Episode 61: Atrial Fibrillation – Controlled vs. Uncontrolled, That is the question!

The goal is to learn , inspire and bring Cardiopalm to the forefront of conversation . Thanks for joining me today and let's get after it . Hello , hello and welcome to another episode of Talking All Things , Cardiopalm . I'm your host , Dr Rachel Barisi . We're going to jump right in today and talk about atrial fibrillation .

I had a whole bunch of patients over the weekend in the ICU , in and out of AFib , and I just received a question this morning , and so I thought this would be a perfect topic , because I don't know if I've specifically spoken about AFib yet . So just a couple of things before we get started . I want to talk about the rhythm itself .

So atrial fibrillation is an arrhythmia . It's a type of arrhythmia where we have basically this erratic response . We have something causing ectopic foci in the atria so that's fancy words for irritation .

We have some irritation points in the atria causing firing , and so we have this basically unsynchronized firing of the atria versus a nice whole contraction of the atria , and so this is the meat and potatoes of AFib , we have this erratic atrial contraction , causing basically a quivering or fibrillation of the atria .

Now the problem with this is , if the atria is fibrillating and it's kind of just like quivering , you're not getting good squeeze from the atria , pushing the blood from the atria into the ventricles . So what happens is you end up with stagnant blood in the atria and now anytime you have stagnant blood , that is problematic .

So the most concerning issue with atrial fibrillation and this resultant stagnant blood hanging out in the atria is that it can develop what's called mural thrombi thrombus . When you have stagnant blood they start to coagulate and can basically cause clots . Those clots tend to get dislodged and hang out in that atrial appendage .

So the atrial appendage is this little outpouching of the atria that is a perfect spot for clot formation to occur and hang out . Afib is probably the number one cause of stroke . Because of this , A-fib increases the risk of mural thrombi , therefore increases the risk for stroke . So A-fib is problematic and has to be dealt with .

So when the physicians are dealing with A-fib they're going to be making decisions about how to treat it medication versus cardioversion versus potentially a Watchman procedure , potentially a maze procedure and it's all dependent on the person , their age .

If there's another procedure that's going to happen , right , it all kind of helps them in their decision-making process , Regardless of the treatment intervention , regardless of the cause . If you are working with a patient with AFib , you kind of want to know a few things . Number one is it new ? Is this like a new onset AFib ? Did it just come on ?

For instance , if you're working in the hospital setting , they were in normal sinus rhythm and now they have switched into AFib . Did it just come on ? For instance , if you're working in the hospital setting , they were in normal sinus rhythm and now they have switched into AFib . You want to know a couple of things . Number one do they know the cause ?

What's the underlying issue ? And this is for the physicians to tease out . Number two , and this is important to you what is their rate ?

So the big thing with AFib is knowing whether the person is rate controlled versus uncontrolled or have RVR , because that's going to basically help determine if it's safe for you to treat this patient , for you to treat this patient . And I had a third piece in there . Third piece is are they going to do anything in the moment ?

Right , Are they going to try to convert them back to normal sinus rhythm . And I do have one more thing Is this normal for them ? Do they have a history of AFib ?

Do they have chronic AFib , persistent AFib , long-term AFib , paroxysmal AFib , whatever you know verbiage , description you want to put around it , but do they have a history of it that matters to you ?

So if you are doing your chart review and you see that the patient has a past medical history and in that past medical history has paroxysmal AFib or has the terminology chronic AFib , that means that the person either consistently has it or has had multiple episodes of AFib .

To me that's less concerning in some ways , right , Because this is a chronic thing that the person is dealing with . They're probably on medication , they're probably rate controlled , but it's information for me to say what is their heart rate , what is their rhythm , right ? It's automatically going to be something that I look at before I go and treat that patient .

Also , I'm not surprised by it , right ? You check the telling . You're like , oh , they're an AFib , you know it already because you read it in a chart . So if there's like a known history , a little less concerning . If it's rate controlled , less concerning , right . So what is rate controlled .

Rate controlled means that a person has AFib and their heart rate is less than 100 . Green light it's safe to play , it's safe to exercise , we're able to work with them , no questions asked . You're still going to monitor and you want to make sure that that rate is staying in a reasonable area .

