EKG meanings?

Specialties Cardiac

Published

Hi!

I have been assigned a cardiac case study for school...and CANNOT figure some of this out.

Any help would be much appreciated!!

TWI v4-6 I can find what this means in v1-v3, but not v4-v6

1-2mm ST elev in III supposedly, this patient suffered a NSTEMI. I was under the impression that there should be no ST elevations?

avR

ST depres in I, avL

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Specializes in RETIRED Cath Lab/Cardiology/Radiology.

gosh, i'm still learning meanings of the different changes in the 12-lead ecg!

i'm not quite sure if what i've found may be helpful or more confusing to you.

without seeing the ecg itself, and knowing more of the pt's history/presentation, it's harder to answer any questions . .

i did a google search using some of the phrasings you posted, and found a few articles:

a quote (link following) about the avr lead:

the augmented limb leads were developed to derive more localized information than the bipolar leads i, ii and iii could offer. for this purpose from the existing limb electrodes, new leads avr, avf and avl were constructed, being unipolar leads looking at the right, left and lower part of the heart with the reference electrode constructed from the other limb electrodes. thus, the purpose of lead avr was to obtain specific information from the right upper side of the heart, such as the outflow tract of the right ventricle and the basal part of the septum. in practice, however, most electrocardiographers consider lead avr as giving reciprocal information from the left lateral side, being already covered by the leads avl, ii, v5 and v6.http://content.onlinejacc.org/cgi/content/full/38/5/1355

st segment depression in avl:

http://eurheartj.oxfordjournals.org/cgi/content/abstract/14/1/4

t wave inversion (twi) in v4-6:

could be a sign of "lv strain:"

http://library.med.utah.edu/kw/ecg/ecg_outline/lesson11/index.html

http://www.101med.com/index2.php?option=com_docman&task=doc_view&gid=271&itemid=99999999

. . ."troponin together with clinical information from the patient history and the electrocardiogram are still the gold standard." for determining if the pt has had/is having an mi.

ecg changes associated with cardiac ischemia are st elevation in at least 2 contiguous leads of at least 0.2 mv in men or at least 0.15 mv in women in leads v2-v3 and/or at least 0.1 mv in other leads. st depression is defined by at least 0.05 mv in 2 contiguous leads. t-wave inversion is significant when is at least 0.1 mv in 2 contiguous leads with a prominent r wave or r/s ratio greater than 1.

the current review suggests that cardiac biomarkers are a primary means of diagnosing mi, but patient symptoms, ecg findings, and cardiac imaging can also play a role in the diagnosis.

http://www.medscape.com/viewarticle/564652

some of the ecg changes can be very subtle, and some are not truly indicative of what's going on w/the pt. as quoted above, the ecg and patient history and troponin findings are what determine if someone is having an mi, not just ecg findings (also, need to compare old ecgs, to determine if there have been changes).

if you are gathering information from the computer readout of the ecg, i'm always told to not 100% believe the computer's analysis!

our cardiologists always look over every ecg and confirm the computer readout with their own analysis.

i hope by now (before i posted :D) you've found answers to your questions.

good luck! :)

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Specializes in RETIRED Cath Lab/Cardiology/Radiology.

You also might see if one of the nurses on the unit could/would take a look at the ECG and help w/your questions. :)

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Specializes in Critical Care.
Hi!

I have been assigned a cardiac case study for school...and CANNOT figure some of this out.

Any help would be much appreciated!!

TWI v4-6 I can find what this means in v1-v3, but not v4-v6

1-2mm ST elev in III supposedly, this patient suffered a NSTEMI. I was under the impression that there should be no ST elevations?

avR

ST depres in I, avL

While dianah's info was helpful, your school is probably just looking for "ischemia". The fact that V4-V6 had inverted T-waves while I and aVL had ST depression indicates likely lateral wall ischemia. There are numerous other causes, but that's the "horse" cause.

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Remember, we typically need to note two or more mm of ST elevation in two or more continous leads to fit the electrocardiographic criteria for STEMI. 1-2 mm of possible elevation in a single lead is not really specific for STEMI. More than 2 mm of elevation in a single lead with S/S would be highly suggestive of STEMI.

ST depression is a mixed bag. Depression is suggestive for Non STEMI or non Q wave MI; however, it can also be caused by reciprocal changes from STEMI or seen with posterior wall infarct. Since your typical XII lead does not look at the posterior wall, posterior changes can present as depression in the V leads.

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On another note:

With lead localization think: "I See All Leads"

I (Inferior Wall)---> RCA/PDA---> II, III, AVF

See (Septal Wall) ---> LCA---> V1, V2

All (Anterior Wall) ---> LCA/LAD--->V3, V4

Leads (Lateral Wall)---> LCA/Circumflex---> V5, V6, I, AVL

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It sounds like u have a silly case scenario (non-realistic).

But u are correct. ST elevations meet diagnostic criteria for a STEMI if they are >1mm in TWO OR MORE CONTINGUOUS LEADS. Why would they give u STE in just one lead?

TWI are non-specific.

The lateral (I, avl) ST depressions are reciprocal changes from your inferior infarct.

i hate unrealistic case studies!

Hi!

I have been assigned a cardiac case study for school...and CANNOT figure some of this out.

Any help would be much appreciated!!

TWI v4-6 I can find what this means in v1-v3, but not v4-v6

1-2mm ST elev in III supposedly, this patient suffered a NSTEMI. I was under the impression that there should be no ST elevations?

avR

ST depres in I, avL

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