How does one manually measure heart rate? (My understanding is that one finds a veinal pulse; counts the number of heart beats over an even segment of a minute (e.g., 15 seconds); multiplies that by the number of those segments in a minute (e.g., (cont.) 4); and that is one’s bpm heart rate. (using the current e.g.s if you count 20 heart beats over 15 seconds your heartrate is (15 * 4) 80 bpm). If my example is incorrect or if there are better/more accurate variations on this theme, please correct me.
(Although my cardiologist and everyone in cardiac is in agreement that a cuff is a practically useless way to ascertaining heart rate—more on that later…) Nonetheless my cardiologist will perform the method stipulated above...
My nurse in the cardiac unit claims that one can accurately measure one’s pulse this way even if the pulse in question is in afib. I believe (by ‘definition’!) this is impossible.
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Hi, Good questions! To measure your pulse you take your index and middle fingers and press the radial artery, along the bone, just below the thumb of your opposite hand. It is always better to simply count for a full 60 seconds to be most accurate.
Even experienced medical people find it nearly impossible to manually count an erratic AF pulse. Checking my radial pulse is something that I do multiple times/ day, just as a reassurance to myself, but when I was in AF, I always listened to my heart with a stethoscope because that was more accurate and easier than trying the radial pulse.
An excellent question and one that has been partly covered in responses to other posts in the past. The comments below relate to people in AF rather than a normal person with a regular heart rate. I am in persistent AF.
In essence the only accurate way to ascertain accurate HR is using an electronic device for extended heart rate monitoring. In hospitals there are various devices and also ones for home use such as the Kardia (aka AliveCor). However even these devices may not be accurate (see below).
The second most accurate are cuff monitors that are designed for AF whether hospital or home use. Home ones like the Microlife WatchBPHome A (A for AFib).
Ones that can be very inaccurate are wrist monitors and finger ones. These could be up to 50% out. I did a comparison between my Kardia and a well known wrist monitor and the results varied by up to 50%!!!
As to manual measurements I believe that the nurse is correct - a person can not measure accurately in almost all AF situations. The faster the HR the more inaccurate it is going to be. Also even for a normal person measuring for 15 sec and multiplying by 4 could easily produce an inaccuracy of 8 HBs or more but it does give an order of magnitude. For instance someone who is in AF and whose HR is say 120 it would be impossible to get an accuracy, apart from anything else just defining what is a HB and what is not a HB every half second (beat strength, etc, varies).
The shorter the period someone measures over the more inaccurate the number is. Kardia minimum is 30 secs. However (having an analytical and a scientific mind) I did various tests and analyses and have set to record for 2 minutes so that a much more accurate comparison can be made between readings on different occasions. The Kardia obviously gives an average at the end of the reading (which it logs) however as you are doing the recording it displays a current average HR over the previous x secs (I don't know over how long). So for instance one recent reading was Average 84 but varied from 65 to 115 (a difference of 50 HBs!!! - and This is having been sitting down in the same position for say 5 to 10 minutes!!! The multiplier is 1.77 or 77%. Normally the difference is around 30 or so.
If you look at the pdf graph of the Kardia result you will see exactly what is classified as a beat by a little mark at the bottom of the scale. For me at least the strength of each beat varies. Sometimes a manual check would not assess them. Also if someone has say 4 beats in a second (HR 240) will someone manually count them as accurate? No!!!
Back to your question theoretically if someone is in slow HR and in AF then if you manually measure over 1 or 2 minutes (not 15 secs) then you could get a reasonably accurate result (on the other hand you many not). However if say around 100 plus you probably wouldn't!!!
Personally I suspect that one of the reasons that some people end up with a HR that is too slow or too fast is because of snap shot measurements and then using that to determine the amount of a medicine. With regular monitoring twice a day it is easy for the GP to see what is happening and make a much more informed decision as to what is appropriate. My GP has done this on HR. The other week I went to see GP because BP was up (normally around 105 / 65 but was up to 135 / 100. She looked at the results and quickly said that she wasn't worried about the systolic elevation but was concerned that the diastolic was too high for too much of the time (mostly in mid to high 90s). Previous morning was 81 but that was not typical !!!
