Does Left Artial enlargement really pose any significance to us?

N

NYMedic828

Forum Deputy Chief
Messages
2,094
Reaction score
3
Points
36
We have the new phillips MRX 15 and these things literally diagnose 95% of our patients with some form of EKG abnormality from Left atrial enlargement to prolonged Q-T.

A textbook NSR w/ all leads isoelectric it will find something wrong with.

My question here, is does left atrial enlargement really matter to us in the field?

From my brief research I saw that it is classified EKG wise by a negative deviation of the P wave in v1 of 1mm or more, and can indicate a mitral valve problem?
 
NYMedic828 said:
We have the new phillips MRX 15 and these things literally diagnose 95% of our patients with some form of EKG abnormality from Left atrial enlargement to prolonged Q-T.

A textbook NSR w/ all leads isoelectric it will find something wrong with.

My question here, is does left atrial enlargement really matter to us in the field?

From my brief research I saw that it is classified EKG wise by a negative deviation of the P wave in v1 of 1mm or more, and can indicate a mitral valve problem?
Click to expand...
If you find p-mitrale on EKG, in the context of failure it can be significant. Mitral valve regurg due to valvular disease or LV dysfunction. Interpret the tracing yourself don't believe the machine; but it isn't hard to believe that a lot of the patients we preform 12 leads on will have abnormalities. The population that gets EKGs on the rig are typically older folks with potential for cardiac disease. I find axis deviations, LVH, RVH, etc pretty often
 
Last edited by a moderator:
The best thing to do would be to hit the MRx repeatedly with a 20lb sledge hammer, douse it in lighter fluid, set fire to it, and bury the remains under the slab of a new high-rise. Not that I have anything against them mind you...
 
Smash said:
The best thing to do would be to hit the MRx repeatedly with a 20lb sledge hammer, douse it in lighter fluid, set fire to it, and bury the remains under the slab of a new high-rise. Not that I have anything against them mind you...
Click to expand...

I like the MRx. What don't you like about it?

The NIBP is finicky but it works just fine if the pt doesn't move their arm while its taking a pressure.
 
Atrial abnormalities are like axis deviation. You can "get by" without knowing it but it can lend support to a diagnosis. For example, let's say you have a 12-lead ECG that barely meets the voltage criteria for LVH. You look at the P-wave in lead II is close to 120 ms in duration and the terminal P-wave in lead V1 is inverted and you could drop a small 1 mm x 1 mm box into it. That's strong supportive evidence that you are in fact dealing with LVH because when the left ventricle is enlarged so is the left atrium (typically). You might also see it with LBBB indicating LVH and LBBB (although most LBBB patients have anatomic LVH with an echo anyway). Is it going to change your treatment? Probably not but with all the whining from paramedics that doctors don't trust their interpretation of the 12-lead ECG one would think we were already better than cardiologists. Knowledge is power.
 
I agree wholeheartedly with TomB. Just wanted to point out that the ECG is not that great a screening tool for hypertrophy, as evidenced by this abstract below. This sort of thing is probably better assessed with U/S (or, as in the study, CT -- I imagine U/S is more commonly used).


Truong QA, Charipar EM, Ptaszek LM, Taylor C, Fontes JD, Kriegel M, Irlbeck T, Mahabadi AA, Blankstein R, Hoffmann U. Usefulness of electrocardiographic parameters as compared with computed tomography measures of left atrial volume enlargement: from the ROMICAT trial. J Electrocardiol. 2011 Mar-Apr;44(2):257-64. Epub 2010 May 27.

--------------------------------

Abstract
INTRODUCTION:

The 12-lead surface electrocardiogram (ECG) is commonly used as a noninvasive modality to assess for left atrial enlargement (LAE), but data comparing ECG against cardiac computed tomography (CT) for LAE is lacking. We aimed to determine the diagnostic performance of 6 ECG criteria for LAE as compared with CT left atrial volume (LAV) and index to body surface area (LAVI) as the reference standard.
MATERIALS AND METHODS:

In 339 patients (age: mean ± mean, 53 ± 12 years; 63% male), we evaluated the quantitative ECG parameters of P duration, P to PR segment ratio, P wave area, and P terminal force in lead V1. We also assessed qualitatively the morphology of bifid and biphasic P waves. Patients were stratified into top and lowest quartile of LAV and LAVI by CT.
RESULTS:

Of the 6 ECG criteria, patients with P duration greater than 110 milliseconds had a 2½-fold increase likelihood of being in the top quartile of LAV (adjusted odds ratio [OR], 2.51; P = .01) and LAVI (adjusted OR, 2.74; P = .007) as measured by CT. For this ECG criterion, the sensitivity and specificity were 71% and 55% for CT LAE by LAV and 61% and 55% for LAVI. The remaining ECG parameters of LAE assessed (P to PR segment ratio, P terminal force in lead V1, P wave area, bifid, and biphasic P wave) were not associated with LAE by CT-based LAV or LAVI (all P ≥ .20).
DISCUSSION:

Only P duration greater than 110 milliseconds was independently associated with LAE based on CT-derived LA volume and index. However, none of the established ECG parameters of LAE have sufficient diagnostic accuracies for predicting volumetric enlargement by CT, thus limiting its clinical utility.

