Strip Tease 9

[FL_Medic]

You could go even further and say that the impulse originates in the area of the left anterior fascicle of the left ventricle.

Why?

What type of bifascicular block presents with an upright QRS complex in lead V1 and a right axis deviation?

RBBB and LPFB.

With RBBB and LPFB, which fascicle depolarizes first?

The left anterior fascicle.

boooya!

haha, very good reasoning.

[Tom B.]

The following is straight out of the Bob Page 12-lead book.

Your primary survey of the WCT patient:

1. Measure the QRS width

--- Good idea. If it's not "wide" it's not a WCT.

2. Determine the axis

--- Should be a part of any 12 lead interpretation. Just be aware that axis cannot rule VT in or out. Does a right superior axis favor the dx of VT? Sure. But that should be your default dx anyway.

3. Look at morphology changes

--- Here's where it starts getting dangerous. If you use morphology to "rule in" VT, then great! If you use it to "rule out" VT, then you're living dangerously. This goes for axis and morphology.

4. Look at concordance criteria

--- Same feedback.

5. Look at signs of AV dissociation

--- This is the best evidence that a rhythm is VT, but it's only present 50% of the time, and it's not easy to appreciate on most ECGs.

6. Get a good patient history

--- A history of MI increases the probability that you're dealing with VT, but again, that should be your default diagnosis for a WCT.

7. Do a physical exam

--- Goes without saying.

Wide Complex Tachycardia > 150: Listed by ease of use, Often seen, & Specificity

1. Extreme right axis deviation (ERAD) & positve v1

2. QRS morphology in v1

3. QRS morphology in v6

4. ERAD & negative v1

5. Concordance in v1 through v6

6. RS interval > 100ms any V lead

7. QRS > 140ms if up & > 160ms if down in v1

--- Once again, ruling in VT is fine.

Extreme right axis deviation:

ERAD is also known as right-shoulder axis, northwest axis, intermediate axis or "no man's land". This is an axis > 180 degrees.

--- I've seen it with nonspecific IVCD, RBBB/LPFB, and hyperkalemia. It's not always VT. But again, ruling in VT is fine.

You can determine this simply by looking at leads 1, 2 ,& 3. If leads 1, 2, & 3 are all negative, the patient has ERAD. If v1 is positive with ERAD, the rhythm is ventricular in origin. It is still possible for a ventricular rhythm to present with ERAD and negative v1, this is just lest specific.

QRS Morphology:

1. When you have the "bunny ear" shape in v1. Having the left ear bigger than the right ear indicates VT. This is also referred to as "big mountain/little mountain".

--- Sort of like this case. Ruling in VT is fine.

2. A single peaked upright R wave in v1 is indicative of VT

--- Negative. I've seen it many times with bifascicular block and even atypical RBBB. But ruling in VT is fine.

3. A single peaked upright R wave in v1 with slopped off end

--- What does this mean? We've already listed a monophasic R wave as a rule-in VT criterion.

4. A fat (> 40 ms) R wave in negative QRS in v1

--- A slurred upstroke of the R wave does suggest VT.

5. A notched down stroke of negative QRS in v1

--- This is called "Jospehson's sign" and I've seen it in VT many times.

6. Any predominately negative complex in v6 suggests VT

--- Or paced rhythm, or cardiomyopathy, or nonspecific IVCD.

Concordance:

1. Negative concordance, meaning negative QRS complexes in v1 through v6, indicates VT or LBBB.

--- That would actually be atypical for LBBB, although sometimes there is a persistent S wave in lead V6 with RVH. Regardless, if it indicates VT or LBBB then it's no help, right? It actually is more suggestive of VT, but that should be your default dx anyway.

2. Positive concordance indicates VT or WPW

--- Or RBBB or nonspecific IVCD.

Measurements:

1. Positive QRS in v1 > 140ms

2. Negative QRS in v1 > 160ms

3. RS Interval is highly reliable. From the start of the R wave to the nadir point of the S wave (the bottom point). > 100ms is VT

--- Ruling in VT is fine.

AV Dissociation:

1. Cannon A waves. These are waves of pressure seen shooting up the jugular veins.

2. P waves out of place and isolated

3. Different S1 (first hear sound).

--- Ruling in VT is fine.

Remember, we are trying to rule out VT. This means that if you have any of the criteria without strong conflicting criteria, call it VT.

--- I missed it, Adam. Where are you ruling out VT? All toads are frogs, but not all frogs are toads! In other words, the inability to rule-in VT does not rule-out VT! That's why these criteria are dangerous. In the absence of compelling evidence to the contrary (e.g., obvious sinus P waves in a 1:1 relationship with the QRS complex and a normal PR interval, an "old" ECG for comparison that shows identical QRS morphology, occasional pauses that reveal flutter waves), regular wide complex tachycardias should be considered VT. There is no algorithm that can safely classify a wide complex tachycardia as SVT with aberrancy.

