 Welcome to nursing school explained in this video on atrial fibrillation, which is one of the most common dysrhythmias that we see in our patients. So what causes atrial fibrillation or what are risk factors? Generally the risk for atrial fibrillation increases as we age, but also all those things that are generally bad for our health and generally bad for the heart can lead to atrial fibrillation, which are hypertension, diabetes, obesity, chronic kidney disease that many times originates from uncontrolled hypertension and diabetes, and then a cardiac condition such as coronary artery disease, congestive heart failure, cardiomyopathy, any kind of valve disorders, pericarditis, as well as hyperthyroidism. So there's a long list right here. And then in terms of electrophysiology, generally the heart radiant rhythm is very organized where the atria are on the top and the ventricles are on the bottom and usually the atria contract and then the ventricles contract and it's this very organized rhythm that we can discern by listening to the heart and listening to the closure of the valves with the love dub. And the ventricles are really what produces the cardiac output, the blood pressure because they squeeze and the blood ejects to the body. What happens in atrial fibrillation, there is not this organized rhythm. These atria they just fibrillate, so they kind of quiver and then the ventricles still contract. And the way that this happens is that typically the impulse, the electrical impulse originates in the assay, the sinoatrial node, but in atrial fibrillation there are multiple irritable cells in the atria that now kind of want to take over as the pacemaker of the heart. And recall that any cell, any cardiac cell can be the pacemaker of the heart. So when they're irritable for whatever reason or due to any of these risk factors they can take over. So now we have multiple cells here. Everybody wants to be the boss and the atria and they just kind of quiver. And so usually the impulse originates from the assay node and then comes to the AV, the atrial ventricular node, which regulates the rate down to the ventricles. But when we have all these irritable cells in the atria, the rate in the atria itself, so just the top chambers of the heart with this fibrillating can be 300 to 600 beats per minute. And that is a lot. But remember, I just said that the ventricles are what controls the actual heart rate and the cardiac output. So it depends on the ability of this AV node here to tell the atria, whoa, slow down. I'm gonna slow down this heart rate and only let certain impulses go through this AV node so that will determine the ventricular rate as the electricity continues to travel down through the AV branches and then also up the purkinje fibers. And if the heart rate that we can measure always by the ventricular rate is less than 100, it's considered controlled atrial fibrillation. But if it's greater than 100, typically we refer to it as uncontrolled. And the higher the rate, the more symptomatic the patient will be. On an EKG, and I have a separate video about atrial fibrillation in the EKG interpretation playlist that you can refer to, I just wanted to quickly mention this here. So there's always a term on an EKG interpretation that we refer to as irregularly irregular. Because now all these excitable cells here want to be the boss and initiate this impulse and fibrillate. And so the impulse might come from many different locations in the atria. And that leads to this irregularity. And there is no discernible P wave on the atria on the EKG because the P wave represents the atrial contraction. If there's no real contraction, we're not going to have a P wave. And so that an EKG will look like this, usually we have a P, Q, R, S and T wave. But here there are so many squiggly lines, so many of these cells in the atria are irritated. Like I said, they all want to be the boss that we can't really see. Is there a P wave? It's hard to say. And then the rate can be very irregular looking at the ventricular rate here with the QRS complexes. Typically it should look like this where the P wave is very easily determined. And then we have our QRS complex following the in the ventricular rate here. And if you are not really clear about this, please go back to my basic electrophysiology videos where I go into detail of what all this means, all the waves and how you can know if it's normal or abnormal. Now for atrial fibrillation, if the onset has been in less than 48 hours, it's considered acute. Patients can also be in what's called paroxysmal or intermittent atrial fibrillation. And then chronic atrial fibrillation occurs generally when it lasts more than a month. So patients can sometimes go back and forth between normal sinus rhythm and atrial fibrillation or really any other rhythm. But generally sinus rhythm and atrial fibrillation, which would be this paroxysmal and then they might have intermittent symptoms. So let's look at what those symptoms might look like. And most of them depend on the rate of the ventricles and of the atria and of those beats that go through through the AV node and on the duration. So the longer the patient is in atrial fibrillation, maybe the less symptoms they have because they've kind of just got used to it. Generally, though, they might complain of lightheaded nets or dizziness and generally all the symptoms will increase the higher the ventricular rate is. So if it's more than 100, it's this uncontrolled atrial fibrillation. But the rate can sometimes get up to 160, 180 beats per minute. And the more the higher the rate, the more symptomatic the patient won't be. The patient might also complain of shortness of breath. They might be anxious, they might pass out, have a syncopal event. They might say that they're feeling palpitations as the heart is beating fast and irregularly and they might also have some chest pain associated with that. And really, the reason is that the atria generally when they're