I also meant to say that as for accuracy as an event or on an occasion then the accuracy of heart rate MAY NOT be that important (eg if someone is measured at 90 but it is really 110) if it is not too far out. However if someone is manually it as say 100 but that in reality it is 150 then that could be quite serious because it could be that the person needs to go to hospital.
Also if regularly measured incorrectly then the patient may not be getting sufficient or may be getting too many medicine(s).
I understand that my question may have been raised before. However, in my case it’s just a preliminary question (ergo “Part 1”) to my main question…
Regarding your response in particular:
(As you assert, and I suspected… My nurse is incorrect. She asserts that manual measurements can be accurate.)
First of all, I’M NOT INTERESTED IN ASCERTAINING MY HEART RATE IN ORDER TO KNOW I’M IN AFIB! (I cannot understand why anyone who knows they have atrial fibrillation would want to confirm they have atrial fibrillation.)
More interestingly…This is why I believe it is impossible, by definition and over any time interval within (manual) reason, to manually determine afib heart rate. PLEASE CORRECT ME IF MY LOGIC IS WRONG.
(Note: I wish this forum allowed one to boldface or underline text. I do not mean to YELL, only emphasize, when I use ALL CAPS.)
For a person who does not have afib: If within a certain amount of time (say 10 sec, for simplicity) one counts 20 heartbeats, one can reasonably say that one’s heartrate is 120 BECAUSE ONE ASSUMES THE TIME BETWEEN EACH OF THOSE HEARTBEATS IS CONSTANT.
For a person who does have afib: If within a certain amount of time (say 10 sec, for simplicity) one counts 20 heartbeats, one CANNOT reasonably say that one’s heartrate is 120 BECAUSE ONE must ASSUME THE TIME BETWEEN EACH OF THOSE HEARTBEATS IS not CONSTANT.
Heart rate change means that the time between 2 heartbeats has changed. Only an instrument capable of measuring the time between each set of heartbeats can accurately measure heart rate. (I assume that machine you’re hooked up to in ER (which in my case seems to beep incessantly!) is doing this and is therefore accurately measuring my heart rate.)
Is my logic correct? Is my argument therefore correct?
Most tablets and many smart phones do allow bold and underlined text on this forum. When my PC and as on Windows 8 it didn't but I haven't tried on Windows 10 now that I have upgraded.
Heart rate and AF are two different parameters. One person in AF could have a HR of say 40 and another in AF it's 120. Also a third person with a HR of 120 could be in NSR so their beat is regular and is approx every 0.5 secs.
Regarding the counting etc you are well on the way to being correct but there are some nuances / bits missing.
For anybody with a low to medium HR whether in NSR or AF it should be fairly easy and accurate to count most of the time. For a HR of say 40 it is likely to be pretty accurate if taken over a minute. However for the person in AF it may not be quite as accurate because although the number of beats is easy to determine some beats that are quite weak may be missed when checking manually but would be picked up by an electronic device. As the HR increases it becomes more difficult to count accurately and by the time HR reaches 120 it becomes much more problematic whether or not the person is in AF. Certainly by the time HR is high (even 180) it is difficult to count accurately. The same proviso for the person in AF still applies. Also for someone in AF the swing can be quite dramatic (see real example in my earlier response). It is this change that could make counting difficult say at an average of 90 because the range say is 70 to 140.
The real inaccuracy is only taking for 15 secs for someone in AF and then multiplying by 4. For example using my real measurements above the overall average was 84 but polled range was 65 to 115. Therefore if you took a 15 sec snapshot at the low end and multiplied by 4 the calc could show 72 bpm but if you took a 14 sec snapshot at the high end it could be 124 bpm. Obviously a big difference!!!
Therefore it's not the gap between two beats that is key but the actual total number and in addition for the AFer the strength.
From what you say, I now understand that there are other folk who have fairly predictable/minimal-swing forms of AF.
Regardless, I understand that AF—from a heart rate point of view—merely means that heart rate is variable, and often highly unpredictable. Maybe my (“chronic/asymptomatic”) afib is different, but I’ve been told I can expect, even within a minute’s time, my heartrate to vary from >50 bpm (I have a pacemaker that’s supposed to keep it above that rate) to…the sky’s-the-limit (minus the effect of daily Digoxin; Metoprolol; Diltiazem). Therefore, even assuming minimal heart rate variation, I see no way any manual form of reading heart rate can be accurate.
