CONTENTS
- Typically, T-wave amplitude is highest in V2-V3.
- The upper limit of normal for precordial T-waves may vary somewhat: (19281932)
- ~10-14 mm for men (up to 16 mm in men <30 YO).
- ~7-10 mm for women.
- Normally, the T-wave height should scale in proportion to the QRS amplitude. As such, a gestalt judgment of a prominent T-wave is probably more accurate than any specific cutoff value.
approach to prominent T-waves
- [a] Look for red flags.
- 🚩 Terminal QRS distortion in V2 or V3 (and possibly V4) is diagnostic of acute OMI (figure below).
- 🚩 Territorial T-waves: markedly abnormal T-waves in some leads with relatively unremarkable T-waves elsewhere in the ECG suggest ischemia.
- 🚩 Tall T-wave in V1 is a potential red flag that might redirect you to a limited differential diagnosis (discussed further below: ⚡️)
- [b] Consider several entities:
- [c] Left with three common options:
[1/7] reciprocal reperfusion T-waves
reperfused posterior MI → large anterior T-waves
- Precordial T-waves:
- Posterior reperfusion TWI sums with anterior T-wave to create a large, broad T-wave.
- This mimics anterior hyperacute T-waves, but they are narrower.
- Maximal T-wave amplitude occurs in V2.
- T-wave in V1 is greater than the T-wave in V6 (loss of precordial T-wave balance).
- Other findings:
- Reperfusion TWI may sometimes occur in inferior and/or lateral leads (posterior MI often involves simultaneous ischemia in these territories).
- Q-waves in the inferior leads may occur if an inferior-posterior MI lasted long enough to cause Q-waves.
- Lack of additional findings that we would expect for an acute LAD infarction (e.g., STE and/or hyperacute T-waves in aVL).
- Like Wellens syndrome, reperfusion T-waves will often occur after the resolution of chest pain. (27473406)
reperfused high lateral OMI → large inferior T-waves
- TWI in aVL.
- Prominent T-waves inferiorly.
reperfused inferior OMI → large T-wave in aVL
- TWI in inferior leads.
- Prominent T-wave in aVL.
[2/7] hyperkalemia 📖 or Na-blocker poisoning 📖
prominent T-waves in hyperkalemia
- Narrow-based, pointy, symmetric, and tall.
- Often most marked in V2-V3.
- Often associated with terminal S-wave in Lead I or V6. (11992348)
key features of hyperkalemia
- 🔑 P-waves widen, PR increases, and eventually, P-waves disappear.
- 🔑 Bradycardia, blocks, and/or pauses.
- 🔑 QRS widening (may mimic RBBB or VT; can be >200 ms).
- 🔑 Infarct mimic (STE in V1-V2; often triangular STE diving into TWI).
- 🔑 Terminal right axis deviation (large S-I +/- S-V6; RSR' in V1).
sodium channel blocker poisoning
- Can closely mimic this appearance.
- Discussion of Na blocker vs. hyperkalemia is here: 📖
[3/7] hypokalemia (extremely rare presentation) 📖
Very rarely, hypokalemia may manifest with large “T-waves” (which are actually TU-waves). Concomitant hypomagnesemia may promote this. (22745618, 3829755) Diagnosis is assisted by recognition of marked QT prolongation.
key features of hypokalemia
- 🔑 Q-TU prolongation with broad, bifid TU-waves.
- 🔑 Diffuse downsloping/scooped STD:
- May produce a down-up morphology.
- Often greatest in the left precordial leads.
- 🔑 Prominent, peaked P-waves in inferior leads.
[4/7] Takotsubo cardiomyopathy (rare presentation) 📖
- Aspects of T-waves:
- Prominent T-waves in a global distribution.
- QT is often prolonged.
- The remainder of ECG:
[5/7] ischemic hyperacute T-waves
six key characteristics of hyperacute T-waves
- [1] Broad-based, fat, and sometimes invasive.
