Heart rate / pulse rate

Technically, heart rate and pulse rate are different, yet it appears the majority of people use the terms interchangeably. My OMRON blood pressure monitor states on the machine itself "PULSE / min." My oximeter is called a "Pulse Oximeter".

HEART RATE
The rate at which the heart beats, or contracts. Any contraction (even if it doesn't result in appreciable blood flow through the arteries) is part of heart rate.

PULSE RATE
The temporary increase in arterial pressure that can be felt throughout the body. Pulse rate can be used to measure heat rate for a normal, healthy heart.

When I'm taking my blood pressure reading, I've noted that there is a wide variance in what the OMRON shows for the pulse, as I'm concurrently getting a reading on the oximeter. For example, the BP machine may show 72, whereas the oximeter will show 50 at the same time.

I suppose one or both machines are giving a faulty reading. Any thoughts based on past experience?

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Rob Wilson
I suppose one or both machines are giving a faulty reading. Any thoughts based on past experience?

I have no experience with a BP machine as I've always used a stethoscope & cuff.

I do have experience with Polar heart rate monitor chest straps and various devices to capture the chest strap signal. I also have several pulse oximeter devices, some of which can record for many hours. In NSR at a low heart rate, I notice little difference. There is a difference in reporting as while the Polar strap signals every beat & my devices & apps will record such, the visual display is a moving average, I'm not sure how many beats are averaged. Hence to get actual beat to beat data, I have to download it to my computer and view the file and a timestamp. My recording pulse ox records every 4 seconds, so that is always an averaged number. As the Polar is looking at ECG signals, that is as accurate as it gets, and they've been tested against ECG recordings with a very high accuracy. Generally were the pulse ox devices have trouble is when there is a variable pulse amplitude, as is common in afib. They will tend to miss the low amplitude beats & therefore undercount. Your finger on your radial pulse can make the same mistake. So generally, if there is a large difference, the pulse ox is low.

Here is an example from 14 Jan 21, copied from this post.
I converted an afib episode with a breath hold.

The green line is the oximeter heart rate. Blue is from a Polar H10 strap captured with the Heart Rate Variability Logger app. Red is SpO2 from the recording oximeter.

Note that when the afib rate is high on the left side, the oximeter heart rate is about 82 and the actual HR is averaging ~150 (from visual inspection). As the afib HR drops, the oximeter heart rate increases to a more real rate.

The oximeter rate is smoothed as the device records every four seconds, as opposed to the Polar, which records every beat.



Note at the end, in NSR, they agree, though the pulse ox doesn't "see" the ectopics. During afib, it undercounts. In the beginning by a large amount. About a quarter of the way in, the rate variability drops, though is still large, then the pulse ox gets closer.



Edited 1 time(s). Last edit at 01/12/2022 01:56PM by GeorgeN.

Whatever the device, I guess there's a threshold where the device decide "it's a beat (or pulse)" or "it's an artifact".
A NSR doesn't usually present any problem. Beat counting is easy.
People having ectopics or afib know, if they make use of two different devices, there can be variations in the results. What one device counts as a beat may be neglected by the other.
A good tracing is reliable for people trained to interpret what it means.

Actually, most medical people use the terms interchangeably. If there's a significant difference between heart rate and pulse rate then there's something wrong with you. As for your machines showing 50 and 72 at the same time, one of them is broken. Take your pulse manually and use that as a gold standard to figure out which one is faulty.

Isn’t the “pulse/hr” reading of the ventricles and not atrium?

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susan.d
Isn’t the “pulse/hr” reading of the ventricles and not atrium?

Yes. Atrial rate is very difficult to measure with consumer devices unless it comes with leads that attach to the chest and has more than a single lead.

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Carey

Isn’t the “pulse/hr” reading of the ventricles and not atrium?

Yes. Atrial rate is very difficult to measure with consumer devices unless it comes with leads that attach to the chest and has more than a single lead.

Thanks! It makes so much sense now. When I present myself to the ER, my IWatch /Kardia readings are faster than my leads on chest…which would be atrium reading. My flutter is 1:1 and sometimes my ventricular readings (from pacemaker) shows higher.

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Carey
Take your pulse manually and use that as a gold standard to figure out which one is faulty.

I think this works in most circumstances, but perhaps not for some in afib. As I mentioned in my post, the pulse amplitude can be highly variable in afib. You can see this with a plethysmograph device (like a pulse ox or even a phone camera app). Especially with high rate afib, it is easy to miss the low amplitude beats with your finger and undercount (and the pulse ox devices do this also). An ECG device or a RR recording chest strap device (which does "see" the QRS waveform) really are the gold standards IMO. My Polar chest straps will miss "seeing" PVC's because of the malformed QRS wave & hence undercount those. Not usually material unless you have huge runs of PVC's.

Can anyone help?

I measure my heart rate with fingers on my wrist. At rest and NSR my rate is about 55.

In AFIB I am usually less than 90 bpm. But what am I feeling in my pulse? Are these ventricular beats or both ventricular and atrial? And can I assume my heart rate in AFIB is 90 or do I need an electronic gizmo to get the true heart rate in AFIB?

Thanks

You don't feel atrial beats. What you feel are ventricular beats. They're of various intensity because of the irregularity of the beats: your ventricles are filled differently between the beats, so some beats are stronger than others.
Unless your AVG HR is very slow while in afib, you're likely unable to count the beats with your fingers. Some beats are so weak and/or so close to another you can't feel them.

Edit : I've an ECG monitor and a cheap oxymeter. The latter is far better at counting beats (even in afib) than measuring blood O2. It can display some sort of "tracing" where I can see the beats. It does not record anything, but it's surprisingly useful.



Edited 2 time(s). Last edit at 01/13/2022 11:49AM by Pompon.

Carey suggested this recordable oximeter when Amazon was having a sale for $20. Currently for less than $25, it’s a great product in which you can download the phone app and record and save to a file. It’s my companion when I make my frequent ER runs. I just have it in my finger flashing a super high number when I arrive at the first desk. It saves time in triage so I don’t wait/exposed in the already full waiting room and results in a faster ekg track to confirm.

[www.afibbers.org]
Look at Carey’s link of saving >$130 to find the product.

Or go directly to:
[www.amazon.com]



Edited 1 time(s). Last edit at 01/13/2022 01:11PM by susan.d.

Hi, Susan. I'd missed this information and didn't knew there are cheap recordable oximeters.
Mine is like this, but without the "connected" option (I bought it many years ago).
On the "pulse waveform", I can clearly see if the beats look regulard or not (but I don't need to, since I easily feel them). The "pulse waveform" wile in afib is really chaotic. And the beat counting (in afib) is accurate, despite being averaged.
Strangely, when I've ectopics in bigeminal pattern, they are apparent in the "pulse waveform", but the device does not take them into account, giving a very low beat count (in the 40s).
(I can say that for I've used the device while using my ECG monitor (with lead wires)).

Thanks for the info. So my ventricular rate in AFIB is usually less than 100. Is that what is important or do I need the atrial beats to also be less than 100 to prevent heart failure?

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MikeN
Thanks for the info. So my ventricular rate in AFIB is usually less than 100. Is that what is important or do I need the atrial beats to also be less than 100 to prevent heart failure?

The ventricular rate is the important one. Atrial rate is usually around 300. The heart failure is associated with the ventricles.

Hi Susan

Over here in the land of golden opportunity, the device is advertised on Amazon AU for $135.
Total rip-off.