Difference between atrial and ventricular rate?

Nurses General Nursing

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does anyone know how to calculate this? okay thanks.

Okay yeah the rhythm doesn't affect the heart rate. That's not my question. My question is how do I find the ventricular rate and how do I find the atrial rate?

I mean, I will just know how to find if it's regular or not. But..I never learned how to find the ventricular or the atrial rate.

For instance, let's say the rhythm is a normal sinus rhythm.

I would figure out if it's regular or irregular. Right?

Okay, it's regular. The heart rate has to be within range. 60-100. Is this the atrial rate? Or the ventricular rate? I have no idea because I was only taught to find the rate.

There's a P wave. I was never taught to count them. But let's just say I tried to figure it out on my own and used the method you have stated (if someone asks I'll just say I looked it up online...but technically it's not in the book) and said there's 10 P waves in the rhythm. So the atrial rate would be...10X10=100? which makes sense because it's still within the normal heart rate. So there would be 10 QRSs...so that'd be 10x10=100. So the ventricular rate is 100. So it's 100 and they're equal because it's a normal sinus rhythm.

Atrial rate=100

Ventricular rate=100

Is that correct?

Sinus Bradycardia

Then I would try to figure out if it's regular or irregular.

It's regular.

So the heart rate would be less than 60. But is this the atrial rate? Or the ventricular rate?

5x10=50..So the atrial rate is 50. Then the ventricular rate would be 5X10=50.

Atrial rate=50

Ventricular rate=50

Makes sense it's all below 60Bpm which is bradycardia.

Sinus Tachycardia

Regular

12x10=120=Atrial rate=120

12x10=120=Ventricular rate=120

Makes sense since if it's over 100 it's tachycardia.

Okay I'm guessing the atrial rate is also similiar to the ventricular rate when it's in bradycardia and tachycardia? Not just when it's a normal sinus rhythm.

Sinus Arrhythmia

Irregular..it's the only one that's irregular here..

7x10=70 Atrial rate =70

Ventricular rate =7x10=70

It's within range 60-100.

Right?

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Okay yeah the rhythm doesn't affect the heart rate. That's not my question. My question is how do I find the ventricular rate and how do I find the atrial rate?

I mean, I will just know how to find if it's regular or not. But..I never learned how to find the ventricular or the atrial rate.

For instance, let's say the rhythm is a normal sinus rhythm.

I would figure out if it's regular or irregular. Right?

Okay, it's regular. The heart rate has to be within range. 60-100. Is this the atrial rate? Or the ventricular rate? I have no idea because I was only taught to find the rate.

There's a P wave. I was never taught to count them. But let's just say I tried to figure it out on my own and used the method you have stated (if someone asks I'll just say I looked it up online...but technically it's not in the book) and said there's 10 P waves in the rhythm. So the atrial rate would be...10X10=100? which makes sense because it's still within the normal heart rate. So there would be 10 QRSs...so that'd be 10x10=100. So the ventricular rate is 100. So it's 100 and they're equal because it's a normal sinus rhythm.

Atrial rate=100

Ventricular rate=100

Is that correct?

Sinus Bradycardia

Then I would try to figure out if it's regular or irregular.

It's regular.

So the heart rate would be less than 60. But is this the atrial rate? Or the ventricular rate?

5x10=50..So the atrial rate is 50. Then the ventricular rate would be 5X10=50.

Atrial rate=50

Ventricular rate=50

Makes sense it's all below 60Bpm which is bradycardia.

Sinus Tachycardia

Regular

12x10=120=Atrial rate=120

12x10=120=Ventricular rate=120

Makes sense since if it's over 100 it's tachycardia.

Okay I'm guessing the atrial rate is also similiar to the ventricular rate when it's in bradycardia and tachycardia? Not just when it's a normal sinus rhythm.

Sinus Arrhythmia

Irregular..it's the only one that's irregular here..

7x10=70 Atrial rate =70

Ventricular rate =7x10=70

It's within range 60-100.

Right?

Um, not exactly.

I think your confusion is that somebody told you to "get the heart rate" off a strip and you didn't understand that "heart rate" for purposes of that discussion is the QRS rate, the same as the pulse rate you would feel at an artery or the lub/dub you'd hear with your stethoscope.

The atrial rate is shown by the part of the EKG that indicates atrial contraction, the P wave. So if you see a P wave in every big box, the atrial rate is 300/minute (not freaking likely)

Every other box, 150/minute (300/2)

Every third box, 100/minute (300/3)

and so on.

Same with the ventricular rate; you see that in the QRS.

This is how you get the rate from a rhythm strip.

A normal sinus rhythm has P>QRST, P>QRST, P>QRST in pairs, because the P wave is the atria contracting and the QRS is the ventricles contracting. You understand that this is normal cardiac mechanics, right?

So atrial rate isn't just "similar to" ventricular rate in bradycardia and tachycardia, it's normally identical to it. Also in sinus arrhythmia, because all that is, is the sinus rate is irregular, but the conduction of the electrical impulse through the heart is normal.

I don't know where you're getting the "10" or the other numbers that you're counting and multiplying, or why, so I can't tell where your confusion is coming from.

Let's start over with normal conduction and how it makes for normal mechanics.