It follows that the more proper way to express heart rate when AF is concerned is to either express it as a range (“my heart rate ranged from 50 bpm to 200 bpm” or “I had heart rates in the X – Y range”); as a rate-in-passing (“in the last hour I had heart rates as low as 45 bpm”); What is NOT correct is for a person in AF to say: “My heart rate is X bpm.” (A statement like “My heart rate is X bpm.” implies that I have a REGULAR heart rhythm.)
It is the range as you say and the average (ie 3 numbers) that are relate to and all three give a much better indication as to what is going on at that point in time and a more meaningful comparison of readings taken at different times or different days.
If you actually are in AF (whether persistent or are paroxysmal and having an incident) then the minimum duration of the reading should be 1 minute but I found by analysis and review 2 minutes was better and more representative. If 1 minute then you would say xx beats in 1 minute and if over 2 minutes then total is divided by 2 to give you an average of xx beats in a duration of 2 minutes.
Then considering the high and low numbers. By definition for a particular device they are an average (low and high) over the defined duration of he particular device. By this if it was say over a 10 sec duration and there were 10 beats low would be 60 and if 22 beats high would be 132.
If you looked at the printout of the recording and then considered just the longest gap between 2 consecutive heart beats and the shortest gap between two heart beats this would be very unrepresentative. If the longest gap was 2 secs that would indicate a rate of 30 bpm. If the shortest gap was 0.2 secs that would be a rate of 300 bpm. However both figures on their own are meaningless because you don't know the proportion. By this I mean that 95% of the time the gaps could be towards the lower end or towards the middle or towards the top end. This is why the total in 1 minute or average over 2 or minutes becomes so important. I know 95% is too a high a percentage but it makes understanding easier.
We also have to be cognisant that the whole of a medics training has centred about average beats per minute and that has been a snapshot over 15 sec and hence multiplied by 4.
When I pointed all these things out to one doctor he thanked me because it put it in a completely different perspective for an AF sufferer and he could see more clearly the effect the variable rate was having on them.
Thanks. I just talked with a longtime ER nurse friend (trying to find out the name of the machine they hook you up to in ER)… She said: “I was told to count the heartbeats for a minute, afib or not.”
I hope to read what you have to say in “Heart Rate Part 2”.
You will find that different hospitals use different machines and if they were re-equipped or built a number of years previously (could be 10 years or more) it will be a what someone thought at the time (which may have not been the best at that time) and not in anyway reflective as to what they would do today.
A little story that I was told by a senior nurse at a private hospital. For general use they use BP and HR machines on wheels (ie not when you are homed up to continuous monitoring) and this is normal practice in most if not all uk hospitals. She had been away for a couple of days and when she came back into the heart ward she noticed a different machine. She looked at it and found that it was one that was about 15 years old and not suitable for AFers!!!
Yes I gave already sent a reply (warning - it's long and has comparisons and results!!!).
Re the nurse's comments.
True for those in NSR but inaccuracy unlikely to make much difference in most cases. If say 20 beats in 15 secs equating to 80bpm this could be say 76 to 84 but that really doesn't alter tge scheme of things because it is tge order of magnitude that's important. If however say 11 beats because person has low HR then a MINIMUM of 1 minute becomes important.
If in AF the 1 minute is the MINIMUM however 2 minutes is much more representative. I did a number of tests on me a year ago using the 2 minute and 5 minute recording duration setting. I then created a PDF of the results and counted the number of beats in each whole minute. That's when I concluded that tge optimum was a 2 minute reading was much more representative than a 1 minute. The 5 minute ones were only very slightly more beneficial (I think circa 2 beats in a minute) and so weren't worth sitting there for the extra time.
I think Grandma has given you a good way to check your pulse if you are in NSR and agree that it is almost impossible without electronic equipment to record true heart rate if in AF. My only question would be why would you want to? A simple check on the radial artery will tell you if you are in AF or not at which point the question is largely irrelevant.
For many years AF Association Heart Rhythm Week majored on random pulse checking in surgeries and even shopping malls to attempt to discover undiagnosed cases of AF. The campaign was called "KNOW YOUR PULSE". Once a person was found to have an irregular pulse they were advised to have a 12 lead ecg done to fully diagnose the arrhythmia.
