STEMI Equivalents: Wellen’s Syndrome (Ode to Dr. Hein Wellens)

We decided to make a series where we talk about STEMI equivalents and we’ll hit on each one in different posts. To kick things off, we’re going to start with Wellen’s Syndrome. Why are we specifically hitting here? Because one of the the founding fathers of electrophysiology unfortunately passed this year and this is an ode to him. His name is Dr. Hein Wellens. Now when you hear Wellens, you might recognize the last name and recall Wellen’s syndrome. That’s what we’re going to master today, but first a little about Dr. Hein Wellens.

Dr. Hein Wellens

Dr. Wellens was a Dutch cardiologist/electrophysiologist who made numerous contributions to the medical community. He is also considered one of the founding fathers of electrophysiology. Some of his most notable contributions is describing the mechanism of action of reentry tachycardias such as Wolff-Parkinson-White (WPW) syndrome. And of course his most famous contribution, Wellen’s Syndrome which was linked to his name in 1982 after publishing “Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction”. So what is Wellen’s Syndrome?

Wellen’s Syndrome

Wellens Syndrome • LITFL Medical blog • ECG Library Eponym

Wellen’s syndrome is an ECG change that suggests extreme LAD stenosis. Now notice I said “suggests” because this is not a 100%er. Now this occurs when the patient had chest pain recently but is now asymptomatic when you acquire a 12 lead ECG. The exact mechanism of this is not completely clear but there are two theories.

  1. Coronary spasm and stunned myocardium cause it
  2. Myocardial edema caused by repetitive transmural ischemia-reperfusion

The picture above has biphasic T waves in the precordial leads with an up-down morphology (T wave goes up and then down). Not to be confused with extreme hypokalemia with a down-up morphology (noted below)

Twelve-lead electrocardiogram taken on admission from a 57-year-old man with severe diarrhea, paralysis of the lower extremities, weakness, inability to walk, and severe hypokalemia (1.31 mmol/L; normal value: 3.5-5.5 mmol/L). Electrocardiography shows bradycardia, a prolonged PR interval, a prolonged QU interval, ST-segment depression, T wave inversion, U waves best seen in the precordial leads (particularly in leads V2-lead 4), and slurring of T waves into U waves (leads II and III), which are consistent with the diagnosis of hypokalemia. Red arrowheads indicate prominent U waves, black arrowheads indicate T wave inversion, and blue arrowheads indicate ST-segment depression.

Now that we avoided calling hypokalemia Wellen’s, we can get back to the progression and pathophysiology of our main topic. Down below you can see the two types of Wellen’s T wave morphology.

Wellens' syndrome — Maimonides Emergency Medicine Residency

But wait… that looks very similar to reperfusion T waves; are they the same?

Well yes, yes they are. If the patient had extreme chest pain and is now asymptomatic, that means that their heart is being perfused again right? So Wellen’s syndrome is basically reperfusion T waves. There’s multiple studies showing pattern A Wellens developing into pattern B Wellens but that’s not always the case. If the patient did not just go through the cath lab, you should be extremely suspicious of this as the patient has a high chance of re-occluding.

Criteria for Wellen’s Syndrome

1. Deeply-inverted or biphasic T waves in V2-3 (may extend to V1-6)

2. Isoelectric or minimally-elevated ST segment (< 1mm)

3. No precordial Q waves

4. Normal/slightly elevated cardiac markers

5. Normal precordial R wave progression

6. Recent history of angina

7. ECG pattern present in pain-free state

These come from the study by Rhinehardt noted in the references.

Wellen’s Syndrome Cases

Wellens Syndrome (Type A Pattern) 2

Here you can see that classic biphasic up-down T-wave morphology in the precordial leads. You might even notice in V1 and V2, there is minor ST elevation. This is your Type A Wellens syndrome.

Wellens syndrome | CMAJ

This 12 lead is from a 70 year old female with 24 hours of left arm pain. Now some providers might not even have done a 12 lead on this patient which would have bit them in the butt. Remember, OUR PATIENT’S DON’T READ THE MEDICAL BOOKS! If you have an elderly patient with some benign, non-traumatic pain just run that simple 12 lead. Some examples of these eye-rolling ER complaints include arm pain, jaw pain, neck pain, back pain, or a toothache. What’s the worst that can happen? You waste 25 seconds putting on some stickers and write a few sentences in the ePCR. If there is nothing, then no harm. If you do notice something (like Wellen’s syndrome) you just saved a life. It’s easier to justify why you did something opposed to not doing something, especially in the court of law. I included this because it shows the occlusion in the LAD. Follow the example of these physicians and just do a 12 lead because this patient had 90% stenosis to the proximal LAD. This is your Type B Wellens.

This comes from Dr. Smith’s ECG blog. Middle aged patient complaining of vomiting. What about this 12 lead? You have biphasic T waves noted in the precordial leads. Is this Wellens? Well if you quickly look at this, you might just jump to that conclusion.

Ha! got 'em! - deez nuts | Make a Meme

Look at the T wave morphology. It’s down-up not up-down and the QTc looks pretty prolonged! Let’s break down the 12 lead.

I circled some of the waves in V6 in red. That extra hump after the T wave is the U wave. The black line shows exactly where it is located from V4-V6 and down on lead II. Move that line over to the leads in V1-V3 and you see that the cause of the biphasic T wave is the prominent U wave. Correlate the U wave with the complaint of vomiting, you can come to the conclusion the patient is hypokalemic. In this case, the patient’s potassium came back at 2.0mEq/L. Remember I told you guys to watch out for hypokalemia! Use these tricks to differentiate between the two.


Remember the criteria for Wellen’s Syndrome. The prevalence of this is hard to nail but one article stated that this occurs in around 18% of patients. Keep a good look out for this finding. Remember that extreme hypokalemia can mimic Wellen’s Syndrome. Wellen’s Syndrome usually doesn’t prolong the QTc as much as hypokalemia so use that as a tool in differentiating between these two. Do your 12 leads and save a life. ECG interpretation is pretty simple. If you look at it and think “Oh that looks bad” it’s probably bad. If you look at it and think “meh” Then it’s probably okay. An advanced 12 lead interpreter learns things that look like “meh” and can put them into the “oh that looks bad” category. Practice 12 leads as much as you can. We look at them all of the time, so shouldn’t we be more proficient in interpreting them?

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This site is meant to be used for educational use only. We strive to push evidence based medicine with no bias to help you obtain all the important information. You should always follow your protocols that have been set in place. And with everything in medicine, it all comes with baby steps.

Scopeducation Team (Matt)


Cadogan, Mike. “Wellens Syndrome • LITFL Medical Blog • ECG Library Eponym.” Life in the Fast Lane • LITFL • Medical Blog, 16 Mar. 2019,

Miner, Brianna. “Wellens Syndrome.” StatPearls [Internet]., U.S. National Library of Medicine, 28 May 2020,

Rhinehardt J, Brady WJ, Perron AD, Mattu A. Electrocardiographic manifestations of Wellens’ syndrome. Am J Emerg Med. 2002;20(7):638-643. doi:10.1053/ajem.2002.34800

Smith, Stephen. “Are These Wellens’ Waves??” Dr. Smith’s ECG Blog,

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