Wednesday, April 1, 2015

A Very Subtle LAD Occlusion....T-wave in V1??

This was sent by a former resident.  Our residents get a 34 hour ECG course from me over their 3 years, and they often see things I don't.

A 54 year old male with no past medical history, but whose father had somewhat early coronary disease, called 911 for one hour of chest pressure.  It was somewhat improved with nitro and aspirin, but he arrived with continued pain.

Here are 4 sequential prehospital ECGs:

At time zero:
There is minimal ST elevation, in a saddleback pattern (r'-wave) in V2.  Saddleback ST elevation is rarely due to MI, but in this case there is also some subtle nonspecific ST depression in II, III, aVF, V5 and V6.
 At time 2 minutes:
No significant change

At 8 minutes after the first:
There is new ST elevation in V3, and the T-wave is larger.

At 13 minutes after the first:
No significant change from 5 minutes prior

Here is the ED ECG:
The computerized QTc was 369 ms (very short, and unusual for anterior MI).  However, there is abnormal subtle ST depression in II, III, aVF and V5 and V6.   T-waves are rather large, too; are they "hyperacute"?

There is also a large T-wave in V1, and it is larger than the T-wave in V6. This is claimed to be a sign of anterior MI (also has been claimed to be a sign of circumflex occlusion and of inferior MI, see references below).  We found that it was present in 36% of subtle LAD occlusion vs. 14% of precordial early repolarization, but did not add anything to the LAD BER formula.

How does the formula perform?  It should not be used when there is inferior or precordial ST depression.  However, this ST depression is so subtle that I might go ahead and use it.
The values are: 1, 369, 10, for a value of 19.7, which is hardly ever LAD occlusion.

Although it has a saddleback and it is negative by the formula, there is:

1. A change in ST elevation in lead V3 from zero (at times zero and 2 minutes) to elevated at least 1 mm in all subsequent ECGs.

2. Several leads with ST depression.

3. Typical pain

It would be perfectly appropriate to obtain and emergent formal echo with contrast before making a cath lab decision.

However, this physician was particularly astute and activated the cath lab.   Fortunately, the interventionalist was glad to take the patient, because there was a 100% acute LAD occlusion, which was opened.

References: Upright T-wave in lead V1 and T-wave in lead V1 greater than T-wave in lead V6

I am unimpressed with the studies (below) on this topic, and I do not find this to be a reliable sign.  I think it is worthwhile as a sign which simply calls your attention to the possibility (primarily) of LAD occlusion, and perhaps should motivate you to scrutinize the ECG further.

1.  Manno BV, et al.  Significance of the Upright T wave in precordial lead V1 in adults with coronary artery disease.   JACC 1983;1(5):1213-1215.   Full Text Link.

2. Stankovic I, et al.  Upright T-wave in precordial lead V1 indicates the presence of significant coronary artery disease in patients undergoing coronary angiography with otherwise unremarkable electrocardiogram.  Herz November 21 2012; 37(7):756-761.

3. Barthwal SP, et al. Diagnostic significance of T I T III and TV1 TV6 signs in ischaemic heart disease. J Assoc Physicians India. 1993;41:26-27.


  1. Sir, are T wave hyperacute in Rt Precordial leads V1 - V3 in relation to amplitude of QRS complexes in said leads?

    1. Yes, but it is not obvious. Early repolarization can have very large T-waves also.

  2. What is significance of upright T-wave in lead V1 , as usually T wave is -ve in V1?
    What is the causes of upright T wave in V1? other than subtle LAD oclussion ? does any patient Who presented with chest pain who's ECG shows upright T wave in V1 which larger than T wave in V6 need cath lab activation?

    1. No!
      This is what I wrote: I am unimpressed with the studies (below) on this topic, and I do not find this to be a reliable sign. I think it is worthwhile as a sign which simply calls your attention to the possibility (primarily) of LAD occlusion, and perhaps should motivate you to scrutinize the ECG further.
      I am unimpressed!
      "Possibility of LAD occlusion."
      It did not pan out as a reliable sign in my study.

  3. While STE presented itself in V3 the amplitude of the QRS in V4 also shrunk. To me it would seem that the subtle LAD equation would show a lower value at time zero compared to 8min later and beyond. While neither met cut off there was an increase. Can we be concerned with this increase even when all values are below cut off? In this particular case, I as a paramedic could request a cath alert b/c we use 1mm in two or more contiguous leads anywhere. But assuming the ECG didn’t meet my overly sensitive protocol can up trending equation values be thought of as dynamic changes? Also precordial QRS amplitude shrinkage, from my anecdotal experience it is often hugely dramatic while ST changes are very subtle but strongly raise suspicion of subtle changes. Are there conditions that could shrink QRS amplitude that ruin the specificity of this observation? Thanks.


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