Call review #1 ***UPDATED

Code 3 for hypertension.

This is a 76-year-old female whose daughter called for a relatively sudden onset of weakness over the past hour. She speaks no English, and her daughter tells us that she’s been generally “fine” except that over the past week when taking a walk she’s been experiencing some mildly increased SOB that subsides with rest.

Pt appears just a tad tired, but otherwise looks fine.

VS: BP 221/83, P 40, R 18, SpO2 94% RA

In a moment of candor, the fire captain says, “I’m not sure what’s going on, but I heard someone say something about a block.” He hands me this from their Zoll:

What do you think? What do you do?

***Update #1:

So, it seems like most people have commented that this is a 3º AV block, which is what I was thinking when I looked at this first strip.

After some interrogation, her daughter tells us that the patient has a history of hypertension and breast cancer that was treated with a lumpectomy and chemotherapy a few years ago, which caused extensive heart damage, requiring the implantation of a pacemaker. She isn’t sure what kind of pacemaker it is, but she mentions that it only “came on sometimes” and does not think that it is constantly firing. She also mentions that the pacemaker was “adjusted” a month ago, but she has no details to offer.

Looking at the Zoll, I wonder if her pacemaker is firing.

We switch her to our LP12, and I’m a little disappointed (not that I wish people were sick, but you know what I mean). I was excited about the possibility of a decent call for a change, but this is turning out to be a bit anti-climactic. Here are a couple of strips, confirming what I half-suspected:


For those of you not familiar with the LP12, to limit distortion to the actual tracings, the default setting suppresses the pacemaker spikes, which are instead represented by the hollow arrows at the bottom of the strip.

It seems that the Zoll simply failed to detect the pacemaker firing, which, after a little research, is something that happens every now and then, according to Zoll themselves. (Probably the same situation with other monitors as well.)

And, here’s the cleanest copy of the 4 nearly-identical 12-leads obtained over 30 minutes:

It looks like there is intrinsic atrial firing at about 90 bpm without any conduction to the ventricles, which are paced consistently at pretty much exactly 40 bpm. I’m certainly no expert like Tom, who in his comments wondered about the possibility of a paced rhythm, but there are some who might say that leads II and III look like there’s concordant ST elevation (based on the positive terminal QRS deflections), whereas I feel that the first upward deflections are part of the T waves, rather than part of the QRS complexes.

VS: BP 212/102, P 40, R 18, SpO2 98% with oxygen 2L/min via cannula

BGL: 120mg/dL

It appears that the pacemaker is firing as intended without any apparent issues, other than the fact that the rate seems on the low side. I wonder if it’s intentionally set this way. And I wonder what pacemaker “adjustment” her daughter was referring to. We transport her code 2 with a saline lock, with the unopened pacing pads and the therapy cable on her lap. And a pair of shears in case I have to cut her shirt very quickly. (I hate cutting clothes if I can help it.) The ride goes without incident or any change in her condition. Her shirt survives. Her BP remains mostly the same.

We leave her at the ED, and a couple of hours later we bring someone else to the same hospital, which is coincidentally the area cardiac receiving center. I check with the original nurse, who says that the rep from the pacemaker manufacturer is in the room.

It’s not often we get to talk to these pacemaker reps. So, I go to meet her. She tells me that the patient has a dual-chamber demand pacemaker with a lower atrial rate limit of 80 bpm and a lower ventricular rate limit of 40 bpm. It was set up this way because the patient previously had occasional brady-arrhythmias due to the chemotherapy but did not require a pacemaker that was always firing.

So, it is thought that some time over the past week, with her atrium still firing normally, she lost her ventricular portion of the rhythm for some reason(s) out of many possible reasons. And now her pacemaker is functioning as intended. Since it’s now the only way her ventricles are contracting effectively, 40 bpm – previously the last-resort rate – is too low. The rep adjusts it upwards to 60 bpm.

Interestingly, her BP is now in the 170s/90s range without any other interventions. No one has an answer for that.

As of this writing, there is no other significant finding.