Uncontrolled is considered AFib with a rate greater than 100 beats per minute . I like to call uncontrolled yellow light because there are times where you're still going to see this patient even though they're not controlled . But this is when you start to play . How not controlled are they ?

So I would call not controlled between 100 and 120 , and I would call that a yellow light . I would want to know if the patient is symptomatic . I would want to know if their blood pressure is holding .

Blood pressure is a nice clinical tool to basically help determine if we have good cardiac output , and so that's what I'm going to be asking and monitoring and deciding . But usually 100 to 120 , you're still in a safe zone . Once you get to a heart rate greater than 120 , this is considered rapid ventricular response .

The higher your heart rate gets , the more problematic cardiac output becomes . Right , If you're thinking cardiac output formula stroke volume times heart rate . If your heart rate is increasing and stroke volume is decreasing , right , it's going to cause issues with your cardiac output .

But then you get to this point where heart rate , let's say , is greater than 120 , and we're in AFib . Right , we want to make sure that we're remembering that we're in this rhythm atrial fibrillation . You have this quivering atria where you're not getting good squeeze from the atria into the ventricles , which means you're losing out on atrial kick .

At base , Atrial kick is known to cause about 15 to 20% of cardiac output . So just by having AFib , even if you're in a controlled rate , you likely have a 20% , 15% , you know , depending on what source you're reading less cardiac output than someone in normal sinus rhythm because you have this quivering heart , you don't have this normal nice squeeze .

Now we increase the rate . When you increase the rate , stroke volume is going to go down . You keep increasing that rate , that stroke volume is going to keep going down . Eventually your cardiac output's going to be very affected . The way I like to kind of check myself is by assessing blood pressure and seeing what that map is .

And if your blood pressure is dropping and that heart rate is like up there , that is a good reason to stop , Okay .

So I'm going to back up just a second and I like to use and I may have said this before , but if you're new to me , if you're new to this episode , I'm going to say it anyway because I think this is a really great education point right , If your patient is resting with a heart rate greater than 120 .

And they have a consult for PT , or maybe they've been seeing PT , but now you see that there's a change . There's a change in rhythm . Heart rate is not controlled , we're going to call it RVR . You might start , you know , being concerned about seeing this patient . You should be concerned , you should have your yellow flag up at minimum , right ?

And now you're weighing pros and cons of seeing this patient . If you're being pushed to see someone and they're an AFib , and let's make it a little bit more extreme , let's say they're sustaining higher than 130 . Maybe they're between 130s and 150s at rest , Even 120s , right , Like I want you to think about what this means .

If they are sustaining at 120 , at 120 , what is their max ? What percent of max heart rate are they resting at ? So let's just do quick method 220 minus age is guesstimate max heart rate and it holds up compared to some of the other formulas . So for easy math , we're going to use 220 minus age .

If you're 80 years old which is a high probability that a person will have AFib you're 80 years old . 220 minus 80 , 220 minus 80 puts you out 140 max heart rate . If we say the patient is sustaining at 120 , they are resting at 86% of their max heart rate . They are working just existing .

So if you do end up seeing this patient , for whatever reason , you need to consider that they are already at the top of their range . You have a little bit of room to play , but not a lot . If you are sustaining in the 130s and they're 80 years old I didn't do my math ahead of time on that , but you're going to be close to that 90% marker .

If they're sustaining in the 140s and the person is 80 years old , they are resting at max . You don't have any room to play , okay , and if you are working with this patient , likely you're doing some sort of activity or exercise . So whatever you're going to do is going to increase that rate .

So usually right around 120 , I'll call it an orange flag , like blood orange . I'm like we have to have some really good reasons why it would be beneficial to see this patient right now versus waiting right ? The questions I would want to know is what are they doing to medically manage this patient ?

If they just put them , for instance , on an IV amiodarone drip , I'm going to let that MEO do its job and they may convert back to normal sinus rhythm , and then you're going to get more out of that patient and be in a safer place , right ? So risk benefit ratio and clinical decision making is so important here .