My personal view is that constant checking is counter productive , only increasing anxiety and focussing the mind on the condition rather than getting on with life. Most of us don't need a pulse check to know if we are in AF.
I read your posts and your replys are always telling people to stop thinking about there af and carry on with life... as i have af and heart failure it is something i cant forget about and maybe you should think about your replys to peoples questions
I prefer to be positive and enjoy what I can enjoy but we are all different for sure. Having survived cancer as well as AF I DO know how fragile life is and value every single moment.
Unfortunately anxiety makes AF worse (the adrenaline increases the incidence and possibly severity of AF), so making the most of the situation, and not thinking about it all the time really can help.
If you have heart failure as well, you may find 'The Sinatra Solution - Metabolic Cardiology' by Dr Stephen T Sinatra an interesting read. He is an American cardiologist, who became interested first in how magnesium may help, and then found other ways to tackle heart problems including heart failure, without always relying totally on medicines, which often have some kind of unwanted side-effect.
Most people with AF certainly don’t need the fact to be confirmed. And for those people it does seem sorta silly to be trying to get their heart rate. HOWEVER, many people, including myself, would like to know when their heart rate peaks or bottoms out. (Because I have been asymptomatic (those who are symptomatic tell me I’m lucky) I was desperate for this information when I first got AF.) With information like this one is able to understand what circumstances (diet, stress, exercise, particular activities,…) might be related to their heart's highs and lows and make the lifestyle changes necessary to better control their heart.
Bob, i see your point but medics usually ask what one's heart rate is/ was whilst in AF.
My wonderful EP only inquired if I was more bothered by afib or aflutter. (I was diagnosed with both) I was never asked to give my heart rate by any of the medics. However, the EP did ask me to tap his desk to indicate what my heart did in afib. So i tapped out the 1812 overture!
I've always been told by medics what my hr is. Only the person on the other end of the emergency phone call asks me what the hr is (protocol to ask) not taking in that I am phoning partly because I can't tell how fast it is.
Oh dear.... some stressy replies here. I have only recently started using a blood pressure monitor to check bp and pulse rate since my ablation. I woke up one night a few weeks ago and recognized I was in af. I used the bp monitor to see if I could measure it and the poor monitor couldn't cope at all.... it jumped all over the place! Fortunately the af soon passed and my pulse rate started decreasing from about 140 down to 90....
I was in chronic... but not persistent af... for around a year before the ablation. After diagnosis I did try to count the beats manually.... but I can concur, it really is impossible. Measuring tachycardia or high pulse rate, atrial flutter etc is much easier. Afib can, on occasion, hit three + beats a second and I would be impressed if anyone could keep track of that kind of racing!
Great question and of course leads me onto my hobby horse which is the use of automatic blood pressure meters especially by GPs.
Firstly of course, unless you have one of the very modern ones (and I am yet to find a GP surgery with one of these) they will not detect AF, so you could be fibrilating away 19 to the dozen, and it will still "measure" your BP (In inverted commas because the measurement is so often wrong)
Secondly, and perhaps most importantly, the BP reading it gives your doctor or GP is wromg, not slightly wrong, but can be horrendously wrong. At a recent "pre-op" check with one of these infernal machines they measured me at 120/115 when I know full well I will be around 120/75 all the time. (and yes with a manual check, which the nurse "did not know how to do" I was measured at 120/72)
Studies have shown that automatic meters can be very inaccurate if you are in AF and usually they get the bottom reading wrong (diastolic) not the top one (systolic) is this important? You bet if you are being treated for hypertension with incorrect information.
Think about how hard it is to measure your pulse when you are in AF, now how the heck is a machine supposed to know which pulse to measure your BP against unless it's specially designed to do so?
in 2013, NICE recommended that all BP machines should have AF alarms built in, and if AF is detected then the medical staff should switch to a manual method of taking blood pressure.
Not only would this help with the diagnosis of the what some 300,000 in the country who remain undiagnosed and therefore at stroke risk, but perhaps it would also change GPs attitude to using the old fashioned, but much more accurate, manual sphygnomanometers (the pump up cuff they used to put on you)
And if you are in persistent AF AND suffer from hypertension (diastolic) then insist your GPs and all nurses take manual BP checks on you, the machines are not accurate enough.
