Aidey
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Really? You've never heard that? Not even playing sports when they tell you how to figure out your max heart rate?
the 100% directionless thread
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Not that I can remember. It very well could have been mentioned and I wasn't paying attention or just don't recall hearing it. Always been the "Greater than 150 BPM is SVT."
So SVT for me would be 197 BPM...I feel like that would be rather uncomfortable.
Now you're making me feel dumb
Aidey
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Not that I can remember. It very well could have been mentioned and I wasn't paying attention or just don't recall hearing it. Always been the "Greater than 150 BPM is SVT."
So SVT for me would be 197 BPM...I feel like that would be rather uncomfortable.
Now you're making me feel dumb
Sorry.
I did sports in high school, and I remember our coaches teaching us that. It wasn't until I went to paramedic school that I understood the physiology behind it.
I've had myself up that high. It really isn't that bad if you are well hydrated. I've also had PSVT, and the sensation is very different (at least for me).
lightsandsirens5
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And of course technically anything 100 or greater originating above the ventricle s is a "Supraventricular Tachycardia."
Aidey
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Fine. 220 - age = Pathological SVT :glare:
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Zing!
Aidey
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Oh shush, you're just mad because I schooled you
No one gets that nitpicky in the ED.
Whatever. You school me on a daily basis :lol:
That's like me writing "PEA" on ever single rhythm strip on a test because none stipulated whether they had a corresponding pulse with them. I wrote the right answer underneath but I had to be difficult
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You're not alone, Rob. I've always been taught >150 could be called SVT. I ran in HS and college and am well aware of calculating max heart rate, but I've never heard a correlation between the two.
Hunter
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I thought calculating your max heart rate included your resting heart rate as well, not just your age.
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Aidey
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I think that is target heart rate.
I know there are more refined formulas than 220 - Age that athletes use for finding their max heart rate. I'm not sure if any of those include resting heart rate.
VFlutter
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Not that I can remember. It very well could have been mentioned and I wasn't paying attention or just don't recall hearing it. Always been the "Greater than 150 BPM is SVT."
So SVT for me would be 197 BPM...I feel like that would be rather uncomfortable.
Now you're making me feel dumb
SVT is just a catch all classification used while making your differential and to immediately identify Ventricular vs non Ventricular Tach. The basic definition of SVT is a supra-ventricular rhythm above 150 bpm. But to say everything above 150 bpm is SVT is stupid even though it is technically correct. I only call a rhythm SVT if the rhythm is indiscernible due to the rate. If it is 160 with a clear P wave then it is just Sinus Tach. If you can see Flutter waves its A flutter, etc. When most people say SVT they are usually referring to a reentry rhythm.
You are talking about two totally different things. 220-age is one of the formulas for calculating maximal predicted heart rate, the other one being HR= 208 - (0.7 × age). Both formulas are pretty much worthless in medicine since there is a significant variation in individuals of the same age and with various pathologies. Even in healthy individuals there is usually a huge difference in predicted and actual symptomatic heart rate. That has nothing to do with SVT.
If a 90 year old patient is in A fib RVR above 130 do you call it pathological SVT?
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NYMedic828
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I love how pretty much everyone agrees that 220-age is not a sufficient means of determining HR.
Meanwhile, FDNY physicians who do your physical to get hired as a firefighter fail you if you exceed 220-age x 90% on your test.
Of my group of 70, almost everyone failed and had to retest.
VFlutter
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"While it is the most common (and easy to remember and calculate), this particular formula is not considered by reputable health and fitness professionals to be a good predictor of HRmax. Despite the widespread publication of this formula, research spanning two decades reveals its large inherent error (Sxy = 7–11 b/min). Consequently, the estimation calculated by HRmax = 220 - age has neither the accuracy nor the scientific merit for use in exercise physiology and related fields."
Robergs R and Landwehr R (2002). "The Surprising History of the "HRmax=220-age" Equation" (PDF). Journal of Exercise Physiology 5 (2): 1–10. ISSN 1097-9751.
Aidey
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Yes it is pathological, it's A-fib. It certainly isn't physiological, which was the difference I was pointing out. Sinus tach is usually defined as a physiological rhythm, not a pathological one. And the presence or lack of symptoms doesn't change whether or not a rhythm is SVT.
VFlutter
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I was talking about asymptomatic/symptomatic in relation to predicted heart rates not SVT. My main point is "220-age" has nothing to do with the definition of SVT or pathological. SVT. Not to mention that the formula itself is worthless.
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Aidey
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I wasn't arguing that you could predict a specific heart rate that would produce symptoms. Just pointing out that as we age our ability to generate a high heart rate via physiological means decreases, and the result is that heart rates above that threshold are pathologic. I am also not saying that you can't have an SVT that is slower than that threshold. A-Fib and MAT are great examples of this.
I am aware that there are a lot of myths in medicine, but considering I was told less than 12 hours ago by 2 emergency physicians that was the formula to use I'm a little hesitant to take your word for it. 220 - Age isn't meant to define what is and isn't SVT, it is meant as a guideline to determine when something is almost definitely not sinus tachycardia anymore.
I am aware that there are a lot of myths in medicine, but considering I was told less than 12 hours ago by 2 emergency physicians that was the formula to use I'm a little hesitant to take your word for it. 220 - Age isn't meant to define what is and isn't SVT, it is meant as a guideline to determine when something is almost definitely not sinus tachycardia anymore.
Jambi
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There is far far too much EMS talk going on in here...
So I just wanted to tell everyone how happy I am that the gubmint took 53.1% of my Christmas bonus :deadhorse:
So I just wanted to tell everyone how happy I am that the gubmint took 53.1% of my Christmas bonus :deadhorse:
VFlutter
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In your original post saying it is the generally accepted cut off rate for SVT made it sound like you were using it to define SVT and that the patient could not have been in SVT since their HR did not exceed 220 - age. Which is incorrect. The way you just described it now as a quick rule of thumb to determine if a rhythm is no longer ST makes a little more sense but is still flawed. If a 90 year old patient has a HR of 130 I am still assuming it is Sinus Tach and not AVNRT or some other variant.
You do not have to take my word for anything but I am just offering another opinion based off my knowledge. It seems what you said confused a few people and I was just trying to clarify.
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