Edited May 26, 2009 by Tom B.

[FL_Medic]

Remember, we are >>NOT<< trying to rule out VT. This means that if you have any of the criteria without strong conflicting criteria, call it VT.

--- I missed it, Adam. Where are you ruling out VT? All toads are frogs, but not all frogs are toads! In other words, the inability to rule-in VT does not rule-out VT! That's why these criteria are dangerous. In the absence of compelling evidence to the contrary (e.g., obvious sinus P waves in a 1:1 relationship with the QRS complex and a normal PR interval, an "old" ECG for comparison that shows identical QRS morphology, occasional pauses that reveal flutter waves), regular wide complex tachycardias should be considered VT. There is no algorithm that can safely classify a wide complex tachycardia as SVT with aberrancy.

I think this was mis-worded on my part. I think you should start out with the belief it is VT as well, and use the criteria to support our decision. None of the criteria listed is conclusive or found in all VTs. They wouldn't work to disprove VT. My bad, I think I have just gotten so use to the term "rule out". Didn't mean to make this confusing/inaccurate.

[fiznat]

Another wide complex tachycardia. Would you feel comfortable about "ruling out VT" in this one? Say it was stable/sypmtomatic, which anti arrhythmic would you pick? (and don't give me that crap about cardioverting everyone, that's no fun haha)

By the way, why was this thread moved to scenarios when all of the other "strip teases" remain in the patient care forum? Can we just decide which one they all go in, and leave them there?

Edited May 26, 2009 by fiznat

[Tom B.]

fiznat -

Any ECG needs to be interpreted in light of the history and clinical presentation, but based on what I'm seeing with this ECG, I can tell you with 100% certainty that I would not give an antiarrhythmic to this patient.

It's an irregular rhythm, with variations in QRS/T wave morphology. I don't know if the QRS is wide, or the complexes are a bizarre combination of QRS/T. Either way, this looks like a pre-morbid rhythm or a patient who has an underlying metabolic derangement.

I wouldn't rule out acute STEMI or aortic dissection (elevated J points V2-V5) and I've seen acute STEMI create tombstones like we see in leads I, II, aVR, and III. Either way, and regardless of cause, if the patient is hemodynamically stable, then I'm falling back on the theory that "a perfusing rhythm is better than a non-perfusing rhythm or no rhythm at all".

The patient should be worked up in the ED, and the Hs and Ts should be aggressively treated. Once hypoxia, acidosis, electrolyte derangements are treated, and serial ECGs or bedside echo are obtained, a treatment plan can be started that may include a trip to the cath lab.

The last thing this patient needs is a drug like amiodarone, altering the shape of the cardiac action potential and prolonging the QT interval. Assuming this a polymorphic wide complex tachycardia (may or may not be true) I would get an expert consultation prior to treating with any antiarrhythmic (and I would hope the ED physician would do this same). You can't take it out once it's in.

As a final thought, if the patient had an ICD, I would consider the application of a ring magnet to disable tachy functions. We had a similar case a few years ago and the ICD shocked the patient x2 into asystole and the patient was not successfully resuscitated. It turned out to be severe hyperkalemia.

Tom

Another wide complex tachycardia. Would you feel comfortable about "ruling out VT" in this one? Say it was stable/sypmtomatic, which anti arrhythmic would you pick? (and don't give me that crap about cardioverting everyone, that's no fun haha)

By the way, why was this thread moved to scenarios when all of the other "strip teases" remain in the patient care forum? Can we just decide which one they all go in, and leave them there?

[fiznat]

Either way, this looks like a pre-morbid rhythm or a patient who has an underlying metabolic derangement.

Heh, it's actually post-morbid. This is a ROSC 12 lead from one of my very few code saves. In any case, it is still a wide complex tachycardia. I wouldn't (and didn't) treat this patient with antiarrhythmics either, but I am curious as to your rationale for so universally avoiding medications for these patients. ACLS still says that we should be giving drugs to those that fit in the "stable/symptomatic" category, and those guidelines were produced using the most up to date research available. If you (or anyone else) are going to go off on their own treatment paths, say cardioverting "early" or waiting on the drugs for a patient who remains symptomatic, I wonder what resource you would use to justify your decisions if things went downhill and the fingers start pointing at you. We're not physicians. Right or wrong, we don't get to make up our own treatment modalities.

Don't take this the wrong way. I respect your assessment of the rhythm and I understand exactly your academic perspective. Still, shouldn't paramedics stick to the guidelines regardless of how many articles they've read? I think it's a good discussion....

[Tom B.]

Actually, the first box in the tachycardia algorithm says:

Assess and support ABCs

Give oxygen

Monitor ECG (identify rhythm), blood pressure, oximetry

Identify and reverse underlying causes

In other words, the Hs and Ts are a higher priority than antiarrhythmics.

