In our last post we talked about the sinus rhythms…sinus bradycardia, sinus tachycardia, sinus pause and sinus arrest. But what about the other atrial rhythms? Namely, atrial fibrillation and atrial flutter. Let’s take a look, shall we?
Atrial fibrillation: what you need to know
In atrial fibrillation (AKA a-fib), the atria contract spasmodically and very quickly…typically at about 400-700 times per minute. Woah! Thankfully, not all those impulses make their way through to the ventricle. Whew!
However, this doesn’t mean that all is fine and good. Far from it. Here are the problems that your patient with atrial fibrillation can have:
- Loss of atrial kick leads to a drop in cardiac output. When the atria aren’t contracting properly, you loose that extra little “kick” of the atrial pushing the blood down into the ventricle. We call this the loss of “atrial kick” and it is going to drop your cardiac output by about 20%. When the ventricular rate is fast, then you also have the problem of decreased filling times…which will drop your cardiac output even MORE. The short version is this: when your patient goes into a-fib or a-fib with RVR, watch their hemodynamic response like a hawk.
- Potential for blood clots. All that blood swirling around in the atria makes it highly susceptible to clotting…and those clots can get kicked out into circulation, leading to…STROKE or, in some cases, pulmonary embolism (though this is less common). In cases like these, we say the patient “threw a clot” and it’s never a good thing. In fact, a-fib is one of the leading causes of stroke (learn more about strokes here).
Identifying atrial fibrillation
So, what does atrial fibrillation look like? Basically, the hallmark of a-fib is that it is irregularly irregular and the P waves aren’t visible. The QRS will be normal and your rate could be below 100 OR it could be really fast. When the rate is too fast (above 100) we say that the patient is in “atrial-fibrillation with rapid ventricular response.” In shorthand, we say “a-fib with RVR” or for even shorter shorthand, we say “uncontrolled a-fib.”
My patient is in a-fib…now what?
So, let’s say your patient is in a-fib. What are the atrial fibrillation nursing interventions? What you do about the a-fib really depends on two things:
- How long have they been in a-fib?
- How fast is the rate?
If the a-fib is new (less than 48 hours), then we try to convert them back to a regular rhythm. Why only if it’s new? The idea is that the blood hasn’t had chance to clot in the atria yet, so it’s typically safe to push them back into a sinus rhythm. If we did this with an established A-fib…the chances of “throwing a clot” and causing a devastating stroke when we get back into a sinus rhythm are just too high.
If there’s a question of the “newness” of the atrial fibrillation, the cardiologist can do a TEE (trans esophageal echocardiogram) prior to converting the patient. The TEE will show if there are any clots hanging out in the atria…if no clots are present, then you’ll typically see that the doc will go ahead with the conversion.
Note that your cardiologist could possibly try to convert someone back into sinus rhythm with an establish a-fib IF the patient has been adequately anticoagulated for some period of time (which varies) AND the TEE shows no clots.
A-fib treatments: meds and electricity
So, how do you convert a patient into a sinus rhythm? We’ve got two options, folks! Meds and electricity.
The medication you’ll see most often used for pharmacologic cardioversion is amoidarone. It is typically given as a bolus, then a continuous infusion, followed by PO medication. And if that doesn’t work (or if your patient is symptomatic…AKA having a drop in blood pressure/cardiac output) you can use electricity in the form of a synchronized cardioversion.
If your patient has a long-standing atrial fibrillation, and you’re not necessarily trying to convert them back into a sinus rhythm, you will want to control the rate…meds used for this typically include a beta-blocker, calcium-channel blocker or digoxin.
Long term treatment: stroke prevention
So let’s say your patient is in long-standing atrial fibrillation. Their rate is controlled and they show no signs of hemodynamic compromise. This patient is still at giant risk for a stroke, so we need to make sure they are sufficiently anticoagulated. Typically we see warfarin, but lots of patients are taking the “new” anticoagulants, which you can read all about right here.
Atrial flutter: what you need to know
Less common than atrial fibrillation is its cousin, atrial flutter. This is another rhythm characterized by a rapid atrial rate, but there are a few key differences:
- the atrial rate is regular MOST of the time (more on this in a bit)
- rate is 200-400 bpm
- p-waves are not visible, but you can easily see “flutter waves” which give the rhythm it’s characteristic saw-tooth pattern
What about the ventricular rate in atrial flutter?
In typical a-flutter, the ventricular rate is about 140 to 160 BPM. Why, you ask? Well, this has to do with the rate of the flutter (200-400, but most typically about 300 BPM) and the conduction ratio of atrial beats to ventricular beats. The most common ratio is 2:1…meaning for every two flutter waves, you have one ventricular beat. So, if you “do the maths” on that…you get a typical ventricular rate of about 150 BPM.
Again, note that with increased ventricular rates, we have a risk for decreased cardiac output…so watch those hemodynamics closely!
Identifying atrial flutter
Typically atrial flutter is pretty darn easy to recognize when you have a conduction ratio of 3:1 or 4:1…that’s because those flutter waves are REALLY easy to see when there are two or three of them in between each ventricular beat. It gets tougher when you’re looking at 1:1 or 2:1 ratios. Why? Because the flutter wave will get “buried” in the QRS or T-wave. Darn it! Just when we thought we had this whole “a-flutter” thing down. If you’re having trouble identifying the flutter waves, try looking at V1, II, III or AVF. In MOST cases, you’ll have positive deflection of the flutter waves in V1 and negative deflection in lead II, III and AVF…just a little tip for ya!
What’s this about the rate being regular only MOST of the time?
When we look at atrial flutter, we look at the conduction ratio…a lot of the time, the conduction ratio is consistent. So, for example, you’d have 3 flutter waves and then BAM…a QRS…each and every time. But sometimes, the conduction ratio will vary. If this occurs, you’ll have “variable conduction” which means sometimes the QRS occurs after 2 flutter waves, other times it’s after 4 flutter waves (for example). This will end up being another “irregularly irregular” rhythm. How you distinguish it from atrial fibrillation is the presence of those oh-so-distinctive flutter waves. You got this.
Treatments for atrial flutter
Luckily, the treatment for atrial flutter is basically the same as for atrial fibrillation. You can expect to see treatments focused on the following goals:
- control the rate (beta blockers and calcium channel blockers are most often used)
- convert back to sinus rhythm if possible (no clots present!)
- decrease risk of stroke by getting your patient on an anticoagulation ASAP, with a goal INR of 3. Piece of cake, right?
In other news…I am super excited to tell you guys that I was the featured guest on Elizabeth Scala’s podcast this week!!!!! If you don’t know Elizabeth, then you are missing out. She focuses on keeping nurses inspired and engaged throughout their careers…she’s an author, a keynote speaker, a podcaster and an incredible resource for nurses at all stages.