- T-wave may obliterate the ST segment.
- T-wave may even invade the QRS complex, causing terminal QRS distortion (figure below).
- [2] Upslope often straightened.
- Should not be deeply concave
- [3] Blunt peak.
- [4] Relatively symmetric.
- [5] T-wave is tall in comparison to the R-wave
- [6] Occur in an anatomic distribution (involving some leads, but not all).
- i) More than one lead (a single transitional lead can look hyperacute without ischemia). Adjacent leads should look concerning as well.
- ii) Not all of the leads (a global change in T-wave morphology doesn't suggest ischemia).
associated with other ischemic features
- STE or STD.
- Loss of R-wave progression can be seen.
de Winter T-wave
- Defined as:
- 1-3 mm of upsloping STD, leading to the takeoff of a hyperacute T-wave.
- Classically, this occurs in the anterior leads.
- Commonly occurs with 0.5-1 mm of STE in aVR. If seen, this STE supports a proximal LAD occlusion. (Berberian 2021)
- Significance:
- Reveals a nearly complete coronary occlusion (a trickle of blood is still getting through).
- de Winter T-waves are recognized as an anterior STEMI equivalent and should trigger cath lab activation.
- This pattern may also occur in inferior or lateral territories.
- Whenever you see hyperacute T-waves, look carefully for mild STD – as this may lead to a diagnosis of the de Winter pattern.
[6/7] ER (early repolarization) 📖
T-wave findings in ER
- T-waves are usually tall and asymmetric.
- STE in V6 <25% of the T-wave height.
other key features of early repolarization
- 🔑 Usually men (75%), <50-70 years old.
- 🔑 Widespread STE (greatest in V3-V4; often limb leads esp. II).
- 🔑 Notching/slurring at the J-point is followed by concave STE.
- 🔑 R-waves and generally tall.
- 🔑 Often associated with STD in aVR.
[7/7] LVH 📖
prominent T-waves in LVH
- Prominent T-waves may occur in leads with predominantly negative QRS complexes.
- T-waves are often asymmetric.
- Other features of LV strain are expected as well (e.g., ST depression with TWI in leads with a positive QRS complex).
- Isolated, tall T-waves may appear in the right precordial leads of patients with LVH and recent onset hypertension. (11992348)
voltage criteria for LVH
TTV1: identifying pathogenic features
- Upright T-wave in V1 may be normally seen in 15% of people, so this isn't necessarily pathological.
- Signs of pathogenicity may include:
- New TTV1 as compared to prior ECGs.
- The T-wave in V1 is greater than the T-wave in V6 (loss of T-wave balance).
causes of TTV1
- Myocardial ischemia may cause TTV1 in three different ways:
- [1] Hyperacute T-waves due to acute anteroseptal MI.
- [2] Mirror-image of reperfused posterior MI (i.e., “posterior Wellen” equivalent).
- [3] Mirror-image of reperfused lateral MI (may cause symmetric, positive T-wave in V1-V2). (de Luna 2022)
- Hyperkalemia.
- LVH.
- ER (early repolarization).
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References
- 11992348 Somers MP, Brady WJ, Perron AD, Mattu A. The prominent T wave: electrocardiographic differential diagnosis. Am J Emerg Med. 2002 May;20(3):243-51. doi: 10.1053/ajem.2002.32630 [PubMed]
- 27473406 Driver BE, Shroff GR, Smith SW. Posterior reperfusion T-waves: Wellens' syndrome of the posterior wall. Emerg Med J. 2017 Feb;34(2):119-123. doi: 10.1136/emermed-2016-205852 [PubMed]
- 34130049 Khir FK, Battikh NG, Arabi AR. The significance of upright T wave in lead V1 in predicting myocardial ischemia A literature review. J Electrocardiol. 2021 Jul-Aug;67:103-106. doi: 10.1016/j.jelectrocard.2021.05.016 [PubMed]
