How fast is my heart rate?

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I know 300 divided by how many squares but my tachy confuses me in determining the formula and hr.
Can anyone calculate my hr?

The resolution isn't great, but you can also use the small boxes to help you (hard to see on what you posted). Looks like about 1.6 big squares between beats or 300/1.6 = 187.5 BPM. Each small box is 20% of a big box (i.e. 1/5). So you can count how many small boxes there are in addition to full big boxes. So 3 small boxes plus 1 big box = 3x20%+1 = 1.6. Then compute rate by 300/1.6=187.5.

Thinking it through, if there was only one big box, then your rate is 300 BPM, two big boxes = 300/2=150. Your rate is in between.

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I enlarged it.

Thanks in advance George. It looks like 3 beats to a large square.
I know my hr wasn’t 450. So how fast was 3 beats between one large square?

[litfl.com]
1500 rule



Edited 1 time(s). Last edit at 02/15/2021 03:55PM by susan.d.

That's about 180 bpm.

Thanks Carey! Better than my last 244 recorded on my Holter monitor.

How did you calculate it so I can learn? It was 3 beats between each large square.

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susan.d
How did you calculate it so I can learn? It was 3 beats between each large square.

I'm posting an image of mine so you can see better. The red outlined "large box" (with my text) is a "large square." See the dots in between? They are the small boxes. In my case, there are 5 large boxes and 1 small box between RR peaks. This is 5 + 0.2 = 5.2. 300/5.2 = 57.7 or 58. Which is what Kardia lists on my report. Carey's 180 and my 187.5 are effectively equivalent and we computed the same way as I explained in my first post above (without printing out and measuring - 25mm/second). To be clear, the heavy dark lined boxes are one second apart. Since there are five large squares inside the dark lines, you can see my peaks are a little bit more than five large squares apart or a little more than 1 second apart. Hence 58 beats/minute.





Edited 2 time(s). Last edit at 02/15/2021 05:38PM by GeorgeN.

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susan.d
How did you calculate it so I can learn? It was 3 beats between each large square.

Simple. I counted the beats in a 5-second period. There were 15 beats, so 15 x (60 seconds / 5 seconds) = 15 x 12 = 180.

Doing it that way averages out beat-to-beat variation and makes it unnecessary to do careful measurements or count little boxes. If the rhythm is super irregular like in afib, I might count the beats in a 10-second period instead.

But honestly, why doesn't your device calculate the heart rate for you? I've never seen one that didn't.

Simple. I had a run of tachy before taking a reading and had some tachy and then I immediately converted to bradycardia for the remainder of the strip. Kardia averaged the tachy and bradycardia together and arrived at 175. I wanted my tachycardia # not average.