Differential diagnosis of wide complex tachycardias – Part IV

Let’s look at a more typical case of wide complex tachycardia.

This case comes from Lt. Jason Kinley of Xenia Fire Division. If you’re not familiar with Xenia Fire Division in Xenia, OH, they have an outstanding prehospital 12 lead ECG program. Jason is also one of the co-moderators at the EMS-to-Balloon (E2B) Challenge! listserv at Yahoo!

Here’s the story.

EMS is called for a 89 year old male with chest pain. Onset 30 minutes ago. Non-radiating. Patient is A+OX4. Skin is moist. Skin color is good. No increase in respiratory effort. Meds for diabetes, hypertension, and unspecified heart problem (patient is a poor historian). The patient is reluctant to go to the hospital. He states he was seen 4 days ago for a possible TIA.



Yes, I know the computerized interpretive statement has been removed. That’s my fault!

Here are the computer measurements:

HR: 150
PR: *
QRS: 126
QT/QTc: 304/475
P-R-T: * -51 110

The treating paramedics correctly identified this as a regular wide complex tachycardia. Because the patient was hemodynamically stable, they initiated a 150 mg bolus of Amiodarone over 10 minutes, with no change to the heart rhythm.

Why Amiodarone?

Because according to the 2005 AHA ECC guidelines, that’s the drug you give for undifferentiated regular wide complex tachycardia. It’s supposed to be therapeutic for both ventricular and supraventricular tachycardias.

You will remember the patient stated that he was seen 4 days prior for a possible TIA. Well, it turns out that the same EMS system brought him to the hospital. As luck would have it, they performed a prehospital 12 lead ECG at that time.

Here it is.


Computer measurements:

HR: 100
PR: 232
QRS: 134
QT/QTc: 350/451
P-R-T: 50 -56 91

Now compare the QRS morphology in the first PH12ECG to the PH12ECG taken 4 days prior, when the patient was in borderline sinus tachycardia with 1AVB.*

Is it a match? You bet! This patient has a pre-existing intraventricular conduction defect (or atypical LBBB). Note the S wave in lead V6.

Was this patient in ventricular tachycardia? No.

Considering the heart rate of exactly 150, the pseudo-R wave in lead V1 during the tachycardia, and the recently history of possible TIA, 2:1 atrial flutter is the most likely explanation.

However, the first rule applies! In the absence of an “old” ECG for comparison, it’s VT until proven otherwise.

The patient didn’t covert to sinus rhythm, but it was a well-executed call, and no harm came to the patient.

* 3:1 atrial flutter is also a possibility. Note the heart rate of exactly 100.

See also:

Differential diagnosis of wide complex tachycardias Part I

Differential diagnosis of wide complex tachycardias Part II

Differential diagnosis of wide complex tachycardias Part III

Differential diagnosis of wide complex tachycardias Part IV

Differential diagnosis of wide complex tachycardias Part V

Differential diagnosis of wide complex tachycardias Part VI

3 Comments

  • Vince D says:

    Just trudging through the site looking for a-flutter cases and came across this post. I'm thinking this one may actually be a case of juntional tach. True, the rate is perfect for flutter, but although I see signs of atrial activity in I, II, aVR, and V1 (the pseudo-S you noted), I'm not convinced that p' wave has a partner 400ms after it to clinch the diagnosis of flutter, leaving retograde conduction from the junction as the most likely culprit (in my opinion). The abnormall flat T-Q segments in the limb leads also strike me at pointing towards a sub-atrial pacemaker.

  • Vince D. – It's a nuanced case. This was discussed a number of years ago on the EKG Club at Yahoo! At the time Tomas Garcia, M.D. (author of 12-Lead ECG – The Art of Interpretation) felt that it was 2:1 atrial flutter.

    http://health.groups.yahoo.com/group/ekg_club/message/1814

    Unfortunately, the really cool graphic he created to help explain it was not retained by the archives.

  • VinceD says:

    Thanks for the quick response, and although I'm still not entirely convinced, I'm finding it very hard to disagree as Dr. Garcia is a very smart man. I suppose I'll just file it away and take a look at it down the line to see what I think then.

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EMS 12-Lead

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Comments
Colleen
68 y.o. male with weakness: “Treat the monitor, not the patient?”
Allergies? O2, combivent, Calcium. Repeat 12lead ekg. 2nd set of signs. Depending on 2nd Ekg and 2nd set of signs with combivent, reassessment of patient after interventions. Depending on reassessment, 2nd/3rd VS, and 2nd EKG, would determine my decision on where to transport. Per Massachusetts protocols.
2014-10-02 05:57:52
Billy Bob
68 y.o. male with weakness: “Treat the monitor, not the patient?”
Well I will lean with Dave and go with more education; this is a classic sine wave EKG and with more education hopefully we all could spot this from across the door because again as Dave said this is something rarely seen in EMS if at all; this is the ONE TIME I will advocate…
2014-10-02 02:49:58
david
68 y.o. male with weakness: “Treat the monitor, not the patient?”
Looks like sine wave. QRS >.15 tall peaked T waves prolonged PRI, indicative of hyperkalemia. Calcium, bicarbonate, 50% dextrose perhaps even some albuterol, insulin at the Ed
2014-10-02 02:44:55
Hollywood Mike
68 y.o. male with weakness: “Treat the monitor, not the patient?”
ALS weakness and fall. Mental status is such that he remembers falling. I'm not going to get all excited about this tracing. I'm treating the guy for his complaint and watching him like a hawk during transport. I've seen some aberrant conduction that makes this ECG look like NSR so I'm jaded by experience (need…
2014-10-02 01:51:00
PandaMedic
68 y.o. male with weakness: “Treat the monitor, not the patient?”
It's great to see so many different points of view and styles, it's sad that so many of us are being critical and condescending towards other practitioners. Dave has a point, in that more education is needed, but there is something to be said for everyone who is here, reviewing these case studies and actively…
2014-10-02 01:45:45

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