Most muscle cells cannot contract without some sort of electrical stimulus telling them to. Cardiac muscle cells are a little different; they can generate their own little electric jolt and pass it along cell-to-cell to their neighbors IF the normal impulse doesn't come through the normal conduction pathway often enough. I am NOT going to talk about atrial fibrillation or premature ventricular beats here, just normal, ordinary sinus rhythm.

1)The normal impulse starts in some specialized cells in the sinoatrial (SA) node, a little patch of tissue that has the ability to do this by itself 'way up in the atria.

2) This impulse spreads thru conduction pathways in the atria, making the muscle cells contract as it goes, in a nice even pattern that empties the atria thru the tricuspid valve (right heart) and mitral valve (left heart) into the ventricles to give them something to do. That's diastole. This electricity looks like a nice round little bump, the P wave, on EKG.

3) There's a teeny pause while the impulse is gathered up in the atrioventricular (AV) node, then it spreads in a nice orderly pattern thru the ventricles, their muscle wringing like a washcloth. (The electrical signature of this action is the QRS, the big spiky deflection on the EKG.) The pressure thus developed closes the mitral and tricuspid valves but opens the pulmonic valve (right side) and aortic valve (left side) and blood gets pushed into the pulmonary artery and aorta. That's systole, and we have...a pulse and a blood pressure.

Please tell me where your confusion lies and if this makes any sense to you.

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In response to GrnTea, yeah, I got the 10 from a homework worksheet...there were 10 Ps and 10 QRS in a normal sinus rhythm and it was regular...I'm not so sure if I can send you a photo of what I mean through pm...it would be a photo of the rhythm I'm talking about...

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Aha!! Was it a six-second strip? Those are often the standard clippings for this sort of thing. If so, and only if you know that (there are markings on the edge at 3-second intervals to clue you in), then you can multiply those by ten to get the number in a sixty-second period. If the rate is regular. Therefore if you have 10 QRS's in a six second strip, your rate is 10 x 10 = 100 beats per minute. Whew. I am glad we got that settled.

But it doesn't matter how long the piece of tracing is they gave you, if you count the big boxes between the (regular) events you want to get rates for, using the thing I wrote earlier.

Does that answer your question?

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How do I know it's a six second strip? And if it's not regular? I kind of get it...

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Specializes in Nurse Scientist-Research.

I thought this was what I remembered but here's from ehow.com:

Count the number of large 5mm boxes between the two R waves. EKG machines are programmed such that each 5mm box represents a time of .2 seconds. The time in seconds between consecutive heart beats can therefore be calculated by multiplying the number of boxes by 5.

Read more: How to Calculate Heart Rate on an EKG | eHow

Most rhythm strips I've seen have little hatch marks above the graph section that come every 2 seconds. If you count the larger boxes (0.2 second ones) and confirm your hatch marks are every 2 seconds, it makes it easy to quickly tell if you have a genuine 6 second strips. When I got my original dysrhythmia certification, they never gave us exact 6 second strips to keep us from being lazy, or maybe they were sadistic. GrnTea has given very detailed and great advice.

I've also thrown this out there several times. One of the experienced ICU nurses offered this website up to us. I find it absolutely fabulous and full of great information. Also quite well organized. There is an area on arrhythmias that has great illustrations, strips. Good stuff. Check it out.

index

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From your questions, it seems that you don't have any idea about the anatomy of the heart, the electrical conduction system of the heart and the various heart rhythms. If you don't understands these, you won't be able to understand what the question is asking you.

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If there are 300 big boxes in a minute (there always are, it's a standard convention), then how many big boxes are there in six seconds?

300 boxes in 60 seconds = ? boxes in 6 seconds

? = 30. So count out 30 big boxes and that will be a six-second sample. Then proceed.

If it's not regular then you have two choices: Get a full 60-second strip and count, for rate/minute, or multiply the number of beats in 6 seconds by ten for a guesstimate of rate in one minute. Generally close enough for government work. :)

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In atrial flutter, how would I get the atrial rate? There are no p waves. So do I just put no atrial rate? But the book states that the atrial rate is 150-450. Okay...that means.. you don't have to have p waves to have an atrial rate...But someone said that counting the p waves will give you the atrial rate..

Help?

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Specializes in Critical Care.
In atrial flutter, how would I get the atrial rate? There are no p waves. So the rate is what? In the book I am using the atrial rate is posted as 150-450 for atrial flutter. How does that make sense? Because how would you even count the p waves if there are no p waves to get the atrial rate? For instance someone posted to count the P waves to get the atrial rate but that's wrong...because atrial flutter has no p waves but there's still a an atrial rate. So what is the atrial rate and what is the p wave and how do I get the atrial rate for atrial flutter?

Thanks.

Atrial flutter does have P waves. They are typically "sawtooth" in appearance in A-flutter.

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What about when you're counting the rate for a normal sinus rhythm with a PVC? Is the PVC counted as a QRS? When finding the ventricular rate?

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And are P waves the same thing as sawtooths aka F waves? Well in the book it's stated as no p waves in atrial flutter, only F waves.

If anyone asks how I arrived at the atrial rate for atrial flutter I'd say I counted the sawtooths aka the F waves and multiplied it by 10...so let's say I counted and there are 26 F waves. 26x10=260...the atrial rate is 260bpm...In the book the atrial rate is listed as 150-450bpm..which is within range...so it sounds right...

Is that right?

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