in an organ and the heart is in an organized rhythm and the atria kick the blood volume down into the ventricles, it's referred to as the atrial kick. And that produces about 30% of the cardiac output. So most of it is produced by the ventricles, but some of it by the by the atria. But if they're just fibrillating, we're losing that 30%. So then as we are, as the ventricles are pumping, we have 30% less cardiac output. Hence the blood pressure might be lower and the more symptomatic the patient will be. And they become anxious and short of breath and syncopal because the heart rate gets, if the heart rate gets higher, generated blood pressure will be lower because we just cannot fill the ventricles with as much blood and they ejected, first of all, because we're losing that atrial kick. But also because the cardiac output decreases as the rate increases, because the heart, whenever it beats really fast, it can only feel so much before it is ejected to the body. And then complications, number one risk of atrial fibrillation is stroke because when the atria quiver, the blood gets swooshed around in this atrium, in both atria and what happens, it goes straight through the heart and then it goes, branches off and the first place it goes through is through the carotid arteries into the brain. So that causes an embolic stroke. And then it also leads to a loss of that cardiac output due to that atrial kick I just described and with that cardiac output, we might lose our blood pressure. And then again, the patient might have all these symptoms. And then for treatment and nursing care, it depends if the patient is stable and asymptomatic, if this is a new onset, sometimes a vagal maneuver can happen. And the vagus nerve is the most important nerve of the parasympathetic nervous system. And hopefully you remember that the parasympathetic nervous system is the rest and digest. So if we stimulate that vagus nerve, we will cause the heart rate to go down. And the way we do that, we can either have the patient blow into a straw, blow against their finger or maybe stick an ice stick their face in a water in a bucket of ice water. So anything that's kind of shocking to the system or increases that intrathoracic pressure can reset that vagus nerve and that SAO to hopefully get back into a normal sinus rhythm. But the longer the patient has been in atrial fibrillation, the less likely that this vagus maneuver will work. Now, if the patient is still stable and asymptomatic and the vagal maneuvers don't work, then we have several options here with medications, generally calcium channel blockers, beta blockers, de joxin and anti-irrhythmics. Any other anti-irrhythmics can be pretty successful in converting this or at least bringing the rate down to below 100 where it can now be controlled, where hopefully the symptoms will be less. And then most importantly, the patient will need to be on anticoagulants because we want to prevent this major risk factor of a stroke here. Again, it will depend on the discussion that they have with their provider, given the patient's risk factors and their lifestyle and whatever works for them. But generally that is the recommendation because there's this major complication of a stroke that can occur. Now, if the patient is unstable or symptomatic, that usually means these two words are defined by a change in level of consciousness and or systolic blood pressure less than 90. So again, the heart rate is so fast that we cannot produce the cardiac output. The patient is anxious, they are syncopal because they're not getting enough perfusion to their brain, to their body, their blood pressure is typically low. Then we need to treat the underlying cause. So whatever might be the cause here of the things that can be fixed, then we need to fix that in order to fix the atrial fibrillation. And sometimes that means that we have to revert to advanced cardiac life support measures. And maybe the patient will need to have a synchronized cardioversion where we actually shock the heart back into hopefully a normal rhythm. And I have a separate video on cardioversion and the fibrillation if you're interested in that. And for nursing care, clearly it depends if the patient is stable or unstable. The more unstable they are, the more measures, the more ER, ICU care they will need. But generally, we want to check the vital signs because we know the heart rate and the blood pressure will clearly be affected. We want to have them on a heart monitor so we know what their rate is like. And remember that whenever the heart rate is irregular, you want to make sure you listen to the apical pulse for a full minute so that you know the exact heart rate. Clearly, if they are on a heart monitor, you can see it right there. But that might fluctuate. This is when you look at the monitor and you see it jumping around from one twenty, one thirty eight, one forty five, one twenty eight. It just depends in a few seconds because the monitor is picking up as this rate is over here irregularly irregular. And that way it's best if you listen, put your status coupon, they'll listen for a full minute. That way you know what the heart rate is for that full minute. We will also need to educate the patients about the medications more, more so on the anticoagulants, but as well as all the medications that might might control their their heart rate. And then also educate patients about risk factors. So if we have patients with any of these more chronic conditions so that we can educate them to decrease these risk factors so that hopefully they won't have atrial fibrillation to start with and therefore be at higher risk for a stroke. So I have several other videos that pertain to atrial fibrillation in one way or another. I mentioned them throughout the video. I'll make sure to put those in the description of the video below so that you have easy access. Please also watch those if you're interested. Thanks for watching Nursing School Explained. See you soon.