Now , the reason why I'm trying to use the word sustain and why I'm saying like a dark orange , like I'm going to call that a yellow flag , but you have to know you don't have a lot of room , no matter what , and so you have to be monitoring . If you are choosing to move forward with this .

Okay , Honestly , that one thirties marker that's kind of where I'm I'm going to hold red flag

. Why ? Because you're probably at greater than you're probably at like 90% of someone's max heart rate . So I did the math for a couple of them . So I just want you to have , like some , I don't know feeling towards this . So if the person's 75 , 220 minus 75 puts their max heart rate at 145 , making a heart rate of 120 , 83% of max , 220 minus 70, .

So person's 70 years old , 150 is their max . If we're at 120 , they're at 80% . So they're at moderate intensity . You know , hanging out 120 . When you get down to 60 years old , 220 minus 60 puts you at max 160 . To 60 years old , 220 minus 60 puts you at max 160 . They're at 75% of max . So we're still like really high on that intensity scale .

Just at rest you have a little bit more room to play . But you don't want to be the reason that the person then flips into sustaining heart rate to 130 to 150s , right , Because now that's a whole different ballgame that we're resting in .

So you have to kind of like really think about reasons to say I'm going to hold or wait right , Because that's maybe a better terminology instead of saying I'm holding today , You're waiting to see if there's a change , and if there isn't a change , maybe tomorrow's another day for that patient . The primary symptom of AFib is fatigue .

I've talked about this before as well . Fatigue is a symptom . So people might say but he doesn't feel it . She doesn't feel it . But they say I feel so exhausted , I feel so tired , I just have no energy . They have no energy because they're resting at 80% of their max . They're resting in moderate intensity , so it makes sense .

They don't have a lot of reserve and you really don't want to kind of push over that threshold . Some other common symptoms sometimes I'll feel a little shorter breath . Palpitations obviously super common , but not everyone feels it . Some people can feel it flip right away Like they feel bracing in the chest . They feel like fluttery or palpitating .

Some people don't feel it at all . Dizziness very common as well as low blood pressure . So dizziness and low blood pressure is because we have this decreased cardiac output . Right , symptomatic patient symptomatic . I had a patient over the weekend . He um went into afib overnight . He was sustaining between 120s and 150s . This was new .

He didn't have a history of afib um . He had been doing great . Actually he the day before ambulated 200 feet . He's post-surgery , which is also common and a common cause or someone flips into a fib is post-surgically . So I go up to see him .

I already knew this ahead of time but I , even though I checked the trends for heart rate , I just want to double check to see where he was at and he was resting at 127 and I said you know what ? We're not going to see him yet . Let's see if I think they put him on a beta blocker . Let's see if he flips .

Let's see if he flips back into normal sinus rhythm . It's not worth pushing . We know he's mobilizing . Well , All I'm going to do is stress the system , and the system is already stressed , Sure enough . 1 , 2 pm he converted into normal sinus rhythm . I saw him later in the day . He was like resting 80s , never flipped back in , which is also a concern .

Just so you know , like if they flip into normal sinus rhythm and you start exercising , you're increasing stress , you're increasing rate . There is a potential they could flip back into AFib . He didn't flip , which was great . So I did ask him . I said could you feel it ? Because I think he was sustaining in the 150s .

At one point he said I couldn't feel anything , which to me I know I would feel it , Because when I'm racing and my heart rate is up I feel it right away of that palpitation or racing sensation . But it's an important conversation . Have those conversations with the nurses , have those conversations with the docs .

The key to this collaborative conversation is really talking about how much room do you have to play and if , because I've had situations where , like , mobility is really important , we really got to start moving them , They've been in this rate for , let's say , three , four days , let's just say , for instance .

Then what I'll typically say is what's your stop , what's your stop marker ? Because I need to know when it's time to call it quits , Because I already know where I'm going to stop . But I want to have that verbal order . What do you feel comfortable working into , Especially in an arrhythmia , right ?

So 120 , you really start to have to start your pros and cons . If we're sustaining above 120 , likely a hold Okay .