I think what a lot of these replies demonstrate is the underlying problem with AF. I've had AF for 4 years and I have to admit I do not know what a dangerous pulse RATE would be per se (I could guess) or even BP but I do know what a dangerous TYPE is (i.e. thready/irregular etc.) I think machines that measure various things are only as useful as the individual situations, although I completely agree on the stupid inaccurate mechanical cuffs (for example I always read higher on the mechanic cuff). So I wear a FitBit and it did alert me to AF because it showed my heart rate unusually high (115) for what I was doing (lying down, usually about 60). But as I kept it on through the whole next 24 hours in AF on the full heart monitor, I could see that it was just all over the place -- a FitBit heartbeat monitor really doesn't know what to do with AF, it kept going very high and then low. So as a gross measure, it worked, but not really as a medical tool. Our problem as AF patients is that we have to constantly ask for (demand?) much more refined information so we can get the care we need and not just be told stuff that is at best unhelpful and at worst could cause us to ignore a problem that would lead to more AF, a stroke, etc. I get a little frustrated because there are a lot of people with AF and it seems that the understanding/advice on the part of many GPs would mean people with AF could really participate much more effectively (and with far less stress) in understanding and managing their condition instead of having to advocate for a common understanding and treatment of the condition.
Once you learn to recognize your normal, non-AF heart rate, at your pulse, it's fairly easy to tell within 10-15 seconds if your heart rate is steady and calm or fast and erratic by checking your pulse at your wrist. I've also used an oximeter (oxygen saturation monitor) that gives me a general idea of my heart rate -- it may not be totally accurate but it's close enough to tell me what I need to know.
I recently had a follow-up appointment after a hospital admission for another condition. Wanting to avoid another admission my main question was that I had instructions what to do for mild symptoms, what to do for extreme, but what to do in between? (Bearing in mind that getting to see a GP urgently is veeeery difficult and one does not want to get the reputation for being an anxious patient). The doctor simply said , ' See someone if you don't feel well'! The letter I received later (copy to GP) said 'Do not hesitate to re refer'. So really what counts is not your HB but how you feel and any other 'measurements' are back up. It is up to a doctor to decide how serious your condition is - but yes, they DO make mistakes!
Interestingly, I had a similar experience early in my Afib ‘career’. I would see a cardiologist and he would say “…well, how do you feel?” It got very disconcerting after a while because I’m not sure what I’m supposed to feel like. Am I supposed to feel the way I did when I was 20? The way people think they should when they are old? And I’m not a particularly good person to ask that question to. I’ve been told I have a high pain threshold so for me mild discomfort might be excruciating for others. It got so absurd that I went in once and reported that I felt particularly good on the days I’d forgotten to take my meds (try it! I still feel better when I forget—though not about forgetting!!) So the doc told me I could stay off the meds!!!
Recently I’ve had sciatica pain. An Xray was done that disclosed a large displacement between (vertebrae) L5 and L4. It was diagnosed as “Grade 1…” (for the sake of this example, Grade 1-what doesn’t matter). Having compared the X-rays with pictures on the Internet, I asked why it wasn’t “Grade 2…”. The reply was that that a “Grade 2 finding didn’t correlate with the pain I described in my buttock and legs.” It’s answers like this that make me feel uneasy (I’d rather be asked: “Do you feel this? Do you feel that? Etc.”) because it’s very likely I won’t describe the pains the doctor wanted to hear about.
My first afib diagnosis came as a result of me, at the goading of my partner, FINALLY deciding to go to the local clinic because I felt tired. Never in my life had I thought feeling tired was a sign of sickness—just a sign of feeling tired. That was my first helicopter ride…
Yes, a high pain threshold is not always an advantage! I had a perforated bowel and apparently should have been in agony, but no. I sometimes wonder if I should ask to have this kept in large letters at the top of my notes!
I take 'not feeling well' to cover feeling worse than normal especially combined with some symptoms and significant tiredness being unable to keep up with your normal activities. In that case a diagnosis of a 'real' condition is quite a relief.
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Heart Rate Monitors
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