Copyright © 2011 Elsevier Inc. All rights reserved.

PMID:
20537347
[PubMed - indexed for MEDLINE]
PMCID: PMC2937190
[Available on 2012/3/1]
 
Dinosaur alert: finer and finer differential diagnoses in the field

Imagine the receiving ED doc. The EMT's hand off report (hopefully to the doc and not another person). So the doc stays "Hm" and starts her/his own algorithm. If the doc is receptive and trusts the EMS people she/he might orient her/his treatment more along their lines, and will be more understanding of the treatment they may have started, IF they have a treatment to do at all besides O2, IV TKO, maybe a little this or that. However, can you believe that if a pt goes sour the MD will want to have to say "I did that because the EMT's told me there was this abstruse condition they couldn't treat anyway".

If there is no field treatment you wouldn't do generically for a cardiac case, and the ED MD will basically restart dx and tx from their algorithms or to continue your treatments plus their diagnostics, then the pragmatic answer is "NO, it does not".

Knowledge is power if it can be acted on or influence others to act (or gets you closer to the next level of competence), and in the case of medical emergencies, the time taken to do those test for which you have no treatment is all against doing them versus getting the pt to a hospital.
 
The problem with this line of reasoning is that most paramedics "don't know what they don't know" with regard to 12-lead ECG interpretation so they end up treating a patient who presents with a panic attack and a right ventricular strain pattern with nitroglycerin because they see ST-depression and T-wave inversion in the right precordial leads (actual case from my own EMS system). The patient had a known history of congenital heart defect. So if we're going to teach 12-lead ECGs we should teach them all the way.
 
TomB said:
The problem with this line of reasoning is that most paramedics "don't know what they don't know" with regard to 12-lead ECG interpretation so they end up treating a patient who presents with a panic attack and a right ventricular strain pattern with nitroglycerin because they see ST-depression and T-wave inversion in the right precordial leads (actual case from my own EMS system). The patient had a known history of congenital heart defect. So if we're going to teach 12-lead ECGs we should teach them all the way.
Click to expand...
That, of course, means even if we Paramedics don't have the ability to "fix" what is broken... frequently that's the case anyway. I figure that, eventually, systems will adapt to Paramedics doing their own 12-lead interpretations instead of relying on the "machine" and that those interpretations will help speed appropriate care along.
 
First thing you need to do after printing off a 12 lead is fold the "diagnosis" portion back under the strip so you cant see it and forget about it. Don't even read it till you've made your own diagnosis based on the patient. Or even better, don't read it at all, read the 12 lead and leave it at that.
 
fma08 said:
First thing you need to do after printing off a 12 lead is fold the "diagnosis" portion back under the strip so you cant see it and forget about it. Don't even read it till you've made your own diagnosis based on the patient. Or even better, don't read it at all, read the 12 lead and leave it at that.
Click to expand...

I do this too. I work as an intermediate and haven't gotten to my internship in medic school yet so my partners are just giving me extra practice.

I wish I understood 12 lead interpretation better. I feel like I have the basics down but the finer, more in depth points haven't made sense to me as of yet.
 
fma08 said:
First thing you need to do after printing off a 12 lead is fold the "diagnosis" portion back under the strip so you cant see it and forget about it. Don't even read it till you've made your own diagnosis based on the patient.
Click to expand...

Agree with this.

Or even better, don't read it at all, read the 12 lead and leave it at that.
Click to expand...

But not this. Treat the machine interpretation as a backup to your own analysis. Acknowledge that it might catch you and stop you from doing something stupid at 0400.
 
NVRob said:
I wish I understood 12 lead interpretation better. I feel like I have the basics down but the finer, more in depth points haven't made sense to me as of yet.
Click to expand...

What would you like to know more about?
 
There is no better way to advance your field and study than understanding the tools already given to you.
 
Why do all these old dinosaur posts keep getting dug up?
 
You must log in or register to reply here.
Back
Top