I didn’t start this blog to write call reviews, but this call is interesting to me in a few ways from a training perspective. We teach crews to do all this stuff but we don’t do a good enough job of teaching them to think about what they’re going to do before they do it. I shudder when I think about how many ways this call could have gone wrong if we didn’t figure out that it was a paced rhythm and not 3º AV block. Even though we’re writing about it now with the benefit of hindsight, I personally know crews out there who would have immediately given this patient Atropine or started transcutaneous pacing based on that very first Zoll tracing.

Please don’t misunderstand me – I’m certainly NOT knocking anyone who thought this was 3º AV block based on the first Zoll strip, because that’s exactly what I was thinking, and without the pacemaker spikes, that’s what it looked like. What I am concerned about is the fact that there are crews out there who would jump right into treatment, unnecessarily in this case, without first looking at a patient who is at most in very mild distress, and without diligently gathering as much relevant information as possible.

Furthermore, over the past 5 years or so, with more and more such tools as 12-lead, CPAP, capnography, etc. at our disposal, EMS is slowly but surely shifting toward a new paradigm, and it’s much more important for us to thoroughly obtain findings and assess our options. It takes some discipline to take that extra minute or two, that extra deep breath, to make sure we do things right the first time. The old way in EMS of providing treatment as quickly as possible based on a limited history and assessment, other possibilities be damned, is thankfully falling out of favor (but not quickly enough). Using Lasix for pneumonia is probably the best example, out of many, of this mindset.

***Update #2:

Tom over at Prehospital 12-Lead ECG is posting a series on pacemakers.

Response to comments:

Regarding ST elevation, as Tom mentioned, the filters in monitor mode (3-lead, 4-lead, when not obtaining 12-leads) are set for different frequency ranges than in diagnostic mode (when obtaining 12-leads). As a result, ST elevation present in monitor mode may not be present in diagnostic mode. Anecdotally for me, every time someone has said “there’s ST elevation” on a call when looking at a 3-lead or 4-lead, I have yet to see it present on a 12-lead.

17 thoughts on “Call review #1 ***UPDATED”

  1. Wow 3AVB and a pressure like that, insane! Bleed? I’m going to retake it manually to double check the machine (also check cuff size, etc).

    12L, lung sounds, LAPSS, etc. With such a wide pulse pressure and her bradycardia I’m pretty worried about increased ICP.

  2. 3AVB with wide QRS complexes and LBBB morphology (monophasic R-wave lead I and left axis deviation).

    Look for a pacemaker pocket to rule out the possibility of a paced rhythm. Sometimes when the battery gets low the device reverts to a more primitive mode (i.e., stops tracking P-waves and paces asynchronously, sometimes at a reduced rate).

    That is an impressive pulse pressure!

    If (big if) we’re seeing the entire depth of the QRS complex, that appears to be excessive discordant ST-elevation, but I’d like to see a 12-lead ECG with the low frequency / high pass filter set to 0.05 Hz.

    Cool case!

  3. 3rd degree block. Since the pt. is tolerating it well…..a little O2 via cannula, an IV, apply the pads in case things go south and you need to pace and a ride to your local cath lab……and whistle “Whenever I feel afraid…”

  4. Well obviosuly there is AV block but the degree of AV block is quite confusing !! .. At the first glance i thought it is II degree AV block Mobitz I Wenchebock fenomenon with the classic progressive prolongation of the PR interval but still i can see in very regular manner P waves sometimes hidden inside the T wave not followed by QRS complex, the rate is suggesting for 3 rd degree AV block , but not sure !! long strip ECG and monitoring is needed to be more wise the diagnosis .

  5. Wish there was a 12 lead of this case, but definitely a 3 degree AV-Block and the QRS suggest that there is a BBB also but wont comment if it is left or right until I see the 12 lead.

    thax for sharing

  6. It 3AVB about the LBBB we haven’t any onformation if it is new or he have in the past The vital sign is Ok for that situation
    We have ask if she get usual B-blocker or simething like that. Tobe shore that it’s not a B-blocker poision.

