low heart rate

[Ms.RN]

hi everybody

i got a question for you guys. what can cause a low heart rate of 32 but normal blood pressure and respiration rate? i had a patient with heart rate of 32 and c/o feeling dizzy but her other vitals are fine.

[SuesquatchRN, BSN, RN]

In theory, yes, this is true. But, just because the rate is low, does not mean it is originating in the AV node or the ventricles. Sinus bradycardia originates in the SA node, and can go as low as the 20s-30s. The AV node and purkinje fibers don't necessarily kick in and take over the pacemaker function when the SA node is firing at a low rate. People can have sinus pauses that last for several seconds with no junctional or idioventricular beats. Real hearts don't always fall neatly into the categories we learn in EKG class. Without an EKG, it's not really possible to say what was happening in this case.

Yes, Virgo, I realize that my explanation was simplistic. I posed it as a beginning, not a comprehensive analysis of all bradycardia.

:)

[Daytonite, BSN, RN]

Well, when I had a heart rate of 38 and my vitals were fine, they diagnosed me with sick sinus syndrome and stuck a pacemaker in me. Now, I'm having some paroxysmal atrial fib and dizziness along with it when it happens. Dizziness is a symptom of the brain hypoxia because not enough oxygenated blood is getting pumped upstairs to the brain. This can be due to the slow rate of bradycardia or the fibrillation of AF when very little oxygenated blood is actually getting pumped out of the heart and up to the brain because the atria are fibrillating.

1. Impaired blood circulation = impaired oxygen transported to the brain cells.
   
2. No oxygen getting to the brain cells = you are going to take a nap (pass out)

When the heart muscle is affected by hypoxia as a result of impaired circulation due to altered heart rates or cardiac output the person gets angina (chest pain).

[Flightline, BSN, RN]

I see sinus rates that low almost daily (monitor tech), and almost never do any of the downward pacers kick in.

32? You see heart rates at 32 daily without escape beats or junctional rhythms, and you see this almost daily?

I must be living on another planet then. To be honest, the only people I've seen with HR that low were coding. My entire nursing career thus far has been either in cardiology or the ICU and I've never seen anyone with a HR that low that we weren't giving atropine to.

If you have a daily experience with HRs at 32 and everything is peechy: Like I said, I must be working with a different speices or something, because that's just not my experience.

[hypocaffeinemia, BSN, RN]

32? You see heart rates at 32 daily without escape beats or junctional rhythms, and you see this almost daily?

Yup. I watch close to 50 patients in a busy hospital, so there's always somebody with symptomatic sinus bradycardia. That is, until they go to cath lab for a pacer.

I must be living on another planet then. To be honest, the only people I've seen with HR that low were coding. My entire nursing career thus far has been either in cardiology or the ICU and I've never seen anyone with a HR that low that we weren't giving atropine to.

If you have a daily experience with HRs at 32 and everything is peechy: Like I said, I must be working with a different speices or something, because that's just not my experience.

Well, it's not peachy keen when they are like this-- just that it's frequent around here. I'm at work and I currently have an elderly lady sitting neatly at 39. Asymptomatic, the nurse tells me.

[nrsang97, BSN, RN]

I had a pt with a resting HR in the 30's going down to the 20's once. BP, RR, normal. Denied dizziness. Pt had guillan bare. The carido doc didn't do too much. This was a long time ago. I don't remember the outcome. He didn't have any weird beats. Just slow sinus.

[Thornbird]

I see sinus rates that low almost daily (monitor tech), and almost never do any of the downward pacers kick in.

I don't think you are talking patients with no complaints. Not to demean you, but monitor techs are not RN's or MD's and I question your interpretation of what you are seeing. Sinus brady that low requires intervention, especially if none of the other pacers are kicking in. We start CPR on patients with rates this low.

Rarely is a rate this low a sinus rythmn. You see it in AV block and SSS, but in those cases the SA node is not doing the pacing anymore. HR's in the 50's are common for athletes. With a rate of 32, I'd send Lance Armstrong to the cardiologits.

[hypocaffeinemia, BSN, RN]

I don't think you are talking patients with no complaints. Not to demean you, but monitor techs are not RN's or MD's and I question your interpretation of what you are seeing.

I'm actually just shy of 6 months from my RN, but I can say quite confidently these are sinus bradycardias I'm talking about. In fact, I teach the basic EKG course at my facility (to RNs).

Sinus brady that low requires intervention,

Undoubtedly so. I never said otherwise. Most of such patients are often monitored closely in IMU until they can get to cath lab for pacer insertion.

especially if none of the other pacers are kicking in. We start CPR on patients with rates this low.

I'm not an RN or an MD, but I certainly hope you aren't starting CPR based on mere numbers. You've got to clinically correlate the EKG with what the patient is experiencing. If their cardiac output and blood pressure are stable and their symptoms are minimal, I don't think the patient would very much appreciate your pounding on their chest. Atropine at the ready, yes.

Rarely is a rate this low a sinus rythmn. You see it in AV block and SSS, but in those cases the SA node is not doing the pacing anymore.

SA node is most definitely doing the pacing in SSS and all non-complete AV blocks.

HR's in the 50's are common for athletes. With a rate of 32, I'd send Lance Armstrong to the cardiologits.

Rightfully so. Nobody said a rate of 32 is spiffy. I just said it's quite common (in the setting of cardiac acute care).

[Valerie Salva, BSN, RN]

I have never had a pt with a HR that low, and I pray my good fortune continues. :)

[SuesquatchRN, BSN, RN]

With a rate of 32, I'd send Lance Armstrong to the cardiologits.

:lol:

[Virgo_RN, BSN, RN]

Nobody here has said that a HR of 32 is not worthy of medical attention or intervention. We've simply stated that it could be a sinus bradycardia.

I certainly would not be running into my patient's room and pounding on their chest simply because they brady down into the 30s. I'd be going in there and asking them how they feel. If they're giving me an answer, they don't need CPR. Heck, we had a guy not too long ago that kept pausing, causing the monitors to alarm asystole. You can bet we kept the crash cart parked outside his room, but he never did lose consciousness, and went for his pacer first thing in the am.

I might have the crash cart warmed up in case they need some external pacing, and make sure the atropine is ready, but I'm not going to go in there guns a blazin when they're perfectly alert and oriented. Most likely, this is what they've been doing for several days now, and only just now decided to seek some medical attention, hence their trip to the ED and their admission to our floor.

You treat the patient, not the monitor.

The OP still has not answered whether or not an EKG was done. I'd be curious to know if a cardiology consult was called, and what was the outcome?

[SuesquatchRN, BSN, RN]

I've had a couple of LOL's regularly in the high 30's - low 40's. Given their levels of dementia it was hard to tell if they were symptomatic. They were certainly conscious.

[SDS_RN, RN]

We had a pt in last weekend w/ HR 30's-40's r/t her pacer battery failing:no:. I agree w/ the others there are several reason why the HR could be low.

Being a nurse also requires you to play detective sometimes.