Further down the algorithm, for stable wide complex tachycardia, the algorithm says:

Consider expert consultation

That's the first recommendation.

It's worth noting that the ECC guidelines were written for physicians. In other words, it recommends that physicians consider an expert consultation (i.e., a cardiology consult) for stable patients.

I don't believe that paramedics are expected to be automatons that blindly follow protocols. Algorithms, by their very nature, oversimplify complex problems. They are not a substitute for sound clinical judgment.

My Medical Control Physician and Medical Director agree.

Tom

P.S. Congratulations on the save.

Heh, it's actually post-morbid. This is a ROSC 12 lead from one of my very few code saves. In any case, it is still a wide complex tachycardia. I wouldn't (and didn't) treat this patient with antiarrhythmics either, but I am curious as to your rationale for so universally avoiding medications for these patients. ACLS still says that we should be giving drugs to those that fit in the "stable/symptomatic" category, and those guidelines were produced using the most up to date research available. If you (or anyone else) are going to go off on their own treatment paths, say cardioverting "early" or waiting on the drugs for a patient who remains symptomatic, I wonder what resource you would use to justify your decisions if things went downhill and the fingers start pointing at you. We're not physicians. Right or wrong, we don't get to make up our own treatment modalities.

Don't take this the wrong way. I respect your assessment of the rhythm and I understand exactly your academic perspective. Still, shouldn't paramedics stick to the guidelines regardless of how many articles they've read? I think it's a good discussion....

Edited May 26, 2009 by Tom B.

[crotchitymedic1986]

It is not ventricular, look at AVF

[FL_Medic]

Heh, it's actually post-morbid. This is a ROSC 12 lead from one of my very few code saves. In any case, it is still a wide complex tachycardia. I wouldn't (and didn't) treat this patient with antiarrhythmics either, but I am curious as to your rationale for so universally avoiding medications for these patients. ACLS still says that we should be giving drugs to those that fit in the "stable/symptomatic" category, and those guidelines were produced using the most up to date research available. If you (or anyone else) are going to go off on their own treatment paths, say cardioverting "early" or waiting on the drugs for a patient who remains symptomatic, I wonder what resource you would use to justify your decisions if things went downhill and the fingers start pointing at you. We're not physicians. Right or wrong, we don't get to make up our own treatment modalities.

Don't take this the wrong way. I respect your assessment of the rhythm and I understand exactly your academic perspective. Still, shouldn't paramedics stick to the guidelines regardless of how many articles they've read? I think it's a good discussion....

Actually in my system our medical director states that we have guidelines, not protocols. He states that most patients we encounter may fit into a category and simply be treated by the guideline. We have the ability, as prehospital clinicians, to treat the patient how we see fit, as long as we are continuing to be an advocate to our patient. Our medical director has insisted that he will defend our actions if we prove we are doing what is in the best interest of the patient. This doesn't mean that we are to go looking up new treatments, or start bringing in new state-of-the-art equipment. Rather, as stated, if a patient is stable but in an abnormal rhythm, we may not have to do anything.

Do you have any idea of the side-effects on the rest of the body from some of these meds. How about that half-life of amio? The problem with the ACLS guidelines is there lack f specificity per care provider. Should I treat every abnormal stable rhythm I am presented with, no matter how old my patient is, how far away the hospital is, or other factors?

I have had patients in rhythms you could call SVT that have broken with normal saline. Rapid a-fib patients usually end up with a Cardizem DRIP in the hospital, and we are bolusing that stuff. A patient with true ventricular tachycardia probably won't remain stable very long. In fact, I have never seen a tachydysrhythmic (except maybe cardizem) given in the ER prior to cardioversion.

With all that said, I still treat atrial fib with RVR and SVT with meds. These patients in my area are usually elderly and very symptomatic. I can't defend not treating there rhythm to alleviate the pain. I am much less likely to treat these rhythms in younger patients because they are more likely to handle faster rates. The younger patient is more likely to get cardioverted in the hospital, and receive an ablation.

I'm interested in seeing what AHA comes out with in 2010, even though I don't think it will be much different as far as drug or shock. It probably should be though.

[crotchitymedic1986]

You should always treat the patient, not the monitor. I worked as holter monitor tech as one of my part-time jobs and I can attest that there are many people walking this earth who have the ugliest complete heart blocks, mutliple runs of vtach, AV dissassociation, 1000s of beats of ventricular ectopy, even 3-4 second pauses who are walking the earth symptom free every day. Many times, due to their underlying health or age, cardiologists choose not to treat it aggressively. Often times, their only symptom was "feeling tired" or had some unexplained symptoms that no other test could provide a diagnosis for, so the doc throws a holter monitor on them for 48 hours and sees what happens.

These are very good strips; the kind that if you showed them to 10 cardiologists, you would probably get 8 different interpretations. Good job, keep it up.