    O2 , 12L AKG , standbuy pace , line , we can try to give Atropin that on the way to hospital and to make monitor to the vital sign

  7. thanks for all your comments. there are 12-leads for this case, and i’ll add them when i update it in a day or two. the subsequent tracings actually are part of the whole point of this particular case.

  8. The history suggestive of a inferior STEMI …
    no chest pain but she is elderly…B/P is up secondary to initial compensatory mechanism…gross ST elevation present with bradycardia …the ECG strip indicative of 2nd degree heart block Morbitz type 2 heart block?…a progressive prolonged PR interval & after the third PR prolongation back to normal and repeat of the same cycle… this in consistence with right coronary artery involvement …. i could be wrong?

  9. AS a” device” nurse I can say the AV dyschrony is apparent in the first strip and although there are no pacer spikes the wide complex ventricular complexes would represent a junctional escape rhythm vs Paced ventricular rhythm (since we know she has a pacemaker). This pt has sinus with CHB and paced Ventricular rhythm …..and also intermittent sunus node dysfunction based on her intermittent need for atrial pacing.

  10. There’s definitely a problem with the pacemaker, although it’s good that it’s pacing at 40 PPM since the patient does not show any intrinsic ventricular complexes at all (pacemaker dependent). Fixed rate ventricular pacing is as primitive as it gets! VOO according to the NBG pacemaker code. A modern dual-chambered pacemaker should be capable of DDD pacing which certainly would include atrial tracking with a prescribed PR-interval. So, the patient needs x-rays to make sure the leads are intact and not displaced (particularly with RBBB morphology in lead V1), and the device interrogation should reveal the % pacing, the battery life, and histograms that show what the device is “seeing” and why it is behaving the way that it is. The case demonstrates one of the many reasons you should always expose a patient’s chest and look for a pacemaker, particularly when a wide complex rhythm is present. It’s a mandatory part of the physical exam! Cool case.


  11. At 1st glance, my initial assessment was 3 degree AVB. I did notice the exceedingly wide pulse pressure, and, like Christopher suggested, considered possible increased ICP/bleed. Then considered a possible compensatory function often times seen in LVH/LV failure. Very interesting. As Tom said, a THOROUGH PE is absolutely paramount. We need to have more faith in our skill/knowledge, and not be so “trigger happy”. This patient is defintely hemodynamically stable, so there’s no need to push Atropine or attempt TCP.

  12. Linked through from Tom’s site.

    “Anecdotally for me, every time someone has said “there’s ST elevation” on a call when looking at a 3-lead or 4-lead, I have yet to see it present on a 12-lead.”

    I have seen this once. Interesting story. My second shift out of recruit school with my new large, metropolitan agency. I’m not yet a medic but have some 12 lead training under my belt. There is a nasty t-storm that knocked out power all over. Call for a 60 something female “sick.”

    We do all the assessments, 12 lead included, unremarkable. After several minutes she says she is beginning to have some CP. I look at the monitor and notice that the morphology of the monitor leads has changed. Quick print and there are elevations. I tell the Captain (me, a second day rookie), who was getting ready to BLS her via private ambulance, we should do another 12 lead. Shoot the 12 and bingo, diagnostic for acute inferior MI.

    We were still doing retavase at the time and I’m getting pumped for this one. The storm had knocked out power and telephone so no ability to transmit to the receiving. Dang.

    Anyway, long story longer! I’ve seen that once in several thousand calls. I wish I was as much a 12L geek then as I am now as I would like to have the initial strips and subsequent 12L from that call.

  13. If the patient has a DDD pacemaker, why is she not AV synchronous? This is the a major reason for a pacemaker. If the patient loses AV synchrony as in this patient’s case, then the pacemaker should restore it. Do you happen to know what mode the pacemaker is programmed to? All i can assume from this is that the patient is in a DDI mode or there is a sensing issue and the pacing electrodes need further investigation

  14. way to not freak out and overreact, weird, but mostly stable, easy and interesting, and she didn’t pee/poop/puke on you, sounds like a perfect call

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