And if you're not holding , you are having conversations , you are monitoring symptoms , blood pressure , heart rate and you're making decisions in real time Okay , let's see , I went on a tangent , so let's see if I have anything else on my outline that I wanted to hit . So yeah , so this is actually a good point .

This gentleman that I saw this weekend he was taken off his beta blocker for , let's say , was taken off his beta blocker for , let's say , five days leading up to his surgery .

So he wasn't reinitiated on that beta blocker because I think he was trending towards hypotension , so they were holding it and then he flipped into AFib and once they added his beta blocker back in , he flipped back . He converted back to normal sinus rhythm . So typically if it's an acute issue , like persons in the ICU , they flip into AFib .

Usually they treat with medication first . Iv medication is very common . The two most common that I see are amio and an IV beta blocker . If they're using a beta blocker for antiarrhythmic , it's usually Sotolol . Sometimes you will see other meds , but that's usually the one that is used , and you have to understand that when patients are on these medications .

Amio is a class three antiarrhythmic , Sotolol is a antiarrhythmic . The primary side effect of antiarrhythmic medications is arrhythmias , so medications don't come without side effects as well , and so you have to be aware that if you're working with a patient , you may experience other things due to said medication .

If this maybe is persistent and the meds aren't flipping them , they might or converting them . I should say they might use or they might trial cardioversion , and usually the person's sedated and they literally tried to . You know , flip that electrical charge . To convert them back Doesn't always work , but sometimes it does , sometimes very successful .

Another option that they might do is an ablation , and so ablation actually might be one of the coolest things I've ever seen in the EP lab , because they literally go and find the ectopic focus and then they cauterize it Like they find it and they cauterize it and then they wait and they basically see did they get it ? Coolest thing I've ever seen .

So ablation is very common . Ablations can be very effective , but they can also work and then flip right back into whatever arrhythmia that you know they were ablating . And then the maze procedure is another option . But a maze procedure won't be performed unless the person is having an open heart surgery .

So once they have the chest open , a maze procedure is essentially similar to an ablation , but they're cauterizing the tissue and they kind of do it in like a Z shape and the goal is really to deflect the signal . Is my understanding . So lots of options . Obviously you want to start with the least invasive .

Sometimes patients convert on their own so they don't even need a medication . They might just flip right out of it . But if they're in that uncontrolled rate or they're in RVR , likely an intervention will then follow suit . So there are tons of causes of AFib . Age , I think , is probably the most common .

You have an increased risk greater than 65 years old and then once you get to 80 , I believe your risk of AFib is like 22% . So age is a huge one . Any change in myocardial tissue , really commonly seen post-MI , right , you have infarction ischemia to the myocardial tissue . You might get remodeling of said tissue . That can be a big trigger .

Heart failure , change in heart failure . You have change in shape , potentially , of your heart muscle , another trigger . And then some other things that you can control , right , Because a lot of that you know you can kind of dive in , Can you control , Can you not control ? But drugs , alcohol , stress , smoking , high risk for flipping someone into AFib .

So if you have a risk of AFib , or maybe you have had it in your past , smoking cessation is huge , decreasing alcohol consumption and then , especially if a list of drugs are on the table , cocaine is a very common one . Cessation of drug use is super important . Lung disease is on the list and sleep apnea has a high risk as well .

So there's a number of causes . Typically , like a lot of the other diagnoses , they have to treat the underlying cause to prevent the AFib from coming back . But in some cases it comes back , In some cases people live with it and you're going to see patients with AFib , I think I don't know .

When I was in school I feel like they scared us about AFib , Like you're never going to work with this patient . I mean , that's not true . You're going to see a ton of patients with a past medical history of AFib or actual AFib . The big piece of it all is that you are paying attention to the rate .

If they're less than 100 beats per minute , they have a known history of AFib . Green light go , You're good to go , You're fine . But you're going to monitor and you're going to pay attention and you're going to watch blood pressure and watch heart rate and make sure that you don't start creeping up into that uncontrolled zone .

100 to 120 , yellow , Yellow light cautious , proceeding with caution , Monitoring vitals closely , Monitoring symptoms closely and if they're starting to trend and sustaining higher on that range , you're pulling back or stopping . And then , greater than 120 , that's RVR . That's usually when you're thinking about holding .

