dysrhythmias, and I won't go through all the information on the card, but I do want to highlight atrial fibrillation as well as atrial flutter.

So with atrial fibrillation or AFib, we have a rapid and disorganized depolarization of the atria, such that the atria will sit there and quiver instead of fully squeezing. And as it sits there and quivers, blood collects in there, and we have increased risk for blood clot formation.

So a key intervention for a patient who has AFib is to put them on an anticoagulant in order to prevent that clot from occurring.

Also, we can treat this condition with cardioversion, which we'll talk about more in my next video as well as antiarrhythmics. So when you look at an EKG strip, AFib will look like lots of little bumps between the QRS complexes.

All right, with atrial flutter, we have an abnormal electrical circuit that forms in the atria and causes rapid depolarization of the atria. So between 250 and 350 times per minute.

So when you look at an EKG strip and you see these sawtooth waves, so these are F waves, that's atrial flutter, and we would also treat this with antiarrhythmics as well as cardioversion.

Next, let's talk about some key ventricular dysrhythmias, including ventricular tachycardia or V-tach.

With V-tach, we have a rapid ventricular rhythm. So over 100 beats per minute on an EKG strip. You will not see any P waves. You will see wide QRS complexes that occur regularly.

V-tach is typically caused by ischemic heart disease.

Treatment of V-tach with a pulse includes cardioversion, as well as antiarrhythmics and correction of any electrolyte imbalances. If we have V-tach without a pulse, we need to defibrillate. V-tach can deteriorate into ventricular fibrillation or V-fib.

With V-fib we have rapid, ineffective, quivering of the ventricles. So on an EKG strip, you're not going to see any P waves and you're really not going to be able to see any QRS complexes. It's just going to be all these little bumps going across the screen.

Treatment of ventricular fibrillation is defibrillation.

So our little chicken hint here is to D-fib, V-fib.

And then finally, we have asystole, which is where there is absence of any ventricular rhythm. So on an EKG strip, this will look like a line. So this is something you never want to see in your patient, but you always want to see on a test because it's really easy to identify that dysrhythmia.

So treatment of asystole includes CPR. So despite what you may have seen on some kind of medical TV show where they attempt defibrillation on a patient with asystole, you cannot do that in real life. So you need to perform CPR on a patient who has asystole.

Finally, let's talk about some AV blocks or atrial ventricular blocks, which are typically caused by heart disease, by myocardial infarction. They can also be caused by certain medications, such as beta-blockers or the digoxin.

With a first-degree AV block, we have a prolonged impulse conduction time between the atria to the ventricles due to a delay in the AV node. So on a EKG strip, you will see a long PR interval that is consistent.

Treatment is typically not required for this type of heart block.

Then we have a second-degree type one AB block, which is where we have a progressive increase in the conduction time between the atria and the ventricles until one impulse fails to conduct at all. So on an EKG strip, we will see a PR interval that will gradually get bigger and bigger until a QRS complex drops.

Treatment is also not typically needed for this type of block, either.

Then we have a second-degree type two AV block. This is where we have a sudden failure of impulse conduction between the atria and the ventricles without a progressive increase in conduction time. So on your EKG strip, you will see a consistent PR interval. It'll either be consistently long or consistently normal, but then suddenly you'll just have a QRS complex that drops off.

This type of block typically requires a pacemaker.

And then finally, we have a third-degree AV block. This is where we have complete failure of any conduction between the atria and ventricles. So when you look at an EKG strip, you will see no association between the P waves and the QRS complexes.

Treatment of this type of block does require a pacemaker.

Okay, time for a quiz. I have three questions for you. First question, what dysrhythmia is associated with an increased risk for clots? The answer is atrial fibrillation. And that's why anyone who has AFib is put on an anticoagulant to help prevent that clot formation. Question number two, what is the treatment for ventricular tachycardia without a pulse? The answer is defibrillation. Question number three, what is the treatment for ventricular fibrillation? The answer is defibrillation, again. So we want to D-fib, V-fib.

All right, I hope this video has been helpful for you, and I hope you enjoyed this quiz. If so, be sure to leave me a comment. I would love to hear from you, and I'll see you on another video soon.


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