You're almost at that red light , pending the situation right . And I kind of want to say that because there's almost no true black and white holds . There are a few , but not a ton . But right around 120 , you're like , hmm , you want to have a good reason . And if they're sustaining on the higher end of it probably not in that moment or you're waiting .

You're waiting to see if an intervention is being applied and then if that intervention works , then you're good to go right . So I always say set the person up for success . If that person is receiving an IV med to help convert them into normal sinus rhythm , then let the med do its job and if they convert you're good to go .

I would still say proceed with caution . If they're sustaining in that higher range and they're at a high age , you have to understand that person is working hard just at rest . The reason why they feel so tired and fatigued is because they're sitting at maybe 80 , 85% of their max heart rate . And that's the conversation I like to lead with .

If I don't feel comfortable with proceeding and maybe you're getting a little bit of push , that's usually the conversation I start with and then I'll ask well , what do you feel comfortable with ? What's your high end of this range ?

That you feel comfortable with this person working and if that person's symptomatic , if that person's blood pressure is dropping , you're stopping right . You have to use your clinical decision-making in real time with that patient and make these decisions , and not every patient is going to have the same decision . So just kind of keep that in mind too .

Anything else , oh , one last thing , little clinical tip before we end this episode Pulse Ox . There's an episode I don't know what number it is , but it's about Pulse Ox . I highly recommend you give that one a listen . The Pulse Ox is a cool little device that gives us a ton of information and let's say , your person's not on telly .

That Pulse Ox can give you a ton of information and potentially notify you that your person is an AFib . So if you put a Pulse Ox on a person with AFib number one it might not be accurate because that pulse rate is all over the place . Number two , it will tip you off potentially that the person is an afib because the number is all over the place .

If you have something like 40 , 110 , 40 , 110 , 40 , 110 . If they have telly , go check that telly . They might be an AFib . If they're not on telly , palpate the pulse . The quintessential term for AFib is irregularly irregular . There's no pattern . There's no pattern because you have this quivering , erratic , not synchronous , atrium .

Okay , you have this erratic beat . It's going to be all over the place and you'll see it on telly too . It'll kind of just move up and down . That's why the word sustaining is huge . They're as low as 105 , but go to 117 , right , there's going to be this range . If they're low as 120 and they're high as 145 , red flag is coming out .

Okay , it will jump around . It jumps around because we don't have that normal atrial contraction . One thing I didn't say , that I want to make sure that I say , is person who has AFib , what their tele looks like and I talk about tele you will have no P wave . That is the big sign that your person's an AFib . So some things to tip you off .

From a , you know , tele perspective , if you wanted to identify AFib , First there's no P wave . Typically it's wavy-like pattern and then you'll see the QRS . The reason why you don't have a P wave is because you don't have an atrial contraction . You don't have depolarization coming from the SA node .

You have these ectopic foci doing its own thing and then the AV node kind of funnels the foci into a QRS . So your QRS is actually normal , but because it's so erratic there is no rhythm to it , so it is termed irregularly irregular , and you will have no P waves . That's the primary way to identify atrial fibrillation .

Okay , I think that's all I have for you , so if that was helpful , please let me know . Afib is such a common arrhythmia that is seen in chronic stable patients as well as new stable patients as well as new acute , uncontrolled RVR . Two very different pictures , one underlying rhythm , right .

So super important to be able to identify it , super important to understand rate control versus uncontrolled , versus RVR , and then also understanding that we might have to be part of the conversation of whether this person is safe to proceed , and also understand that , if they are in RVR , that that person is resting at a very high heart rate compared to their max

heart rate , so they're doing a lot of work , just resting and existing in that moment , which is primary reason why their symptom is fatigue and extreme tiredness . So never ignore fatigue . Ask more questions , make sure you're assessing vitals , because sometimes you're the first person to identify that there is actually a change .

All right , so if you have any questions , please reach out to me , Thank you , thank you for listening

. If you enjoyed this , if you got one gem of information , drop me some stars , write a great review . It is 100% appreciated . All right , I hope you all have a wonderful day and whatever you have to do , get after it . Thank you .